Is there a way to know if someone is drafting behind without turning your head back or trying to hear the noises? In a group ride when I'm the one pulling, I often unknowingly leave my friends behind until I turn my head and see them in far distance, then I had to slow down.

Is there a way to know that they are still tailing me without turning my head every few seconds? like, does it feel different somehow? or maybe there is a way to peek that I didn't know of?

A group riding together and cooperating will ride to a set speed, so you'll be surging if you exceed that speed for long.   A simple wheel-magnet speedo and bike computer helps show this on your bars without being big or expensive.

An ad-hoc group will ride with varying speeds depending on who's in the front and whether they are trying to make a break away or if they're just sick of waiting for the rest of the group to cycle through the paceline.

Some riders need short pulls and some can cope with long pulls at the front.  Separately some people need short rests out of the wind, and some people require quite long periods behind someone else to regain their pace.

The best groups work together for the end goal which is a good training ride.

In racing, your team is your group and the other teams are NOT your friends so they're working for themselves.  A race peloton is therefore an adhoc group of teams who are not working together.

If you face some decent climbs in your route, then groups tend to fall apart as everyone climbs at their own pace.  For training and bunch rides, stop at the top and let everyone get there, then rest till the last arrival is ready to carry on.

Otherwise the first arrivals are rested while the last people are shattered and the group breaks up or is held back.

Same goes for downhill - strava segments work on segment time, not first-down time :)

More thoughts - A shoulder check every half minute should show you if the rest of the paceline is there still.

If you don't have a speedo, riding to a set cadence might be enough.  Try and memorise the speed of your feet while in the paceline, and simply maintain that rhythm when you hit the front of the line.  Sing a song in your head of the right speed, or count off like marching if that works for you.

Getting expensive - there are race-radios like the pros wear.  They are essentially Personal Shortrange UHF radios with an earpiece and a small transceiver in a pocket.  The aerial/headphone cable runs up the back and is often taped on.  Some new ones are small enough to work with the helmet.  These talk to each other in the team and to team car, who then relays messages onwards with a second radio or maybe a cellular phone.   Some are even bluetooth based and just associate with one~four other units.   Motorcycle riders might wear these under their full face helmets.


What are simplest rideable bikes over history? I copy-catted the question from moz here because he did not ask it himself.

I try to keep my bike design as simple as possible so I need to learn from mistakes in the past.

What are the simplest rideable bikes?
Did they work and what were their limitations?

Example things simplified bikes:

air tires (no big wheelers anymore)
inner hubs (ambiguous: common belief is that it is harder to fix inner hubs, despite I have fixed them with no expertise what-so-ever, but its outside design is simple
belt-driven chains (no lubrication)

Please, tell for which kind of purpose your bike is meant. I am particularly interested in recumbent bikes, i.e. comfort bikes and no racer bikes for long journeys, but feel free to suggest anything. Keep it simple and stupid! Explain why it is simple to some earlier model. Any simple bike out there or some historical bike from which we may learn something?

Mechanical Simplicity

A hobby-horse is as mechanically simple as it gets. Two wheels and a seat, even steering is optional. Many of them did not even have padded wheels, "solid" meant iron. Today these are built for children who are learning to ride (the "like-a-bike" is one such product).

Next is an ordinary (or penny-farthing) There's only five axles and the whole thing can be made using basic tools. These are still made today but primarily as replicas of historical bikes. There are national and world championship competitions. The modern "tall bike" is in many ways similar but often has gears, brake and so on so lacks the simplicity of the ordinary bike.

For a modern bicycle, a fixed gear bike is as simple as you're likely to want to ride. Chain drive, but no freewheel and brakes are not strictly necessary (but may be required by law). Generally they have ball bearings rather than plain bearings, but they're quite simple to assemble or fix compared to other modern bikes. However, since a freewheel is a single part as far as most bike machanics are concerned a BMX or trials bike is effectively as simple to deal with. Especially "street BMX" bikes that often have back-pedal hub brakes. The 406 wheels and lack of rim brakes mean that the wheels are very strong and don't have to be especially true. Most fixed gear bikes have limited clearance around the wheels so they have to be quite close to true or they hit the frame.

Once you add gears, hub gears are simple for the owner both in operation and maintenance. With wide, straight chain, full chain case and commonly also hub brakes mean there's little maintenance to do. Hub gears have a single shifter and the gears are "in order", meaning that shifting up always produces a higher gear, and it's always the next higher gear. This makes the bike very simple to operate. With a derailleur system there's usually two gear levers (for the front and rear derailleurs), and the shift pattern to go from lowest to highest gear is non-trivial (and varies between bikes).

Likewise, hub brakes usually require less maintenance and are more effective than rim brakes. They're also heavier and more expensive rhan rim brakes, but if your criteria is simple to operate, hub brakes win. Maintenance is generally infrequent, with cable operated disks requiring most frequent maintenance and some hub and hydraulic disk brakes being almost maintenance free (lasting decades of use in gentle city riding).

It's not unheard of to fish a 50 year old bike out of a garage (or canal) and find that the hub brakes and gears still work.


What is an "unreasonably short leave-pass"? I'm reading "unwritten rules for calling a ride" and #4 mentions something about "unreasonably short leave-passes". What does that mean?

Your family or significant other will only give you a few hours leave(like Annual leave) from home to go out riding.


Chainring sizes for 11 speed cassette I have an 11 speed cassette 11-32 teeth. I am running a 52 teeth chainring on the front. What would be a good recommended smaller chainring for the front?  It needs to be big enough to take up the slack of the chain when i am on the smallest cog at the back.

As was mentioned in the comments, this question will depend on what derailleur you are using both front and rear (since they have a rated capacity). Too large a difference and the front derailleur will not shift well, but you also have to make sure the the total difference between large-large and small-small is within the range of the rear derailleur so that it takes up the slack and does not overextend. The specifications for your derailleur should have these numbers listed and then you can pick an appropriate sized ring to fit your crank from there.


I got a 27.5" fork for my 26" bike, what size wheel should I run? I have an Ellsworth AM bike that's running a 26" rear wheel. I just scored a great deal on an x-fusion sweep fork that's 160mm travel (same as the frame) but for a 27.5 wheel.

I am in search of a new wheel for it, and I wasn't sure if I would be better off running 26" wheels all around, or if I would be better off running a 27.5" wheel up front with a 26" wheel in the back.

Just looking for some advice before I bite the bullet on a new wheel.

Thanks!

You probably have a different offset and a different fork height now, so whatever you do, you have already messed with the geo noticeably.

Borrow a 27.5 and a 26 front wheel from a friend for a day, go ride, figure out which one feels better. I would guess 26 would feel closer to how it used to but it should still handle differently due to the different offset, but who knows you might prefer the 27.5 even though that should leave your geo even more altered :)


Replace asymmetrical BB with symmetrical cartridge and spacers? My bike has a square taper 68mm width cup and cone bottom bracket that is wearing out. I was hoping to replace it with a sealed cartridge (shimano UN55 or similar) but then I found that the spindle length isn't the same on each side - the right spindle end is 4mm or so further from the centre than the left. I think that modern cartridges are symmetrical, so the two ends are the same distance from the centre. Is it possible to mount a 68mm symmetrical cartridge slightly off-centre using a spacer? If I put a 2mm spacer on the drive side then the new (symmetrical) cartridge would be the same as the old (asymmetrical) cup and cone. But I'm a bit worried that a) there wouldn't be enough screw threads engaged on the drive side or b) the non-drive cup won't screw far enough into the frame to hold the cartridge steady. Has anyone tried this? Does it work?

In principle it is doable. Normally sealed BB have 15 to 20 mm of thread at each side, so 4 millimetres of spacer wont make trouble regarding how deep the shell will thread in.

Regarding symmetry, it is even a possibility that you don't really need to install the spacer, because what defines this is the chainline, that is, on a single speed bike, the front chainring should align perfectly with the rear sprocket. On a triple chainring setup with multiple gears in the rear, the thing gets a bit more fuzzy, but (I) roughly watch for the middle chainring being aligned with the centre-most sprocket. I mention this because some cup and cone systems have huge tolerance and can be off axis without any apparent trouble, and in your case, it is a possibility that the spindle is just 2mm off to one side.

The second factor is whether the cranks rub or collide with the chainstays. Both arms should pass by at roughly the same distance from the chainstays.

So, before deciding whether you need a spacer (and if you haven't disassembled the bike yet) check the chainline and the distance from the cranks to the chainstays, and see if you can detect any misalignment there.

Consider that there are some BB units that don't have a "lip" un the threaded side and therefore a spacer is not actually needed, they are locked in place just by the pressure from the locking cup on the other side, this type of BB can be set off to a side without a spacer (there is actually no way of installing a spacer). Other BBs actually have this lip to hold certain type of front derrailleur in place. In this case the spacer is optional, it is used just to fill up the space left by the absence of the derrailleur's mount ring.

The definitive yes/no compatibility issue is whether the theading on the bb shell is the same. Most sealed BB units I've seen have normal right hand threading on one side and left hand threading on the other. As long as your current cup and cone system is the same in this regard, you should be able to do the upgrade.

One final factor that may come in is the taper on the spindle. If by any chance the one you have is thinner or thicker than the replacement sealed unit, the crankset may "sink" in deeper or not deep enough.

Since you are going to do an upgrade, not a direct replacement, I advise to take the bike to a shop and compare (using a caliper if possible) your actual spindle to the one on the sealed unit you plan to install, just to be sure.


Feedback on Bern Helmets for winter I was thinking about picking up a new helmet this afternoon.  My current helmet:

Has had a few accidents
Isn't very warm in the winter.
Doesn't have great clearance for ski goggles.

I was thinking about picking up a bern helmet I was toing to get either the:

Bern Brentwood Cycling Helmet
Bern Watts Cycling Helmet

Both helmets are:

"All Season" which means they support putting warm weather inserts into the helmet and have a slot to put a ski goggle attachement on the back.  See: http://www.bernunlimited.com/Innovation/All+Season
Both helmets meet: ASTM F 2040, CPSC and EN 1078 safty requirements.

