Bicycle crank is wobbly My bicycle's crank is sorta wobbly - it tilts left or right, according to pressure applied to pedals.

How do I fix it? What tools do I need?

Video showing the wobble.

The "bottom bracket" assembly is loose.  It may just be that it's a one-piece "cartridge" and is rattling around in the frame, or it may be that the unit is "loose bearings" and the bearing caps need to be adjusted.  Or there may have been some sort of failure of the bearings.

Regardless, the whole mess will need to be disassembled to a degree, and that requires some special tools (mainly a "crank puller").  So it may be best to take it to a bike shop.

Ran into virtually the identical situation today, working on a donated bike.  To do the job properly you need a crank puller, a "spanner" for the lockring, and a Park HCW-11 wrench for the "slotted" bottom bracket cup.  There are ways to do it without those special tools, but you risk mucking up the threads, etc.  And you probably need a new set of bearings (they're likely in "cages").


Recommendation for lightweight pedals for use with SPD or without Are there any nice looking and lightweight pedals meant to be used with or without SPD shoes? Would be nice to be able to ride even without my special shoes, but not if such pedals look bulky and heavy.

Shimano make several models of pedals with SPD one side, and flat on the other. So they can be used with SPD shoes or normal shoes.
Options include:
PD-A530

These are designed for road/touring bikes, so are fairly slim, with a small metal platform. (Not to be confused with the PD-A520, which are one-sided SPD pedals, without a flat platform). Personally I use these, they work pretty well, with either SPD shoes or non-SPD shoes.
Weight: 383g (pair)
PD-T780

Designed for trekking or commuting bikes, they have a larger plastic platform. So they look a bit bulkier, but are not actually much heavier. They have reflectors built in, which is useful if that is a legal requirement where you are.
Weight: 392g (pair)
PD-M324

An older model, with a large metal platform, so a bit heavier. They have the option of adding reflectors or toeclips. Weight: 533g (pair)


Replacing grip shift shifters on department store bike with thumb friction shifters? I have a department store bike with a twist grip shifter (3 chain rings, friction shift and 6 sprockets, index shift - Torque Drive One derailleur) and I want to replace it. I am not able to get sufficient advice on bicycle forums because it is a Bicycle Shaped Object apparently and not worth any money on fixing.

I have my reasons, and basically I am looking at something like http://amzn.to/papmPF or http://amzn.to/osZcI0 .. Is it possible to replace my current twist grip shifters with this? Is it a difficult process?

I particularly want a friction shifter, so is this possible?

I've done it, on donated bikes we were rehabbing for Christmas Anonymous.  (Those twist grip shifters seem to fail pretty quickly.)  Don't recall any special problems, other than you have to refigure the cable routing, and you may need a different length cable.


Levels of derailleurs, freewheels and chains What are the levels of derailleurs (Shimano probably) I know Altus and Acera but don't know the higher end ones. I am putting this on my Sondors Fat ebike. I will be using a 7 speed freewheel, and a single sprocket in the front. 750 watt motor, 52 volt battery so I need strong chain, freewheel and derailleur. Thanks in advance.

The higher end groupsets (Alivio and above) would not be the right Speed as you plan a 7 speed freewheel and they are all 9 / 10/ 11 speed.

Shimano's webpage has in the Trekking section:
Acera - 9 speed,
Alivio - 9 speed,
Deore - 10 speed,
Deore XT - 10 speed

In the Mountain bike range there is (lowest first):
Tourney TZ,
Tourney,
Tourney TX,
Altus,
Acera Altus,
Acera,
Alivio,
Deore,
Zee,
SLX,
Deore XT,
Saint,
XTR

I think the only derailleurs Shimano would say that work with 7 speed would be the Tourney rear derailleurs and the Acera RD-M360 8 speed derailleur, unless I've missed some.

But I can't see a reason that a 9 speed rear derailleur wouldn't work as the actuation is the same. The cage may possibly be fractionally narrower as its designed for the narrower 9 speed chain but I have heard of people running this with no issues. You would have to use a 7/8 speed chain though and not a 9 speed one.


Getting my first Road Bike Background info about me:

Previously, most of my riding was done in the desert on a mountain bike.  That was a different time and different era (when the beer belly was not around mostly!).  Since then, I am a bit removed from being physically able to do mountain biking.  Gaining weight makes it harder to climb rocks (actually almost flipped backwards at one point trying to pop my wheel up) and I have also suffered from injuries while I was running track.  I have spent much time trying to rehab my leg but I am not able to run like I used to and my trainer suggested I should get into road biking.  I would also like to make a note that this leg injury is not fresh but a 10 year old problem I have been dealing with.
 I do agree that road biking would be better as I can maintain a constant cadence that you cannot do in the mountains which puts less twitch strain on my leg.  Oh I am also 29 for those that want to know my age in relevance to goals/body shape.

Goals:

Get in shape
Morning / weekend riding
Improve endurance
Eventually join a cycling club
One day possibly enter into a local race
Try to hit and maintain a 20+(hitting close to 30 would be nice) mph base speed (currently can do about 15-17 on an exercise bike but not sure how that compares to actual riding).
Morning rides of about 20-30 miles with weekend rides hoping to hit 100 miles.

Features:

I understand asking about product recommendation is off topic so I will do my best to also keep it objective.

Gear wise and body type wise, I am pretty limited to a few frames and gear sets based on my budget and I also understand it would be off topic to ask anyways.

I am undecided on the geometry I should do.  Some bikes have a flat back, others allow for variety/hybrid of an upright or flat back.  I understand asking for opinions is just that, open ended opinions, but if anyone can provide facts to why one would be better than the other for where I am at and where I would like to go, that would be appreciated.

I understand it is hard to tell without testing bikes and the best solution is "go to a bike shop and test ride" but it is hard to test a bike for any length of distances as most of the bike shops in my area just let you ride it around in the back lot for a couple minutes.

Let's take a quick look at some of your bigger goals:

  One day possibly enter into a local race
  Try to hit and maintain a 20+(hitting close to 30 would be nice) mph base speed (currently can do about 15-17 on an exercise bike but not sure how that compares to actual riding).
  Morning rides of about 20-30 miles with weekend rides hoping to hit 100 miles.

All of these goals would suggest a bike with a lower riding position (i.e., what you termed "flat back") that is generally indicative of a sport road bike with drop bars, rather than a hybrid with flat bars. The lower riding position (more horizontal back) means you present less frontal area to the wind, the lower drag makes higher speeds easier to maintain.  Lowering your drag is necessary for racing or riding at high speeds (hitting and maintaining 30 mph on the flat without assistance is not trivial). I would term this a more aggressive road/sport geometry.

While, a road/sport geometry may be needed for your ultimate goals, it also requires flexibility and core muscle strength to maintain such a position, especially if you wish avoid injury.  For many road cyclists this is a position that is honed over time after building up flexibility and strength. The body can accommodate all sorts of bad postures, but they can catch up with you.  Given that you are already dealing with injuries, I would be cautious on this front.

As an anecdote, after improving my flexibility in my 40's I ride a position that is 1 inch longer (i.e., handle bars are 1 inch farther away) than when I was in my 20's - the handle bar height has not changed. I had worse mid-back flexibility when I was younger, which lead me to unknowingly adopt a compensatory  posture which eventually lead to worse flexibility and  back pain. This did however eventually work out in my favour as it lead me to focus on flexibility and core strength and ultimately better posture on the bike (and life in general).

As such, I would suggest that start with a bike that gives you a more upright position, one that you hopefully you find more comfortable. Hybrids definitely feature this upright position, but some drop bar road bikes  (e.g., endurance, gravel, adventure - and other market speak) also have a more upright position despite having drop bars.  Race road bikes typically have a more aggressive position, and should be generally avoided until more experience has been gained.

The bike geometry that you may need for the long term goals (highlighted above) may not be the right bike geometry for you right now.  Be prepared to change over time, this may mean simply changing the bike setup (e.g., lowering the bars), re-configuring or even selling and buying again.

Good luck.


Frequent fork swapping, best practice? For folks who frequently swap forks (i.e. rigid fork for one race, suspension fork the next weekend, back/forth) how do you manage headset/crown race compatibility? I assume you end up with matching crown races on the forks so that you don't have to remove/install with each swap? I'm not seeing many resources online where one can buy an extra matching crown race for my headset....is this common? Maybe it's just not something that is 'retailed' often but the LBS would have to 'special order' it from the manufacturer's catalog? Any known retailers sell complete headsets with TWO crown races? Or am I way off track - is there a different way to approach this?

I have done such a thing for many years with a rigid carbon fork for winter and a suspension fork for summer. At the beginning I simply called the headset manufacturer and ordered another crown race for my headset.

Many reputable manufacturers sell crown races separately (or give them away if you call and ask nicely).  It is quite common to damage a crown race if it is not removed properly during a fork swap and SHOULD NOT require buying a whole new headset.  If your manufacturer won't sell you another crown race, I would highly recommend you buy another headset from a manufacturer that will and be done with it.

Companies that won't sell small replacement parts for their products generally have a "disposable" mentality for their products.  If they consider their products disposable, you should as well.  I personally avoid such companies as I would prefer to not ride or deal with disposable parts.


How much light is enough for year round commuting? I used a Cateye Single Shot for 5 years until it died. Now I use a Cateye Single Shot Plus that I picked up on Ebay for $50. It's noticeably brighter than the Single Shot, but with my new commute I'm finding I need something much brighter. Dead animals, collision debris, Mother Nature's debris, a faster road, and long stretches that aren't illuminated.

I've searching in vain to find any sort of lumen estimation of the Cateye Single Shot Plus, and I've read a number of critiques of the various candlepower to lumen conversions being flawed.

Have my eye on the Light and Motion Urban series--specifically the 800 Fast Charge. 800 lumens for $180 seems a good lumen/dollar ratio, and $180 is about my spending comfort limit. Put the Urban on my handlebar and move the Single Shot Plus to my helmet.

If money were no object, I'd get a pair of 2000 lumen L&M Secas--one for my handlebar and one for my helmet. However, I don't think I could successfully pitch $1,000 worth of bike lights to the wife.

Does this seem like overkill?

Going fast on unlit roads you definitely want a decent light. Personally I find the combination of my 100 lumen dyno headlight plus another 100 lumens on the handlebars to be enough, but I ride relatively slowly and on a manoeuvrable bike. On a faster bike with handling and brakes designed for speed you want more. Perhaps not 2000 lumens - that's off road singletrack territory. And price. If you get a better quality 200-300 lumen light that actually puts out 200 lumens you'll be much better off than with an off-brand "500 lumens" that is actually 200...

