How does a bike absorb all the energy in landing from a big drop? There are countless videos showing BMX/freeride/downhill etc. riders jumping and dropping from heights. For the unprofessional spectator, they seem impossible to survive.
From the physical point of view, the bike reaches the ground with a given kinetic energy which is dependent on the height of the drop and on the combined mass of the rider and the bike. Where is all this energy dissipated? I assume that most of this energy is absorbed in the bike, and some by the rider. How is this energy distributed in various components of the bike?

Physics!
Landing big jumps is all about dissipating the inertia that pesky old gravity has created on your trip back to earth. The better you dissipate that inertia, the better the chance that you wont kill yourself. There are several factors in play here:

The Transition of the Landing.The landing is almost always sloped downwards. Combine forward momentum with a downslope and you've got a significantly softer landing than you would landing on flat ground. That's one of the major reasons you see riders get hurt when they overshoot a landing transition.

Suspension.A little bit of suspension goes a long way, and a lot of suspension goes even further. The amount of impact damping that even an inch of give will provide is enormous. Think about it in terms of what it feels like to fall backwards onto a mattress vs falling backwards into tall grass or snow, distance being equal. The give of the soft surfaces decreases your velocity and dissipates your inertia which is what keeps you from cracking your head open as you would on concrete. Big-hit bikes can have 8 or 10 inches (or more) of suspension travel. That's a lot of travel to dissipate an impact. Even the tires provide a little bit of squish which is especially important for BMX riders (and it's also why rigid mountain bike riders tend to run larger volume tires).
Proper Landing (how you leverage your bike and the bike's suspension)Notice how most riders will land rear wheel down first, especially on flatter landings which are common in trials and street BMX. This further reduces impact because the rider can, in a way, leverage the give of the front and rear of the bike in succession. This is effective for both rigid and suspended bikes. By landing on the rear wheel first, you can use the bike as a lever of sorts - absorbing part of the impact and decreasing your body's velocity before the front wheel lands. This is achieved if your weight is balanced correctly by bracing against the pedals and handlebars. The effect is even greater for a bike with suspension. As the rear wheel hits, the rear shock soaks up what it can, then the front wheel comes down and the fork soaks up even more. Compare this to landing totally flat (both wheels at the same time) where the bike will provide roughly only as much suspension as the averaged travel of the combination of the front and rear shocks, or for a rigid bike, only as much as the tires would give (ouch!). Landing rear wheel first doesn't mean you get double the travel, but it certainly gives the bike more time to dissipate the force of the landing.
Knees and Elbows (even more suspension)Really, this includes most of your joints - any part of the body that can flex and move to soak up the impact. You don't see riders taking big jumps and landing seated. That's because they're using their arms and legs to take up as much of the impact as they can that the bike couldn't.

When you combine all of these elements in harmony you've got a really substantial amount of movement, and although it only takes a fraction of a second to land a big jump, it's enough time to slow down a rider's mass and keep them from becoming a grease spot at the bottom of The Tooney Drop.


What is randonneuring? How to get started? Thanks to darkcanuck and this site, I have learned of randonneuring.

So, my basic questions are: What is randonneuring exactly? And, how does one get started?

I typically ride in 2 - 4 organized/supported Century rides each season; and additionally wind up on rides with friends in the 80 - 120 mile range. I think my riding may be hitting the category of randonneuring, but not in any organized fashion.

Randonneuring sounds like a lot of challenging fun. What are good resources (online and other) to get me started?

The short answer is "marathon cycling".  Others have called it "touring with time limits".

As a sport, randonneuring is based on rules laid out by Audax Club Parisien (ACP).  Rides are known as "brevets" and are organized by local clubs.  They may have slightly different interpretations, but you can count on brevets being basically the same around the world.

I won't go into all of the gory details, but here are some of the highlights:

Randonneuring is a non-competitive sport.  You get credit for finishing a ride within the time limits, but there are no rankings, no awards for coming in first or setting a great time.  Some ride just to see if they can finish, others are trying to set new personal best times.  This means that you can team up with a group of similarly paced riders and help each other make it to the finish, which is very helpful when you're new to the sport.  All the riders I've ever met have been very generous with information, tips and motivation during brevets.
Riders must be self-sufficient.  You're riding on regular roads without a sag wagon or cheering throngs of spectators.  Some brevets might have a lot of volunteers, so there may be food & water at some of the checkpoints.  Other rides might only have someone at the start & finish.  In between, you're on your own so you need to be able to sort out mechanical problems and take care of food & hydration.  Being prepared is essential since some routes can send you through very remote areas.
Controls (or checkpoints):  you have to follow the specified route (instructions given out at the start, or possibly in advance) which passes through a series of controls.  At each control, you need to get proof of passage.  Typically this means getting a control card signed or stamped.  Sometimes this might be done by volunteers, other times it's a bewildered 7-11 clerk or cafe owner.
Time limits:  there is a time limit to make it through each control, including the final (finish) control.  The limits are generous and are based on maintaining 15km/h for rides 600km and under.  Keep in mind that this includes rest/food breaks, mechanical problems etc so you need to average above 20km/h to keep ahead of the cutoff times.
Distances start at 200km.  A basic series would be a 200km, 300km, 400km and 600km brevet (depending on your club they might be spaced 2 weeks apart).  So for a 200km you have 13.5 hours to finish; 600km has a 40hour time limit.  It's a running clock, so the longer distances will involve plenty of night riding (on a 600km it's possible to build up enough of a time buffer for 4hrs of sleep, more if you're really fast).  Other distances include 1000km and most of the premier events are 1200km (90hr limit, typically), including Paris-Brest-Paris.
Paris-Brest-Paris (PBP) is the biggest event on the randonneuring calender.  This is a 1200km event which draws thousands of riders from around the world.  It only runs every 4 years, and 2011 is the next one.  Participation in randonneuring clubs usually spikes during a PBP year, so it's a great time to get into the sport as there will be many other new riders.

My favourite resource is the BC Randonneurs website (very biased, since I'm a member).  The links at the bottom of the page go into more detail on what I've covered.  Randonneurs USA will probably be useful if you're looking for a US-based club.

If you love riding, enjoy challenges and are very persistent (read "stubborn") than I'd highly recommend it.  Most clubs run shorter rides called "populaires" which are open to non-members and give people a chance to try the sport with only a 50-100km committment.


Rear 700C tire on hybrid bike flat/deflating seemingly at random I have a hybrid bike and I am having a very strange problem with deflating tires.
My bike has 700C 35/43 tubes
I have changed 3 tubes in the last 2 weeks because something very strange is happening.
Tube 0

That I had for a long time punctured
I found the small hole

Tube 1

I change the tube and pump it to the suggested pressure of 80-85psi.
I ride it for 1 day, check the pressure, it stays at 80-85
I leave it overnight, check the pressure, ride it for 1 more day, check the pressure, everything is fine
I leave it overnight, the tire is completely flat. I

Tube 2

I change the tube and pump it to the suggested pressure of 80-85psi.
I ride it for 1 day, check the pressure, it stays at 80-85
I leave it overnight, check the pressure all is fine, ride it to the supermarket, pressure is fine. Go in for 1-2 hours, come out, tire is flat.
I pump up the tire, ride home, check the pressure, everything is fine.
I leave it overnight, check the pressure in the morning, everything is fine.
ride to the office, check the pressure, everything is fine.
come out for lunch 3 hours later: tire is flat.

Repeat with one more change of tube. Same result. Completely random deflation.  I visually and tactilely inspected  the rim, the tire, the tape and cannot find any problem. The tire is not new, sure, but it is not bald either. Should I replace the tire? The whole rim/wheel (more expensive, also, the cassette is difficult to remove and I have never done it)? The whole wheel with cassette? The whole bike?
I am somewhat technically minded so I tried to understand but my observations essentially are useless as I can find no logical pattern. Has anyone had any similar experience?
Thanks!

Something subtle is in the tyre puncturing the tubes. It may be rubbing rather than piercing, and it may be imperceptible without pressure, but it's there. To help you locate it, align the logo on the tyre with the valve every time. Then when you find the hole in the tube you know where to look in the tyre (with some margin for error, and you might flip the tube over, so check the other side of the valve too).
As well as glass, wire, screws etc. I've had the threads from a nearly worn out tyre appear on the inside and cause slow punctures, and I've had the inner end of ice spikes wear holes in tubes.
Slow punctures are odd. They can seem to hold for a while then drop suddenly. Whether that's real or just that you notice suddenly, I don't know, but I've had a couple recently do odd things like that


Jammed Giant brand U-Lock. Unable to insert key The other day I locked my bike to a fence and upon my return about an hour later, I found the lock jammed. I am unable to insert my key fully into the keyhole. My friend suspects that while locking the bike, I might have removed the key too hastily, resulting in the lock pins being misaligned.

The lock is a Giant brand U-lock. The key goes in about half way and is unable to turn. I tried forcing the key to turn which resulted in me snapping the key (luckily, I have a spare). Any help in the matter is much appreciated.

I've had this same issue happen with my Masterlock, and generally remedy it with lots and lots of wiggling. It mostly happens to me in the winter when a bit of moisture gets in there, so I don't know if it's the same issue or not.

My method was to stick the key in as far as it would go, and then repeatedly try and wiggle it back to the most locked position, while moving the key back and for laterally (or whatever the perpendicular direction would be to whichever way it turns.) Just go back and forth a lot - sometimes it works quickly, but sometimes it takes ~15 minutes. Either way, that's always eventually worked for me.


Things to consider when upgrading crankset I am considering upgrading my crankset, or rather I am considering considering to upgrade it.
I would like to gain a few teeth since I am permanently riding on the 48/13-15 making the 38 pretty useless.

I currently have this: Suntour NEX, 48/38/28.
If I were to upgrade to something like : http://www.rose-vpc.fr/article/shimano-pedalier-fc-2303/aid:417044 what should I consider? Do I need to buy a new bottom bracket as well?
Will my derailleur require any update apart from raising an inch higher to accomodate the 4 extra teeth?

The crank you point to would probably fit on your bottom bracket, but might result in a bad chainline.