I have a couple questions:

Anyone have experience with these helmets?  How did you like it?
Was it warm enough to wear in -10C weather?
Any other feedback welcome.
Any preferences between them?

(Note the helmets linked do not include the winter insert.  I still need to figure out where I can get one of those.)

I ride Colorado winters, and use a Bern Brentwood with the winter insert. In order to feel warm above the neck, I recommend the following.

I would go with the Brentwood and avoid the Watts. The brim on the Watts can interfere with your goggles. I tried goggles with the summer visor on the Brentwood and they never felt good.

The winter insert is a must. It keeps your ears warm, as well as the back of your neck.

Get some ski goggles. I carry clear OTG (over the glasses) Smiths, but I find that any sunglasses I wear underneath fog up, even if they goggles don't. I mostly need the goggles in the day when it's snowing, in which case it's not very bright out. At night they add extra warmth. Keep the goggles clipped on your helmet so they're around whenever you get caught in bad weather or extra cold.

Bundle up your neck with a SmartWool neck gaiter. I cover my nose, cheeks, and chin with the gaiter and strap it down with the helmet. With sunglasses your breath will shoot right up and fog them, but with ski goggles it will seal off your exhalations and stay nice and clear.

And while I'm on the subject, I recommend a couple other things for winter riding. I love my Swrve Milwaukee ES hoodie. I have an older model; it's only improved since then. I've worn this down to 5º F with only a t-shirt underneath and been comfortable (a very dry 5º). If it gets colder than that, just add a layer or two. The pit zips let you wear this in less freezing temps, but it gets to be too hot above 40º. You won't think it's enough, but on the bike, it's plenty. Rain, sleet, snow, it's fine.

Waterproof dress shoes are handy. I wear Ecco Berlin with Gore-Tex.

I love having ice-climbing gaiters for the wet and snowy days. They keep your pants clean, out of your chain, and give a little extra warmth on the shins.

For hands, I hate lobsters because I can't work the brakes, so I go for the warmest ski gloves I can find. I like these because they let me use touch screens: Outdoor Research Ambit Gloves. You will want to use a glove liner on the really cold days, but they're too warm for anything above freezing.


Removing a stuck pedal I'm sure this question must have already been answered somewhere here, but it doesn't show up in any search results I make...

I'm changing the pedals on a 40 year old bike. Pretty sure the pedals are original. The left one came off fine. Unfortunately, I got the thread directions mixed up and tightened the right one by mistake!

Now the right pedal won't come off at all. When I apply force to the pedal wrench (in the correct, counter-clockwise direction), the crank just backs up, and the pedal doesn't budge.

I have two questions:

Short of making the trek to my LBS (which is a little out of the way) what are some ways I could try to get the pedal unstuck?
Is there some way to immobilise the crank? I don't think I have the tools necessary to take the arm off the bike.

Things already tried:

Penetrating oil in the screw.
Hammering the wrench.

Things I don't have the equipment for:

Heating the screw.
Lengthening the wrench.

EDIT: An additional note: It seems the reason the pedal wouldn't come out is that there's something wrong with the threads on the crank. I can't get the old or my new pedal to go in past the second turn. Going to have to take it to the LBS anyway...

Your best bet is to use mechanical advantage to your benefit. What you want to do is line the wrench up with the opposite crank, so that your hands are as close together as possible, now straddle the frame and force the two apart. Here's an image from Park's description of how to remove a pedal that illustrates it well:

The worst position for the wrench is 180 degrees opposite, so that the crank and the pedal are still parallel, but opposite. It will be almost impossible to remove a pedal in this orientation.

You are correct that the drive side pedal will have a normal thread, and needs to be turned counterclockwise for removal.

It generally takes a lot of force to remove pedals, because they tighten themselves as you ride due to precession. If you find this method still isn't working, refer to Scott's answer about lengthening your tool to gain leverage.


Generally, why Bicycle tires are thinner and Motorcycle tires thick? I know, not all bicycles have thin tires nowadays, but generally why bicycles have much thinner tires than the motorcycles?

With the exception of fatbikes, the widest bike tyres are narrower than the narrowest motorbike tyres.  I'll ignore fatbikes as somewhere between too specialised and a novelty.

You'll also notice that all motorbikes have significant amounts of suspension.  Fat tyres and suspension both absorb energy from vertical motion.  This can be a good thing, for example if you ride over a pothole, or a bad thing, if the vertical motion is from pedalling hard.  Motorbikes aren't propelled by pedalling so don't have to worry about this.  They also go much faster so the consequences of hitting a pothole are more severe, or would be without something to absorb the hit.

Motorbike tyres are likely to have higher rolling resistance. With the rims to support them they also have much higher weight and rotational inertia, meaning bigger brakes -- but you need those anyway given the speed.  The rolling resistance is significant in terms of human power output, but given that even a 125cc motorbike can put out 11kW continuously and a pro cyclist more like 500W it's not significant in motorbike power terms.  This higher power (and higher braking force) has to be coupled to the road somehow, and that's through the contact patch.  Typical bike tyres wouldn't last long until even modest motorbike acceleration, or give enough grip for hard acceleration/braking.

In summary: motorbikes can have bigger tyres because they've got more power, and they need to because they're faster and more powerful.


Why are 3 inches mountain bike handlebar hard to find? I'm looking for a new handlebar, ideally 3 inches. But looking in some of the online shops it seems quite hard to get 31.8mm  bar clamp diameter handlebar with 3" rise.

Do you know if there is any reason for that?, is it maybe because people change the stem as well?

I can theorize. A higher rise would mean that as you bump along, you apply more torque to the handlebar.

I bet that above a certain threshold, the rise becomes so great that preventing the handlebar from spinning in the stem becomes a real problem.


Am I going to get injured mountain biking if I don't have rear suspension? On the several occasions I've gone mountain biking, I was using a nice borrowed bike with full suspension and it felt nice.

I'm told that rear suspension, though nice, is not necessarily a must-have. I have notions of the bike seat bludgeoning the ol' undercarriage without it. What is the ride like without rear suspension, what do I lose? And are there any suitable substitutes or ways to compensate for the lack of rear suspension?

First off, when riding over rough terrain you should be hovering above your saddle, not sitting on the saddle.  This holds whether riding a hard tail (no rear suspension) or riding a full suspension bike. If you are sitting you have less ability to move your weight around, and therefore less control of the bike. When sitting it is easy for a large bump to throw you off balance making you crash or swerve into a crash.

When the trail is really steep and rough not only you should be off the saddle, but you should also be putting your weight behind the saddle.  Example below pictured below.  These riders are on downhill/freeride bikes (tons of suspension travel, 6-8 inches) and they are not sitting on the saddle.

So what advantages does rear suspension provide?

When the terrain isn't too rough (smoother than the above picture) it can allow you to sit down and pedal in more circumstances than on a hard tail, which can especially help when climbing (assuming an efficient pedalling suspension design)
Although your legs are the ultimate shock absorber (when hovering above the saddle) rear suspension supplements this natural suspension.  This can be critical when:

absorbing hits from big obstacles
landing off drops and jumps
absorbing a g-out
absorbing a series of fast rapid bumps as your legs may not react fast enough.
rescuing you from stupid mistakes or a bad line.

Depending on the suspension design, the rear suspension can also improve braking as the rear tire is in better contact with the ground.  (Although in some suspension designs braking can negatively affect rear suspension performance and therefore traction.)

What about hard tail?

To compensate for lack of rear suspension travel you need to use your legs more.  You should be riding above the saddle more often than with a full suspension bike.  For example, if you are pedalling over roots or rocks you need to learn to pedal while hovering over the saddle.  This lets the bike move over the terrain, maintaining traction and forward momentum.

So what are the advantages of a hard tail?

Hard tails are typically lighter bikes (less parts), and can be more efficient to pedal especially on long climbs. As such they still have a following among Cross Country (XC) mountain bike racers on smother courses.  That said, I have personally found the efficiency gains can be easily lost in rougher terrain (e.g., Squamish BC).  Hard tails are also cheaper to manufacture (the frame doesn't have any moving parts) so you can get a better equipped bike for your dollar.  This makes hard tails good first bike.

Hard Tail or Full Suspension

Whether or you choose hard tail or full suspension really depends on your experience, budget, riding style and roughness of your terrain.

What constitutes rough differs from area to area.

I personally live and ride on the North Shore of Vancouver Canada which has some incredibly rough and steep trails (pictured above).  My XC bike has 5 inches of travel front and rear and I use all of it on XC rides.  It does not have enough travel for some of the more advanced downhill trails in our area.

When I was visiting Bend Oregon, the riding was so smooth that my 5 inch XC bike was a rather silly choice and I would rather have been on a rigid (no suspension) bike.

In the end the choice is a personal one and the cost/benefit will be different for every rider.

Injuries

Injuries really depends on a combination of your bike handling skill, your riding terrain, and your risk tolerance.  There is also the probability of crashing combined with extent of injuries.  Full suspension often lets people ride harder terrain than they might otherwise, which has potentially bigger consequences. Anecdotally, I have observed those with the most suspension also tend also to have the biggest injuries.


Is it fine to clean bearings with gasoline? I've been searching all over the web about washing bearings with Gasoline (and other gas products like desiel and kerosene). I've found some mixed answers. Some say it's good some say it isn't.
I want to remove dirt inside my bearings. (we don't have roads so it would always get dirty even it is shielded) And I know soaking it in a container filled with gasoline with remove those. But is it alright?
Won't it damage my bearing in some way?

I don't have access to any cleaning substance because I live in the forests of the Philippines.

Gasoline was used for many years as an inexpensive readily available solvent. There are a couple of real life issues with using gasoline for a solvent. It is very flammable thus a fire hazard. It is absorbed through the skin and it is toxic when inhaled in high concentrations. You have to find a way of disposing of the remaining dirty solvent. Pouring it on the ground can contaminate drinking water. If you have no other means of cleaning the bearings you can wipe them with clean rags. That still leaves the issue of disposing of the dirty rags .