One consideration is how people coming towards you. While it's annoying to hit a small, dark-coloured lump and end up on the road, it's worse to blind an oncoming motorist and end up as a hood ornament. It's not as bad on bike paths, you're more likely just to get beaten up if you blind someone. Paying a little attention to how much light, and where you're pointing it, is important. With a high powered helmet light it's really important not to look at people's faces... when normally you should be looking there. My preference is to have a relatively low-powered helmet light for that reason - I can still look at faces, and people will see me but not be blinded unless they're already very close.

Nathan's Bike Light Database is a good place to start.


Behring custom made bike Hoping someone can help me as I don't know much about bikes.

I bought a 10 speed bike at a garage sale which the owner said was custom made by a bike maker in St. Louis, MO.  She said the frame was chromoly steel.  The frame has the name "Behring," which I assume was the builder, and there is a label on the bottom tube which says "Columbus Tubing."

Is anyone familiar with a bike of this description?  I have some pictures if that would help.

Apparently George Behring used to be a framebuilder in the St. Louis area, and was a racer and a member of the Saint Louis Cycling Club. Unfortunately, like many small builders of the 1980s, there's very little information about him or his bikes on the web.


Shimano MegaRange what type? Can anyone identify this Shimano derailleur?

That's Shimano's C050 rear derailleur. It is comparable to Atlus and Tourney in quality and I believe only came as a 7 speed, like yours.

I've attached the technical manual so you can see how to set it up properly. If you're looking to replace it, Shimano provided a lot of high end 7 speed rear mechs. For a mountain bike that would include things like exage, deore lx, and so on. The same time period for road and commuter bicycles would be exage, some rsx.


Hope pro 4 rear hub wear When I removed the Shimano 5800 cassette from the Hope 4 Pro hub I noticed that there is a significant axial play of the freehub body. Also I am able to slightly twist the driveside spacer from side to side. The hub have seen 3000 km. The QR was loose when I was removing the wheel. I replaced the cassette, mounted the wheel and tightened the QR properly.

The freehub body play disappeared and the hub seems to roll well, there are no unusual sounds when I ride the bike. But I plan the 3000+ km trip with approx. 15 kg of additional load and I want to know whether I can rely on this hub. I don't know its internals. Is there anything inside that can break after further equal amount of wear and stop me in the middle of nowhere?

Edit:
I found the exploded view of the hub

What may cause the play of the freehub body? Maybe I closed QRs too tight and the axial load damaged the bearings?

There are no circlips securing the bearings on the axle tube. The QR endcaps should be held in the axle by their o-rings. If these have been allowed to move apart (e.g by an inadequate or loose skewer), the overall width of the knurled surfaces that contact the frame will be more than 135mm. Assuming no damage to the endcaps or axle, pushing these back in should be enough.


Widest tire on a 23c rim? Alright, I've seen this question around the web a bunch but the other questions are always including limitations and restrictions by brakes or fork/frame capabilities... So my question is, what is the widest tire you could put on a 23c road bike rim, leaving out frame/fork and or brakes limitations.

I ask this because I am looking for cyclocross tires for my fixed gear for some snow riding and I have a Surly Steamroller which has (what seems like) an endless amount of room for wide tires, but I can't find an answer on how wide I can actually go. I'm not planning on going oversized, mainly I'm wondering if a 33-35 would fit on a 23.

Also any recommendations on good tires for winter would be great! Thanks

See for a definitive (imho conservative) answer the almighty Sheldon Brown(bottom of page). The rim width can vary a little between wheels.

Having said that, I have been running 700-35c Cyclocross knobby tires on standard Shimano Ultegra road racing wheels for years without any issue.

Another really good tire for commuting and light offroading (gravel) to get on a CX bike is the Schwalbe Delta Cruiser (be sure to get the 700x28c version). Almost as fast as road tire, much higher comfort, long lasting and decent puncture protection.


9-Speed Ultegra (6500) with Mountainbike Derailleur I want to go bikepacking with my old road bike. The road bike has a standard crankset (53/39, double not triple), and an 11-28 cassette. The groupset is Shimano Ultegra 6500.
Because I want to do some large climbs in the Alps, I would like a lower gear. I considered changing the crankset, but that seems a bit expensive.
I also have two old city bikes that have mountainbike derailleurs that I could remove: One is a Shimano Deore LX 9 speed, the other is a Sram s500 RD 9 speed.
Can I use one of these derailleurs to fit a 12-36 cassette to my bike, or will that exceed the total capacity of the drivetrain with the non-compact chainset?
I mention both the Shimano and the Sram derailleur because I think the Shimano is more likely to work, but in slightly worse condition than the sram - so if the Sram works too, I will try that.

All nine speed Shimano shifters index with all pre-ten-speed Shimano MTB derailleurs.
All nine speed long cage MTB derailleurs with long (SGS) cages will have total capacity sufficient to run any cassette they can clear with a double in front.
36t large cog cassettes came out late in 9-speed mountain's life. Only a very few Shimano 9 MTB derailleurs are rated to clear a 36t for their largest cog spec. Most do 34 and a few only 32.
The SRAM you have is a 1:1 and has no compatibility with the shifter.


How much faster when using drops How much faster would a person on a road bike go when using drop handlebars in drop position vs. using flat handlebars? Assume that the power output is the same in either case and that one is going on long stretches (as opposed to commuting).

BikeCalculator attempts to quantify these different positions. I find it tends to overestimate speeds a bit (probably thinks all roads surfaces are smooth/good).
In my experience you gain about 0.5mph for each of these position shifts:
Flatbar -> Tops of drop bar (narrower hands) -> hoods -> drops -> aero hoods (flat forearms) -> puppy paws (forearms on the tops)


Why does RockShox say you shouldn't use a bolt on axle on their fork? I bought a RockShox suspension fork for a trekking bike I'm building. My plan was to use a wheel with a Shimano XT Shimano DH-3N72 hub dynamo I have from before on it. The hub has a normal bolt on (9mm?) axle. Before installing the fork, I'm reading through the manual, and they specifically mention you should only use a quick release or thru axle on it, "Do not use a bolt on axle with you fork". When I try, the wheel and axle bolts seem to fit perfectly.

I understand that fork instructions are not something to ignore lightly, but I'd like to know why they advice so clearly against this?

You have to tension the bolts with a torque of 6 - 8 Nm, which is more than quick release I imagine. But I couldn't imagine this would have an effect on the fork?

Also, would it be easy to replace to bolt on axle with a quick release or does the hub need to be different for that?

Edit: correct hub type

Edit: add pictures of the hub to clarify the kind of bolts.

I came to some assumption why you should not use bolt-on axle.
It is hard to screw the axle preserving fork sliders in one plane. They can get positioned ascrew, because of screwing the nuts in the opposite directions. It is not a problem in motorcycle suspension because of lack of fork brace. But here? let's say you sit in front of your front wheel and have two wrenches, one on each nut. When you tighten left-hand nut, left slider is pulled back by the nut and when at the same time you tighten the right slider, it is pulled forward. Fork brace prevent sliders from returning to initial, single-plane position. This result in suspension that does not move freely, because more tension is put on "fore-surface" of left stanchion.

This "ascrewing" is easy to observe when you're mounting an old fashioned mudguard with mudguard stays mounted on the axle.

I'm sure, that you are able to use bolt-on axle and screw it properly (by using proper nut and spacer and by greasing spacer - nut interspace). Keep in mind, that user/service manual has to be idiot-proof.


Cannot locate mysterious crunching/grinding noise I've seen other posts on this general subject.

My BB seems tight, new chain installed by bike shop, gears all checked ... I am second owner of this Raleigh so no knowledge of past usage or maintenance ... could it be BB bearings?  Cannot detect what or where noise comes from ... any ideas?

OK, the question is kind of vague (as others have pointed out) and it would help if you could say more about the (apparent) source and timing of the noises, but I just wanted to add a couple of thoughts:

I chased what I thought was a bottom bracket / crank arm clunk for quite a while before I noticed that my saddle wasn't clamped well. I'd moved it back as far as it could go (or actually a bit farther) and the seatpost wasn't able to get a solid grip on anymore due to the bend of the seat rails. I would still swear that the sound was coming from the bottom bracket…
My cleats are noisy. I figured this out one day when I rode with shoes without cleats. The noise seems to be specific to the particular shoes / pedals combination. Don't have any noise with the same shoes on a different bike with the same make/model of pedal.


Is UK National Cycle Network Route 20 fully open? Is UK National Cycle Network Route 20 fully open and fully signed  all the way from Wandsworth (in London) to Brighton?

While the sustrans website can get a little behind, they're normally pretty prompt to announce route openings.  And they say it isn't yet.  But you should be able to plan a route to link the sections that are open -- after all, much of it is planned to be on road anyway.

Even with a signposted route it's unwise to rely on the signs, especially in urban areas. The signs are small and easily missed if you're concentrating on the traffic. I've been caught out by this on NCR4. So I suggest spending some time with maps first (cyclestreets, Google, or paper). Cyclestreets shows gaps in the route, and doesn't use all of what does exist; this is based on openstreetmap data which I would expect to be reasonably up to date on a major bike route.


Shimano M355 brake handle parts My son has a Diamondback Recoil Comp MB with Shimano M355 brakes.  The rear brake lever got messed up somehow.  The snapring that holds the plunger/piston into the master cylinder assembly got popped out and is missing.

I was hoping someone knows the part number for this snap ring so I could buy that rather than a whole new brake lever assembly.

Does anyone have a parts manual or parts sheet/drawing of this brake lever assembly?

The part number on the brake lever assembly is Shimano P/N BL-M355.

The circlip and master cylinder are not shown in the Expanded View or Dealer Manual. I looked up EV-BL-M975 for a lever I own which I know uses a circlip and that document doesn't show it either.

I don't think Shimano intend for the levers' hydraulic internals to be serviceable, whereas many of the reservoir covers and seals, lever blades, pivots and other parts are listed with part numbers.

A machine shop may be able to identify a compatible circlip by examining the other lever. As Shimano's hydraulic brakes seem to be compatible throughout the range, I expect the cylinder diameter will be identical and the same circlip will be used.

If the circlip was pulled out, it's likely the groove will be damaged. Personally, I would buy a used Shimano hydraulic brake lever (any model should work but it's best to get one which uses the same fitting size) and fit that.


