how much a good bike can cost? I bought a new bike few months ago and it cost me 375€, which for the most people it is a lot for a bike, but it is really cheap in bike world. I already have some problems with my seat (and seatpost). I changed it but I still getting problems. A good quality seat even for casual riding can easily get up to 100€ or more. The same goes for almost every component. That made me ask: How much you must spend in order to have decent bike?

In a sense decent enough to not have to change any component (which at the end makes your bike more expensive) and have a good experience on it.

Is there a minimum price or some frontier like: starting from this price you are getting real bikes?

As other people said this is difficult to answer within the subjective field of "decent" "good quality", etc.

There are two main components to the price of bike(part)s:

Weight (lighter is generaly more expensize)
Quality (which is a catch-all phrase for durability, the technical sophistication needed to make a part, complexity of the part, extra effort made to enhance comfort, etc. anything other than lowering weight.)

Increasing price will get you a bit of either, or mostly the first or the second, depending on what the supplier of your bike considers important. From your question I think that you want to focus on quality more than weight, so don't go spending on carbon, titanium, and other exotic stuff. This rules out most bikes above about $2000 - $3000, so there is your upper limit.
I'm not sure what you expect from your bike in terms of features, and when and how you'd expect to use it.

You can get a pretty decent quality no-frills single speed bike for the price you paid for your bike, but it will be bare. No fenders, lights, no chainguard, no luggage rack, coaster brake.

If need more than that the price starts to increase, and all I can say is: "it depends" but you'll stay within the upper limit I gave above even if your definition of "decent" can compete with my "very good" as long as you mostly ignore weight.

To give you one last pricepoint: For a decent daily use commuter bike (15k one way, mostly flat, wet/cold winters, full time riding) I need fenders, a rear luggage rack, a full range of gears, lights, leak-proof tires, low maintenance- high durability components, a comfortable saddle, mountainbike handlebars with bar ends, and very good and dependable brakes. I would expect to pay about $800 $1000 for this bike. I would expect to ride this bike for 5+ years, only replacing brake pads, tires, chain, chainrings and cogs, and maybe the occasional brake- or shifter cable, or spoke.


Can I use brake pads designed for linear-pull brakes on my side-pull cantilever brakes? I have side-pull (dual-pivot) cantilever brakes. My friend gave me brake pads that are 'for all linear-pull brakes'.

Can I use brake pads that are advertised for linear-pull brake systems with my side-pull cantilever brake system?

Linear pull brake blocks come with a stack of washers designed to provide toe-in (a gap at the back of the brake block to reduce squeal) and different thickness washers to get the cantilever arm vertical to the rim.

Side pull brakes have none of that, just a simple washer for the outside surface of the brake arm.

Put the linear pull brakes in to your side-pull brakes with the whole washer stack on the outside, tighten it up and you should be good to go. You can experiment with putting the extra washers in for that toe in or omit the concave/convex toe-in washers entirely. But do use at least one washer on the outside.

Just make sure that when you have tightened them up that you cannot twist the brake block around with your hand and that the brake blocks meet parallel with the rim neither touching the tyre or falling off the bottom of the rim. Test before you go down any big hills.

Hope that helps!


European pedal thread size Can North American pedals with a 9/16” x 20 TPI thread be used on a European rental bike or is there a metric requirement?

Apart from special cases (IIRC one-piece cranks, really old french bicycles), the standard you mentioned is the universal pedal thread standard. So unless you specifically rent a bike with obsolete pedal standards, no technical reason will prevent you from using American pedals.
(You should obviously make sure that the owner of the bike is fine with changing the pedals!)


Difference between various Campagnolo rear derailleur tension adjustment screws The rear derailleur tension adjustment screw on my 1997 or 98 Veloce 9speed bike is broken. The correct replacement part seems to be the Rd-At115 screw.

However, there seem to be at least two more such screws with part numbers RD-DA004 and Rd-Sr014.

Here's my question: What is the technical difference between these three screws (that seem to do the same thing)? Diameter (outer? inner?), steepness of the tread? Something else I've overlooked?

Also, if they are indeed different, what would be the reason to change the specification of this rather trivial part?

RD-AT115 has a screw thread pitch of 0.8 mm, the standard size for a 5mm metric thread. The later RD-DA004 and related rear adjusters, including RD-SR014 all have a thread pitch of 0.5 mm, standard size for "M5 fine".