Restoration project, help needed I've been gifted this frame by a family member and would love to restore it to its former glory. I literally don't know where to start. The brake levers are frozen solid and don't move at all. The gears are downtube. Obviously the first place to start is with some wheels - but Im not sure what cassette size I should be looking for. All in all any pointers or advice would be most welcome. Thanks!

The first question you should ask yourself is are you going to do this project is for fun and experience or for money? There is surely money to be made, otherwise the workshops like Steel Vintage Bikes from Berlin would not exist.

As I can see you have been donated a (pardon my judgement) rather a generic frame and you won't be looking for substantial value of the finished product. Still in for fun and experience? Welcome to the enthusiasts world and read on.

Inspect and catalogue your item
Carefully inspect all the parts that you have, that are in reasonable condition for reuse and that you want to reuse
Decide what style you want the build to be done
It can be full restoration to original, you can improve/upgrade sticking to the era of the bike or go for full modification keeping the vintage frame and putting modern components (Campagnolo offers some groupsets in silver making them suitable for this retro-look)
Strip the frame
After disassembling all the parts look again what can be reused
Paint the frame if desired (or have it painted)
Depending on the condition of the paint of the frameset and the desired effect you can paint the frame yourself, have it painted or go for so called "rustoration" (clear coating the frame as is keeping paint chips and rust)
Collect all necessary parts
Some components can be reused, clean them, polish, grease, make them great again. The missing parts need to be acquired externally. Depending on the type of build you either have to source those second-hand (internet, local flea markets, dedicated events, etc.) or buy them new.
In my opinion the components such as:

brake pads and brake cables should always be placed brand new (your own safety).
derailleur cables should be placed new for reliability and convenience.
bar tape goes new - hygienic and aesthetics. There is wide variety of retro and vintage style of the bar tapes available on the market, pick your favourite.
for the leather, Brooks-style saddles, it's a lottery. It will either fit you or not. I haven't heard of successful refits of the leather.

Assemble, adjust and enjoy

And that's pretty much it. If you have more questions, please ask. I'd be more than glad to share my experience in restoring bikes.


Storing bike outdoors Possible Duplicate:
  How to store a bike outside and still avoid rapid decay?

I'd like to store my bike on the balcony. I use it daily and don't mind lugging it up the stairs but I'm tired of leaving it out at the mercy of the elements.

Since my balcony is open, I was thinking of a tarp. Also, I'm in the midwest and winter's coming!

Any other (cheap) suggestions?

I've used a bike cover with great success in the past. Something like this Topeak Cover from REI is great. It covers the bike well and has a self contained pocket that it folds into for easy storage when not in use. There are several similar products that range in price if you're looking for something more cost effective. You will still need to do routine maintenance throughout the winter like lubing your chain, but this will keep a majority of the snow and ice off of your bike while it's being stored outside.

Don't forget to lock your bike while it's out there. If you live on a 3rd+ floor it's less of an issue but I've had friends and fellow bike commuters have their bikes stolen off 2nd floor balconies many times.


Shimano Nexus 8 Hub Alignment Mark No Longer Visible I've got a Shimano Nexus 8 IGH, and was previously able to adjust it properly by aligning the two yellow tick marks in the 'window' as described here.

However, I then removed and replaced the rear wheel a couple of times to change a tire, clean, etc. However, I can now no longer see the second (outside) yellow tick mark in the window, and can't seem to get the gear adjustment dialed in without it. I have been using the painted yellow tick marks, but lining them up doesn't seem to dial in the shifting quite as nicely as it did when I lined up the tick marks in the window. Any idea what went wrong, and how I can get the second tick mark back again?

EDIT: It looks like someone added a photo--thanks. My issue is that when I look at my hub, the second (bottom in this photo) tick mark is not visible no matter what I do, so I can't use it for alignment. The window is clean, and the first tick mark is clearly visible.

You can flip the bike over; there is a second set of alignment marks on the bottom of the cassette joint.

Shimano Nexus Hub Adjustment

Scroll down to "Gear Adjustment"; there are drawings that are helpful. This page in general has great information on Shimano's internally geared hubs; worth the read.

You can also purchase a new cassette joint. I've never seen the adjustment marks become completely eradicated; if you cleaned the bike with strong solvents or cleaners, this may have lightened them.


Rear mech cage stuck, how can I take it apart? This is a shimano ultegra 6700 rear mech.

The swing arm/cage is incredibly stiff where it connects to the derailleur. I can just about rotate (red arrows) it a small amount but requires a lot of effort.

I tried to loosen up using an hex key (at the blue arrow), but it seems incredibly soft and I think I may have rounded out the thread, it would not budge.

What can I do? Without any motion in that mech cage means that when I shift into the higher gears on the cassette, it doesn't take up the slack in the chain, causing it to drag along the frame and close to the ground.

Get some WD40 or PB blaster and just shoot the heck out of it. Do this a few times while manually moving it with your hands and it should start moving again. Throw some chain lube in there afterwards to keep it moving nice and clean.


How are the racing categories in the US decided? I have heard mention before of racing cyclists in the US being, say, a Category 2 racer.  What are these categories and how are they decided?

Usually, it is the USA Cycling racing categories that people are referring to.

Road Upgrades
Guidelines and Notes by Category:

5-4:   Experience in 10 mass start races.
         Local Associations may also establish policies where upgrade
         credit is given for taking asanctioned rider education clinic.

4-3:   20 points; or experience in 25 races with
        a minimum of 10 top ten finishes with
        fields of 30 riders or more, or 20
        pack finishes with fields over 50. 30
        points in 12 months is an automatic upgrade
        - USA Cycling-sanctioned rider camps and clinics that are
          approved by the Local Associations for upgrading will
          count as a maximum of three upgrade points when upgrading
          from category 4 to 3

3-2:   30 points
         40 points in 12 months is an automatic upgrade

2-1:   35 points
         50 points in 12 months is an automatic upgrade


Slick tires and Knobby tires vs Bumpy roads! My question is if Slick tires can support bumpy roads better than knobby tires?

I ask this because I'm currently working doing delivery all around Manhattan and unfortunately I get some bumpys roads on the go while riding with my Road bike. The constant flat tires I get every week got me thinking on take the ride on a MTB bike but if I use a MTB, I want to go as fast as possible like I do in my road bike, so I found that changing the type tire to a slick one can do the job and there is where my question come now

Can Slick tires support bumpy roads better than knobby tires?

I also know that air pressure have impact in this situation but I want to know if there is any difference beside of this that make Slick tires better to bumpy roads than Knobby tires!

Thanks!

YES smoother tyres are better than knobblies for road usage.

Knobblies means your tyre's carcass is a little higher off the road, and if your knobs land on the corners of the bumps, then there's a lot more rubber between the compressed air and the edge.

Downside is knobbly tyres (tires) tend to be less thick between the bumps.  So if you hit the obstacle between tyre knobs, then there's less thickness.

Generally you want smoother tyres for on-road.  Commuter or touring type tyres tend to have more thickness, at the cost of more weight.  Racing tyres tend to be made thinner, for weight.

Also your cornering on smoother tyres feels better, because knobs tend to squirm sideways under load.

But the biggest thing is your technique.

don't go over bumps and into potholes, if you can avoid them
If you're riding up and down curbs/kerbs, stop it.
Unweight your saddle when going over bumps - get up on your hands and feet only
Clipless pedals are good for quick spontaneous last-second jumps, more-so when in the unweighted posture.


Grand Tours - Total Ascent (By stage, particularly the giro) I'm looking for information on stages of grand tours, particularly the upcoming Giro.

I can find details of total distance by stage, and the amount of ascent on the key climbs of a stage, but I'm interested in the total ascent and distance by stage.

I can work it out for myself, if I can find an appropriate file with the route in. For example a GPX, KML, TCX etc, but I can't find them either.

Has anyone found a source for this information?

I have found a site with a user who appears to have gone to considerable effort to plot and upload many stages of many tours, including Tour De France 2013 and Giro D'Italia 2013 and many others.

You can view his list here:

http://www.gpsies.com/trackList.do?username=Daniano

From my sampling, they appear to be pretty accurate, but, they are not official.


Can I use 26 1 3/8 tire to replace a 27 1 1/4? As in title, can I use  26 1 3/8 tire to replace a 27 1 1/4?

Is this workable with some elbow grease?  Any negative consequences of trying?  It is an older road bike with the original tires (27 1 1/4).  I went to a local store and closest match was 26 1 3/8.

No.  Bicycle tire sizes are a dogs breakfast of standards. The only standard that is consistent is ISO.

According to Sheldon Brown, 27" is ISO630 and 26"  (the common sized MTB tire) is ISO 559.

ISO630 (27x1/14) are available with a search on the internet e.g. Sheldon Brown / Harris Cyclery (not a recommendation)


Were there always teams in road racing? Did bicycle road racing always have teams? Were the early road races competed by individuals who were racing for themselves?

At what point was it realized that having a team would confer huge strategic advantages?

In this interesting video about the history of the Tour de France, at some point the narrator explicitly mentions the period (during the 70s if I remember well) when great cycling events beginned to change from a one-to-one fight amongst a few super-strong riders (typical example: Merckx) to a teamwork fight amongst well-orchestrated, hierarchical teams (typical example: Armstrong).

I think (and the video also mentions it) that this is due, among other things, to an increased understanding - and acceptance - of the importance of aerodynamics (LeMond), and also to advances in scientific training, which leveled the differences between well-prepared riders, I think.

Also, the role of the team in one or another era can be inferred from the very title of another excelent video, "Stars and Watercarriers".


Can you identify this Sachs hub? I recently picked this up along with a couple of old wheels.

I don't know it's age or history. I've only got as far as identifying it as a Sachs.

There are no other markings apart from the logo shown in the photo.

Your hub is a SACHS Maillard 'New Success'. Don't pin me down on the date, but it's got to be from the late 80s - a couple of years before the branch was acquired by SRAM.


How does brazing and welding not ruin the heat treat on steel tubes? How does brazing and welding not ruin the heat treat on steel tubes? With such high temperatures, wouldn't the heat treat be ruined?