Are these steel rims safe? I recently bought an old Eastman ten-speed. It's got 700x23 tires on steel rims.

The walls of both rims bend out slightly, maybe 10 degrees each. I'm not sure if they were built that way, or if they've bent slowly over time.

I want to know if this bike is safe to ride with the tires at 80-100 psi. I don't want the (front) rim to explode at 40mph.

Does the fact that they are steel (instead of aluminum) remove the risk of a blowout?

Here's a picture:

Some old wheels do not have a hook to hold the tire bead, which limits you to around 70 PSI. Straight wall or a slight flare, doesn't matter, 100 PSI is not doable without the hook, afaik. (Wikipedia says the hooks were invented in the 70s)

In my experience, the tire will come off within an hour or two, and the tire will pop off with a bang as the tube explodes. With straight walled rims, I think 700x23 tires are unusable. There may be some uncommon rim design that I'm not familiar with, but if your rim wall looks more or less flat, it's not going to work.

And the fact that they are steel makes blowout more likely if anything, because they are more likely the old design.

If they have a hook on the rim, I would ride them after I let it stand for a day, but steel wheels really do suck for braking.


Would rotating or flipping disc brake rotors make any sense? Front brakes take the brunt of braking forces - so the front rotor wears faster than the rear. With mechanical disc brakes, the rotor gets pushed in one direction only so wear is also uneven.

For extreme cheapskates, would rotating your rotors front to back make any sense (assuming same size discs)?

Would flipping them make any sense (or even be feasible)?

Flipping is not feasible as rotors are directional in design.  You could rotate between wheels ensuring they are in the correct orientation. But I am not sure what you gain, eventually you will need to replace both at once rather than one at a time.  Replacing one at a time could make it easier to spread costs out.

While most cable actuated disc brakes move only one moving piston (note there are some dual sided designs out there, e.g., TRP Spyre) the majority of braking (and friction = wear) happens when the moving piston pushes the rotor to come in contact with the stationary side.  At this point the friction is pretty even on both side.  If you are noticing different wear rates of pads this is likely happening when the brake is not engaged (i.e., rubbing).  As such this is more of a set-up issue rather than an issue with not being able to flip the rotor orientation.

If you are worried about rotor life, you should be using organic pads rather than sintered pads, as these use a softer compound. But I am not sure that this would save you money as you will be replacing the organic pads more frequently.

That all said, rotors typically take a very long time to wear especially if the use isn't extreme (e.g., commuting/causual riding versus sessioning a world cup downhill run).  If you want to minimized maintenance costs there are other consumables to best focus ones attention on.


Disk brake wheels - multiple wheelsets I have a cx bike with disk brakes. I bought a second set of wheels to run road tyres while not off road. On my road bike there's always a minor adjustment to make to the brakes when changing wheelsets, and I assumed this would be no different on the disk brakes. However, it takes me the better part of an hour to readjust the brake calipers on my cx bike as they seem to be so vastly different.

Was this my mistake, should I have mounted the wheels before purchase? What do people here do with this sort of thing? Should I just dedicate more time to learning to efficiently adjust the brakes?

I have Avid BB5 mechanical brakes with Bontrager and now Shimano wheels.

This is normal for using different wheel sets. Not all wheels are precisely the same.

I have a similar thing with wheels on one of my bikes.

Learn to align calipers quickly it's a simple process (with wheel on):

Loosen calliper
Squeeze brakes twice
On third time hold brake in
With brake held in re tighten calliper

With practice should be about a minute a wheel.


How to secure and transport panniers when on foot during a bike trip Context

I would like to go on a solo two weeks bike trip in Europe (mid & east). I am planning on camping (with a 2 person tent), so will not go to any hotel. This means that I will be buying food supplies on the way. It will be my first experience of bike touring, and I am planning on visiting cities along the way. My bike equipment would look something like this:

Questions

How to secure/transport my bags while:

visiting a city by foot
going to buy groceries
...

The easy answer would be: "Just take your stuff with you", but I don't feel like carrying 4 bags full of equipment + a tent. So I am wondering if there's any experience bikers out there that have tips&tricks for me. Cheers !

I use two different strategies for the short and long absences.

  visiting a city by foot

When I'll be away from the bike for a long time I take the valuable stuff (cash, id, small tool kit, phone, charger, camera) and leave everything else. If I'm in a formal camping area or in a secluded location I'll leave the tent pitched and my sleeping bag and clothing inside the tent. In most of Europe you should be able to do this if you're officially camping, but seclusion seems unlikely (in Australia and NZ we have public wilderness areas where there are few people, so camping where no-one goes is possible).

If I'm not camping or otherwise need to leave the gear with my bike I'll look for somewhere that I can lock the whole thing in a room. Either the luggage area of a train or bus station, a backpackers or hotel, or a bike shop. Those will generally cost a small amount of money, but it's cheaper than losing easily-removed stuff or discovering that someone has opened everything up and left what they don't want scattered all over the place (has happened to a customer in India).

  going to buy groceries

For short absences I usually just take my chances. I lock my bike using a small D lock and leave it (I have pitlocks so the wheels are locked to the frame, so that's fairly easy). However, unlike the picture above I tie/strap my panniers onto the bike using bungee cords/ocky straps. That reduces load wobbling while I'm riding and makes things less likely to fall off the bike, but it also means that actually opening the panniers is slower.

I will try to park the bike where I can see it, and if it looks as though there's space in a supermarket or mall I will wheel the bike inside and lock a wheel to immobilise it in the actual shop. I've occasionally been stopped from doing that and I just politely accept and park it outside, but more often staff just look at my bike and accept me.

Edit: I also have a vaguely-related technique that I use mostly for city-fringe camping and once in the wilderness when I left my bike for several days. Since I usually sleep in a hammock and carry a few lengths of lightweight rope, I can if necessary hoist everything up a tree. I'll tie my luggage and/or bike to the rope, climb some distance up a tree and haul the stuff up, then lock it to the tree. Even fewer people will notice it if it's above head height, but it takes time and is hard work to do (lifting significant weight using a 3mm line is hard on my hands).

Edit: As @jqning reminds me below there are metal mesh wraps you can buy that might help here (I have too much to say for a comment). I've only used those for backpacks, and my experience was sufficiently poor that I gave the thing away after one trip. While it might have worked as a theft deterrent, it was sharp, bulky and hard to use. Packing it was problematic, as it had to be folded carefully then stored in a bag to protect the rest of my stuff from the sharp metal edges. It was the size of my stove, only less useful.

BUT on a bike that might be less relevant. When touring I'm willing to carry more weight than a backpacker will, and I have spare nooks and crannies on my bike where the ugliness of the shape doesn't matter. You could hang the mesh bag across the front or your handlebars, cram the wrapped mesh in behind your seat tube or under your rack, and so on. The way it would be accessible when you want it but not in the way the rest of the time. With care you could not only draw the bag tight and lock it, you could put your bike lock through it to prevent someone just removing the whole "locked" bundle. The problem might be locking the bag around your panniers, as they're usually designed as drawstring bags and they're not big enough to close around a whole bike. So you'd be drawing it tight around the rear half of the bike, or taking all your panniers off and locking them inside the bag nearby. Or using one per pannier. Still, I think it's worth considering.


New chain skips when old chain was replaced at 0.75% mark I have a 3x8 hybrid bike that I use for commuting. I clean and lube the chain about every 200km, and regularly check it for wear using a chain cheker. I usually manage to ride between 1300 to 1600 km before the chain wears out beyond to the 0.75% level, at which point, to my understanding, an 8-speed chain requires replacement.
The problem is that every time I've tried replacing a chain that was worn at the 0.75% level, the new chain skips on all hub sprockets, even though these never look particularly worn out, and even at low load. As an example, see the attached photo with the latest worn hub.

Every time, this forced me to keep riding with the old chain until it broke, usually between 3000 and 4000 km, and then replace the entire drivetrain.
I tried changing the chain earlier, and so far I've got it down to 1200 km, but the issue remains.
Contributing to chain wear are the following: I am over 190 cm tall and weigh over 100 kg; I live in northern Europe, where the climate is rainy from autumn to spring and the grit on the road is granite or other hard stones; I often carry my son in a trailer, adding 40+ kg of pulled weight.

In your experience, is it normal that an 8-chain skips at every turn at the 0.75% wear level?
If so, given the information above, when would you suggest me to change the chain to avoid wearing the hub down?

To me, that looks pretty worn.  My guess is that as the chain elongates, it grinds further into the gear valleys, making the "flattened" profile.  The chain and cassette become mechanically paired, wearing together until the chain breaks.  The cassette longs for its lost chain and will not take another mate... er, is mechanically incompatible with other chains.   The wider profile probably leads to periodic instances of 2 rollers in the same gear valley, sort of riding the top of the valley and unable to lower a single roller.
So, options...  1)  Clean frequently, and maybe consider a different lube.  Lube minimally, just on the rollers.  I use Muc-Off dry ceramic for our gritty trails, but it's very dry here.  I have no idea how it'll handle your wet grit.  2)  Replace the chain sooner.
For comparison:


Still skipping cogs when shifting after indexing and replacing shifter I have been having problems with cogs being skipped when shifting up or down.
Heavy pedaling will cause shifting sometimes.
To fix this I tried resting the high and low limit screw and reindexing the rear derailleur.
That did not fix the shifting problems so I replaced the shifter and adjusted the derailleur.
I still have the same shifting problems after getting a new shifter.
Is this an issue with the rear derailleur? It is about 8 years old and has been bang up plenty of times.
Is the hanger bent?
any thing else I should be checking?