There are two things to consider when replacing your cranks: the interface between the cranks and the bottom bracket, and the distance from the centerline.

Your old Suntour cranks and the Shimano you link to both use a JIS square taper. So the interface is fine.

However, your old cranks are designed to be installed on a 122-mm bottom-bracket spindle (and I'll assume that's what you've got), while the Shimano you link to is designed for a 113-mm spindle. You would be going from a triple to a double, which would make up for some of the difference, but I think the Shimano would wind up riding a few mm farther outboard than it's intended.

If you could find replacement chainrings that fit your cranks, that would be an easier and cheaper option, but large chainrings for mountain-bike cranks are apparently impossible to find. And I'm not sure what the BCD measurement is on your Suntour cranks.


Thule Helium Pro hanging bike rack - assembling problem I need to assemble the Thule Helium Pro 2 rack, which came in a box as two separate parts. I'm supposed to insert a metal bolt in the hole, but I can't do that cause there is a small metal piece inside this hole (please see the picture), which doesn't let me to do that.

Is it a defective rack? Or I'm supposed to do something (what?) with these parts to open the hole in full?
(I've sent email to the Thule support and got a robotic confirmation only - a week ago! I tried to call customer support and was on hold for 20 minutes, then gave up)

It looks like a defect in manufacturing to me.   Appears to be a daggy piece of metal left over from the drilling process, aka swarf that is still connected. I'd suggest putting a bolt in and then tapping it firmly with a hammer to dislodge or shear off the flake.  Maybe use another piece of metal to avoid damaging the bolt.  You might be able to grab it with some needlenosed pliers and twist it off.
If the obstruction is thick then you may need to drill it with a drill bit that is the right size for the bolt.
Either way, add some paint or grease to protect both the bolt and the frame from the elements.  Having removed some paint will allow rust to form there.
You could try sending the whole thing back for replacement or refund, but to me its a minor annoyance that will be fine once drilled.    It is disappointing to see this quality-control, and wonder whether other parts on the rack are similar.
Whether this voids any warranty, that's another question that only the manufacturer could answer.


Tube adhering to tire I was fixing a flat this morning and discovered that the tube was adhering to the tire casing. The tube pulled free from the tire, with about as much force as it would take to pull off well adhered (but not "baked on") masking tape.

I don't think I've ever encountered this before and I'm wondering if it is indicative of a problem?

Tubes sticking to tires are pretty normal and not a problem, especially if the tube has been in the tire for a long time. Some people put talc or whatever in a tire to avoid this, but its not necessary.


Leaking fluid from hydraulic brake caliper Shimano BR-M355 rear caliper.
I've very quickly managed to contaminate three sets of brake pads through fluid leaking (I think) from the bleed nipple. I've twice taken advice from local bike shop who inspected the caliper and assured me nothing was wrong, advice was to buy more premium end sintered pads. Fair enough I thought, give it a try. Few weeks later and back to square one - no braking power and very noisy.
The dust cap is missing from the bleed nipple, but I assumed this was one way and wouldn't cause it to leak?
Essentially, the question is can I fix it by replacing the dust cap, top up fluid and replace pads, or is it a case of replacing the caliper and starting again?
Any advice gratefully received. Thanks

Are you 100% sure that it is leaking from the nipple?
There are other ways to leak oil:

From a badly crushed olive in the hose connection
Cracked piston
Damaged piston seal

And other issue could be "pad glazing". This has similar symtoms as getting oil on the pads.
If you are 100% sure that the bleed nipple is the issue. You can just replace and bleed the brakes.
You can't just get a new dust cap though. You would have to get a new bleed nipple. The dust cap has nothing to do with making sure the system doesn't leak. It's purpose is to keep dust out so when you bleed the system, the dust doesn't contaminate by mixing dust in with the oil. Adding a dust cap, won't stop a leak. The pressure from braking will still push the oil out.


Can I swap from 46/36 chainrings to 36/28? I ride a 2015 Cannondale CAADX (Sram Rival) which has an FSA Gossamer crankset fitted with 46/36 chainrings.  It has 5 bolts and a 110mm BCD.  I'm an old man with bad knees.  I never ride on the 46 ring, but I could surely use a granny gear.  Is it possible to swap my chainrings for a 36/28 pair, e.g., say a Vuelta SE Plus Chainrings 110mm BCD Black 36T and a Vuelta SE Plus Chainrings 74mm BCD Black 28T, or say these Sugino Chainrings?  Is there any reason (beside aesthetics) that I couldn't move my current inner 36T chainring to the outer position?  If the change is possible, do you recommend any particular chainrings to look at?

I realize that I will have to shorten the chain and possibly shift the front derailleur.  Is there anything else that I need to be aware of?  Thanks very much for any help!

You’ll need a sub-compact (also called super-compat) crankset. With 110mm BCD the smallest chainring possible is 33 or 32 teeth.

There are sub-compact cranksets with 74mm BCD for the inner chainring and 110mm BCD for the outer chainring which should allow you to install something like 28/36. This Sugino OX2-901D Compact Plus+ for example. Looks like their smallest possible combination would be 24/34.

Keep in mind that a road bike front derailleur is not made for such small chainrings. Especially if you have a braze-on mount instead of a clamp for your front derailleur you could be limited in how far you can slide it down the seat tube.

Maybe a 33 teeth chainring combined with a 11–32 cassette would be good enough for you?


How to use Garmin's battery more effectively? I've bought a second hand Garmin Edge 800 for a while ago. So far, I'm nothing but delighted about the device and the battery life. However, since I have to plug it in in order to upload my rides, it usually gets charged when plugged in so my battery level almost never gets under 50-60 percent, sometimes not even so.

That makes me wonder if I'm doing the right thing. About batteries, sometimes I hear that it's better to empty the battery and then fully charge it. What are your opinions about this? Do you do anything to extend your device's battery life? Or do you worry at all?

From my research, the Garmin Edge 800 uses a 1Ah lithium ion battery.

In general, these do not have a memory effect like older rechargeable batteries. But some care is still worthwhile, for example storing the battery completely charged (in a hot environment) or completely discharged is damaging.

Partial discharge cycles are generally seen as good for them. A full discharge and recharge every 30 uses is recommended by some sites.


Are velodromes symmetrical? This question establishes why velodromes all operate in an anticlockwise direction. Are velodromes designed this way, to make the left hand turn easier, or would it be just as easy to cycle clockwise around them?

Specifically: are there two lines of symmetry in the shape of the velodrome, one through the pursuit finish line in the middle of the straights and the other through the middle of the bend? Is this true for all velodromes?

Source: about 15 years ago I used to ride lots at Manchester velodrome, and I remember someone claiming this from around that time, and reporting that a novelty clockwise race had been really difficult.

UCI Regulations for Track cycling provide a very loose definition for velodromes (see page 75) even up to the Olympic level. The only strict requirements beyond track width and markings are that velodromes must be 133-500m long (250m exactly for Olympic events), the track shape should consist of two parallel straights connected by two bends and that there is a smooth transition between the straights and the bends. There is no requirement for a consistent radius or banking throughout each bend. There is no requirement that the straights should be the same length or relative elevation either.

Exact dimensions of various velodromes are difficult to find, however to give one example How the velodrome found its form features an interview with the engineers responsible for the velodrome used for the London 2012 games where they note:

  The track in the London Velodrome doesn't have the usual reflection symmetry you find in buildings. "If you folded the track in half lengthwise, the two halves wouldn't match," says Weir. The track does have rotational symmetry, it looks the same if you spin it by a half-turn. But the slope of the track going into and out of the turns is not the same. "This is simply because you always cycle the same way around the track, and you go shallower into the turn and steeper out of it."

While it is likely that most velodromes feature rotational symmetry and many of those will also feature reflective symmetry this is not a requirement for a UCI homologated track.


What is the best bicycle lock on the market? What is the best bicycle lock on the market, defined by:

Best security
Easiest usability when securing your bike
Easiest method of transport
Lightest without other compromises

Edit:

In addition, what do you think of the lock design below? Secure? Transportable? Would you use it if you had it? Is there something else that you would prefer, or something about it that would keep you from using it?

Edit 2:

I am looking for a way to convince my roadie friends that securing a bike on a long ride for lunch stops/etc is doable and practical. The weight is a killer, and they just won't buy it. That's also why I'm not just doing something like one of the Kryptonite Chains or a U lock.

This question was inspired by this Kickstarter project. No relation to me. I just think it's cool.

Some years ago, Bicycling magazine did a shootout on available locks and the Kryptonite "New York Chain" came out on top.  Unfortunately, it weighs more than many bikes and is not easy to carry either.
Fine if you can leave it where you lock your bike.

I'm with the police department at a major university, and we have a program through Kryptonite where we give the kids a (heavily subsidized) Kryptonite U-lock for a mere 20 bucks.
Over the 30 years I've been here, we've had only a handful of these locks defeated. Most all the bikes we have stolen (lots...) are locked with the sort of cable shown above.  The thief uses a rather small bolt cutter and removes it more rapidly than you could by using the combination.
The U-locks are easy to carry, not overly heavy, and offer a "good" level of security.

Anything can be defeated with the right tools, time, and opportunity.  Deny the thief these things and you have a better chance of hanging on to your bike.
Or....Buy a beater and save your nice bike for weekend rides.


Shimano 9 speed shifters I have bought myself a Shimano Deore M592 set without shifters.

I am now in the process of getting them as well but am not sure if I can put any 3/9 speed shifter on it.

Do I only need to take care of this or is there something else I have to watch for when choosing shifters?

You should use Shimano mountain bike shifters (Acera, Alivio, Deore, etc.) which have the same # of chainrings and same # of cogs on the cassette. So if you're running a triple in the front and a 9 speed cassette in the back, you want a 3x9 shifter set. The road bike ones (Sora, Tiagra, 105, Claris, Ultegra, etc. - even flat bar ones, like the Sora flat bars) will not work because they use different cable pull in the front.

You can't use SRAM shifters other than the SRAM Attack line (which are friction front, indexed rear, so you'll see the ones for a 3 x 9 setup just marketed as a 9 speed setup), since they have different cable pulls.