Edit: Specifically in this video

             it shows Hincapie using what looks like an oxy-acetylene torch to fillet braze. It looks like the tubes are getting red hot which is sure to ruin any heat treat. Is fillet brazing impossible with heat treated tubes? Also barring high tech manufacturing techniques, how does a small frame building operation preserve heat treats when mig or tig welding?

tl;dr heating chromoly to brass-brazing temperature doesn't really change it, at all; the steel was born hot and heating it back up does nothing to it other than oxidizing the surface if you don't protect it with flux. For special proprietary exotic steel tubes heating them up may or may hurt or it may help; there is no rule.

There is much wrong, and not-even-wrong information on this topic. If it helps, I build bicycle frames, by both welding and brazing, and I'm also a materials engineer.

The first problem is use of the word "heat treated" which is almost meaningless, because there is an unlimited spectrum of heat treatments and material responses, and all steels are processed through heat treatments. So the question of the topic really isn't an answerable question as-posed.

I can guess the thought process behind this question, and I will try to explain the common thought process which is not really wrong but is not even wrong:

In terms of carbon steel, a simple steel which is common, and which is sort of the "canonical" steel, if carbon content is in a range considered "high carbon", then it can be hardened by heat treatment. Then you can use it as a knife or needle or a file or saw blade or use it cut other steel. So hardenability is important technology, and it's possible to understand this without knowing much metallurgy. It is true, for such high carbon hardened steels, if you overheat a piece of hardened steel afterwards, like a knife or something, it loses its hardness and can be ruined. This is probably why people think heating up steel is somehow "bad".

Incidentally, there is nothing magic about "red hot". Steel turning red doesn't signify any material change has taken place. It just turns red when the combination of temperature and the sensitivity of our eyes overlap. Steel turns red when it gets to 800C, but so does literally every other material. Some steels can maintain hardness at red-heat, and some will lose hardness before red-heat. The color is just the color, it doesn't mean anything is changing in the steel.

This is all not very applicable to bicycle tubes because hardness is not an important property for bicycle tubes. Most bicycle tubes can't be hardened in the first place. Common steel frames are either chromoly or medium-carbon steel. Neither steel is particularly hardenable. So there's no real hardness to be lost here. "Hardened" is actually slang for any number of morphological transformations.

Default, basic chromoly is normally supplied in a "normalized" heat-treat condition. It can be welded with a variety of processes most notably the classic gas welding with mild steel filler. It can then be used without further heat treatment and gives very good service with no propensity for cracking if welded properly. It is also possible to weld with chromoly filler with post -heat treatment, but it's a rare process since welding with mild steel filler is so satisfactory. Chromoly literally exists because it is a supremely strong steel which is also very weldable steel.

Any brazing process is less hot than welding. There is no problem heating chromoly to brazing temperature for any reasonable time. It doesn't become weaker. As mentioned above, the steel doesn't have any hardness to lose. Nothing is really happening to it. If you quench hot orange-hot chromoly in water it will harden to a limited extent and can cause stresses or possibly be a liability for cracking, but nobody does that. Don't get scared if you see somebody quench hot chromoly braze joints though because as long as the steel is cooled down below brazing temperature quenching is harmless. Basically as long as it's not glowing at all it's cool enough to quench in water with no harm.

Let's now talk about other steels. Within bicycle frame history, there are/were some fairly exotic steel tubes which are specifically heat treated for strength. There is crossover between hardening here and the treated steel is actually harder, hence marketing describing some tubes as "hardened" or "heat treated". In this zone, we have ventured away from classic chromoly, and all rules are gone. For those tubes, if you want to preserve the properties, you have to observe certain conditions. Otherwise, you will let out the magic and end up with something only as strong as classic chromoly, or probably worse because it might crack or something. But there is no generalization possible; it depends completely on the individual tube and manufacturer instructions.

Tubes with special heat treatment were often silver brazed with lugs. Usually, they don't get hot enough to impact heat treatment this way, so the tube is not really changed. But check the datasheet because it depends.

Some tubes are designed with heat treatments, which, somewhat like chromoly itself, are actually designed with welding in mind. If you follow a certain welding process then the tube will end up with a certain heat-treat state after welding. An example is the famous "air hardening" Reynolds tubing which basically means you can weld it and you don't need a heat treatment oven to heat treat the whole frame afterwards; supposedly, it will return to a planned state of treatment after welding, which is supposedly/hopefully still stronger than regular chromoly. This steel exists so that Reynolds could (over-)sell their fancy steel not just to makers of lugged frames but also to fabricators who welded. But it only works if you follow the correct process, and it's mostly rot anyway since ALL steels from the cheapest department store mystery-steel to the most exotic have the SAME STIFFNESS, and almost all frames are built for stiffness, so stronger material is not as advantageous as the marketing can make it sound.


Compatibility of 41mm x 107mm bottom bracket shell Hi I have spent several days looking for a bottom bracket and crank. At this point it seems that there is nothing but 1 traditional pressfit bottom bracket and 1 crank that fit this shell. However, I want to make sure that nothing else fits before giving up.
Bottom bracket shell dimensions: 41mm internal diameter and 107mm width
Type: press fit (non-threaded)
Do threaded-together bottom brackets for this shell exist? This means, a bottom bracket that is not pressed into the non-threaded shell, but each cup screwed into the other cup, like the image:
The reason being that pressfit bottom brackets mis-align in time and start creaking quite fast. Then it becomes and endless buying of bb every few months. I have experienced it with my road bike. Threaded-together BB (or whatever name they have) do solve the problem.
Regarding the crank, it seems that the only crank that fits a 107mm BBshell is the Truvativ Hescendant DH, which is the only one that has in the description this BB.
Any regular MTB crank's spindle will be too short, is that correct? I do not know the length of the crank's spindles, it is never mentioned anywhere, as if there was only 1 length.
Thanks in advance.
*Edited because it seems it was not clear.

Your frame is only compatible with bottom brackets that are connected with the frame using the press-fit interface of the right dimension (there are many standards - open or proprietary). Threaded bottom brackets are screwed into the frame and are not compatible with your frame.
What you have in your picture is a press-fit bottom bracket as well, not threaded and it may or may not creak. One cannot say in advance whether a press-fit bottom bracket will creak in your frame or not. It depends on the quality of the alignment of the bottom-bracket shell in your frame. The threaded sleeves inside of the bottom bracket ("thread-together BB" as Weiweg Ng commented) in your picture may or may not help with that, one cannot say in advance.
When it comes to the allowable cranksets, you just have to follow the specifications. The manufacturer always says to which bottom bracket shell width they can be used as discussed in Picking a crankset for a 107mm BB on a downhill bike . Cranksets like the Praxis downhill cranks or Shimano FC-820 or FC-825 (but these are 104 mm) might be applicable, provided you frame can accept the respective required BB (here BB107  Shimano SM-BB71-41C ). There should be more alternatives around.


Just bought a Nicol bike and not sure who makes them I just bought a road bike and the only logo on it is Nicol, does anyone have a clue who made this bike and what it’s worth?

Thanks

the person who founded ibis bicycles is named Scott Nicol.  Ibis is known for mountain bikes so maybe it is an early pre Ibis by Scott Nicol or maybe not.

more pictures might help

The braze at the seat post looks like a hand braze, but its hard to tell from the picture.  It might be a hand built frame.

I would send an email to ibis and ask. Their web site says they have around 20 employees. It might be worth something to them.


What variables best determine bicycle fit for an individual without riding it? Trying to decide a bicycle purchase, not sure how to choose the best fit bike for my body type.  Should I measure my leg length, torso length, arm length, body build, does my gender make a difference?

One thing that does make a major difference is the type of bike.  As a very general rule, the faster the bike is intended to be ridden, the more important the fit.  I'll address this from the point of view of what most beginners ride -- things like Euro-style city bikes, hybrids, and basic mountain bikes.

So most bikes that most beginners (based on your tags) would start riding on are quite forgiving. For a conventional geometry, leg length (i.e. seat tube length) is the biggest factor.  This is the key number in the frame size, and the frame is the most important thing to get right as there are no (cost-effective) adjustments or substitutions possible.  When cheap bikes are sized by a single number, it's usually based on this length, but comparison between makes isn't simply a matter of the length.  To some extent a too-small frame can be compensated for by raising the saddle, but it's much better to keep this for fine-tuning as too much seat post extension often results in the handlebars being too low. A frame that's too big can lead to disomfort or injury, even if you don't have to worry about a top tube.

The reach (approximately top tube+ stem length) and stack (handlebar height) are secondary.  They scale with the seat tube so should be about right for a typically-proportioned person. Both are also quite adjustable, though to get the most adjustment means swapping out parts.

The effect of this is that most people can buy a flat-bar bike based on top-tube height / frame size alone, and only worry about anything more than the most basic adjustments when they start considering longer rides.  Of course extra care is needed if you have back/leg etc. problems.


Shimano 105 5700 in 2019 I want to begin with road biking as a sport and are currently trying to find a decent bike.

Some friends recommended to get the Radon R1 2019 with a complete Shimano 105 R7000 groupset.

In a bike-store I found a new no brand bike with a complete Shimano 105 5700 groupset.
It also features an aluminum frame, a carbon fork and weighs about 10.5kg for less than 300€.
Is it still relevant in 2019, as it is almost 10 years old, or is it comparable with newer Shimano Sora groupsets via trickle-down?

There seems to be a lot of myths and opinions on various groupsets, but is there some "evidence", which indicates a different performance?

This is very much opinion based question. I'd say that 5700 is still above current day Sora and a very solid choice indeed. I'll also argue with some of the comments that 10.5kg is heavy, especially at the price point of 300 EUR. As a comparison Triban 520 RC (praised to be extremely good value alu/carbon bike for packing partial Shimano 105 groupset in 750 EUR) is 10.3kg. There are very few bikes under 9kg that cost less than 1000 EUR and probably none under 10kg for 500 EUR or less.

Actually, at this price point, this is probably way above anything else you might be able to get.