The cage and it's pulley wheels look fairly straight up and down...so close that it shouldn't be an issue with shifting, although this is a game of millimeters and one can't absolutely rule out an alignment issue from a single photo.  One thing I do notice is that the photo appears to show the upper, jockey wheel doesn't  seem to be directly under the cog the chain is on.  If this is true, than the system is not properly indexed. The guide pulley (jockey wheel) should  run right beneath the the selected cassette cog.  The barrel adjuster should be manipulated to get that in position (after appropriate shift tension is demonstrated by shifting successfully from 1 to 2 and 2 to 3).  Specifically, here you would loosen (counter clockwise rotation)  the barrell adjuster which tightens the inner cable causing the derailleur to move more inside where it will line up underneath the cog the chain is on.  Obviously you'll want to make sure that the shifter is at the correct detente correlated to that gear.  The limit screws will be set by now, but it's not unheard of to adjust the H or L screw by an ⅛ turn if there is trouble encountered when shifting to the extreme most cogs on each end of cassette.
You need also to evaluate the wear situation of chain and cogs. If the chain is worn (stretched) significantly, it will begin to ride over the teeth of the worn cog. This may be exacerbated by increased tension on the chain when peddling hard.  Ghost shifting is also a symptom of wear and/or excess friction in the cable system (many causes).  Look also to compatibility issues. The shifter and rear derailleur should be the same brand in most all situations: Shimano with Shimano, SRAM with SRAM. The cable actuation ratios of the 2 manufacturers' rear derailleurs are different and their shifters' cable pull differs because of this. As a result, mixing brands of shifters with the other guy's derailleur causes shifting to be very quirky.  Any rear derailleur marketed as a 7, 8, or 9 speed will work with the 7 speed shifter (which I assume you are using) as long as they're the same brand.


Compatibility for old Sram 7-speed shifter A buddy asked me to fix his bike. The shifter is broken. It's an older bike with a Sram SRT300i-71 shifter. I found an exact match on that is fairly cheap on ebay, but I also found a similar model on REI for even cheaper. I was wondering if this or any other newer 7-speed Sram shifter would be compatible. I'm not super familiar with older model shifters like these.

Edit: Just checked an old copy of Sutherland's Handbook for Bicycle Mechanics (6th edition), and the SRT300i is actually Shimano-compatible, pulling 2:1 ratio. I've updated the comment below to correct that mistake.

Many SRAM shifters, are only compatible with SRAM "1:1 Actuation"* derailleurs. Shimano shifters and derailleurs use a "2:1" ratio of cable pull to actuation - the MRX you linked to at REI is one of the few SRAM models that are designed to be Shimano-compatible, like the SRT300i you have now.

(The SRAM ratio is actually closer to 1.1:1, while the Shimano ratio is about 1.7:1, but the common terminology rounds these values. The spacing between cogs in 7- and 8-speed systems is 5mm. In practice, this means that one click of a SRAM shifter pulls about 4.5mm of cable to move the shifter over 5mm, while each click of a Shimano-compatible shifter pulls only 2.9mm of cable to do the same.)


Front derailleur hard to move due to gear cable angle To avoid chain rub on the inside of my derailleur when in the smallest chainring and in the biggest cog on the cassette I've turned the L-screw out / counter clockwise. Now the rub is gone but due to the angle the cable is pulling the front derailleur it is nearly impossible to get into the largest chainring.

Turning the L-screw in a bit more pivots the derailleur into a more horizontal position so that the force of the pulling gear cable is no longer towards the derailleur's center of rotation and thus can actually move the derailleur.

To fix this I'd probably need to either get the cable to pull from a position closer to A or at least to somehow generate some force towards A.

The other solution would be to turn the L-screw in again and avoid the chain rub in a different way.

How do I do that?

Tried:

I've already tried to move the derailleur on its braze-on mount.
I also turned the small chainring around so that the numbers imprinted are facing the outside.
I'm sure it's not about friction in the cables. Shifting works fine in both direction if the L-screw is further in.
The manual mentions that the little pin around which the gear cable is lead can be rotated by 180°. I've tried both positions, the left one improves the issue slightly.

Bike is a Cannondale Synapse Women's (Cann-S2), 9-Speed R3000 Shimano Sora, front derailleur: braze-on type.

The green line is the gear cable.

Having looked through the manual it seems that your shifter cable emerges from the frame on the right hand side of the bike, so the converter should be installed with the pin to the left, which should result in an acceptable angle between the shifter cable and derailleur lever.

I'd definitely rule out all other possibilities that might result in excessive effort required at the shift lever. Detach the cable from the derailleur, put some tension on it (may need to grip it with pliers), actuate the shifter and make sure the cable runs freely. Check the cable run from the shifter to the derailleur make sure there are no snags, housing is properly inserted into stops on the frame etc. You may even want to remove the cable and clean and lube it.

I'd also check the derailleur adjustment. especially alignment. You say the chain rubs at the back end of the cage - if the back end of the derailleur cage is toed out sightly it may be causing the rub. Park Tool has a great step-step video on front derailleur adjustment that can be found here: https://www.parktool.com/blog/repair-help/front-derailleur-adjustment


Are carbon hubs a good idea? I'm beginning to see manufactures making carbon hubs and am wondering if they have the potential to perform better than conventional metal hubs or if they are just a way to save a couple of grams of weight, possibly at the expense of performance.

 Edit:
These are the hubs I was originally asking about, manufactured by enve.  They have a full carbon shell and flange.  The flange is not drilled, the holes are molded as such.

Which hubs are you thinking about?

It would be very hard to make a carbon hub flange strong enough to withstand spoke tension, assuming you are building a wheel with conventional spokes.  Most carbon hubs I have seen use aluminum flanges, and the few which offer significant weight savings are ultralight equipment not for general use.

Carbon probably won't replace the axle, bearings, freehub, or quick release, either.  So you're talking about a few inches of tubing being carbon instead of aluminum, and you're trading the one-piece hub shell for something assembled.  The hub is subject to considerable stress from riding so it's not an area where it makes sense to compromise.


screeching noise in bottom bracket There is a very loud screeching noise when i pedal hard on the down stroke. Be it moving off or climbing up a hill. It is not coming from the front wheel, which i originally thought came from brake rubs, because when the sound still arises when i put my bike on the trainer. i am pretty sure it comes from the bottom bracket and only arises when i pedal hard. if i am coasting at 30kmh, there are no sounds, but if i pedal hard to raise the speed, then the loud screeching noises will arise again. please help! thanks

With this level of information, the only good answer is to say,"Find a competent bike mechanic, and ask them to look at it."


I keep getting flats right at the valve! I changed 3 inner-tubes, they keep getting cut right at the bottom of the valve. I sanded down the hole where the valve goes, it had a sharp edge! Flats still happening...

As Paparazzi said: make sure the valve goes straight through the valve hole, i.e. perpendicular to the tube. This is likely the solution, but I've seen it happen that even after properly aligning the valve it somehow wasn't aligned anymore after a couple of rides. Which resulted in the bottom of the valve getting cut by the edge of the valve hole in the rim. Which means the tube did not (or not completely) stay in place, i.e. at least a part of it shifted with respect to the rim (and possibly the tyre, hard to tell). As far as I know two things could cause this, first one more likely than the other:

if your tube diameter is bigger than your rim and you force it in the tyre anyway, there whill be one or more wrinkles in the tube. If this wrinkle is near the valve, it's not too hard to see that it's possible that under stress the tyre can move a bit, resulting in an unaligned valve, resulting in cutting
even with a proper tube diameter, if your tube sticks to the tyre around the location of the valve (caused e.g. by lack of some antistick agent like chalk, water getting in, ...) and there is quite a lot of stress on the tyre, the tyre could in theory move with respect to the rim and drag the tube with it. Can, as far as I know, only be caused by skidding or incorrectly landing jumps or so: unless the tyre is the wrong size, it requires sheer force to rotate it over the rim.


What is a “Boris bike”? They are black and blue, are not light, however what is one?

Have you had any experience of using one?

It's a bike sharing scheme in London, the "Boris" part comes from the mayor's name.

Wikipedia article on Barclays Cycle Hire
There's also a small Boris Bikes community forum

(Photo credit)


A test ride for a new bicycle Update... What should I actually do on the test drive? The LBS has been kind enough to allow me to try out a brand new bicycle.

What things should I consider when test riding bikes that I am considering for purchase at a LBS? And what should my procedure be while on the test ride? Also plan to test ride between 2 - 5 similarly priced bikes.

This will be a hybrid (urban) bike intended for daily commuting. The LBS will do some minimal adjustments prior to the test ride, so how do I determine if it's a good/bad selection vs needing customized adjustments/fitting?

This goes against accepted wisdom, but I think test rides are overrated. Not useless, but overrated.

You're going to own the bike for a long time presumably. You're going to be able to play with the tire pressure, the handlebar position, the seat height and fore/aft, the seat itself, the pedals, the cranks. As you develop cycling muscles, your position on the bike might change a little. If the frame size is "close enough", all of these things can be adjusted to lock it in once you get riding it.

I could give you the same bike with different tire pressures and you would say, "wow, that one was a comfortable ride" or "wow, that was a fast ride". You get it home, change the tire pressure, and all of a sudden it feels like a different bike.

Like sillyyak said. . .some of the important stuff for you is going to be standover height, weight, ability to accessorize. And almost none of that is learned on an actual test ride.

As long as price and model are similar, I think it's a good idea to get a bike at the most convenient shop, or the shop where you like the people the most -- you will be going back there (repairs, clothing, helmet, lights, accessories, etc). I wouldn't rule out a test ride, but just don't use it as the deciding factor. The things a test ride reveals are not necessarily the things that matter in the long run, and can even be deceptive.

Let use know what you end up getting.


Sram trigger shifters for flat bars I have a Kona Rove ST (specifications here).

I'd like to change the drop bars by flat bars (it will be better for the travelling I'm planning, but that's not the point). But I don't know what shifters I should take (if only there are some compatible, but I'd guess so).

I'm not that concerned by the weight, so I prefer the cheapest of the shifters if the only difference is the weight.

The Kona Rove model you referenced has SRAM Rival 1x11. What you would need is an 11 speed rear shifter that uses the same derailleur actuation ratio as the drop bar shifter.

Actuation ratio is the ratio between cable length pulled per shift and the lateral movement of the derailleur cage. To get the derailleur to index on all sprockets correctly the cable length pulled multiplied by the actuation ratio must equal the sprocket center-center spacing.

SRAM gives names to the different actuation ratios they use SRAM Rival 1 used 'Exact Actuation' which means the ratio is 1:1.

As far as I know all the SRAM MTB systems use 'X-Actuation' which is not compatible with 'Exact Actuation', so none of those shifters will work.

SRAM makes road specific flat bar shifters. The page does not specify the actuation, but does say that the shifters are compatible with 11 speed rear derailleurs.

The SRAM Road Compatibility Document is a somewhat hard to interpret but I believe it says that these shifters are compatible with Rival 1x11 rear derailleurs. Look for the 'x11 Road Compatibility' page, note 'S-500' series is listed in the rear shifter box.