Microshift also make ones compatible with Shimano as well in the XE Marvo line (but I don't know anyone who has actually used a Microshift shifter on a mountain bike - usually its just their bar ends on a Surly road bike or similar).


Can given crankset have limit on spindle width? I would like to buy new crankset which is described as having 54 mm chainline for 110mm bottom bracket (this is square taped BB). Since I need 50mm chanline I calculated that I would need 102mm spindle, luckily I found such bottom bracket.
My worry is whether there is some other unspoken factor here, I mean can I just use this BB with shorter spindle or do I have to check something more? If more checks are needed what are they?
I currently run 44/32/22 chainrings and those are exactly the same as in the one I would like to by. The only differences are BB type (I will convert from HTII to square taped, same width, 68mm, both BSA) and crank length.

You are taking the right approach to figuring your chainline per a given spindle, but yes, there can be other limiting factors.
If you go too far, it is possible for the crank body near the spindle interface to smack into the bottom bracket shell or the cartridge body, or be low-clearance enough that flex and grit wear a groove into the crank. Low-profile cranks increase the likelihood of this. Using something like a Phil BB that has zero protrusion from the shell can avoid the problem where a Shimano or similar will run into it, which can be useful if you absolutely need a certain spindle length.
The above is not super common, but you can get it to happen in some situations. I've seen it mostly when putting 135mm-oriented era touring triples, i.e. the Sugino XD600 and XD300, on bikes with older chainline numbers or when trying to get the Q minimized. I think I've seen it at least once when someone was configuring a road crank for track chainline with the ring in the clean-looking outer position.
Interference between the ring(s) or spider and the frame is also possible.


How to lubricate noisy joint on Dahon foldable bike? My Dahon foldable bike makes a huge noise whenever I fold the frame and unfold it. I tried spraying a lubricant into the joint. I do not know if the problem is continuing because the lubricant went around the joint and didn't enter it, or because I used the wrong lubricant.

Has anyone else had problems with the fold across the frame with their Dahon bikes? How did you lubricate this fold?

For similar things on cars I use white lithium grease (e.g. this stuff on Amazon)—it is a good lubricant and sticks around the joint that you apply it to.

Any similar thick grease should work for this joint, but the crucial thing is getting it into the right place.  Taking the joint apart and applying grease to the mating surfaces is the best bet.


What are the advantages of investment casting? I'm starting to see more and more frames using investment casting for head tubes, drop outs, seat tubes, etc. Such as the new WTP c.r.e.a.m. frame . It looks nice, but I'm suspect on how much more strength this gives you over traditional welds. Does anyone have more info on this technology?

The current version of this frame has a traditional seat tube and head tube.

  For 2014 we have done quite a bit of work to the C.R.E.A.M frame. The
  advanced invest casting junctions have been replaced with a more
  conventional welded design. The main reason for this was to make this
  beautiful frame more affordable.

I think the investment casting of the entire headtube is something particular to BMX bikes. It makes sense, for reasons outlined below.

Typical parts of a bicycle which can be investment-cast are:

Head lugs
Dropouts
Seat clusters
Bottom bracket shells
Seat-stay and chain-stay bridges
Fork crowns

The easiest way to see why investment casting is preferable is to compare it to the alternative ways the same items can be made: (modified from here)

Investment Casting: This is the most common method of making high quality lugs.  This is the oldest form of metal forming on the planet.
Stamped & Rolled: This is the lease expensive way to make lugs in large quantities, as they can be stamped from a flat sheet, and formed into the required shape.
Bulge Forming: Relatively rare, this involves placing a steel tube into a shaped mold and using hydrostatic pressure to expand and shape the tube.
Welding/Brazing Tubes Together & Filing:  This is also a common method, but intricate and time consuming.
Machined/CNC'd: Possible but not really used. Wastes a lot of material.

The two biggest problems with all the alternative methods are:

They are formed into a different shape from a cold, pre-formed piece of metal (Stamped, Bulge, Machined/CNC'd), thereby reducing strength, or
They have some weak spot (Rolled, Welding/Brazing), thereby reducing strength.

In investment casting, the steel is allowed to settle into its final shape while it's hot and allowed to slowly cool. This means that in it's final form, the metal is under absolutely zero stress trying to maintain it's shape. Furthermore, it ensures very even distribution (for example, rolled steel may be thin on the convex side and thick on the concave side).


Replacing 14" x 1.95" With 14" x 2.125"? I have a super quick question here, my daughter (she's 5 years old) rides her bicycle extensively, to the point of the actual tire has worn clear through.

I didn't think it would be this difficult, but I can't seem to find a direct replacement for her tires anywhere (her tires are 14 x 1.95).  I see plenty of 14 x 2.125 tires, would that work and be a direct replacement that'll fit?

I'm not sure what else to do at this point, but if we can't find new tires then we'd be forced to unnecessarily buy a whole new bicycle for her.

Any thoughts or ideas?  I have searched common stores, as well as checked online and there just seems to be no 14 x 1.95 tires available.

Thank you in advance!

14" tires are actually quite common on department store bikes (Wal Mart, etc), but they are not found on "bike shop" brands. I think this is where some of the confusion on this issue has come in.

You will almost certainly be fine with the slightly wider tire. For one thing, there is no true standardization on tire widths. I.e., every company uses its own gauge for what it means to be 1.95", etc (I once had a 2.55" tire from brand X that was narrower than a 2.2" tire from brand Y).

To be on the safe side, make sure you have a little clearance wherever the tires pass the frame or fork; but I would bet money that the 2.125" tires will fit, and on top of that you probably won't be able to tell any difference between the old and new tires.

EDIT:
Apparently I don't have enough points or something to comment on the answer that links to the Schwalbe website. I was going to say, "Those tires with fractional widths on the Schwalbe website will be entirely different from the tire with a decimal width mentioned by the O.P. If the O.P. gets a 14" tire with a decimal width he will be fine. In the USA I doubt there is anything else to be had."

Finally, if Wal Mart does not sell replacement tires for its own bikes (regardless of the marked width), any bike shop can order the correct tires for you and offer you a guarantee that they will fit.


Possible to repair a pushed in braze-on? I have a Trek 7200 (Alpha aluminum frame) and it has two water bottle holder mountings, the top braze-on on the seat tube seems to have broken from over-tightening and has sunk into the frame. These braze-ons are recessed into the body of the frame tubes, as if they were somehow attached from the inside.

Is it possible to repair this braze-on? Is it something some super-glue could help with, or am I looking at a permanent wound?

Bosses in aluminum frames are typically rivet nuts, aka "pem nuts", which have a head that should be too large to slip back into the frame.

For your frame, it sounds like the Park Tool directions for securing bosses on carbon frames should work equally well.  The top mount on the seat-tube is also the easiest to repair using this method, so you're in luck.


Another front friction shifter problem A search gave me the 2011 thread about slipping shift levers, but I'm not convinced what my problem is quite the same. Manual on my '88 Bridgestone 400 says it has an AL11GS L434 lever SIS downtube mount type. I can read the SIS, and it's on the downtube, and the original owner paid no attention to this bike so I'm sure that's what it still has. I've had and ridden the bike for about a year. I had to tighten the tensioning bolt once a couple of weeks ago, which was no surprise. It loosened yesterday to where it settled on the smallest chainring, and I screwed the bolt tight again. My commute is not much more than 3 miles, and that bolt came loose both going in and coming home. I'm now riding with a stubby screwdriver in my pocket.

What could have changed? What part of this wears, and has to be replaced? I don't like the sound of Loctite as a solution. Holding the lever in position to be able to ride in the middle gears is not a good option. Help! Thanks.

mh

Friction shifters eventually need to be taken apart, cleaned, and re-lubricated to solve the problems you mention. Be very careful to keep the parts in order. You'll find advice on the above mentioned other thread not to lubricate them, which is wrong. All the surfaces should get a thin film of oil or grease, ideally something that doesn't harm plastic presuming your shifter has plastic washers, as most do. Using a mild or medium strength Loctite is optional but is a good further safeguard against slippage, and won't keep you from loosening them on purpose. Some people use beeswax as a substitute.

The plastic washers inside can degrade, which wouldn't be surprising on a 30 year old bike. If so you probably just need a new shifter unless you want to get crafty and find or make new ones.


Essential regular things to do I am a beginner cyclist.So ,I want to know which things I have to do regularly.And what will be the time interval ?

Example :Pump,tuning etc.

Check your tire pressure regularly.  Different tires (tubes, actually) have different "leak down" rates, but at a very minimum check once a week, and probably every 3 days (or before every ride).
Clean/lube your chain.  Depends a lot on riding conditions, but in "average" conditions you should clean/lube every 200 miles or so.  More often in wet, sloppy conditions or in extremely dusty conditions.
Inspect your wheels.  Hold the end of the bike up and spin the wheel.  Check for any wobble (watch right next to the brake blocks for rim brakes) and check that there are no serious bulges in the tires.
Check your chain for stretch.  Get an inexpensive chain stretch gauge and check after you clean the chain.  Replace the chain when it's too far stretched (about every 2000 miles).
Check your sprockets for wear when you replace the chain.  How to do this is a bit involved for a short answer.
Check your brake blocks for wear maybe every 500 miles.  The blocks should be mating nicely with the rim and not worn to the point that the metal holder is close to scraping the rim.

There are others I'm not thinking of at the moment.  And this question is likely a dupe and there are other threads with more info.


Why do freehub and cassette have only one position that matches? When I'm installing cassette on my freehub, I need to make sure that the spaces align correctly. That is, there are 9 splines on the freehub and 9 corresponding splines on the cassette. My first attempt was just to put it in any of 9 positions but then I found out that one groove on the freehub is slightly bigger and the corresponding spline on the cassette matches it. So in fact, there is only one acceptable position. Why is this like this? Why aren't all of the splines the same size?
Naturally, I managed to replace the cassette, so I ask this out of pure curiosity because to me this "feature" seems annoying because I need to look closely to match corresponding splines, so I thought there must be some smart reason for this behaviour.

Early cassettes (Suntour Accushift and Shimano Uniglide being some commonly encountered examples) weren't like this. The splines were all the same and there was no hunting for the little spline or big gap.