Fettling issues - slow shifting rear gears while riding I've recently had an issue with my gearing, struggling to shift down onto the last few cogs on the cassette.

I've got a Shimano Ultegra 6800 groupset, but when I shift whilst riding, I get a "tick-tick-tick" then it shifts.

This isn't the issue though.
I understand that a tweak of the barrel adjuster should sort it.

My issue is that when I put my bike in the bike stand, it doesn't happen.

I have thoroughly cleaned the bike and groupset, and re-lubed it. When shifting up and down to test, everything flies smoothly!

I then took it out on a test spin to make sure everything was hunky-dory, and my shifting issue was back!

Does anyone know of a way that I can replicate the riding conditions/forces on my bike whilst on the stand?

You need a local test route for this and other things. For some things just up and down your street will do, but for this issue you might need to put the bike through its paces properly.

Ride your test route, paying particular attention to the feel of the problem. Stop the bike, tweak something relevant (your best guess) and ride it again. Better or worse? If better but not perfect - adjust some more the same way, if worse go the other way.

You may be able to use your commute in the same way if commuting on this bike is an option.

In your case I'd get it perfect on the stand, then tighten the rear derailleur cable a little. Test ride and see.

Actually of course this is a tedious version of normal adjustment procedure. The nice thing about a rear derailleur adjustment issue is you don't need the bike on the stand for minor tweaks.


Are electric bike speed limitations set in stone? I'm thinking of getting an electric bike, and like most, it states the speed limit at 25Kph, which also happens to be the speed I typically cycle at. My question: is this speed set in stone? Is there a limiter of some kind preventing me from going faster? If there is, is this limit defeatable?

The limit is set by law depending on the country. There's nothing to prevent you from going faster if you can pedal harder. The limiter just cuts off the electric assistance above 25km/h, so you'll have to rely on pedal power alone above that speed!


Will this crankset be a good replacement I removed my 3 ring crankset from my old mountain bike and it was welded together so I have to replace the whole thing. The bottom bracket is square taper. The chainrings were 48, 38, and 28 teeth and there's an 82mm BCD. Will this crankset be ok? It seems like it might work because it's square taper (the only thing I took into account.)

https://www.amazon.com/gp/product/B00U1S6TVK/ref=ox_sc_act_title_1?smid=A1E5K32CINJQSZ&psc=1

The BCD is irrelevant cos you're changing the whole thing.  BCD only matters when you're fitting replacement chainrings in the future.

The only measurements that matter are BB interface (square taper, OK),  crank length (165mm - is this suitable), and chainline (which is set more by the BB axle than the crankset)

Since you're replacing a triple with another triple, should fit fine.

However the new one is 42/32/22T  and the old one is 48/38/28T so you'll probably have to remove 6 links from your chain (6 half links, or 3 wide and 3 narrow links, or 3 complete links, depending on how you want to count them.)

Also your front derailleur mech will probably need to slide down a bit, which means adjusting your front derailleur cable.  May as well fit a new one while you're doing this - inners are cheap.

DO NOTE that this will make your gearing lower by ~10% so the top-speedy hard gears won't be there, and you'll have a bit more at the low end for going up steep hills slowly.  Do you run out of gears at either end currently?


Mounting a 12v motorcycle light on bike seat rails? So now that I built a 12 volt (more like 11v) battery for my bike I would like to accessorize it with some 12v lights to get a unique look. I'm looking at motorcycle tail lights, but they all have two parallel bolts coming out the back 82mm apart. The rails on a bike seat seem to be about 50mm apart.

Is there something I get at the hardware store to jerry-rig a solution?

Back of the bike seat: (two horizontal rails 50mm apart with an angle at the end). Maybe I could zip tie in a ubolt pipe clamp somehow?

Similar lights are often fitted to pannier racks, especially on e-bikes. I've had a plastic part with the right holes that would be easy to modify, but it came with a topeak rack.

It wouldn't be hard to fabricate something. The easiest way is probably to start with a saddle mount for a water bottle cage and make an aluminum plate. Some sellers of offcut sheet metal on ebay will cut to size, then you'd only need to drill the holes, but you can cut it with a hacksaw. I'd probably use 3mm plate.

I assume you've been sensible about light levels and colours and won't dazzle or confuse anyone.


Upgrade suspension on hard tail MTB I have a Suntours xcm (spring 80mm) on my hard tail.
I drive more frequent and more pretentious. So I consider to upgrade my fork.
How can I tell if I need a better one? What can a good air-suspension  better than my current?

And what would be a good replacement?

edit:

conclusion

less weight
more adjustments
higher responsiveness

XCM is an entry level fork - typically found of bikes at the low end of the price range. Its not hard to imagine you have out grown the fork and it is limiting your enjoyment and performance while riding.

The only way to tell if a better fork is needed, (or is that wanted?) is to take a bike with a better fork for a ride. The main consideration is how much money are you prepared to spend. However, if you take a bike out with a better fork, it will almost certainly be a better bike in every other way as well - so be careful of the comparison - you could esily set yourself up to be disappointed.

To make a measurable difference, you would need to install a fork that was of far better quality than the rest of the bike, and much of shocks improvement (hence the money) would be wasted by the bike.

It is rare that a fork upgrade (as opposed to a replacement of a faulty fork) makes sense - the manufacturers build a bike to a cost and the quaility/performance of components match. Forks are very expensive - probably more than the bike is worth. 80mm travel is not enough for serious trail riding - you might push out to 100mm without upsetting geometry too much, but that is still low by today standards.

Upgrading the whole bike is a much better idea. Put the money you get from selling the bike and the amount a fork would cost into a new (or even better - used) bike.


What are my options for a bike trailer? I took my car off the road to save money but sometimes I need to transport large heavy items like a 60 pound flooded lead acid golf cart battery.  Is there anything I can attach to my bike that can handle weight like that such as a cargo trailer?  What about 2 batteries (120 pounds total)?  What (if any) requirements are there to make this work?  It is mostly flat where I live and my lowest gear is about 22 gear inches and I have 3x7 gears (21 speed).  Thanks.

There are several options, you could make your own if you are the handy type. Or there are many ready to purchase from a local shop or online. Most of the ones that I see have a 120lb limit. So you would be close but probably fine as the max weight is generally higher than that listed for liabilities sake.

As for store bought option there are a lot of different companies that make trailers for bicycles both for hauling cargo, and touring applications as well as child carriers of course.

Here is one design just to give you an idea. The last time I saw a similar one in a shop I think it was about 200 bucks.

http://www.jbi.bike/web/checking_product_description.php?part_number=98014

The type shown above attaches to the rear axle by way of that long arm at the front. Building one could be tricky if you don't have the proper tools and I imagine you would need to buy an axle intended for it.

If you want to go the DIY route, I found this write up that looked interesting and could be helpful.

http://www.instructables.com/id/Bicycle-cargo-trailer--200-lb-capacity,-$30-for-pa/


Burley Flex Connector, square tube vs round tube, does it really matter? I have a new flatbed trailer that uses a square tube tow bar instead of a round like my kid trailer has.  Since I'm setup on the Burley system, I need to use a flex connector for the new trailer.  I bought one of each with the trailer so I was prepared when it showed up.  While looking at them either one will fit but the square tube connector has ridges which are just as round as the rest of the connector.  Other than increasing the diameter of the connector, does the ridges really matter, or can I use either one on this trailer?

I'm sure I get no support from Burley since both trailers are not Burley and the packaging for the connectors clearly state not to use them on other trailers.

My kid trailer is a Pacific Voyager II and the new one I bought is a Aosom/Mwave/somebody "wonderer" flatbed.

Flex connector for round towbar:

Flex connector for square towbar:

Here is the side-by-side photo of the connectors I received:

These trailer hitches are interchangeable and I have no issues.  I'm using the round connector in the square tube since it physically fits.  I have put some miles on it on it hauling kids bikes, pulling kids in sleds (recommended to keep the rope out of the tire and carry a spotter), and a 90 mile weekend camping trip.  I have had no issues with it.

As a bonus here I took a round connector out of another trailer that really has some miles and years on and put it on a new trailer (Trek branded Chariot).  The tongue was squared tubed and too small for the connector but I was able to take a stone grinding wheel to the connector and re-size and shape to get it to fit.  No issues found in it at all.


Road bike or hybrid bike? I am buying my first bike as an adult person and I am torn between getting a road bike or a hybrid bike. I will be using the bike primarily for transportation (I am a college student living in a city) but also sometimes just to ride for fun. I am a fan of the handlebars used on road bikes as I find the flat handlebars uncomfortable, but the tires of the hybrid bike make me happy.

Overall I'm not very educated when it comes to bikes so the only difference I can notice between the different bikes are the tires and the handlebars.

The style of bars you referring to are drop bars.

Hybrid / city / multi-use bikes now come with both styles of handle bars.
Not endorsing this bike.  It is just an example. MultUseWithDropBars

One thing to consider is a used cyclocross and put touring tires on it.  It has drop bars and will take larger tires.  You can get great deals on used as many racers upgrade every season or two.  And this is the end of cyclocross season.  Or a used touring bike but you don't get as good of deals on used touring bike as you don't have racers flooding used market.  But if you don't know bikes then you can get burnt used. This is a cyclocross set up with 35mm touring tires that I use for training and crashing around the city.


Good 9-speed cog configuration for touring and which low-cost quality cassettes? Alert: this cassette conf cannot be used in all touring locations because of poor support. I use it only in 1st world countries.

The largest cog at the back is about 12-14cm. The length from hole-to-hole-opposite is about 10.5cm. The length between adjacent holes is about 7.86cm. The hole is the thing by which the cogs are attached to the bike and there are four holes. "Mega Drive Train" is written on the cog-thing. The derailleur-thing is LX Deore Shimano. I upgraded to a new chain PC-951 but it jumps a lot with cogs 2 and 3 (did not jump that much with the streched old chain). So I want to upgrade to new cogs/cassettes. The cog configuration is:

Back

largest cog: 32 teeth
smallest cog: 11 teeth

Front

largest cog: 48 teeth
smallest cog: 26 teeth

so how can I know which cassettes I can buy? I can find a variety of cassettes advertised for "11-32 cassette" but 26-48 returns none in eBay, perhaps a calculation err (any fast way to recheck?!).