Can I use the regular Shimano 2300 shifter/brake levers with Shimano 105 callipers? Can I use the regular Shimano 2300 shifter/brake levers with Shimano 105 callipers?

I’m looking to upgrade to Shimano 105 throughout but at the moment I can’t afford a full groupset so looking to pick up bargains on eBay.

If I can get 105 or Ultegra callipers will my current levers work ok?

Shimano is great about publishing specification and compatibility charts for their cycling products. They can all be found here including PDF files of previous year's information.

The latest doc that has info on 2300 series Claris shift levers and brakes is here. In section 4. Brake systems interchangeability we see that ST-2300 brake/shifter units are not strictly compatible with BR-6700 Ultegra or BR-5700 105 calipers (and I assume that means the same for 6800, 5800, R8000 or R700 calipers as well).

However, we see that ST-6700 and ST-5700 are compatible (with a caveat of reduced power) with brakes used in 2300 series groupsets, so you might be able to get away with using R-6700 or BR-5700 calipers.

If they don't work together keep the original calipers until you swap shifters. Use the compatibility charts to make sure shifters and derailleurs will work together when you consider upgrading those.


Welding mounting plates on mountain bike frame I'm replacing my mountain bike soon, and have been looking at how to improve it as a work bike. Basically I want to weld some plates onto the frame to use as mounts for things. The stand bent shortly after I got it because it was in the way of the pedal so I got rid of it. So I want to weld a plate further back along the bottom arm for a stand as well.

The other main ideas are to weld on some brackets to hold a dismountable car baby seat at the back, a pannier at the front and maybe a mount for a trailer. I've already made everything except the trailer, but I may not need a mount for that anyway depending how I decide to do it.

Does anyone know how much abuse frames can take doing this sort of thing? It's a pretty thick frame so at this point I'm assuming it's not a close tolerance thing and I can safely do this sort of stuff, just wondering if anyone else has tried.

I'll be arc welding, not gas.

It depends a lot on the fine print of the bike, and how good you are at guessing where forces will go. Broadly, if you make a solid structure and mount it properly the bike will usually be fine, but most parts of a bike are not designed for forces in new directions.

Generally muffler tube is 1.6mm or more and mild steel, where even cheap bikes are 0.9mm or thinner and a harder alloy. If you're confident stick welding muffler pipe you can probably weld the thicker parts of a cheap bike, and if you can somehow magic up some really thin rods it'll be much easier. You want to be down around 30 amps for much of the welding, and most transformer stick welders struggle to maintain an arc at that sort of current. Modern switch mode ones work better, even without HF start, because they can up the voltage to keep the arc active and drop it back when the arc starts, on a millisecond-to-millisecond basis. You can't do that by hand :) If you can get gas a TIG kit for a switch mode welder might be worthwhile, but I suspect you might struggle to do that based on your comments.

Normally I wouldn't spit on a gasless MIG, but for you it might be the least worst option if you get the chance to try one in civilisation on day (FFS don't mail order one sight unseen). Maintaining the flux cored wire is not much more hassle than keeping welding rods dry, but you can weld thinner tubing more easily. Or you just just decide to burn 10 or 20 rods getting the hang of thin wall tubing (or just design so you don't need to weld it very much). Running a bead along something solid so you're just barely melting into the thin tube might be the least awful solution. You can't easily join two thin tubes, but you can still do a lot. Or maybe "pre-set your filler" rod by tying non-galvanised wire along the join before you weld, to bulk it up a bit. I haven't done that with stick, but I do it occasionally with TIG with I have something really tricky to weld (a sudden transition from 6mm dropout to 0.6mm tubing, for example)

Welding a new stand plate on, for example, should be fine as long as you can weld the thin wall bicycle tubing. Look closely at the existing plate, most of them are kind of )o( shaped, with the tapered ends designed to give a gentle transition in the amount of force applied, so that the thin tubing of the bike can better cope with the load. Cheaper bikes sometimes fake this with tack welds, or just don't bother because the cheap tubing is thick enough that it doesn't matter. But then you go and load the bike to twice what it's designed for and it does matter.

Panniers and load platforms can often mount to existing attachment points. The hassle is that welding to the seat tube has to be done very carefully, and if you can back purge with TIG that's even better. If you even roughen the inside surface of the seat tube it can make getting the seatpost in difficult to impossible. Filing that smooth requires a half-round file hand patience (or a rotary tool with a filing bit plus skill and luck). You're trying to file 0.1mm off a tube that's 0.9mm thick at most.

Ideally you'll add vertical loads to or very near the axles. If you're lucky the dropouts will be cut rather than cast, and will take welding well. In that case you can just leave enough space to do up the wheelnuts and weld directly to the dropout. Making a rack out of whatever you have, as one piece, is usually fairly easy. Making it light and strong is the hard part/ So give up on light :)

My limited experience is with chopping up bikes to make prototypes, and they seem to survive that better than I expected. Skim the "I built it" section of my site and you'll see a few hacked-about-with bikes. http://moz.geek.nz/mozbike/  and specifically the "Bin Bike prototype" which was a BMX with extras, including a rack largely made of 10mm reinforcing rod.


Does every drink bottle fit into every holder? I have a Specalized drink bottle holder and was always using normal 750ml plastic bottles, but they never fit very well. I was looking online for water bottles and now I'm wondering if all bottles that can be found online (e.g. on bikester.com) will fit into my holder or do I have to be careful with what I buy? Are there different sizes of bottles and holders or all they standardized?

Thank you in advance.

The inexpensive bottle cages can be bent to make them a little smaller for a tighter fit. If the type you have is a closed  loop type you can add rubber bands to the bottle for a more secure fit if it is loose. There seems to be a lot more size variation with generic "sport bottles" than the bottles marketed to cyclists.


How to loosen stiff kids brakes My eldest son has a Hoy Bonaly 16" but we've always suffered with very stiff brakes. (https://www.evanscycles.com/hoy-bonaly-16-inch-kids-bike-EV203129)

It has Tektro RX1 levers I've tried loosening the spring tension in the calliper which made only minor difference.

I suspect my next step would be to lube the cables and see if that helps. There are no kinks or tight bends in the cable run so is there anything else I can do to ease these off?

It looks like the issue for one brake stemmed from a ferrule on a cable outer pinching too much. And the other brake seems a little better after checking/straightening the routing and lubing.

All inners and outers look to be in perfect condition which is why I hadn't stripped them down up to now.

Thanks for the pointers chaps.


Rear bike stand: 2 points of contact vs 1 When choosing a rear bike stand, does it make any difference that it clamps to 1 or 2 tubes of the chassis?

My bike can happen to be parked with rear paniers.

A single-tube clamp has to be fairly tight to prevent rotation, especially if the bike is heavily/unevenly loaded.  A double-tube clamp doesn't have to be as tight.  Whether this is enough to allow you to use the double-tube version on fragile materials is another matter.

The fit of the double version has to be much more precise. With some frames it just won't work.  I wouldn't be confident about getting it to fit with rear disk brakes.


Mountain bike shorts for commute I was recently given padded mountain bike shorts. Are mountain bike shorts good for commute? (around 11 km one-way)

Mountain bike shorts are ideal for commuting. If they fit, are comfortable and you like the look of them, you won't find a better commute short.  If you a fast rider, over 11km the extra drag of baggies will cost you a few seconds over a lycra skin suit.
However, if you are riding a road bike, you are breaking Rule #18 :)


What tool do I need to disassemble this 5 speed freewheel I have a 5 speed freewheel that I need to take of from hub, but the standard freewheel tool that I do have does not fit.

On the freewheel following text is engraved:

UC SHIMANO SIS
MF Z015 China

It seems to me that tool would need to have 12 splines.

I found a bunch of forum posts from people with similar problems. Shimano freewheels made prior to about 1985 have smaller diameters, about 20mm instead of 22-23mm that they have today.

A search for "Shimano freewheel remover 20mm" brings up some useful results. It looks like Bicycle Research Tools makes a remover called the CT-4 which is designed for older Shimano freeheels.

Good Luck!


Intersection detection doesn't notice me, what should I do? I have just come to the USA (Bay Area) and got a bicycle to commute to my university. Being new to this place I kept wondering why sometimes I have to wait for a long time for a green light to make a left turn, and then a car comes along and the signal switches to green in ten seconds. Today I waited for a green light for five minutes and it did not come, since there were no cars in my lane. I started thinking I was insane, but then found this: How do Traffic Lights Notice Bicyclists? Sure enough, there are cameras in the intersection.

So how do people deal with this? Wait for a car? Turn on the red light? Use the pedestrian style of making left turns? Wave to the camera?

In most states it's the law that if the signal is malfunctioning you can proceed through "with caution" against the signal.  Forester and others have argued that if a signal does not appropriately recognize the presence of a bike it's "malfunctioning" and you're on reasonably firm legal ground to invoke the "malfunctioning signal" provision.  (However, I've never heard of this being tested in court.)

Do note that the presence of a camera does not necessarily mean that the signal is video-controlled.  It may be that the cameras are there for general traffic monitoring, and the signal is still triggered by buried loop, radar detector, etc.  Also, often there are sensors installed for detecting oncoming emergency vehicles that look a little like a camera but are not.

If it is a buried loop you can usually tell by observing the cuts in the pavement where the loop was installed (though of course a buried loop may be subsequently converted to video control).  But with a buried loop the best place for the bike, to optimize detection, is more or less directly over one side of the loop, vs being in the middle of the loop.  (As a last resort, lay your bike down over one side of the loop.  I used to deal with one intersection where I could trigger the signal by just leaning the bike to about 45 degrees.)  Note that a steel bike will usually be more effective than an aluminum one, and a carbon fiber bike is unlikely to be detected at all.


Cartridge hubs vs loose-ball hubs My LBS recommended cartridge hubs to me. Here are my doubts.

Seeing as how I never ride in the rain or any such wet substances, I don't really need the "completely sealed" feature.

Sheldon Brown says that if taken care of, the body of a loose-ball hub will last indefinitely. (not the balls and cones). So if you maintain your hub, you should be able to indefinitely avoid having to re-spoke your wheel.

Sealed bottom brackets make sense, because it's easy to pull your cranks off and swap it out. But if you have a cartridge hub, when it wears out you will need to re-spoke your wheel. Am I right about that, or do cartridge hubs have a system for just replacing the bearings?

Also, is it possible that a cartridge hub would last as long as the rim? Then you would just replace the whole wheel once it started having problems.