To summarize a bunch of history, these cassettes were current at the same time as early indexed shifting. Accushift and early Shimano SIS both functioned, but not all that well by modern standards. The cog teeth on some of them had various thinned out or axially twisted bits to act as a primitive shift aid, but they were substantively like the freewheel cogs that came immediately before them.

Arguably the key innovation in Shimano's entire history, the first Hyperglide cassettes were released in 1989. Hyperglide uses a system of mapped-out chain exit and entry points (the different profiled teeth on modern cassettes) along with pickup ramping on the sides of the cogs to facilitate smooth shifts that demand a bare minimum of finesse on the part of the rider. It's the piece of the puzzle that made indexed shifting start working really well, and has been universally copied. But by nature, in order for it to work, the cogs have to be in an as-designed position relative to one another. Hence all modern cassettes only go on one way.


Shimano Sora rear derailleur install, U-ring on bolt I had a slight bend with my mech hanger so I took off the rear mech to get the hanger out and fixed.

Now that the hanger is fixed, I noticed a U-shaped ring around the bottom of the bolt on the rear mech is preventing me from fully tightening the mech to the hanger.

There is a opening on the top that seems to fit around the hanger but because of the ring, the mech is not fully engaged and the opening's edge ends up scratching the hanger.

Any ideas?

Thank you

Update:

Not the best angle but this is what it looks like when screwed in furthest. Ring is still in groove and B-screw is on tab.

From here if I were to increase B-screw angle, that open would move over and scratch the hanger, which didn't seem right to me but I couldn't find anything about this from Shimano manuals.

Just tried to align both open ends, still a gap there.

More info: Not the best angle but this is what it looks like when screwed in furthest.

@Argenti, yes ring is still in groove and b-screw is on tab.

From here if I were to increase b screw angle, that open would move over and scratch the hanger, which didn't seem right to me but I couldn't find anything about this from Shimano manuals.

That black strip to which your derailleur is attached, which can be assumed to be the hanger, looks strangely narrow, like a metallic popsicle stick. Is that by chance a part related to the Shimano Direct Mount (TM) system? Some sort of adapter link plate? It seems incompatibly narrow for the derailleur: it's fitting entirely into the semi-circular gap in the derailleur's bolt plate (what we're calling "the opening" in this Q&A.) That shouldn't be happening; the hanger shouldn't be pressing against the axle retainer clip at all.

Assuming there is no other compatibility issue, and you want to keep that hanger, one way to fix this would be to put a suitably dimensioned stainless steel washer between it  and the derailleur, to effectively make the hanger look as if it has a larger area around its receptacle for the derailleur to mate with.

The real fix is to install a traditional standard mount hanger that is compatible with the Sora.

For reference, here is a picture of how my Sora is attached to a standard type hanger. Notice also how the hanger is angled; it doesn't protrude rearward, but slants forward, so it doesn't anywhere near align with that opening recess in the derailleur's end plate.


How to setup triple front derailleur with a double crankset I want to use my front derailleur which is a tiagra on a 3x10 speed setup with a compact double crankset making it a 2x10 setup.

What is the proper procedure for setting up the triple chainring front derailleur as a 2x10 setup compared to setting up a standard double chainring setup? Will I be able to use limit screws to set limits properly for top and bottom ranges?

As with many things bike related, it might not meet the specs, but that doesn't mean that it won't work.

Some questions that will help answer the question:

Are you using friction or index shifting for the front?  If friction (such as bar-end shifters) you should be fine.  If indexed, you might have incompatibilities with cable pull, especially if you're trying to use the same shifters or switching between a road vs. MTB derailleur.
Do the limit screws allow adjustment to the range of motion that you require?  If so, you might be OK, but it really depends on the number of teeth on your derailleur.

If you happen to already have the parts and have worked on bikes a bit in the past "just try it" usually works for me.  You might be pleasantly surprised.  If you have to buy the parts or pay for labor it might not be worth the trouble.

Far more information on the topic can be found here:

http://sheldonbrown.com/front-derailers.html


Need to choose crankset for 135mm rear hub of MTB I replaced older 8 speed cassette on my Cannondale Trail with new Shimano Deore M6000 10 speed cassette (11-42). But since the axle spacing is of older type, want to get a matching crankset (2x preferred). Any suggestions?
Deore M6000 crankset I presently tried, but has chainline issue.

You can look up the specs of Shimano cranks here: https://productinfo.shimano.com/#/spec/MTB/Front%20Chainwheel.

The tables give the OLD (over locknut distance) aka rear hub spacing for each crank. Most are for 142 or 148mm.

Many cranks for 142mm rear spacing have a chainline of 48.8mm, which is just over the old standard of 47.5.mm for triple cranks on 135mm spacing, so any of those should be fine. You just want to avoid cranks with chainline of 50mm or or more.


Redline BMX or is it Redline decals on something else? I got this bicycle at a yard sale and thought it was a Redline BMX as that is what the decals on it are and same with head badge. Someone said it was not a Redline because the rear dropouts are not a Redline style. The original forks on it were genuine Redline forks as they had the RL stamp on the drops.

I had to replace forks with generic ones after the dealer had to cut the forks to get the headset off for an overhaul, because the plumb was rusted stuck inside. It says made in Taiwan on the headset and has Diamondback handlebars and grips. The serial number is on the rear dropout non chain side with another number on chain side rear drop out reading G0187 serial number is 7014544.

thanks for helping if you can!

GO187 is the date code from Giant (Taiwan manufacturer), which is Jan '87.

Frame looks to be an '87 Diamondback.


Please tell me what type of bike this is? http://www.njuskalo.hr/image-bigger/mtb-bicikli/rog-kanin-dosta-novih-dijelova-slika-2716844.jpg

Weight...heavy ca. 17 kilos

Mountain?

It seems to be what some call a BSO: Bike Shaped Object. (This is a derogative term).

It indeed mimics a Mountain Bike, a Dual Suspension Mountain Bike, but as you state it is really heavy, it means it is made of steel, and not necessarily good grade steel.

From what the picture shows, it also appears to be fitted with low level components, but the headset appears to be 1 1/4 inch and fitted with a good RST fork with threadless steerer tube and stem. The rear suspension looks really cheap.


Installing a chainguard on a bike with derauiller My pants always get caught in the chain (and wearing shorts is not an option). However, it seems that it's impossible to have both a derailleur and a chainguard so what is the solution?

Can I just lock the front derailleur in place and slip the chainguard past it. (locking the bike in top gear?)
Do I have to remove the derailleur entirely, by breaking the chain?
Can I just remove the smaller front gears and lock it into third? How difficult is this? Do the gears just pop off or is there more to it?
Does anyone make a metal chainguard so large that it could encapsulate both the derauiller AND the front crankset. (a preferred solution, but not easy to find)

Example of a chainguard to protect the pants from getting ripped. It also proctects the rider in case of a fall so that the gear teeth don't puncture the leg. (It happened to me and is just as nasty as it sounds! Gear teeth are dirty.):

Note: The winning answer will suggest a chainguard that covers both the top of the chain and the crankset (as seen in the picture above). Suggestions of tying, clipping or banding pants are not an answer to the question being asked. However, an answer that involves modifying the bike in some way to accommodate a chainguard will be accepted.

This StackExchange site has its limitations, in that product recommendations are not allowed because of regional differences and products/pricing going obsolete. However I think the answers are no you don't have to break the chain, remove the derailleur or lock off any gears. Products exist but are quite unusual so you will have to do some searching online or in bike shops in your local region.

Using Google, I found a couple of examples. The first one I got to a website which sells chainguards and browsed through the ones which say compatible with a single gear, and discovered some which say compatible with a triple ring like this style:

Another Google search along the lines of "chainguard triple derailleur" and I found this image, which has a more conspicuous allowance for the derailleur to remain fitted and usable:


Need help replacing old cassette and chain I have an old bike with a cassette and chain that needs replacement.  The problem is that I can't identify what kind of cassette it is or how to remove it.

There are 14 teeth on the smallest cog and 28 teeth on the largest cog on the cassette.  How do I remove it? There are only two nuts.

Will the bike take any Shimano chain (that matches number of links of the current chain?)

From comment:

I took the wheel off, i watched the video from Parktool but couldn't see any groves inside the cassette

If it's 5 speed, it's probably a freewheel rather than a modern style cassette that slides on a freehub.

Park Tools do a tutorial video on how to change one:

Additional information can be found on the Park Tools blog


how much cable beyond the pinch bolt I was trying to solder my bike cables because those crimp on's they fall off then the cable just unwind itself. After the painfull process I managed to use the cutting end instead of the crimping end to install the crimp.

A 20 quid park tool cable cutter isn't any good if u don't use it correctly lol

So is there an optimum length you leave sticking out of the pinch bolt?

Certainly the cable should be long enough to be under full compression by the tightening screw.

The extended length beyond that I have found is a trade-space between design and preference.  Some derailleurs and brakes have nice little routing features that allow you to tuck the extra behind a controlled point preventing annoying rubbing on your legs or tires.... If there is too little extra you may not be able to utilize this feature.  Some components don't have the routing  feature,  In that case I usually provide anywhere between 2 to 3 inches.  I have found that length is best for tucking out of the way.. and if in the rare case I need to pull some slack our of the cable I have enough to get a good purchase without the use of pliers.

If adjusted correctly the first time.. it is rare that you will need to let out cabling at the point of contact with the brake or derailleur but keep in mind that rare does not mean never so if you think its too short it probably is worth getting a new cable.


Mixing Dura Ace 9000 drivetrain with ultegra? I'd like to mix the DA9K drivetrain (chain, chainrings, front and rear mech, excluding the cassette) with my current ultegra 6800 setup. I dislike the DA shifters, but I'm ready to upgrade my shifting and braking cables if need be (suggestions welcome).

Is this going to work?

I believe Shimano uses the same cable pull ratio for all 11 speed groups, so 11 speed DA derailleurs and 11 speed Ultegra shifters should work just fine.