Can I change the number of cogs?
If I can change the cog amounts, are there some tables to look for good tested configurations?
I have no clue why just these cog amounts were selected to my Crescent Sport bike. What would be a good cog configuration for touring?
Which cassettes and cogs would you recommend for low-cost quality choices (a bit like SRAM PC-951)?

First, in the front they are called chainrings, god knows why they need to have a different name, but they do.  The fronts can be sold as a set, but can just as easily be gotten individually.  I actually purchased a 26T chainring in the front for something like $10.  For chainrings you will need to know the diameter (in millimeters) of an imaginary circle that would pass through all the bolts that hold the ring on and also the number of bolts that hold it on.  Often there is one diameter that holds that smallest ring and another that holds the two larger ones.

In the rear, you don't need to know the diameter, just the number of gears.  Cassettes are often sold as a group and the two big names are SRAM and Shimano and for 9 speeds they are compatible with each other.  At the small end of the cassette, your current setup is about as small as you will find (11T), but if you are wanting more climbing ability they make big cogs up to 36T (or bigger if you want custom).  There is currently an option to go with 10 speeds but that will require replacing your entire drivetrain, not a cheap option.

Before you go replacing the chainrings, try the cassette first and see if that resolves you skipping issue.


How to know a good pump? It's painful to pay the local price of 15-30€ for a pump that is "very good, durable and small". To me, it is just consumable that I will use until it breaks, so I have no interest in investing too much in such a thing. How can I know what the pump is like? Are there some factors to look at to judge its quality?

I got a Topeak Pocket Rocket a few years back at the LBS spring sale for ~$25. Works great. I made $10 the first time I used it because I didn't have to pay a $35 cab fare to get back home after a flat on a country road.

Fits in my pocket, the nozzle has a snap-on cover, works with Presta/Schrader, it's made of aluminum, feels solid and most importantly gets my tires to an adequate pressure.

For floor pumps, you can check out this thread: What is the best floor pump?


I'm 37, can my legs still grow? I turned 37 this summer, and started ridding quite a lot (about 3500km in a little less than a year). When buying my carbon bike, and then aluminium commuter, I was careful to set the saddle height using the same method: putting the heel on the pedal and stretching the leg. That way, my pedal stroke has my legs still being slightly bent when reaching the furthest development. I had to fine-tune during the first week, but soon found the most comfortable position.

About 2 months ago, I started having the feeling that my knees bend a bit more than they use to. I also noticed sometimes light pain in the knee, the same as described when position is not good. It's not permanent, but it happens sometimes.

Oh, and my seat post hasn't gone down the tube. Saddle posts are marked, and didn't move.

Is it possible for my morphology to change with constant effort? I try to ride quite often 150km on the weekend and I commute everyday.

Your observations are confounded with time and lots of things can change in the intervening time, this include your flexibility (e.g., hips and/or hamstrings) and your components (e.g., your saddle).

Flexibility, is often the first thing to change, if you were relatively inflexible in your hips you may have adopted posterior rotation of your hips (i.e., the top of your hips backwards) when riding, which could effectively shorten your leg length on the saddle.  This is often part and parcel with short hamstrings.  As flexibility improves you may have been able to rotate your pelvis to a more neutral position, which would have effectively lengthened your leg reach.  As an aside, flexibility  is also one of the first places people should look when they think they have a leg length discrepancy, structural leg length discrepancies are much rarer than asymmetrical flexibility.

Equipment can also change over time.  If you are running one of the classic leather hammock style saddles (e.g., Brooks) these can stretch and sag over time, which would lower the effective saddle height. Even some modern synthetic saddles can "break-in" (i.e., the supporting plastic frame becomes more compliant), which would cause the top of the saddle to sag a bit more than new when you put your full weight on it. This might be harder to pick up as the saddle should return to the original height when you get off, due to the memory property of plastics.

Sorry, you are not growing

It is highly improbable that you are growing at 37, as ~19-21 is the maximum age by which most people stop growing.  It is possible to develop a tumor that stimulates your pituitary to produce excess growth hormone, this actually happened to a friend, but since you have stopped growing in height this will result in your bones getting thicker and heavier not longer. Gigantism can also cause excessive height, but would have shown up earlier in life during your growth phase.


Seat mounting rails bent out of shape Recently I crashed my bike, and since then, the seat has been tilted towards the left side.
I know very little about bikes and the associated terminology, but I think what happened is that the rails that are used to mount the seat have been bent out of shape in the accident; see the images attached below.
What I'd like to know is:

What's the proper terminology here (e.g. regarding the "rails")?
Can I, or a repair shop, bend the rails back into shape without seriously compromising safety?
It looks to me like the seat itself is secured to a mounting plate (which is connected to the rails) with something akin to Allen screws. Are these mounting plates standard parts that I can replace, to salvage the seat? If so, what are they called?

Thanks!

(Saddle) rails is the correct term. They are part of the saddle/seat. I’m not aware of any saddle where they are replaceable.
You might be able to bend the rails back but it could compromise stability. Considering a new saddle only costs a couple of euros I’d just replace it.
For a crash to bend the rails like that it takes quite some force. I recommend a very careful inspection of the frame, seat post and all other parts of the bicycle.


Catastrophic failure My rear wheel suddenly became loose in traffic today. It is completely off axis. The axle looks fine from the outside. I remember being told something about loose cones.

Should I bother to repair this beater bike or should I invest in a road bike? This is a department store mountain bike.

And yes I took apart the rear brake because I thought that was the source of the problem ... (I.e that's not something that broke) ... Risky I know ... But I had kool stop salmons on the front so I thought that would provide sufficient stopping power. Nonetheless the wheel kept grinding against the frame as you can see in the picture so I stopped again and realized the wheel was completely off center.

Most likely the source of the wheel going loose was loose nut. Department store bikes are not likely to have quick release which is safer because it does not become loose with time.

Put the wheel back and screw it on tightly. Don't forget to check the front wheel too, because if that goes loose the consequences will be very unfortunate.
The wheel on the picture looks off centre which is likely because it is not properly in.

The question is whether you need need to invest into more serious bike. If cycling is interesting to you, the answer is definitely yes. Just don't buy those bicycle-like objects in department stores anymore.


How to repair large holes in inner tubes? I find that any hole, cut or tear larger than a pinprick is impossible to repair with normal patches because they are too soft. Even a 2-3mm slit will cause the repair patch to balloon out and burst at that point. Is there a way around this?

I don't think that you will have a problem with the patch ballooning out as long as the tube is inflated while fully mounted with rim and tire. To my experience there just won't be any room to balloon to.

If you fear that this will be a safety risk, I would recommend a new inner tube when the old one has such a big hole. When you are on a ride and have no spare tube at hand, even with a 2-3 mm slit a standard patch should be enough to get you home.


Can you change a 7 speed freewheel to 6 speed Can you change a 7 speed freewheel to a 6 speed

In general, yes. They use the same thread/attachment to the hub and they are almost the same width. If you have friction shifting it will work fine, but if you have indexed shifting that will obviously not work - the spacing between cogs is different.

There's more information here


Is the frame material of Specialized AWOL Comp and Elite the same? I'm looking at these to bikes:

AWOL Elite
AWOL Comp

From the specs I can't decifer though if the frame material and/or alloy is the same on the two bikes?

I know the frames differ in other ways, but I won't need other drive trains, so I just want to know I can just as well buy the cheaper Elite.

Same frame material. Not sure why it's not more detailed on the Elite specs, but there are several shops marketing it that reference the same frame materials as the Comp, like this one.

Makes sense when you think about it. The Comp and Elite ultimately refer to different component packages (just like those annoying and less meaningful letters that come after car models), though I'm not sure why they don't just call the frame an AWOL!


can down tube shifters be used with a gear set of 21 gears? (3x7) I have two bikes - one a vintage 12 speed with down tube shifters - the other a twist shift gear conversion with 21 set shimano gears. I want to put the 21 gear set on the intage road bike - can I simply connect the downtube shifters in place of of twist shift?

You're going to have a few problems most likely. For example, you need to probably respace the rear dropouts to get a 7 speed wheel in (assuming its a right size/close enough size that you can get the brakes to work). Then you have to make sure the triple clears everything on the new bike. Then, you have to make sure that the FD can be mounted on the new bike and can shift a triple (they're different between doubles and triples) and the RD can move enough to get through all the gears (which also probably means swapping the RD's).

Once you have all that, with friction shifters, all you need to check is that they can pull enougyh cable to shift the FD appropriately and the RD appropriatley (i.e. from small to large).


Installation of round bike cadence sensor - in the end of crank screw? I got a "LIVALL® P1 Smart Bicycle/Bike Nano Cadence Sensor", round and flat which appears to have a screw in for the end of the crank. However on all the bicycles I see there is the hexagonal screw nut and a black thing around it... just about the size of the threads.

Is this compatible with some way to remove that black spacer or do I need to try to awkwardly zip tie it to the crank somewhere to not rub on anything?

 from Maker's Website

Looking at the video (the English version I linked in the comments), there are several options for installation.  The sensor can act as a replacement for the dust cap found on many cranksets (methods 1 and 2). The dust cap sometime screws in.
This doesn't work if the dust cap and crank bolt are combined (as on Octalink, and similar to what you describe).  I don't think the sensor is designed to replace the crank bolt in that case, but even if it is, I'd be very cautious.  Instead the 3rd option (cable-tied to the inside of the crank arm) is probably the best bet


Is storing bikes in an enclosed trailer a good idea? I too am running out of space in my house to store my bikes.  I have three bikes inside my house and my 5 kids bikes are outside in a shed (which is also over crowded).  My idea is to buy a 6X12 enclosed trailer to store our bikes and modify it to also be like a bike shop.  We take our bikes everywhere.  My concern though is keeping the bikes in an environment that is not controlled.  Although they will be completely sealed off from rain, etc., they will still be exposed to varying temperatures and humidity.  Does anyone think storing these bikes in a trailer is a good idea?