Most hubs these days claim to be "sealed".  This basically means that if you look the hub from the axle end you can't see the balls of the ball bearings, because there is, at least, a "dust shield" that leaves only a very narrow opening between rotating hub and fixed axle.

There are also "cartridge" hubs, which were the original sealed hubs popularized by Phil Woods, back when standard bearings had no dust shields and were pretty crappy.  These use a (theoretically) replaceable cartridge on each side of the hub, where the cartridge is an industrial bearing cartridge similar to what's used in electric motors (and similar to what's used in bottom-bracket cartridges).  However, replacing the cartridges requires special tools, and likely many bike shops would just give you a dumb look if you talked to them about replacing the cartridges.

Both of these schemes are a significant improvement over the original open bearing style, since, not only do they keep most moisture out, they also keep out dust and dirt.  For the average rider, though, the cartridge scheme is probably not worthwhile, since it is not possible to simply rebuild the bearings.


SG-X chainring compatibility issues Must I swap my SG-X chainrings with SG-X replacements or can I use anything with the same BCD?

My current Deore LX FC-M560 has 26-36-46 rings and I was thinking of replacing them with TA rings. However, I've read I must use SG-X and rings that come as a matched set due to the pickup being matched to the rings. Is this correct?

Anyone used non SG-X rings and had issues?

TA chainrings have their own system of ramps and pins, which in my experience works quite well.

It is possible that Shimano has found a way make chainrings that work only at the combination they are designed for. They certainly market parts as if it was so. In my experience, TA works fine even in non-standard combinations (28-38-50 on 4-bolt MTB crank in my case).


Does a 700c wheel help you go faster? Someone suggested going with a 700c wheel to go faster, and after thinking about it I am wondering if a larger wheel actually does go faster. I understand that your gears will cause a wheel to rotate once and if the wheel has a larger circumference it will travel farther, but this comes at a cost to leg power, and why not just get a larger sprocket? So cut out the gears and such and talk about the physics.

I was lead to believe that rotating weight is what slows you down, so a larger wheel will have more mass, thus making it harder to push, hence slowing you down. A bike with 12" tires going the same speed as one with a 700c will have less rotating weight so will it be more efficient? If you are on a flat track with thin, hard tires and your bikes are geared to be equally efficient to pedal at low and high speeds, which wheel will make you faster?

The increased weight of the larger wheel (if indeed it does increase) will of course add weight to the bike, but additional weight adds very little rolling resistance (though it does of course affect hill climbing).

It is a myth that "rotating mass slows you down".  In terms of top speed there's no difference between weight on the wheel rim and weight anywhere else on the bike.  Added weight on the wheel rim does reduce acceleration, but 10 grams on the wheel rim only has the acceleration-limiting effect of 20 grams elsewhere -- it's not really enough to notice.  (And once you've accelerated to speed this effect goes away.)

A larger wheel can ride over slight irregularities in the road with less energy expenditure, and so can be more efficient (and less tiring) in some circumstances.  And a larger wheel generally is more stable (though at the expense of maneuverability).


How do I figure out what rear axle to purchase for new wheel? I have a Voodoo Bizango 2016 and recently purchased a new rear wheel for it as I’m a larger rider and kept popping spokes.

It’s a Halo vortex 29" wheel with a Shimano HG freehub.

I’m trying to start doing work on the bike myself and just finished swapping over the cassette and brake disc when I noticed that there was no space for the quick release skewer to go into.

Do I need to just purchase a new axle and skewer? How do I get the correct size?

UPDATE: Halo like a number of other manufacturers make conversion kits  for converting between the different rear axle standards on a bike.

That is a 12mm thru axle rear wheel, which has become the new 'standard' for heavy duty mountain bike disciplines, like what the Halo Vortex has been designed for. I couldn't see any suitable adapters on the Halo website that allows you to convert the wheel, so I'd return the wheel and get something that fits.

Unfortunately the days where everything was 26" in diameter, 135mm wide and QR compatible are gone. The things that you need to check would be:

wheel diameter
axle type (QR or 12mm thru axle)
rear wheel spacing (135, 142, or 148)
you may also need to note down rim width depending on the width of tires that you're using


What do these rim numbers mean? I just noticed these numbers on the inside of my Reynolds AR58 carbon wheel (see picture). The left paragraph seems to provide information about the product and manufacturing date/place. Does anybody know what the numbers/codes in the right paragraph mean?

They're build QC tolerance numbers for side to side (lateral), up and down (radial), and offset (dish).


What is the effect of adding weight to a wheel vs adding it to the frame? There are claims often made that, eg, "An ounce of weight at the rims is like adding 7 ounces of frame weight." This is "common knowledge", but a few of us are skeptical, and our crude attempts at working out the math seem to support that skepticism.

So, let's assume a standard 700C bicycle tire, which has an outside radius of about 36cm, a bike weighing 90Kg with bike and rider, and a tire+tube+rim weighting 950g. With the simplifying assumption that all the wheel mass is at the outer diameter, how much effect does adding a gram of additional weight at the outer diameter have on acceleration, vs adding a gram of weight to the frame+rider?

I asked this question over in the physics Stack Exchange.

The answer I got was 2x -- adding one ounce (or gram) to the wheel at the outer diameter (ie, the tread) is equivalent, in terms of force/energy needed to accelerate, to adding twice that amount to the bike frame.

The answer was a bit involved and takes careful reading to fully understand, but the answer can also be explained with this thought experiment:

If you have a theoretical weightless wheel, fixed to a stationary axle (ie, not rolling on the ground), and you add a mass to its outer diameter, the energy needed to accelerate that added mass to some tangential velocity is the same as the energy that would be needed to accelerate the mass to the same linear velocity (ie, as if it were attached to a weightless bike frame).

But if our theoretical weightless wheel is not fixed on a stationary axle, but is instead attached to our theoretical weightless bike, we are accelerating the mass both tangentially AND linearly so we add the two energy requirements together, meaning it takes 2x the force to achieve the same acceleration and 2x the energy to accelerate to a given speed.

So the answer is 2x (and not 7x or 10x or whatever is often quoted).


Rear wheel keeps moving forward in frame no matter how hard I tighten the bolts. Any solutions? This is occurring on my Avanti Discovery 8, which is a hybrid bike with an in-hub 8 speed.

Problem is I seem to be applying so much torque it's pulling the rear wheel forward in the frame, loosening the chain. I've tightened the rear nuts as hard as I can - to the point where the nuts got a little damaged (hex edges started to 'flatten' inside the spanner) - but the wheel keeps moving forward as soon as I go up a hill and apply pressure. You can even see the scrape marks where the nut and washer has been digging into the frame and being pulled forward.

Is there any solution to stop this?

Take a look at something like this:

http://surlybikes.com/parts/small_parts/monkey_nuts

Edit: this may me more along the lines of what you're looking for

http://surlybikes.com/parts/small_parts/tuggnut

I'm sure other brands make similar things.


3 Speed Front Derailleur can't reach small gear I bought a new frame and put my old Campagnolo Racing T components on it.
The seat tube has a diameter of 35mm and I use the Campagnolo 35mm clamp for the Racing T derailleur.

The problem is the derailleur can't push the chain to the small gear because a part of the derailleur touches the seat tube.

Is the frame incompatible with a 3 speed crank or do I just need a compatible derailleur for frames with a wider seat tube, maybe the ATHENA Tripple?

Parts

Frame: BULLS Desert Falcon, Seat Tube 35mm
Crank: Campagnolo Athena 11s
Derailleur: Campagnolo Racing T
Bottom Bracket: Campagnolo BB90 Power Torque

Images:

Derailleur touching the frame:
Crank:

The chainwheel does not sit at the correct chain line is the answer.

The most common cause is that you have an axle length shorter/longer than the ideal chain line. In this case, you have a shorter axle length.

Did you add another chainring into your crankset? If the answer is yes, you will need to tweak around: either adding spacer (not recommended) or find a compatible front derailleurs (better get to the LBS for trial/error fitting).
If the answer is no, then it will be the frame that cause you the problems, albeit unlikely. I always solve this problems by finding a correct axle length for my crankset.

You can refer to this article for more information, from Lord Sheldon.
http://www.sheldonbrown.com/chainline.html


Get off bike on crosswalk? I go to school at Lafayette, CA. Can't find the local laws here, but people sometimes shout at me to get off my bike on the crosswalk. Even though many other students ride over the cross, I'm wondering if I should not. There seems to be no problem with it, usually there aren't many people around.

EDIT: Usually I bike on the sidewalk, but started using the bike lane. There's traffic with little space for bicyclists a lot of the times, so I usually turn onto the sidewalk again. When there's a green light on the right-most lane, other bikers/pedestrians cross (move parallel with the traffic), so I follow since the direction is with traffic. I usually take this into account when biking on the sidewalk, so that I wouldn't have to stop to push the signal button. It looks like there's two paths for bicyclists to take: the bike lane when the light signal is green for cars, and the crosswalk, where bikers should disembark and walk with pedestrians, also when the traffic light is green? If so, can I ride on the sidewalk (allowed in Lafayette) and switch onto the road when the traffic light is go?

Here is a good reference for California's bicycle laws.   Lafayette's laws are here.

I found nothing prohibiting riding on sidewalks, and nothing specifically mentioning riding in the direction of the crosswalk.  However both the state and city codes require bicyclists to yield to pedestrians in crosswalks.


Jc higgins manifold bike I have a jc higgins bicycle with manifolds and I want to no if the model number is correct the number is mod 502 307 thanks

Surprisingly, googling "jc higgens bicycle with manifolds" shows that it is a real thing.

  The bike was sold by Sears in the last couple of months of 1950. The bike was discontinued because of the metal pipes on the tank got in the way of pedalling. The bike had a code number stamped into the frame 502-307, denoting this bike was built as a manifold tank bike and not a colour flow. I have talked to a number of bike experts and very few have ever heard or seen one of these bikes. The original colour was red and black.

From http://thecabe.com/forum/threads/j-c-higgins-manifold-tank-bike.13806/

Opinion: its definitely a cool bike and worth repairing.   If you don't want it, pass it on to someone who can do it justice.


How do I maintain my weight while cycling more? I started cycling more to get fitter and lose a little bit of weight. I started taking a longer route to work and upped my daily ride from 6 miles to 16.

After 2 months of this and consuming less biscuits I've lost almost a stone and am now really happy with my weight. My main aims now are just to be healthier, to improve my indurance a little bit and mainly just to have fun. I really enjoy my longer ride and would like to keep doing it.