The older, typically 8 and 9s RDs did not need such a fine adjustment to cable tension, simply because the precision required of the system as a whole was not as high and the rear derailleur return spring has, over the years, been gradually reduced in strength - in fact there are two slightly different strengths in use according to the derailleur model and year, and have been since 2002.

This has meant that the pitch of the screw and so the amount of variation in tension per full turn that the screw induces, has needed to be changed.

There are also materials differences that affect the overall price of the derailleur but not the function - so some adjusters are made of a simple Magnesium Zinc Aluminium alloy, others are made in polished stainless steel.


Chain "jumping" every few crank rotations After a few pedal-strokes the rear derailleur completely gives out and the pedals drop to catch up.
After much googling it says the most common thing is rear derailleur adjustment is needed, so I have done that which was pretty straight forward but the problem persists.
Video: https://photos.app.goo.gl/XnrwqW4WatoFc7ee8
Excuse how shaky it is, the bike is hanging on a washing line...
I followed this guide when adjusting:

After hours of thinking it was indexing, I slowed down and watched the chain only to learn that it was a single stiff link in the chain.
Thanks to @Warren Burton who helped me get there.


What are the values of Average Power Phase in the .FIT file? I'm trying to understand the Average Power Phase values inside the .fit file. There are four of them, for example  avg_left_power_phase: (355.7812555590821, 199.68750312011724, 202.50000316406255, 97.0312515161133) for certain lap. I assume that the first is the start of the peak phase, the last is the end. But what about those two remaining? Similar four values are for peak power phase, for example avg_left_power_phase_peak: (59.06250092285158, 125.15625195556643, 66.09375103271486, 91.40625142822267).

I looked to the fit file specs, but there is nothing.

UPDATE - I'm using Favero Asioma Duo power meter pedals. They have implemented all Garmin PCD metrics, except the cleat offset.

Looking at the ANT+ Power profile from this page.  'Power phase' and 'power phase peak' are different.
'Power phase' is where the positive contribution starts and ends.
'Power phase peak' are the start and end of peak power is being produced.  Peak power is potentially a configurable amount but defaults to 50% of the total power.
Angles are measured clockwise from vertical.

The 4 number you have are Start angle, End angle, Arc length and Center.  This is from looking at the FIT SDK.  The arc length and center look sensible given your numbers.


What is the proper way to cut brake cable housing? Unlike this question, mine is about cutting the housing.

All I've used with random success has been a pair of pliers with a good sharp inner cutting tool. Is there a better way, or a proper tool for the job? I am trying to avoid pulling the inner wire cable and fraying them. Thanks

There is a proper tool that is probably the best solution. They cut so that it does not smash the ends or the metal inside of the housing. Many also have an awl in order to help reform the end if any smashing or deformation does occur.

Most look something like this:

It is also possible with a brand new razor blade but the proper plier like tool makes it a lot more quick and easy.

For hydraulic hoses they differ slightly because of the difference in hose material, there are two type of hydraulic hose cutters, one that looks a bit like a pill cutter such as this:

Or the handheld variety that function quite similar that looks like this:


Creaking sounds from the saddle tube? I've started to hear creaking/clicking sounds from the saddle tube. Is the frame giving up?
I could look for a longer saddle post, if that would relieve some of the strain on this part of the frame, but I'm not sure what length to get.

I've measured the outer diameter of the post to be approx. 27mm -- but what is the proper name/size for this dimension?

It's a 58 (cm/in?) aluminum frame with 28" wheels, roughly 10 years old. I've got the saddle fairly high, but I'm a tall guy (192cm, 95kg) so it needs to be like this. When I put a heel on the lowest pedal, my leg is practically straight. Perhaps I should buy a bike with a bigger frame, if that exists, but I am hoping to avoid significant expenses. The bike is otherwise in good condition.

Updates to comments:

Saddle post is 1cm lower than its "max" mark. Close, but okay - perhaps too close, given my weight? (95kg)
frame and post is metal, presumably both aluminum.
Creaking goes away when standing. That's why I suspect this area.
Saddle clamp and rails seem good on visual inspection.

Often, dirt gets between the seat post and seat tube. Remove the seat post. Clean the post. Clean inside the seat tube. Grease the post and re-install. Hopefully the noise will be gone. You say the post is close to the max mark. For a little added safety, longer seat posts are available.