Minimalist setup for a "travelling bike mechanic"? I have very little living/working space of my own and so, in order to keep my personal bike in working order, I need to be able to transport "bike mechanic stuff" (e.g. tools, screws, cables, inner tubes, etc.) in an efficient, safe way to places where I can work on my bike and have access to bigger things I can't own (e.g. repair/truing stands). Additionally, I need to be able to have these assorted things well-organized and easy to move without a lot of packing/unpacking: I've had stuff stolen† from me while using communal workspaces which were busy because I either had stuff spread out so far that it wasn't quite within my "personal bubble" of control or I had to leave my space looking for something and, when I came back, something important was missing. Finally, even without the threat of theft, I nearly always lose at least one washer/screw/annoyingly-small thing when working on my bike.

Since I assume I'm not the only person in the world who has this sort of situation, are there any sort of guidelines on ways to quickly and efficiently store/transport bike repair/maintenance gear on one's person (e.g. in a backpack)?-- I haven't got a car, so I need to be able to easily carry it myself.

† I write "stolen" rather than "accidentally taken from me" after I shouted: "Hey, did anyone take a thingamabob from this location a few minutes ago?" and no one answered: Even if you accidentally took something, if you don't fess up, you're no better than someone who took it deliberately without intending on returning it.

I'd be very tempted to make a tool roll. You'll need access to a sewing machine that can handle 2-3 layers of canvas, but even most home machines will do that if you're careful (and buy a canvas needle!)

You see them mostly today with sets of ring spanners, made of cheap plastic. But in the older days people would generally make them out of canvas, often double layer with oilskin/oiled cotton on the inner layer (before chrome plating meant most tools don't rust very easily).

The extra material at the top of this pic lets you fold the "flap" down to stop tools falling out when it's packed up.

A reasonable sized roll will also let you lay out parts if you need somewhere less dirty than the floor. And it can be roughly rolled up with tools and parts loose inside it if you want to carry it a short distance, or just to make it less inviting to thieves.

Make the first one any old how, because there's a bit of a learning curve in what works for you.

As a secondary thing, I carve my name into tools with an engraver. Those are fairly widely available these days, or most key cutting places will have one. My decent/valuable tools I keep with me at all times, or just don't take to places where I'm worried about losing them.

I also still lose tools at events like this, almost always by lending them to someone who doesn't return them (often innocently, by giving a tool to someone else and saying "it's Mσᶎ's, give it to him when you're finished with it"... and after a few people have passed the tool on it's impossible to trace). I'm in a financial position where I can afford to hit bargain bins for cheap tools, because the ones that go missing are usually adjustable spanners, 15mm or 10mm ring spanners, and 5/6mm allen keys. All of which turn up in bargain bins for under $5. So every 4-10 trips to community events I spend $50 on new cheap tools. Often tools I wouldn't personally use if I had a choice :)

I'm thinking of buying 10 or more of the "S shaped" double ended 5mm/6mm allen keys because I expect I could get usable ones for about $2 each, and I'm willing to spend that to not have to worry about losing them. I expect that I could probably sell them rather than lending them at that price.


What is this fox fork front axle part called and where can I find a replacement? I've got a fox 36 talas RC2 from year 2006 and it's missing one of those black threaded inserts that pinches the front axle :

the part is M5 threaded, and approx. 28mm x 8.05mm
How is this called and where can I find a replacement? Is there an archive of parts numbers like for cars somewhere? I've only managed to find year 2015+ square pinch inserts so far like this one :

Thanks in advance

The one you have pictured is called a "pinch bar" or an "axle pinch bar"

I was unable to find a vendor who sells a 2006 version like yours. The one on your fork appears to be rounded. The newer ones appear to be square - like the last picture in your post. Here is a link to a vendor with a 2015 version (not a recommendation).
Here is a link to a 2005 manual for your fork. Sadly it does not list the pinch bolt anywhere but it has other information that may help.


Can you identify this bike/frame? Hello  though this might be a good place to ask this.anyone knows this bike?

Ross Piranha 1986

This is my best option based on the standing platform the fork and chain stays.

http://bmxmuseum.com/bikes/ross/89509


Recommended transmission for a commuting bike I want to get a new transmission group for my bike and I'm quite confused, so I'd really apreciate some help from the community. Here's some context:

I own, since last October, a Giant Escape 2 (https://www.giant-bicycles.com/us/escape-2-2016) which I use for my daily 22km commuting (11km from home to work and 11km back) plus daily errants and the eventual lay-back ride with my GF or friends. It has a 3x8 Shimano M191-Altus group.
My regular route has several elevation changes and a couple of steep climbs along the way. According to Runtastic Road Bike, I have about 74m of elevation up and 50m of elevation down and I have realised that I mainly use the middle cog on the front crankset, going from the 3rd (on full stops and uphill) to the 5th gear, and the large cog of the frontal set when going faster, applying the 6th and 7th gear. I have an average speed of 20Km/h.

So, for my question, I'm wondering if I could do better with a 1x11 or 2x10 transmission set, since there's one frontal cog which I've literally never used in the 2500k that I've rode this bike. Or is it me that I'm not using it properly?
If you think I should replace my transmission, which one would you recommend? Considering that I don't want to spend any body part on the upgrade =)

Thank you very much for taking the time to read my amateurish-bad-english-nonsensical question and a big kudos to those who will reply it!

New you can't do it for less than $200 unless it is off brand (not Shimano or SRAM)

Shimano does not offer 1x11 in the lower end groups.

It would be like 1/2 the value of your bike.

Not using the smallest up front is not a big deal.  I would just keep what you have.

You can remove the smallest and adjust the range if you want to.

Or you could swap to double crank.  Not sure if you can still use the same shifter or front derailleur.

Not seeing many used 1x11 yet.  Maybe look for a used 1x9.  I don't think there are any true (narrow wide) 1x8.


Rear Cassette worn + needs replacing - what other components to replace? I have picked up a bike (Specialized Allez) recently that has a very worn cassette from not replacing the chain for an extended period of time. Therefore am looking to change it. I was wondering what other components need to be replaced at the same time due to chain extension causing wear? My current list is:

Cassette
Chain
Chainring

Do I also need to replace the Rear Derailleur? And is the chainring required to be changed as well?

From the drive train, Chain/Cluster/Chain ring(s) would normally be enough and should be done together, or the old components would wear out the new one quickly. Although you can get by not changing the chain ring if you replace the chain often, if the chain is badly worn, a new chain ring is strongly recommended.

Check the pulleys on the derailleur for wear, and replace if needed. The derailleur itself may or may not be worn out - Unless obviously sloppy, I would leave buying a new one till the new drive train was in place, I had replaced the cable and checked hanger alignment and still could not get it to shift well.

Based on the wear on the drive train, I would presume the bike has been somewhat neglected. Check the BB and pedals  while the chain is off. Check the headset and wheel bearings, ideally clean and repack.

Unless in obviously new condition, I would replace shifter and brake cables as they are cheap, although if you don't have cable cutters and they are working well its possibly more effort than it worth.


Trailer hitch between a bike and trailer? I want to make a bike cargo trailer.  It seems to me that making the hitch will be one of the most difficult parts so I opened a separate question for this.

How would you attach the trailer to the bike?  Would you attach it at the seatpost (high) or near the wheel axle (low).  How would you allow the trailer to pivot both up and down and side to side?

See also: How to make a cargo trailer.

I would also go the commercial route, buying the hitch and building only the trailer itself. The handling (during cycling) of an axle attached trailer is much better than if you attach it on the seat post. Handling is best if the hitch parts can move as little as possible relative to each other. The Chariot hitch is pretty good, especially considering the fact that only one axle/quick release module fits a wide range of dropout designs.

Still, everything can be improved: The German company Weber makes a hitch system with the following highlights:

extremely rigid connection
very simple and fast to use
fits most frames perfectly by providing different frame/quick release attachment parts, even for geared hubs etc.
fits basically any drawbar, by providing inserts for any commonly used tubing size
can easily be locked (although the lock won't scare a good lock picker)
an integrated bike stand is available
quality and safety are top notch, and the parts last a long time

Weber hitches are easy to get hold of in Germany. It should be possible to get them exported to almost everywhere. Unfortunately the information is in German only, and the system is rather complex with all the different frame and drawbar fittings.


Replacing a Force Chainring with a Red Is it possible to replace a compact 50T chainring from my Sram Force set-up with a 50T Red chainring, they both have the same 110 PCD so I don't see a problem, does anyone know if I'm wrong?

Thanks

It is possible, as long as you use the SRAM Red Black Edition 2011 or earlier.

The new 2012 Exogram SRAM Red requires a different front derailleur design, and while it will physically bolt up, it won't shift well at all.

Any other SRAM compact (110 BCD) chain ring will work fine.


How do I true Kinetix Pro wheels? I have a pair of Kinetix Pro wheels on my Dahon folder. The front wheel has developed a wobble, so I got out my spoke key to fix it and.... there are no spoke nipples next to the rim. (The slight bulge you can see in the picture is due to the butting of the spoke, it's not a spoke nipple).

Presumably it's possible to true them from the inside of the rim, but if possible I'd rather not rip off the rim tape only to find out that I don't have the right tool - so if anyone knows what I need, I would be very grateful.

This wheel uses internal (inverted) spoke nipples.

You need to take off the tire and tape and true from inside the rim, as in the picture below:

(Source: Park Tool SW-15 documentation)

The tool will be something like Park Tool SW-15/16/17/18/19. You'll need to look up what the particular right tool is for this job -- I don't know which one is the correct tool.


How long do brake pads last in storage? I’ve discovered in my parts box some rim brake pads that have been there for several years. Aside from age, they are in fine shape (some are new). Can I put these on my bike, or is there hidden damage?

In other words, how long do stored rim brake pads remain safe?

I have already bought some pads that the LBS had for more than 4 years, and they work perfectly. I think the specific compounds from which brake pads (and tires, most probably) is not prone to self-degeneration if stored in a "normal" environment.

So, the suggestion would be to take a ride and check if the pads brake well. If so, use normally.


How much resistance comes from each part of a bicycle? How does one decide which part of a bicycle is the best candidate to upgrade or tune if the goal is higher speed for the same energy? For example, should one upgrade wheels, or tyres, or change to lighter parts, or to reduce aerodynamic drag with fairings?