So long as the trailer is reasonably weather-tight it shouldn't be a problem.  Since there's nothing in the trailer generating humidity, no significant condensation will occur, and, within reason, temperatures won't hurt bikes.  (The only caveat would be that you maybe should have some vents that can be opened if temps rise above 90F or so, so that temps don't get over about 150F inside.)


Canyon Spectral:ON different wheel size (29''/27.5'') Canyon Spectral:0N boasts a different wheel size: it has a 29''/2.5'' as front wheel and the 27.5''/2.8'' back. This difference in wheel size should make the bike more nimble and the extra-wide tyre back should maximize traction on difficult slopes (traction for going uphill and breaking for the downhill I guess). The smaller diameter wheel on the back leaves the space for a shorter chainstay, thus more maneuverability. All the reviews I found on the internetz are quite positive.
I was wondering:

Anybody has experience with different wheel sizes?
Any considerations for pedaling on level ground with this setup?

No matter what the reviews say.
No matter what anyone tells you.
You need to ride this bike and decide for yourself if this bike does what you need it to do.

According to Canyon's Spectral:ON spec sheet they are running:

27.5 X 2.5,  63-584
29 X 2.6,  66-622

From bikccalc.com
Rear:
Rim:650b/27.5 Tire:2.50 inch Rim (iso):584 Tire:63.50 Wheel diameter:711.00

Front:
Rim:700c/29er Tire:2.60 inch Rim(iso):622 Tire:66.04 Wheel:754.08 (rim diameter plus 2 x tire)

754-711=43mm difference in diameter.
The chain stay runs the radius of the wheel so it is theoretically possible for the chain stay to be 21.5mm shorter than it would have been with the same size wheel.
Can you feel 21.5mm on a full suspension electric bike?
Only you can say for sure.

Smaller rear wheel has been done before, more than once, on a mountain bike.
Here's a picture of a 1988 Cannondale SM 600 with a 24" rear wheel and a 26" front wheel.

(I know it's not the same thing as a full suspension electric mountain bike)

I use to ride with a guy who had a bike like this. He didn't love it enough to keep it longer than a year.

The 2009 Trek 69er 3x9 had a 26" rear wheel with a 29" front.

Here is an interesting discussion on bikes with different wheel sizes on the Bicycle Stack Exchange.


Possible faulty Schrader valve I have a Schrader valve that is leaking air. I have a feeling that I over inflated the tyre. Recommended was 40-65psi and gaugue was showing just over 60. Up until that point it was pumping fine and then air started escaping and now leaks as much air as it takes in.

Any ideas what the problem might be or what issue I might have caused by over inflating, if I have?

In my experience, when a Schrader valve starts leaking suddenly, the most common reason is that there is a small piece of debris that prevents the valve from closing. The easiest way to remove them is to slightly overinflate the tire, then fully open the valve by pressing the center pin. If this does not help, the valve might be faulty and the tube should be replaced.


Tubless rims with non tubeless tires -- what rim tape? I run tubeless rims (specifically the new Mavic Open Pros) with the non-tubeless Continental GP GTs. The tires have lots of life left in them so I want to make the most of them in the meantime.

However recently I've been getting loads of punctures, and I think many of them are down the the rim strip not fully covering the whole rim bed (which is very wide). When I take the tire off I can see that some of the tape as been pushed right into the corner of the rim bed.

Should I just use tubeless rim tape with these rims & tires despite the fact I am not using a tubeless tire? It makes sense to me to use tubless rim tape as when these tires do wear out I probably will switch to tubeless.

Tubeless tape is an acceptable substitute for any rim strip and, in many cases, will likely be an improvement over factory-installed rim strips. Just be certain to apply the correct width of tubeless tape (it should cover the entire width of the rim's interior from bead to bead) and prepare the rim's interior surfaces well by thoroughly cleaning/removing any residue from the previous rim strip adhesive, and any single threads from the beads if it was a cloth type of rim tape. Also ensure that the valve body hole is taped over first, then punctured only as much as is absolutely necessary to press the valve through as that helps with forming and retaining the airtight seal when switching to tubeless.


Mavic crossmax freehub doing strange noise at high speed coasting MY MTB is fitted with Mavic Crossmax 26" wheels (early 200x model). The freehub sometimes makes a strange noise when coasting at high speed that stops if I pedal forward once. In the past, spraying chainlube at both ends of the hub solved the problem. I tried that again this time and the issue is not happening that often, but it still does occasionally.
Is there something I can do other than take it to a repair shop?

There's a few different Crossmax/Crossride/Crosswhatever iterations for how you get to the freehub guts to service it. For the one you have, I think your probably just pull off the endcaps, or take them off with a 5mm wrench on each end if there are such wrench flats there. You don't have to take the cassette off; I always do anyway, but it's fine not to if you don't have the tools.
When you take it apart, your chief concern is the pawls or springs flying somewhere and getting lost. It's good to do this operation suspended over a tub or similar so they have nowhere to fly to. The symptoms you're having mean there's some possibility one of the sets is out of place or otherwise unhappy.
Clean everything, and then lubricate it. Mavic freehubs are pretty insensitive to what you use, but typically go with a medium to heavy weight oil. Mavic neutral support mechanics are known to favor Shimano mineral oil. Make sure to keep track of the washer you'll find in there.


What should I look for in a good pair of cycling shorts? I don't currently own a pair of cycling shorts. I just wear a pair of running shorts underneath some running leggings. I'm thinking of getting my first pair of cycling shorts, but as there are so many choices available, what should I be looking for? In terms of padding, is there some type of padding that is better (more durable, more comfort) than others?

What type of shorts?

First you need to work out what sort of cycle shorts you are looking for:

Regular cycling shorts - these are your classic lycra bike shorts, no bibs, no extra fancy bits.

Generally quite comfortable
They do have a tendency to "roll up" under your gut a bit, particularly for those of us that carry a bit more weight than we should.
Obviously a lot easier to relieve yourself with these - probably an important consideration on longer rides

Bib shorts - like regular cycling shorts, but with a "bib and brace" arrangement that go over your shoulders to keep the shorts up.

Even more comfortable than regular cycling shorts as they don't have the tension of the waist elastic around your waist and they tend to stay in place better.
They don't roll up under your belly like regular shorts
They are more awkward to go to the toilet with, requiring you to either remove half your clothes, or stretch them around a bit.

Shy shorts - basically normal looking shorts with a cycling short liner.

Less comfortable on the bike than proper cycling shorts, but still a lot better than non-cycling specific shorts.
More durable, which is often a good thing when mountain biking
If you are not comfortable wearing lycra in public, or are going to be off the bike for a while during the day, they can be less embarrassing to wear.

Undershorts - like regular shorts, but usually made of a lighter mesh fabric to allow them to be worn under other shorts or trousers.

Allow you to have most of the comfort of bike shorts with any of your regular clothing.

What features to look for?

Now, what are the features that you are looking for in good quality bike shorts:

A high quality chamois - these days this means that the chamois should be "3-D" molded and offer a reasonable degree of padding, but not too much.
Good quality material - look for the fabrics that have 4-way stretch rather than 2-way stretch. they will fit your body more closely.
Leg grippers - good leg grippers at the bottom of the shorts will hold the shorts in place without being excessively tight. Often they will have a "tacky" rubber feel.
Number of panels - the more panels, the more the shorts are tailored to fit your body.
Height at the back - not really applicable for bib shorts, but regular cycling shorts should be long in the back so that they don't expose your back when you are bent over in a cycling position. Some cheaper shorts don't do this.
Compression fabric - a more recent trend, but some cycling shorts are being made with a compression fabric that applies more pressure to your muscles to help them perform better.


Good tires for road riding in winter weather? What are some good tires to install for riding the roads in snow, ice, other winter conditions? Besides letting some pressure out for better traction, what tires should I use?

Different tires for different conditions.

For bare/wet roads I've been real happy with my Continental Grand Prix 4-Season with Vectran tires.

With snow, it depends on the clearance through your brakes...
On a typical road bike with standard brakes, you may not have enough room to add tires with traction. If you have a cyclocross bike or bike with V styled or even disc brakes, you can put on something with a bit of traction for snow and packed snow conditions. I like the Challenge Grifo 700x32c Black/Brown Clincher. On my mountain bike, I love to ride in the snow and use Kenda Nevegal tires.

I tend to not ride in icy conditions, but you can create your own 'studded' tires with zip ties. About every 2 inches cinch up a zip tie around your tire and rim.


Should square taper cranks be greased before installation? There’s a fierce debate over whether the interface between a square taper spindle and crankarm should be lubricated or not. Adding to that, everyone seems to have their own take on the issue. Here’s some opinions I’ve heard thus far:

Perfectly clean and dry. (Use solvent to clean the spindle.)
Coated with a complete layer of grease.
Extremely thin coating of grease. This entails putting some grease on, then wiping it all off again to leave just the thinnest layer of grease remaining.
Oiled

Proponents of installing cranks dry say it’s to stop the spindles from excessively deforming the crankarm. Proponents of lubricated install say it’s to ensure the the crankarm gets smoothly and consistently pressed onto the spindle, and to prevent galling/corrosion. Everything else falls in between these two extremes.
Is there a definite best practice?
I honestly can’t believe this question hasn’t been asked already!