Which Tern is suitable for a beginner commuter? I live in Dublin, CA. I have a 5 miles commute each way from my house to my office. There will an upward climb on the way back home.

Google map with biking route

I am a beginner when it comes to biking. I haven't biked for years since I was a kid. Previously I lived in a city where transport is very convenient so there's no need for a bike commute. I just relocated to Dublin, CA for studies and work, it's a suburban area with swathes of land so I have to bike to get from point A to point B. I have to commute to Stanford via trains/bus as well, so it's helpful to have a bike that can fold.

I'm looking into buying a Tern. Brompton is too expensive; I don't know how to appreciate the higher-end folding bikes since I haven't rode a bike in years. I thought I'd start off small with an affordable but sturdy foldie like Tern.

I'm looking into two options: Tern Link Uno or Tern Link D8. Link Uno is cheaper as it is single-speed, and it looks aesthetically pleasing as well. I'm not sure whether I can handle multiple gears since as I said, I haven't cycled in a long long time. However, judging from the bike path, as you can see on the Google Map, there will be an uphill climb near to the end of my journey home. I'm not sure such a climb is considered steep; you should know that I have no prior experience biking in such a suburban place (I lived in a city all my life). Hence I seek your expertise on this matter. Will that warrant for a Link D8 instead? It has multiple gears so that I guess it can take care of the uphill ascent.

Hills aside, which bike do you think is more suitable for a complete beginner? I'm 6'1" tall, 187 lbs, in generally good shape.

If you can afford gears, buy them. Having an uphill section at the end you will want to shift up in order to make it easier. Going the oposite direction you will also like the ability to go to a smaller gear to get a little more speed downhill. Looking at the pictures linked, it seemed the that the single speed have a rather small rear cog compared to the geared bike.

If you can't handle shifting rapidly you can always leave it your geared bike in one speed, but at least you'll have the option of chaing it for those morning where you feel weaker or have less energy.


My rear cogs (not sure on the correct name) turn at force even when stationary. I got a new bike and was riding it home and every so often it felt like the chain wasn't there and my feet pedal a little faster and then all of a sudden it would go back to normal. I looked in to this when I got home and discovered that when I have both brakes on and try and pedal, with some tension the pedals would turn a little bit with the cogs at the front and rear.

Not sure if this is a new thing they put on bikes as I have not had one in a few years so just trying to figure out if it is a problem or not.

It's not normal to be able to move the pedals forward without moving the wheel. There must be something wrong with the ratcheting mechanism on the rear wheel.

On a brand new, original bike from a reputable brand, this is simply unacceptable, a defective part and should be covered by the warranty.

However, on low end bikes, a warranty may be non-existent and for the price level, it may not even worth the hassle.

A note on terminology:

The ratcheting mechanism may be built into the hub, then it is called a freehub and the cogs are a one piece unit. If the ratchet is built into the cogs, then they are called a freewheel. Only the rear gears are called "cogs". The front gears are called chainrings, and together with the arms that hold the pedals -the cranks- they are called the crankset.

I know from experience that some low end freewheels have cogs press-fit into a central piece. Sometimes they are made of soft metals so the joint can slip under the force of the pedals. If this is the case, then you can upgrade the freewheel. Shimano freewheels are affordable (in most places). Changing a freewheel is not complicated but requires a special tool to unscrew the freewheel from the hub.

Make sure the slippage occurs on the freewheel, because, similarly, a low end, poorly built crankset may suffer from the same kind of problem. (pedals/cranks slipping respect to the chainring(s)).

A freehub is very less likely to suffer from this, at least on reputable brands, but with low end manufacturers you can never know...

Another, very unlikely possibility is that the mechanism is clogged with dirt or too thick grease. Since the bike is new, dirt is unlikely. If this where the case, the solution is to have a qualified mechanic take the mechanism apart, clean and reassembly while aplying fresh grease

Another possibility is that even though you just bought the bike, it was assembled a long time ago, (several years) so part of the solvents in the grease evaporated, leaving a thick, gooey paste that may be sticky enough to keep the internal pawls to engage the saw tooth on the body of the freewheel/freehub. However, this is very unlikely on a reputable brand bike, it may happen on low and very low end bikes (which use cheap lubricants). When this happens, the bike doesn't make the tic-tic-tic-... sound when coasting, and the pedalling action feels "spongy". If this happens to the freewheel, it may be also the case with the hubs, then the wheels won't spin freely and the bike feels harder to pedal than it should. If this where the case, the solution is the same as previous case: take apart, clean, apply fresh lube and reassembly.