Is there any way to compare the influence of each part? How much power can you save, and is it significant enough that you can recognize the difference? For example, do aero improvements make sense if speeds are very low and, if not, how can you determine the speed above which it does make sense?

We are reinventing wheel here.
Aero formulas from Sheldon Brown and racing bike chart

Few similar links answering this question:
- resistance types

- aerodynamics part 1

- aero (exploratorium.edu)

- human body front area depending on pose in case it will be possible to ride in horizontal position drag must be way smaller as front area will be at least 5x smaller.

Answer: This question cannot be answered in a simple tabular format because the resistance of every part depends on every other part.

IE, a wheel and tyre and spokes will have an effective "cross section" which is the hole it has to punch through the air.

That area is mitigated by the shape's curves.  From wikipedia:

So for simple shapes in isolation, the drag coefficient is known, and you can measure the cross sectional area in square metres.

Your problem is that a bicycle is not a sphere or anything simple - its a complex series of parts and they're hitting the air at different delays.  So when the air hits your downtube, its already been distrupted by the front wheel, forks, and headtube, as well as being in close proximity to your shin which is a periodic displacement of air.

To approach what you're asking - you'll need either to buy time in a wind tunnel, or fit a power meter on your bike and measure your times.

Doing this with scientific rigour means

doing each run at least 3 times
riding to a set power that you personally can maintain for the whole distance - no more and no less.
riding a distance of at least 30 minutes
having a route with no chance of stopping at traffic lights or similar
in an environment with consistent winds/temperatures/humidity across all your trials
and having a way of measuring your time as accurately as possible between a well defined start and stop point.

Then swap the one part you're testing for the other part, and repeat the three runs.

The difference in time will show you how much power you've saved/lost with the one variance.    If you want to test 5 types of pedals, that's 15 runs.

A circular route will help too, if you can find one that works for all the above requirements.

Ideally your rider would not know which parts are being tested on each run, so they can not be swayed to push harder or softer subconsciously.

One might reasonably assume that Manufacturers would release this kind of data, especially for their high-end items.   And they do with statements like "saves 17 seconds in a 40 km time trial, over last year's model."  Which is relatively useless as a comparison.

tl:dr - there's too much interdependence to make a simple table that is also accurate.


Ways to protect suspension from wear I'm looking at getting front suspension for my bike for long (several months +) off-road tours (think Great Divide).  I was thinking about whether it would prevent requiring maintenance/servicing to cover & seal my stanchions with something.  For instance, I could take a large innertube, slide one up each leg of the fork and tape it to both the crown and lowers to completely seal off that area from grime and wet.

Note that normal boots don't actually seal off the area in this way.

Would this or any other similar measure prevent wear on the suspension?

There are a couple products that already exist for doing what you describe.

Although i think you could also probably use a tube like you said, however if dirt did get in, the tube might keep it pressed against the stanchion which could result in scratches. The tube may also balloon when the fork was compressed due to the non-breathable nature of a tube.

The first that comes to mind of existing products is the Lizard Skins Fork Boot, they also make them for rear suspension as well which i have used. I have not used the Fork Boots but i have been happy with every other Lizard Skin product i have used. They are a breathable neoprene material but protect the stanchions. Image below

In addition, in my opinion the best defense is keeping it clean and well maintained. Wiping off the stanchions when they become dusty in addition to using a proper lubricant designed for stanchions to reduce friction can go a long way for fork life. One example is Wet Seal by Miles Wide, there are a lot like it though. Wet Seal was developed in part by Suspension Experts who in my opinion do awesome fork work so it is what i would recommend but there are others available as well.

This stuff also works pretty well for stanchions, just don't get it on your brakes!


Gear for incline - Internal Gear Hub? I'm new on the cycling scene and I'm looking to build a bike. I'm a bit worried about my route home, since although only 5KM it's quite steep in places, with 0.25KM being at a 16% incline, and the rest floating somewhere between 3-6%.

Start altitude: 14 metres
End altitude: 99 metres
Maximum altitude: 99 metres
Minimum altitude: 11 metres
Distance: 5 km
Total ascent: 125 metres
Total descent: 40 metres
Maximum gradient ascending: 16% at 2.6 km
Maximum gradient descending: 8% at 3.4 km

I quite like the idea of an internal gear hub, but I'm wondering if that's a bad idea given the gradient and my lack of experience. Is it as simple as just using the pedal gear to vary the ratio going into the IGH, or is it a case that the IGH is simply not a sensible choice for this kind of gradient.

By using a larger sprocket and/or smaller chainring, you can gear an internal hub to cope with just about any gradient. (There is an eventual limit where input torque can destroy the hub.)

(Edit: @Rider_X is right that the Shimano limit is more restrictive than I remembered. There are people using lower gearing and reporting no problems, but you might have to be careful. On the comparison chart below the Rohloff could be geared quite a bit lower (30:16 rather than 44:16, see Rohloff), but the Nexus is following Shimano recommendations according to this forum post))

A cheap hub will give you three gears with big gaps between them and a limited overall range, and although you can make the bottom gear low enough for a steep gradient you might find it too restrictive; a very expensive Rohloff hub will give you 14 gears with gaps and range comparable to a derailleur system (but without overlapping or duplicate gears - a 27-speed derailleur system doesn't have 27 usefully different gears).
In between those, there's a range of hubs available giving you more gears, more overall range, and smaller gaps, as you pay more. See, for example:

http://www.cyclinguk.org/cyclists-library/components/transmission-gears/internal-gear/internal-gear-ratios
https://hubstripping.wordpress.com/internal-gear-hub-review/


How can one estimate drag for a bicycle? I am curious how to estimate drag for a bicycle. This has two different framings:

Find the amount of power required to ride at a certain speed. That is, when one is traveling at a constant speed, the power added to the system (with my effort and/or coasting on a descent) equals the power subtracted by aerodynamic drag, rolling resistance, ascending, deflecting objects thrown by spectators, etc.
Find the amount of pushing force required to maintain a given speed (again, the pushing forward equals the pushing backward at constant speed). The most obvious example is aerodynamic drag, which one can feel “pushing” back when one is riding at speed.

Online calculators and formulas exist, but they assume coefficients of rolling resistance or aerodynamic drag, or assume that I can provide these coefficients. How do they make these assumptions, and/or how can I make those estimates myself?

(Credit goes to R. Chung for urging me to ask, in the commentary of this question.)

Your question is simple but a full answer is complex. The simplest answer is to point to Part 2 (especially chapter 4) of Wilson and Papadopoulos (2004), or the recent review by Debraux et al. (2011), or the paper by Martin et al. (1998). However, even these papers do not cover approaches that take better advantage of the data available from modern bicycle computers and GPS units. Some background on the power-drag equation will help you understand why there are so many different ways (with accordingly different levels of accuracy, precision, difficulty, and cost) of estimating drag.
The equation to convert speed to power is well-understood. Total power demanded has four parts:
Total power = power needed to overcome rolling resistance +
              power needed to overcome aerodynamic resistance +
              power needed to overcome changes in speed (kinetic energy) +
              power needed to overcome changes in elevation (potential energy)

Of these, the simplest piece is the power needed to overcome changes in elevation. The power needed to account for the change in potential energy, and to overcome changes in speed are straightforward:
watts(PE) = slope * speed in meters/sec * total mass * 9.8 m/sec^2
watts(KE) = total mass * speed in meters/sec * acceleration

There is a small part of the KE component due to moment of inertia in the wheels but for bicycles that tends to be small and we often ignore it. However, the equations needed to describe the rolling resistance and aerodynamic resistance are a bit more complicated. The article by Martin et al., cited above, gives more detail but if we can ignore wind then the aerodynamic component simplifies to
watts(aero) = 0.5 * rho * CdA * (speed in m/s)^3

where rho is the air density in kg/m^3 and CdA is the drag area ("A" is the frontal area and "Cd" is the coefficient of drag; CdA is their product and can be thought of as the "equivalent" area of a cube held perpendicular to the direction of the wind with a face of area A). If there is non-zero wind, the aerodynamic component is approximately
watts(aero) = 0.5 * rho * CdA * (groundspeed in m/s) * (airspeed in m/s)^2

When there is no wind, airspeed and groundspeed are the same so the equation simplifies to the one above. A headwind increases airspeed above groundspeed while a tailwind decreases airspeed below groundspeed. I say "approximately" because these are approximations when the wind comes from directly in front or behind (or is zero); when the wind is off-axis, it affects CdA.
Finally, the power needed to overcome rolling resistance (which includes tires, tubes, and bearing friction) is
watts(RR) = Crr * total mass * 9.8 m/sec^2 * speed in m/s