I thought I would find a new ideal weight for my new higher level of activity, but this hasn't happened yet. I am losing weight slower so should I wait for this to happen or should I eat a little bit more? And, if I do need to eat a bit more what sort of foods would be good?

Update: As some people have asked for it my BMI has gone from 23.7 to 21.9. So I've always been in the normal weight BMI category (18.5 – 24.9), but I was getting towards the top end of it.

I worked as a physician (not anymore nowadays, got into medical systems design), and I can guarantee you that either people and health professinals overemphasize the importance of the weight as if it was a single "magic number" regarding health, and it is not.

Body fat percentage, cardiovascular endurance, muscle and joint flexibility, dietary habits and psychological stress level are much more important.

Besides that, two things you must consider:

When one increases pedalling distances and speeds, fat is lost and muscle is gained. Muscle is much more dense, so even if you look lean, you do not lose so much weight, but you exchange a very risk-related tissue (fat) by a much more healty one (muscle). And even while at rest, muscle burns calories much more than the same amount of fat, so the very existence of more muscle implies a higher methabolic rate;
When you commute by bike, you get REALLY HUNGRY. You must eat, because food is your gasoline. Actually, wanting to lose weight by eating less then necessary is dangerous for bike commuters, because you might get weak during a ride, which greatly increases discomfort and accident risk.

What I do is to eat just enough, take a lot of salad and vegetables when possible (helps to provide anti-oxydants for the body, much useful for us who breathe pollution, etc.), and try NEVER to ride "out of fuel".

EDIT: (from wikipedia)
Some common body fat percentages (not a recommendation!)

            Women   Men
Minimal     10–13%  2–5%
Athletes    14–20%  6–13%
Fitness     21–24%  14–18%
Average     25–31%  18–24%
Obese       32%+    25%+

"The bioelectrical impedance analysis (BIA) method is a more affordable but less accurate way to estimate body fat percentage. The general principle behind BIA: two conductors are attached to a person's body and a small electric current is sent through the body. The resistance between the conductors will provide a measure of body fat, since the resistance to electricity varies between adipose, muscular and skeletal tissue."

I am not a native english speaker, so some words might not be correct.

Hope it helps!


Can I put 700c tires on rims made for 27 x 1.25"? It's getting hard to find any selection for my old Avanti 12 speed. it currently uses 27 x 1.25 inch tires. Can I put 700c tires without needing to buy new rims?

No!!!

I tried this when I was knee-high to a grasshopper and it so-did-not-work! I actually managed to get a Michelin Select 700 x 28c tyre on the 27" wheel but the inner-tube was so pinched and pierced that no amount of that gunk you can spray into tubes could save it. I did get the size wrong but after many hours of struggle 'hoped' to get a low-profile tyre on my front wheel.

The bead diameter of the 27 inch wheel is 630 mm, the bead diameter of a 700c is 622 mm (I properly learned those measurements that day). 8mm is a big difference, believe me!

If your LBS does stock 27" tyres, do not part with your cash until you have read 630 on the sidewall. If they do not stock them, ask them to get them in. This will save you the postage of mail order. Their suppliers will carry them and they should be able to get them in for next week if you ask nicely and put down a deposit.

There are specifications for wheel sizes and tyre sizes - ETRTO. Schwalbe have a good intro and list of sizes:

http://www.schwalbetires.com/tech_info/size_markings

The 27" size for your bike will be 630, 609 is the size for older bikes with 'rod' brakes and no sidewalls to the rim.

Normal 700c inner tubes will go in a 27" wheel with no problems.


Why does a Shimano centerlock rotor have free play? I have an electric road bike that has SM-RT64 Shimano centerlock
brake rotor in the front. I have noticed that when I press the front
brake and try to rock the bike back and forth, there's some free play
somewhere in the braking system.
I checked for free play in the headset to find nothing.
I checked hub (HB-R7070) bearings for looseness but they weren't loose.
I checked that the disc brakes have the pad retaining screw tight.
When I rock the bike back and forth, it doesn't seem to be the brake pads that
are loose. The looseness seems to be at the centerlock brake rotor. It is not
the fixed rivets connecting the spider to the disc that are free; instead, the
brake disc seems to be rocking back and forth at the hub, and the lockring
seems to be rocking along with it. Thus, the brake disc - hub connection is of
suspect.
Related information found online:

https://forum.cyclinguk.org/viewtopic.php?t=116894
https://forums.mtbr.com/wheels-tires/front-hub-play-980620.html
https://forums.mtbr.com/brake-time/xtr-disc-brake-play-386036.html
https://forums.mtbr.com/29er-components/disk-has-1-2-play-when-braking-914595.html
https://forums.mtbr.com/brake-time/linear-centerlock-play-792697.html
https://forums.mtbr.com/brake-time/centerlock-rotor-slop-1055472.html
https://forum.bikeradar.com/discussion/12768497/play-in-centrelock-rotors
https://forum.bikeradar.com/discussion/12719436/rotational-movement-on-centre-lock-disc-brakes-normal
https://www.bikeforums.net/bicycle-mechanics/360397-little-play-front-disc-normal.html
https://www.bikeforums.net/bicycle-mechanics/1121066-centerlock-rotor-slop.html

https://www.pinkbike.com/forum/listcomments/?threadid=177747
https://www.reddit.com/r/MTB/comments/3wajho/my_first_mountain_bike_has_a_loose_disc_brake_is/
https://forums.mtbr.com/brake-time/play-between-disc-hub-centerlocks-710730.html
https://forums.mtbr.com/brake-time/loose-rotor-centerlock-adapter-369055.html

What could be the cause?
Is the brake disc defective?
Are the aluminum centerlock splines in the hub damaged? (I hope not as it took
about 5 hours to build the front wheel, and swapping the hub to another would
take another 5 hours).
Or is the centerlock design just too weak for the massive braking forces I need
(my weight is over 100kg)?

The cause is a missing aluminum shim between the centerlock lockring and the
brake rotor.
I removed the brake rotor from the defective front wheel. Then I removed a
brake rotor from a known-good front wheel. When closely inspecting the
lockrings, I noticed something the known-good front wheel has that the
defective front wheel didn't: there was a very thin aluminum shim between the
centerlock lockring and the brake rotor.
When I built the front wheel, having had no prior experience with disc brakes,
so I thought the aluminum shim is something that should be removed and the
centerlock lockring should be tightened without it.
Now I have swapped the lockrings and the brake no longer has free play.
The missing shim probably has been thrown out along with garbage, so I have
to purchase a shim somewhere.


Brake fluid squirts out of brake lever We noticed tonight that one of the brake levers, whenever you actuated it and let go rapidly, brake fluid would squirt out (black and oily substance).

I'm wondering if there would be some things that I could look for at home before bringing it in the shop. Maybe, an easy thing to look for? I would hate for it to be just a small screw to tighten or something.

Gear list:

Brake Levers Tektro Auriga
Brakes   Tektro Auriga, Hydraulic disc, 160mm

If it were coming out around the bleed screw, then checking the tightness of the screw and/or the condition of the o-ring it's hiding would be in order. Taking the screw out to look at the o-ring is something you should only do if you're prepared to bleed the brake, but it sounds like that's probably in order anyway. Bleed port o-rings getting out of place or mushed is a thing that happens.

You can also check the hose connection. Pull back the rubber shield around the hose and make sure the compression fitting is snugged in nice and securely. That coming loose would be kind of scary/weird so if it did happen you would definitely want to make sure all the threads, the olive, and the hose end and barb all looked good.

If it's anything else you probably need a new lever or complete brake. Aurigas are decent brakes but replacement seals and other rebuild type parts for them are unobtanium.


Is it safe to wear a helmet without a plastic covering? A friend of mine gave me a foam bike helmet had the plastic covering removed from it. Besides for the plastic being removed, the helmet is in excellent condition. Is there any issues with using this helmet for riding locally as far as safety is concerned? I think the plastic cover was thin to begin with so I think it wouldn't make much of a difference.

The foam protects the head from impacts by deforming. The plastic cover obviously protects the foam from wear and aging. However it also serves safety aspects in most helmets:

A good helmet has a smooth outer shape, preferably close to a ball, to allow it to slide over tarmac or other hard surfaces in an accident. The hard and smooth plastic outer shell helps this by reducing friction and it prevents snagging.

A reason why we want the helmet to slide rather brake ones horizontal movement is to prevent rotational acceleration of the skull. Due to its inertia the brain resist that acceleration. This in turn exerts a force on the brain (warning, oversimplification the brain is in large parts mechanically decoupled from the skull by a gap filled with fluid). This so called rotational impact is thought to be an important contribution to concussion (cf Kleiven 2013).


How much of the saddle rail is suiteable to use Is it possible to safely set the seat to the max to get the saddle as far forward as it will go. Or should it only be clamped within the marked range 0 to 3.5? I have marked the points in red. The reason I ask is because I don't want the saddle to tilt forward while riding if I have it set to max.

As long as no part of the clamp touches the rails outside the max lines, you should be safe.

The scale is simply there to help you. It would be nice if it ran right up to the max lines, but it might still be helpful depending on the size/design of your clamp.


I think I have installed my new rear deraileur incorrectly, can anyone give me some advice I have replaced the derailleur on my daughters Dawes Academy 26, but I think it looks wrong.
On the lowest cog (gear 8) the derailleur looks like this: enter image description here:

I assumed that the derailleur should be more verticle. Also the small cog nearest the wheel seems to be nearly touching the rear wheel cassette.
The derailleur is a Shimano Acera, which was a like for like replacement. I also replaced the derailleur hanger too.
It does seem to work, but we haven't been for a proper ride. I'm concerned that once we are out it something will go wrong.
Can anyone give any advice?
Thanks to everyone how has replies so far.
Re. the chain is the original so it shouldnt need reducing.
Re. the B-screw here are a couple of photos. Not sure how useful they are. TBH adjusting it doesn't seem to do much.

From your picture, there are a couple of questions.