On bikes with freewheel, this part is screwed into the hub, Sometimes it is not tightened when assembled so the pedaling action tightens it. Nonetheless this should happen only once and the freewheel won't perform a full rotation respect to the wheel.


Fixie chain stuck between cog and hub I had my chain jump off on my fixed gear when I hit a pothole, and it's gotten completely wedged between the cog and the flange of the hub. I've removed the lockring but can't get a chain whip around the cog to loosen it and the chain is completely wedged tight in there – no amount of force I've been able to generate has budged it at all. Any suggestions for how I might get the cog loose to free the chain?

Yeah, I managed to do this one one of my bikes once. There was no way I could brute force the chain from between the cassette and the spokes.

My suggestion would be to use a vice, or do you have one of those Workmate things?

The first thing I'd do is to break the chain and get the whole "wheel and chain" mess away from the frame. It just gives you more room to work. Then, I'd clamp the teeth of the cog in the vice (as I say, I've had good results with my Workmate). Then you undo the lockring, which admittedly can be fiddly. If it has been on a while it will be tight, as you have discovered, and you might need to use a mallet to coax it loose. (I have tried chain whips in the past too, but never even bother nowadays, a vice is far more efficient.)

If you don't have any way of clamping the cog, the only other suggestion is to take the wheel to a shop, who will use their vice to loosen it. With the right tools, it is really only a 30-second job so you may be able to sweettalk them into doing it for free.

Lastly, you should probably spend some time thinking about how this happened. Could be you just got a jump because the chain was loose, but it is probably worth checking your chainline to satisfy yourself that everything is ok.

You might also want to check your spokes for any damage from the chain.....better to replace them now, while you've taken things apart, than have them break later.


How to identify galvanised and stainless cables? Recently I bought some stainless steel gear and brake cables. I have 3 packets of cables from 3 Ebay shops. How do I identify if they are genuine stainless steel cables or if I've been ripped off?

Using a magnet - 2 packets stick to the magnet, galvanised cables also stick to magnet with similar force.

Can I use anything from my kitchen to test the cables. Something like vinegar, lemon juice, cola or even bleach. I could rub them with something abrasive and then leave the cables in salty water for a period of time.

Any ideas?

If you really want to test, you can cut a small piece of cable on each and put them in bleach.

Stainless steel would corrode with rust forming evenly.
Galvanised steel would mostly corrode on the cross-section of the cable (where the cut is made). The (correctly) galvanised area will likely to be white.

A little note:

For your time testing, just buy a better cable from a reliable shop next time
The reaction may produce harmful gas, don't put them indoor or unventilated area


How to care for a steel frame? I'm considering getting a steel frame to upgrade from my aluminum xc bike. As it will be my first steel frame I'd like to understand if there is more after ride care required than my current bike. Usually after rides now I generally just wipe off the staunchions and wash only on the weekends. If I had a steel frame that had been rust proofed would I have to do much different?

I ride a steel frame fixed gear nearly daily in tropical conditions, and near the sea. It really puts the frame through its paces. As far as my experience goes, there's nothing that can be totally rust proofed.

Using any sort of metal lubricant on the inside of the tubes will certainly help prolong the life of your steel frame. Some may insist on using the tried and proven J.P. Weigle's Frame Saver. The seat tube and bottom bracket are where rust forms the quickest, as moisture gets to them easily. Always remember to lube them, especially after wet rides, as the lubricants can be easily washed away by tire spray and water seeping between the crevices.

Apart from the inside of the frame, do note that the quality of the paint/clear coat has a great impact on how "rust-proof" the frame is. If the paintwork is chipped, which can easily happen if you ride often, there's a chance that the frame will start rusting from the chip.

Do care for your steel frame as you did with the aluminum frame. It may be prone to more visible wear and tear, but as long as you take care of it, it's bound to last a lifetime. Steel frames are durable and great to ride on. It's worth the time to take care and maintain them.

As an extra precaution, I remove almost all the components, except for the crankset/bottom bracket, and give them a thorough wipe down and re-lube once every two months.