Crr is the coefficient of rolling resistance.
Now, if you go to an online calculator like the one at Analyticcycling.com you'll see that you must provide values for rho, Crr, Cd, and A; then, given a particular value of speed and slope, it will calculate power. It's easy to find online calculators for the air density, rho, but much harder to find estimates of Crr and CdA (or separately, Cd and A).
The easiest (but most expensive) way to estimate CdA is in a wind tunnel. There, an object is mounted on a scale (basically, a very precise and accurate bathroom scale), wind at a known speed is applied, the air density is measured, and the total force on the object is measured by the scale. Watts are force (in Newtons) * speed (in meters/sec) so force (in Newtons) = watts/air speed = 0.5 * rho * CdA * (airspeed^2). The tunnel operator knows rho, knows airspeed, and the expensive bathroom scale measures the force so you can calculate CdA. Wind tunnel estimates of CdA are considered the gold standard: when performed in a good tunnel with experienced operators, the measurements are precise and repeatable. In practice, if you want to know the Cd separately, you'd measure the frontal area A with a digital camera and compare it to a digital photograph of an object (like a flat square) of known area. As an historical aside, nearly 100 years ago Dubois and Dubois measured frontal area by taking photographs of a person and a reference object, cutting out the photos along the outlines of the object, and then weighing the cut-outs on sensitive scales.
However, the resistance in tires, tubes, or bearings are not affected by air speed, so one cannot estimate Crr from wind tunnel data. Tire manufacturers have measured rolling resistance of their tires on large rotating drums but they cannot measure aerodynamic drag. In order to measure both Crr and CdA, you need to find a method that measures both and allows you to differentiate between the two. These methods are indirect field estimation methods and they vary a great deal in their accuracy and precision.
Until the last 20 years or so, the most common indirect field method was to coast down a hill of known slope and to measure either maximum speed (also known as terminal velocity) or else the speed when passing a fixed point on the hill. Terminal velocity doesn't let you differentiate between Crr and CdA; however, if one measured speed at a given point and were able to control the "entry" speed at the top of the hill, you could then test at different entry speeds and get enough equations to solve for the two unknowns, Crr and CdA. As you might expect, this method was tedious and liable to poor precision. Nonetheless, many ingenious alternatives were explored, including coasting down wind-free corridors or inside large airplane hangars, and measuring speed to relatively high precision using "electric eyes" or timing strips. Some of these methods are described in the review by Debraux et al., cited above.
With the advent of on-bike power meters, new opportunities emerged to measure aerodynamic and rolling drag. In short, if you could find a flat wind-sheltered road, you would ride at a constant speed or power on the road; then, repeat at a different speed or power. The requirement of "flat and wind-sheltered at constant speed" meant that you could ignore the PE and KE components of power and only had to deal with the rolling resistance and aerodynamic components so the overall power equation simplifies to
Watts = Crr * kg * g * v + 0.5 * rho * CdA * v^3; or
Watts/v = Crr * kg * g + 0.5 * rho * CdA * v^2

where g is the acceleration due to gravity, 9.8 m/sec^2.
The latter formula can be easily estimated by linear reqression where the slope of the equation is related to CdA and the intercept is related to Crr. This is what Martin et al. did; they used an airplane runway, averaged the runs in both directions, and measured barometric pressure, temperature, and humidity to calculate rho, and measured and corrected for wind speed and direction. They found that the CdA estimated by this method agreed to within 1% of the CdA measured in wind tunnels.
However, this method requires that the road be flat and that speed (or power) be constant over the length of the test run.
A new method for estimating CdA and Crr has been developed that exploits the recording capability of many modern bike computers and bicycle power meters. If one has moment-by-moment recording of speed (and optionally, power) then you can directly measure changes in speed so the KE component of power can be estimated. In addition, if you ride around in a loop, the road need not be flat since you know that upon returning to the start point of the loop the net elevation change will be zero so the net PE component will be zero. This method can be and has been applied to coasting down hills of known net elevation change (that is, you don't need to have constant slope, and if coasting you know the power is zero). Examples of this approach can be found here and here and, when performed carefully have been shown to agree with wind tunnel estimates of CdA to well within 1%. A short video presentation on the method can be found starting at about the 28:00 mark here. A short video of the method in use on a velodrome can be found here


Diagnosing hub wobble (Shimano Nexus) I have a Babboe City cargo bike with a Shimano Nexus 7 rear hub. Just coming into home on my last ride there was a bit of noise from the drivetrain and, on closer inspection, some other symptoms. The back wheel now has a wobble that is coming, as far as I can see, from somewhere inside the hub (i.e. this is not a broken spoke or similar issue, the hub wobbles along with the wheel). I tried taking a couple of videos, apologies for the shaky camera but I hope the issue is visible. I think it's probably clearer in the first link below. The wobble is present when turning the pedals backward, i.e. the drive is not engaged, and seems to be unchanged when I change gears.

Along with this, the pedals get 'pulled along' by the rear wheel (another video below). Holding the pedals in place will allow the read wheel to keep spinning without any horrible noise, but there is some rubbing noise coming from inside the hub (?) which causes the back wheel to come to a stop rather quickly. To my ear the noise sounds like bearings rubbing (?), but not crunching or grinding.

I'm trying to assess whether I'm looking at a repair, either to be done myself or by a shop, or looking into replacing the hub (or wheel). I'm reluctant to open it up without a plan, since from the diagrams I've seen it's not the simplest of mechanisms. In terms of overall maintenance skill level I'm reasonably experienced. I have an '80s era road bike that I maintain myself, and I either have or would be comfortable adjusting or replacing any part on that bike. However, I've never worked on an enclosed hub.

The hub likely needs normal maintenance. The kind of noise and drag you're getting is fairly normal when these need lubrication. Hopefully it hasn't gone so long it's been damaged. Play developing also implies needing overhaul.

Shimano 7 and 8 hubs come apart in layers. The first one is pulling the core of the hub from the shell, which allows you to tank it in an oil bath and grease the bearings as indicated in the product manuals available at si.shimano.com. This constitutes normal maintenance and needs to be done for the hub to last. It's not super technical, maybe approximately on the level of overhauling a cup and cone hub. In some regard it's easier because all the small stuff stays together as a unit.

The second layer is taking apart the hub core into what you could call its subassemblies. You can grease some things that would normally be oiled by doing this, and some are advocates of doing that for weatherization/local climate resistance purposes. The other reason to do it is to find and replace broken things that can't be seen or accessed otherwise. The second layer is more technical than the first. You mostly just need to go slow and keep things in order; it's not fidgety or difficult to figure out, and it only really goes together one way. Shimano does publish procedures for this.

I can't see the wobble you mention. If it's looseness coming from the hub bearings being loose, you'll be able to adjust that out at any time as a regular hub adjustment. If it's coming from elsewhere, that would imply something being broken as well as I can figure, and you might need second layer type service to figure out what and whether there's a replacement available.

The dealer manual files for your model will let you know what special tools are needed, cone wrench sizes etc. Substitutions for the proper Nexus/Alfine disassembly tools and how prudent it is to go there is a whole other conversation. Same with substitutions for the Shimano hub bath oil and Nexus grease. My station in life has me always and only using the Shimano products so I don't have a ton of opinions there. The oil is expensive and intended to last many, many hub dunks. Many on the internet report success using gear oil instead.


Fog on camera case with chest mount I've got a chest mount for my camera (sony hdr-as15, if it's important). I went on a race last Sunday - it was like +15-17 Celsius. After about an hour of riding I've noticed that the case is all foggy and the picture turned from this
 into this:
So, what can be done to prevent this?

Normally I would not expect this at 15C-17C, its something that happens at 5C.

Presuming the case is sealed and was dry before closing it up, the cause is because the inside of the case was warm with high humidity before being taken into colder air. Most likely the warm air inside your home is damp, or the case has been sealed up for a while. When taken outside, the air in the case cooled, and was no longer able to hold the water vapour so it  condensed on the coldest part - the lens that points away from you as that gets no body heat.

To prevent this, leave the camera case open when in storage, and store in a dry location (stuffed in you gear bag with your damp cloths and shoes form the last ride is really not a good idea). If the temperature changes is high - e.g when I head out on 0C degree morning, I leave the camera and case open in cold outside air before sealing it up for the ride, ideally for at least an hour.

An alternate, if conditions are suitable, is to use a non-waterproof case that has massive slots  to allow airflow.


Barn Bicycle Find Information appreciated I am seeking information on this bicycle found in our farm shed.  The bike is blue with very thin white stripes.  There is a serial number on the top of the bike where the seat attaches.  It is 4E8736  It is located in Canada, possibly Canadian or US made. Any information greatly appreciated, thank you!

Can't tell a great deal from that picture alone... Can you supply some clearer pictures?
in daylight side on view looking at the chainring side would be best.

The tubing looks a bit too angular to be a Western Flyer - but some of those did have dual top tube.

Those slim rear stays look like Raleigh or RMI Roadster.
Maybe even a Humber... although, I've not seen one with twin top tube.

What size are the tyres? it doesn't look old enough but if they are 28" there's a possibility it could an old Elgin.

If you can provide more information I can try to provide a better identification.

Thanks


What's the difference between Weldtite Dirtwash citrus de-greaser spray and the WD40 chain de-greaser? I m planning buying a chain degreaser for my bike,  I gone to two bike shops and they sell different brand of degreaser.
First bike shop i went to is the shop where I got my ATX fromand He sells wd40 chain degreaser, the second shop i went to they sells some weltite brand lubes and dirtwash cirtus degreaser.
I m wondering if there is any difference in performance between these two degreaser.
I have used the WD 40 Chain degreaser before and it performed really well, but I havent tried the Dirtwash Citrus degreaser spray and i wanted to see which one worth buying.

Degreasing chains and other metal components is not unique to bikes. There are way to many degreasing products out there to list. On aircraft, we mostly use varsol, but on my bikes, motorbikes included, I have used dish soap and thoroughly dried the chain then oiled it. Lately I've been washing chains in gas mixed 2 cycle motor oil, hehehe, works good.
Dirtwash Citrus degreaser spray is natural environmentally friendly degreaser that is soluble in water, and reasonably easy to rinse off.
 WD40 chain degreaser is more of a surfactant with petroleum additives. They say it is environmentally friendly, but it contains butoxyethoxy, isopropano, propane, n-butane, and proprietary surfactants.


Choosing new tires: can't find my size on schwalbe site My bicycle is Merida Crossway MD-40. I Measured the tires and got the following numbers: 701mm x 41mm. Or 27,42 In x 1,6 In.

I wanted to buy one of Schwalbe tires for it. But to my surprise my size was missing on their site.

Is my size somewhat non-standard? Why doesn't Schwalbe produce this size? Are there other companies that do? I wanted to buy slicks with puncture protection.

Your bike had these tyres as stock in 2015 Cross 40c Front - Cross 40c Rear according to http://www.tredz.co.uk/.Merida-Crossway-40-2015-Hybrid-Sports-Bike_74298.htm

2014 version was listed as Tyres:  Cross 700 40C

So you have a 700c rim which can take a 40mm wide tyre.

Confirm this by looking at the sidewall of the tyres, it should say 622-40 or 40-622 somewhere on it.

Any cyclocross tyre should be good up to a width of 40mm, and you might be able to go a little bit larger if the frame and brakes have clearance.

TBH tyre sizing nomenclature is a horrendous mess.  If you want to know more, click here How are tire sizes measured?