Is the B screw in the correct place.
Is the chain the correct length

Please watch this video on installing a deraillieur and 1 minute in, they mention the B screw and it's corrct position. Note the two different types of fittings, the direct bolt to the hanger, and the bolt to the tab and then to the hanger. The video shows both methods.
Or update the question with close ups of the area where you attached the derailleur to the hanger.
You didn't mention whether you replaced the chain too. If you did, please make sure it is the correct length. These links discuss more on chain length.
Chain length link 1
Chain length link 2


Bleed port repair on Shimano road brake lever? I noticed that a small amount of mineral oil had leaked from the bleed port on my Shimano road brake lever. I inspected the bleed port screw and saw that it was loose. The threads on the lever appeared to be damaged. The threads on the bolt ("Y0C698030") appear to be fine.
I was able to screw the bolt back in, pumped the lever a few times and it seemed to stay put. No further mineral oil leaked and the braking does not feel spongy.
However, now I'm not sure what to do:

Is the brake safe to use?
Can I repair the thread, perhaps with a helicoil or threaded insert? If so, what are the dimensions?
Do I need to replace the entire shifter?
Should I make a warranty claim with Shimano?

Here is the brake/shifter diagram for clarity:

I would re-tighten the bleed port screw and watch for leaks. If you get no leakage and the screw does not loosen then you are fine.

A partially damaged thread should not be a problem as the bleed port screw does not have any load on it. (There should not even be any fluid pressure on it during braking as the reservoir is cut off from the line by the piston when the lever is pulled.)


Tapered suspension fork on a 2003 Surly Karate Monkey frame Is there any way I can run a modern tapered 1 1/2" to 1 1/8" tapered suspension fork on a 2003 Surly Karate Monkey (Original frame style with V-brake and Disc Brake Mounts). I think it only works with 1 1/8" straight steerer forks now. Are there any headsets that I could install which would make my frame compatible with a modern tapered suspension fork?

FWIW, I'm currently running a Chris King No Threadset for straight steerer at 1 1/8" diameter.

Beyond rebuilding the frame with a tapered headset, not practical.

Effectively you need to fit an 1.5" OD tube into a 1.125" ID hole. This could theoretically be done by using a spacer and locating the taper part of the steerer under the frame.

The effect would be raise the headset height and change the bikes geometry. The advantages of the tapered headset would be negated very quickly by the changed geometry, and the loss of stiffness and extra weight using a spacer would offset all the advantages of a tapered headset. i.e. The bike would be less stiff, heavier and have a poorer geometry.


How can I avoid getting chain grease on my trouser leg How do you solve the problem of stained jeans? I'd prefer to avoid modifying the bike itself or rolling up the hem on my pants.

Of course, riding with short pants is out of question, now that the winter is coming :-)

Leg straps or clips (especially on the chain side) are the way to go.  Not only does this keep the pant leg clean, but it prevents the cuff from chafing or hanging up on something.

You can improvise with a large rubber band, but the Velcro straps are readily available and very easy to get on/off.  When not in use they can be wrapped around your seat post or some such.

(And if the straps -- you can use two per leg for really baggy pants -- don't do it you can buy "gaiters" that cover the entire ankle and lower shin.)


I have changed the chain after my gauge showed that it's .75 worn. New chain jumps anyway. Why? How to deal with it? I am riding MTBs for over 8 years and either the rules and tools to measure the chain wear do not work or I don't understand how to use them..

I have bought Canyon Exceed with 1x11 SRAM drivetrain. I have been measuring the chain wear and after 1500 km the chain gauge showed .75, which as I understand means, that the chain is worn and need to be replaced, but the cassette should be ok. So I have changed the chain. Well guess what - it skipped on two sprockets. I was shocked. I had the same situation on my 3x9 Drivetrain. there I even tried to change the chain after 500km and the chain skipped on the 2 smallest sprockets.
I keep my drivetrain quite clean, and lube it frequently, of course this new bike was always washed and lubed..

I don't know what I do wrong.. I expected that the 1x11 drivetrain will help me to avoid this problem, since all the shifting happens only on the cassette side and not on the chainrings.

Maybe some of you have some suggestions, how I can avoid this problem - next to that will the SRAM x-sync 32 chainring (small aluminium chainring) be worn too if I will put the old worn chain again?

Thanks a lot! Gidi

The previous answers appear to have missed the fact that with 11s and higher drivetrains, the current consensus appears to be replacing the chain once it hits 0.5% wear. At .75%, riders will frequently need a new cassette. While this obviously seems expensive, many 11s and higher cassettes are even more expensive. On the road, our outer chainrings are also very expensive, and we really don't want to wear those.
In comments, the OP said they used a dry lubricant. Dry lubes contain some lubricant, usually wax-based, in a carrier fluid. The fluid evaporates. Some empirical testing has shown that many dry lubes are poor lubricants. White Lightning's dry lube is a particularly clear example: if you examine a bottle that's been sitting on the shelves, you'll see that it's mostly a clearish fluid, and a small amount of residue at the bottom. The residue is what dries off and lubricates the chain. In a wear test of White Lightning Epic Ride, Adam Kerin agreed that it made for a clean running drivetrain. The price of this was one of the highest wear rates he has tested. He described the test chains as sounding dry very quickly, which is an indicator that there is not much actual lubricant in the chain.
High-performing dry lubes (i.e. produce long chain life and low drivetrain friction) do exist, but they require very thorough cleaning of the chain before application. This involves repeated solvent baths, and preferably removing any solvent residue with an alcohol bath afterward. I think that the OP's choice of a dry lube probably shortened their chain life. I would suggest switching to a good wet lube. If the OP just does the same chain cleaning routine described in the comments, I bet this would produce markedly better chain life.
If the OP wanted to go one step further, I think that an on-bike chain cleaner is relatively simple to implement. I am not sure how much difference wiping the chain with degreaser on a rag makes; what you ideally want to do is to get the dirt off the chain surface and out from inside the chain, at least as much as possible. A rag and degreaser shouldn't clean inside the chain. I'm not sure if it will remove more dirt than simply wiping the chain.
Fun fact: in chain wear testing, i.e. when comparing different chains (as opposed to different lubricants) for durability, Kerin now uses White Lightning dry lube to shorten the chain life, so that he can complete the tests in a reasonable interval. To my knowledge, he only has one test rig.


Shimano revoshift 7 speed use I just got a Nishiki cross bike and it has a Shimano Revoshift 7 speed.  The bike is about 3 years old or so and did not come with a manual and I am a biking novice.  The shifting I understand.  The left handlebar has a Revoshift friction handle with a "+" and "-" setting.  What is the purpose of this and what is the best setting?  I noticed that if it is set for least friction the chain came off the gears.

A friction shifter allows you to continuously move the derailleur. The point of this on a front shifter (the left) is to trim the front derailleur. Trimming the front derailleur is when you tweak the position of the front derailleur to account for the change in chain angle with shifting, e.g. eliminate the chain rubbing on the cage of the derailleur.

There isn't a "best" setting -- you'll adjust it depending on which gear combination you're in.


Repetitive strain injury risk, seated vs standing on pedals At the same cadence and torque, and hence at the same power output, which generally presents the lower repetitive strain injury risk: pedalling seated, or out of the saddle?

How does the distribution of forces on the body and the risk of injury change as force on the pedals goes up, both for seated and for out of the seat cycling?

For an aging recreational cyclist, with no great need to sprint, is it always the better choice to downshift and remain in the saddle, rather than to get up and stand on the pedals?

(Edited: made clear I'm interested in repetitive strain injuries specifically, rather than injury in general. Apologies to those who answered with respect to general injury risk - these answers are interesting, but not what I was looking for)

This depends entirely on the conditions one is riding in.  Crashing on ice, one is probably better seated as the fall has a lower drop and sliding is easy enough.  In a rock garden, you may be better standing so that you can clear obstacles and not have your bike as an extra factor involved with the crash.  On a busy sidewalk, being seated and stopping more quickly might avoid entangling pedestrians/additional cyclists, etc.  On a roadside, it might be preferable to stand and roll away from the road to avoid the dangers of laying in a heap on a roadside with your bike.

Additionally personal skill comes into play, people who don't know how to roll with a fall are perhaps more likely to be injured from a higher fall (standing).  However, there are skills that help with a sitting fall as well.  Taking a sitting fall on your side (rolling up from hip to shoulder without slamming knees or elbows) is preferable to going over the bars while sitting or putting an arm out and breaking it.

I think conditions and personal skill with falls will make a larger difference than what position you start in.


Can I change my derailleur without changing my shifter? I have Shimano V-Brake 8-speed shifters on my bike. These have the brakes and the shifter in one component. I'd like to change my derailleur can I put in a newer 8 speed Shimano derailleur that will still work with the old shifters? It'd save me from buying new shifters AND brake levers.

Yes.
All Shimano MTB groupsets up to 9 speed all used the same derailleur actuation ratio (how far the cage moves for a given cable pull), so all 8 speed MTB shifters are compatible with all 8 speed MTB derailleurs.


What does a flashing yellow arrow traffic signal mean? While bike commuting in an urban setting, I've started noticing that some intersections have flashing yellow turn signals during part of the light cycle. What does this mean? If I am on my bike in the turn lane and a flashing arrow appears, can I proceed with the turn or should I wait for the arrow to turn green?

Flashing yellow arrows have been introduced in the US recently to help ease congestion at intersections. This signal should be treated similar to a yield sign or a turn lane not controlled by its own traffic signal. If there is no oncoming traffic, you may make a left turn if it is safe to do so, but you must yield to any oncoming traffic and to any pedestrians in the crosswalk you would cross when turning.

Although laws vary regionally with regards to how bicycles are treated in traffic, in most cases a cyclist would handle this situation the same as any other vehicle. If there is no oncoming, you can make a left turn, but be wary of traffic coming the other way. It may be safer to wait if you don't have a full view of oncoming lanes (i.e. if there is a blind corner or low visibility), since it will take you longer to clear the intersection than a motorized vehicle, and drivers coming the other way will not be expecting a bicycle in the intersection during their green light cycle.

This animation from the Alaska DOT shows how the flashing yellow arrow sequence works:


Is there any reason not to buy 2x11 GRX shifters for a 1x setup if I don't plan on adding a dropper post? I plan to buy a Shimano GRX 1x11 groupset. My understanding is that Shimano offer two left-hand shifters:

2-speed for 2x11 setups
Dropper-post lever for 1x11 setups with a dropper post

I do not plan to run a dropper post in the future, but I might switch to 2x11 if I decide that 1x11 does not offer enough gears.

It seems more sensible then to buy 2x11 shifters and simply not connect the shifting cable on the 2-speed lever to anything. If I choose to move to 2x11 speed then I do not need to buy any new shifters.

Is there any reason not to do this?

None that I can think of. It will be much easier to use the 2x shifter, rather than swapping out the dropper lever for a shifter later down the road.