Understanding e-bike power/torque In the UK e-bikes are currently limited to a maximum of 250W assistance if you wish to use them on public roads. However, it seems that the motors do vary in terms of the available torque - from around 40Nm on some of the lighter e-bikes to 80Nm on those that are described as more "powerful".

Now clearly they are not more powerful as they putting out the same 250W max, but what I don't quite understand is what difference that extra torque makes.

I'm used to measuring my power output in watts and thought there was a linear relationship between power and speed, so I don't quite understand where torque comes into it, and what difference this makes in practise.

Very quick answer - the torque numbers that are quoted are maximum torque values which do not correspond to maximum power.

Power = torque × rotational speed, so, at slow speeds the motor unit can provide more torque (and hence more acceleration) while staying within the power limit.

A bit more:

There a decent page here on the characteristics of DC motors. The essential takeaway is that DC motors can provide less torque the faster they spin.

Re:

  [I] thought there was a linear relationship between power and speed.

The power at constant velocity is that needed to balance the forces resisting forward motion - rolling resistance and aerodynamic drag for a bicycle or other vehicle. Those resistance forces generally increase with the cube of velocity.

If you want to play with the numbers there is an interactive calculator here.


The back brake on my bike is not functional, is it illegal for me to cycle in the United Kingdom? I live in the UK and cycle to and from work. I recently noticed that the back brake on the bike is not functioning. Is it legal for me to be cycling on the road (the front brake works fine but it is a bit difficult to stop at, for example, pedestrian crossings)

Yes, technically.

Most sorts of cycle are required to have at least two efficient braking systems, by which the front wheel (or wheels) can be braked independently of the rear wheel (or wheels).

The likelihood of you receiving a ticket, fine, or other punishment is infinitesimal. It could happen, but it almost certainly will not.

Practically, the front brake is much stronger than the rear brake. Most experienced road cyclists almost exclusively use the front brake. Why is it "a bit difficult to stop" in some circumstances?

That said, you should absolutely have it fixed. Having redundant brakes is important for your personal safety. Brakes and brake cables can fail.


Is it better to get a commuter bike with a front suspension or without one? Is a commuter/city bike without front suspension comfortable?

Commuter or city bikes are designed for paved surfaces. A suspension fork on such a bike is not going to add much comfort, except perhaps when riding over potholes or kerbs, which are avoidable.

Suspension forks add weight, which brings a different type of discomfort as you have to exert effort to move that weight around.

This gets worse the more inexpensive the bicycle is. Low end suspension forks are heavy and have poor performance.


Who grants ebike-ready certifications for tires (aside from manufacturers)? I have tires with (among others) official-looking decals implying (with varying wording and symbology) that they are "ebike-ready" (EBR) and rated to speeds of either 25 km/h or 50 km/h. I recently wondered, "who certifies these?" I.e., is there an independent certification authority (e.g., UL or one of the many organic food certifiers), or can any bike-tire manufacturer just slap this on the sidewall {at will, with no external verification}?

So I did some websearch and ... got surprisingly little. I did find one good Medium post about ebike certifications generally, but it has nothing about tires other than a mention of ISO 5775, which (IIUC--which I might not!) only regulates tire and rim sizing.

Edit: Thanks to @Affe, I eventually found something that's almost, just tantalizingly close to what I want. The Dutch standardization org NEN publishes (though only behind a paywall) a standard (NTA 8776) for helmets for "speed pedelecs" (which AFAICS == ebikes). More importantly, they publish this table of NTA-8776-certified helmets (archived here) which not only includes the make and model of each NTA-8776-certified helmet, but also the Certifying Body ... which appear to be independent. (FWIW, the values in field=Certifying Body are in each current case one of

CSI
Telefication
Vias Institute

). So I'd be very interested to see similar data regarding standards, compliant products (per the standards setter--i.e., not the maker/vendor), and certifying bodies for {ebike, speed pedelec} tires. (FWIW, I searched for this on the NEN website but found nothing.) Until then, my guess is there are standards for ebike tires, but the tire maker self-certifies to the standard.

For the name brand tires that are certified 50km/hr there is an actual international standard that the tire manufacturer is certifying against.  These are tires that are built to the UNECE motor vehicle tire specifications instead of bicycle specifications.

For example all Schwalbe tires (at least for 2019 product line) that bear their  "Energizer" badge printed on the sidewall are certified to that standard.