I started getting seriously into bike work circa 2002 and was lucky enough to come across Jobst Brandt's view of the topic around that time. Since then, most of which time I've spent working as a mechanic, I've observed that the Brandtian observations of the mechanical dynamics at hand are wholly correct, but I don't agree with him on what to do about it.
He posted a number of times on rec.bicycles.tech on this subject, material that can be found if you look, but there's an excerpt on sheldonbrown.com that I'll repost here:

My cranks get loose, quite quickly too; over about 10 miles or so from being solid to flopping about in the breeze. Any suggestions?
One or both of the cranks are ruined! Once ridden in the "floppy"
mode, the tapered square bore of the crank has been deformed and can
no longer be secured on a spindle. Install and properly tighten new
cranks on the spindle after greasing the tapered square ends of the
spindle. Proper tightness should be achieved with a torque wrench or
by a skilled hand.
The admonition not to grease the spindle finds life mainly in the
bicycle trade. When I discussed the "dry assembly" rule with crank
manufacturers, I discovered that they had warranty claims from
customers who split cranks. However, cranks cannot be split by
overtightening them. This can be proven by attempting to do so. An
M8x1 bolt is not strong enough to split a major-brand crank.
Failure from "over-tightening" is caused by repeated re-tightening of
properly installed cranks. In use, an aluminum crank squirms on its
taper, and because the retaining bolt prevents it from moving off the
taper, it elbows itself away from the bolt and up the taper ever so
slightly. The resulting loss of preload, after hard riding, can be
detected by how easily the bolt can be turned.
Loss of crank bolt preload is greater on left than right cranks,
because left cranks transmit torque and bending simultaneously while
right cranks transmit these forces separately. The left crank
transmits driving torque through the spindle to the right crank and
chainwheel while the right crank drives the chainwheel directly.
Besides that, the right crank transmits torque to the spindle only
when standing on both pedals. Doing this with the right foot forward
(goofy footed) is the only time the spindle transmits reverse torque.
Mechanics, unaware of why crank bolts lose preload (and commensurate
crank tightening), have re-tightened bolts until cranks split. No
warnings against re-tightening properly installed cranks are evident
although it is here where the warning should be directed rather than
at lubrication.

Because friction plays no role in torque transmission, preload in the
press fit must be great enough to prevent elastic separation between
the crank and spindle under torque and bending. This means that no gap
should open between crank and spindle facets under forceful pedaling.
Crank bore failure occurs when the press fit is loose enough that a
gap opens between spindle and crank. Torque is transmitted by both the
leading and the trailing half of each facet, contact pressure
increasing and decreasing respectively. In the event of lift-off, the
entire force bears only on the leading edge of facets and causes
plastic deformation, causing the bore to take on a "pincushion" shape
(loose crank syndrome). Subsequent tightening of the retaining screw
cannot correct this because neither the retaining bolt nor crank is
strong enough to re-establish the square bore.
The claim that a greased spindle will enlarge the bore of a crank and
ultimately reduce chainwheel clearance is also specious, because the
crank cannot operate in a plastic stress level that would soon split
the crank in use. However, increased engagement depth (hole
enlargement) may occur without lubricant, because installation
friction could ream the hole.
With or without lubricant, in use, cranks will make metal-to-metal
contact with the spindle, causing fretting erosion of the steel
spindle for all but the lightest riders. Lubricating the spindle for
assembly assures a predictable press fit for a given torque. Without
lubrication, the press is unknown, and galling (aluminum transfer to
the steel spindle) may occur during assembly. After substantial use,
spindle facets may show rouge and erosion from aluminum oxide from the
crank, showing that lubricant was displaced.
Crank "dust caps" have the additional duty to retain loose crank
bolts. Because crank bolts lose preload in use, they can become loose
enough to subsequently unscrew and fall out if there is no cap. If
this occurs, loss of the screw will not be noticed until the crank
comes off, after the screw is gone.

In other posts he put forward the theory that Campagnolo was the originator of the dry taper rule in cycling, because they were having issues with their cranks splitting at the taper bore with repeat tightening. Light vintage racing cranks such as old Record are in fact quite prone to this with lubricated spindles and repeat tightening. It is far harder to get such a failure out of any but the very fanciest contemporary square taper cranks. Most are pretty chunky.
In my experience, it is exactly right that square taper cranks squirm on the taper. It is also exactly right that if you grease the taper from the beginning, torque the crank bolts properly, and leave them alone, it will be fine. I've been doing this on my own bikes for about 17 years now with zero issues ever. I use 44 Nm as a generic square taper crank bolt value.
However, where the Brandtian line falls apart is that in practice, mechanics need to be able to rapidly torque check everything on a bike. We do it not necessarily because, as Brandt suggests, we don't understand that cranks squirm, but because poor initial assembly is rampant and we have to be able to correct it in an expedient fashion. That means crank bolts throughout their lives are going to have mechanics repeatedly putting a wrench on and tightening them until they hit full torque. A dry taper getting this treatment tends to reach a bottoming point where it's not going to squirm up the spindle any further, and where re-torquing the bolt won't drive it up the spindle any further either. If the interfaces were more commonly lubricated, splitting the taper would be a more widespread issue.
In some sense the ideal thing would be for mechanics to remove cranks all the time, grease the spindles to help ensure, as Brandt pointed out, the press fit is coming out as expected for a given torque input, and somehow compel the owner to make sure the crank bolts are never tightened again. In reality it's just not practical, and so we're left with the somewhat flawed de facto system of dry tapers as the norm. Brandt is correct that some galling of the mating surfaces can occur without lubrication, but it's rarely a meaningful problem.
Also, the nature of a press fit is that there's no room in there, so there's little if any difference in function between heavy and light lubrication. A thin coating leftover from the factory or applied as a rust inhibitor is pretty close functionally to slathering it with grease.


What is the difference between "front" and "rear" disc brake? When I browse on-line bike shops disc brakes are listed as "front" or "rear" e.g. here. I have never noticed any difference between front and rear brakes - disc or V-brake, hydraulic or mechanic. Except the cable/tube length(but moat brakes are sold without attached cable/oil tube). So what is the difference between a front and rear disc brake, if any?

The length of the cable/hose and the braking lever - Left for front, Right for Rear. There really isn't any real difference. If you change out the cable/hose you can hook either up and they will work the same.

This is generally true for most brakes, the differences generally deal with bolt, spacer, and cable/hose length.


How do I choose a replacement Derailleur? I have a Psycle Werks downhill-bike and the derailleur got bent and cracked I need it to get replaced does anyone know or have any suggestions on where I can get a new one or what I should do?

Let's say that your new derailleur is dependent on the number of gears you have on the back and sometimes brand dependent. SRAM and Shimano, have (they used to have at least) different pull ratios and/or inverted numbers (which is not a problem, only a funny fact), so this are the first thing to check out.

Then as you said you do DH, so you need in my opinion a short, or medium length derailleur; so it doesn't bounce that much and also to have a little more clearance for obstacles.

That said there are some derailleurs that have clutch systems so the cage won't move as you hit bumps and obstacles, for a more consistent pedaling.

If you have the money go for a Shimano Saint, Hone or SLX. Then again if you don't have it, go for a Shimano XT 98. If you have a small ratio transmission in the back (tooth count doesn't differ that much from gear to gear) you can get a away with a derailleur made for road bike, small and light.

PS: You can get your old derailleur straight with the use of two french-wrenches (crescent wrench), one to set the direction to bend and the other to apply force to the first one.

Cheers.


New tubeless setup: losing air through spoke holes It's my first time setting up tubeless. The tyre seems to have seated fine, but I'm losing air through three of the spoke holes when I go much above 20 psi. Details:

new rim, new tyre (new bike in fact)
29" DT Swiss M 1900 Spline - tubeless ready
2.3" Minion DHF - tubeless ready

I've added more sealant (must be getting near 200ml now) and shaken it about, concentrating on the leaking areas; air has stopped leaking but that might be the loss of pressure - down to 10-15 psi I think. Will leave it to sit overnight at the lower pressure and see what happens in the morning when I add air.
But in my limited reading so far I haven't seen this specific problem mentioned. Wondering if I'm wasting my time trying to seal this, and instead have a problem with the rim tape or even a defective rim?
EDIT: just for clarity - it's a tubeless-ready rim, factory taped, which I'd have hoped would rule out any errors of tape selection or technique.

It seems like there is a problem with the rim tape. The tape should seal the spoke holes without milk. Try cleaning the rim and replacing the tape if it is still loosing pressure.


Why don't cyclists wear all-encompassing motorcycle-style helmets? It is possible to get a helmet that covers your entire head and face, and in theory would protect you against more kinds of falls. In particular, Why don't bicyclists wear them, and why do motorcyclists wear them?

I'm not asking whether helmets are a good idea in general. (Please try to answer this with complete answers, rather than the single-point style of the currently running helmet thread.)

Some bicyclists do wear full-face helmets; in particular, downhill mountain bikers and BMXers will frequently wear full-face helmets, as the chance of a crash causing you to land on your face is greater.

The problem with full-face helmets is that they're hotter; your head is great for getting rid of excess heat, and the full-face helmet helps trap more of that in. Motorcyclists aren't pedaling furiously, and don't need to lose as much heat; heat management is essential for bicycling.

Furthermore, motorcycle accidents tend to happen at higher speeds. On a bike, you're pretty unlikely to wipe out at 60 MPH, while on a motorcycle, it's all too possible. Between the lower risk on a bike, the heat issues, and the extra cost of full-face helmets, for most people it's not worth it to wear the full face helmet on their bicycle.

Any safety feature is a trade-off, between the costs of implementing the feature and the harm or damage that it prevents. When the cost of implementing the feature exceed the expected value of the feature in harm reduction (taking into account the likelihood of the particular form of accident happening, and how severe the damage is), then it doesn't make sense to use that feature. People all assign different values to certain types of harm or damage, and also have different risks based on how they ride and what their environment is like. For some people, wearing a full-face helmet may be worth the extra expense and heat, but most people don't find it's worth that trade-off.

Sadly, for many of these decisions, we don't have enough information; there isn't very much conclusive real-world data on the efficacy of bike helmets, let alone different types of bike helmets.


Bottle Cage Mount on Carbon Bike I have fitted a frame bag to my carbon bike frame so I have lost my water bottle mounts.  As it's carbon frame I'm aware that you can't mount clamps on the carbon like you would for steel.  However, I have come across the Top Peak Versamount, do you think this will be ok?
All help and views appreciated.
Mike
https://www.topeak.com/us/en/products/accessories/1093-versamount,

There are also seat-post mounted bottle cages.
See Profile Design Aqua Rack ii Dual Water Bottle Cage (Black) (Seatpost Mount) for an example:

That one even has places for screw-in CO2 cartridges.