What's the best way to stow (winter storage) an all-carbon bike? As the number of bikes in the house grows, storage becomes more of a problem.  I have some hooks that I hang my touring bike and the gravel bike on (hanging from the front rim), but they both have durable aluminum rims.
I now have to find a way to store a new all-carbon road bike, one that has aerodynamic carbon rims, a carbon seat-post, etc.  I don't want to leave it sitting on the floor, lest I forget to keep the tyres pumped up.  I don't want to hang it from a hook, since I'm sure that's not how the rims are expected to be loaded.  I could use a clamp to hold it by the seatpost, but again since that would leave it under a certain amount of torque for months, I'm not comfortable with it.
A quick search didn't turn anything obviously better, and I thought it best to ask for suggestions before trying to bodge something together.

I don't see a problem hanging a bike from a carbon fiber composite rim. The amplitude of the load would be much, much lower than when riding over even moderate bumps. OK, the load is radially outward rather than radially inward but the wheel is not weak in that direction.
Maybe of the inside edge of the rim is particularly narrow in profile you could damage it, but suitable padding would prevent that.


Flat bar conversion - shifter is skipping a gear I am in the middle of converting my bike with road handlebar to a flat bar.
The old road bar has a Shimano 105 brake/shifter and 105 derailleur.
Something like this:
https://www.mec.ca/en/product/5055-021/105-ST-5700-L-STI-2x10-Speed-Lever-Set

The bike is a 10 speed.

I bought some Tiagra Road flat bar shifters: SL-4700-R 10s and SL-4703-L

The Left hand SL-4703-L works perfectly.
However, the SL-4700-R right side shifts up nicely for about 4 to 6 rings, and then skips a ring.  Playing with the tension just changes which ring gets skipped.

I take it I screwed up and the new shifter is not compatible with the derailleur / cassette.

Is my only option to return the shifters and try to find something else?

Thanks!

Edit: Found a video -

Correcto, unfortunately for you, the latest (4700) Tiagra system uses a different cable pull to previous 10-speed groupsets, therefore the shifters are pulling the wrong amount of cable for your derailleur. It won't get better, however much you change the tension.

You could get a new 4700 derailleur, which would match the shifter and work with the existing cassette, keeping the flat bar.


Can a BBright bottom bracket that now houses a 24 mm spindle be changed to 30 mm? Cervélo bikes use a bottom bracket standard known as BBRight. I recently bought a Cervélo with a Shimano crankset, but I'd like to use a Quarq BB30 crankset.

I read that BB30 was compatible with BBright, but didn't do my homework properly. The Shimano spindle is 24 mm in diameter, while BB30 cranksets are 30 mm.

Can the BBright bottom bracket be changed to one that'll accommodate my Quarq power meter crankset?

As you found in your research, BBRight is based off of the BB30 standard, differing only in the placement of the bearings relative to the centerline of the frame.  Shimano has never really supported BB30 or any of the related BB standards, instead steadfastly maintaining compatibility with their own Hollowtech II (24mm) standard.  This means that any frame manufacturer wishing to use a full genuine Shimano drivetrain, including crankset, has had to either continue to build frames with the Hollowtech II shell specs or to include adapters from whatever standard they chose.  In Cervelo's case, they elected to continue to use a BBRight shell (which is not coincidentally their proprietary standard) and develop an in-house bottom bracket that acts as its own de-facto 30-24mm adapter.

So what does this mean for you?  It means that you can run the crank you want if you replace the bottom bracket with an original BBRight one, which is pretty cheap to do.  A cursory google appears to indicate to me that these now carry the designation BBRight 30x90 to differentiate them from the Shimano-compatible 24x90 version.  Other, non-Cervelo BB30 bottom brackets also may include the necessary spacers to work with BBRight (again, the only difference between the two is the bearing locations), but you'd have to do your research before ordering to be sure.


What type of bicycle is closest to European city bike? I am looking for a bicycle that would be closest to the design that was popular in Russia, something with a high handlebar, relatively large wheels, and relatively short distance from the saddle to the handlebar. Which types of American bicycles should I look for?

"Dutch bike" is a good answer, but it won't necessarily find you all the possibilities; "transpo(rtation) bike" tends toward the Dutch. Besides what you already mentioned in your question, these bikes typically have:

mixte or other step-through geometry
internally-geared hubs for ease of maintenance
simple shifting, typically 3 or 7-8 gears (though with today's internal-hub selection, 11 can be found)
clothing protection, from chain guards and fenders to (less commonly) skirt/coat guards on the rear wheel
racks or rack braze-ons, minimally in the rear but sometimes front as well

US bicycle brands that offer bikes of this sort include Electra (Amsterdam, perhaps the Townie), Civia (Twin City), Linus (Dutchi, perhaps the Mixte), Breezer, and Public (mixte and step-through models). Trek made one called the Belleville that was discontinued (it was a heavy and inflexible beast; I considered buying one) but might still be available used.

In the UK, Pashley makes several models of Dutch bike (e.g. the Princess and Roadster models). A few US distributors will import a Pashley, I believe.


What kind of freewheel/cassette is this? I bought some old bike from netherlands, I wanted to restore it.
Rear wheel is broken and I wanted to exchange it but there is this strange freewheel which I cannot identify, do you have any idea what it is?

It's called a Helicomatic. The idea was to make a freewheel that does not need a lockring that has to be torqued tight. The helical splines make the freewheel tighten itself.

Amazingly we had this exact question about a month ago, so I flagged this as a duplicate question.


Upgrade 1x8 drivetrain I have an Orange 2017 Diamondback Hook that came with an SRAM 1x8 drive-train.

I'd like to upgrade it to increase the range. What are my best options?

Thanks!

As you have a 1x drivetrain with non-integrated brakes and shifters upgrading it to one with more gears is relatively simple. You need to replace the shifter, rear derailleur and cassette and chain at a minimum. You can also replace the crankset and bottom bracket.

As you have an 8 speed cassette the freehub body will take up to an 10 speed cassette with no problems. Some 11 speed cassettes will fit (but I would not put an 11 speed system on this bike).

You can take your pick of SRAM and Shimano 9 and 10 speed drivetrains and decide how much you want to spend, taking into account paying a bike shop to do the installation or buying necessary tools if you do it yourself. In the latter case you may have to do research to teach yourself how to do the installation properly also.

I would not spend money to upgrade more than a few steps above SRAM X3 on this entry level bike. You won't see the benefit as the frame, wheels and brakes are all still at the lower level.

Very often, especially with low end bikes, upgrades are not worth it, it's more cost effective to simply buy a better bike (and sell the old one). That way you get an upgrade of all the components in one go.


Adjusting TRP RG957 deep drop rim brakes I've got a lovely new bike for my daily commute, a Condor Italia. I've done about 1,500 km on it and I need to adjust the brakes. I would expect to just turn this bit:

But that will not turn, and it even lifts up and drops back down. It's clearly attached to a threaded barrel, so I don't understand why it won't turn, not why it can just lift, given that it is threaded.

How should I be adjusting these brakes?

I may resort to undoing the nut/screw securing the brake cable, pull a bit of cable through, and then tighten the securing screw, but there must be a simpler way to take up the slack from brake pads wearing and cables stretching.

Yes I have had these brakes for about 4 years. Turning the adjuster anticlockwise no problem (I have to do this to remove the wheel), but to adjust the brake for wear, you are right, it won't turn clockwise UNLESS I first pull up on the cable to relieve the pressure.


Where can you park your bike? I've started biking and see its potential for being able to go around the local area. But when you are running errands (biking to a store or the bank or something) you have to physically put it somewhere while you shop. The one time I ever did this was to pick a pizza. I put it in the place of a car, grabbed the pizza inside, and left. (I put a light lock on it) I don't know if this is proper or even legal. This is a very stupid question, but I can't find the proper phrasing for an answer.

You have various options, mostly depending on your local regulation, facilities and length of your parking time:

Bike lockers
Bike stalls
Trees, poles or rails (ironically in the picture the bike is locked to a signal pole telling that bikes parked outside the allowed spaces will be removed)
Bike parking spaces
Building facade
Car parking space

The last two are less recommendable, as

your bike won't be linked to something hard to move (a thief can simply load it on a pickup and remove the lock with calm in a quieter place)
it might be unlawful or impeding others (pedestrians, drivers)
it might not be appreciated (I have seen bikes thrown in the bushes when left in the car space, and 3) understandably really pisses off car drivers)

I am leaving out naive or dumb other parkings

which are possible but, well, do not praise your smartness (I have seen people locking their bike to a stranger's one)


New MTB makes it feel like too much weight on arms? How do I make it better? My 10 year old montain mountain bike has quite an upright seating position and front tyre, which is what I think makes it very comfortable to ride for long periods of times.
Having recently bought a new mountain bike, with modern geometry and ridden several of my friends new mountain bikes with modern geometry as well, I noticed they all feel the same.  Wide handle bars, where you lean more forward when riding and it feels like there is slightly too much weight on your arms, which over time makes it them much more uncomfortable to ride than my old mountain bike.
I'm not sure what it is about these new MTB's but I am trying to figure out what I need to adjust to make my new MTB more comfortable.
How do I reduce the effect of too much weight on my arms? Seat up / down? Back / forward? etc.
EDIT: My new bike is size Medium and this is the geomtry table:

I normally try to keep the saddle as high as possible and I'm 5ft 10 tall.  My old bike has 26 inch tyres and this new one has 29's.

What I can tell you is limited without knowing further details like the model of both the new and old bike. But, looking at the geometry chart, seems like the new bike is most likely an XC/backcountry bike. The geometry on XC bikes is optimized for going fast on flat and uphill, so the stems are longer. However this bike seems to be halfway between a trail bike and an XC bike, as it has 120mm of travel and has a slacker headtube angle than most XC bikes.
So, without being able to look at your old bike to figure out what it was that made you more comfortable, my best guess is that you are used to a shorter stem. Try switching to a smaller stem, but make sure you also get wider bars or the steering will become very awkward. The longer the stem, the skinnier the bars should be and vice versa. Also, as stated in the comments, the bike may just take some getting used to. When I made the switch from XC geometry bikes to trail bikes, for a few weeks it felt like everything was off. But now I'm used to it.
I hope this helps. It's the best I can do without seeing both bikes.