For tires that are recommended for 25km/hr it appears to be purely manufacturer's recommendation.


Oil or grease leaking, I think, from hub Black oil or grease is leaking from my brand new src3 hub. Is this normal? I thought internal geared hubs like this are supposed to be sealed.

This the bottom of the hub with the bike upside down. I wiped away a bit of the oil because it looked like it was about to drip.

Definitely not normal. I'd take it back to the dealer where you bought it. If you bought it online, I'd contact the reseller and let them know you're taking it to a local bike shop to get fixed - and that you'd like to be reimbursed.


10-speed shifters work with one wheelset but not with another EDIT: Answer at the bottom

Hi, all

I have an issue with the shifting for my bike, a Giant TCR C1. It seems like the shifters for the Giant TCR work only with one 10s wheelset but not with another 10s wheelset.

I have 2 bikes: a Giant TCR C1 & a Cannondale

Giant TCR C1:

Dura-Ace 10s Shifters

Ultegra 11s Crankset

Ultegra 10s Chain

Dura-Ace 7800 Rear Derailleur

Cannondale CAAD9 R5:

Shimano 105 10s Shifters

Shimano 105 10s Crankset

Shimano 105 Chain

Ultegra 10s Rear Derailleur

I have 2 wheelsets: an Ultegra wheelset for my Giant TCR and a Shimano wheelset for my Cannondale. I'll be referring to the latter wheelset as my Cannondale wheelset.

When I put the Cannondale wheelset on my Cannondale, the shifting works fine. Same for when I put in the Ultegra wheelset. I don't have to adjust the barrel adjuster to adjust the position of the chain.

When I put the Cannondale wheelset on my Giant TCR, the shifting works fine also, albeit a bit more slowly on the descent from the biggest cog down to the small cog. However, when I put the Ultegra wheelset in, the shifting doesn't work properly. I have to adjust the barrel adjuster to align the chain with the cassette, and even then the shifting isn't smooth. It goes up fine but doesn't come down smoothly. It gets stuck in the biggest cog until I shift twice; then, it jumps the second-biggest cog and lands on the third-biggest. I adjust the barrel adjuster so that it descends properly, but then it has problems with shifting upwards, getting stuck on the smallest cog until I shift twice and then it goes up to the second cog.

I had initially thought it was an issue with the shifters, 11s crankset, rear derailleur, or possibly the rear derailleur cable, on my Giant TCR. However, the shifting works fine when I have the 10s Cannondale wheelset on the Giant TCR, so those are not it.

The Ultegra wheelset had originally had on it an 11-speed cassette, which I've swapped out for a 10-speed cassette. I had also initially thought it was an issue with the cassette, but the shifting works fine on my Cannondale when I put on the Ultegra wheelset with the 10-speed cassette, so I don't think it's an issue with the cassette.

Does anybody have an idea on why this is happening?

Solution

It turns out that the issues were with the rear derailleur cable and the rear derailleur. The cable was bent in two places and the derailleur was either incompatible with the brifters or not fully functional. I've replaced the rear derailleur cable and swapped the Dura-Ace 7800 derailleur out for a Dura-Ace 7900 derailleur and the shifting has started working smoothly.

It's very likely that an 11 to 10 speed cassette spacer was used on the 11spd wheel that's not exactly the Shimano-specified 1.85mm thickness.

There's some range in what thickness of spacer will physically do the job. For example, people are always using 1.8mm Mavic cassette spacers for Shimano for the purpose, which works fine as long as you're not swapping wheels. But the 11 speed Shimano freehub was designed to have a 1.85mm be the size to create interchangeability with 10 speed native hubs.

If for some reason the hubs locate the cassettes differently even with the correct spacer, that would be surprising between two Shimano road hubs, but by the same token you could potentially use spacer tricks to compensate.

Once the cassettes are located right, chain/cassette wear and is worth looking at next. Wear can have enough of an influence on shifting ability to cause these problems. It's possible but not likely for it to be the decisive factor.


How to add rear rack to a full suspension bike? I'd like to carry 20 - 40 pounds or so in panniers on my rear rack.
I've carried that much on my hard tail so it's not a problem for the biking itself.

The cantilevered rack style that is supported only on the seatpost is a non starter. I have a carbon fiber seat post. It can't hold more than 10 pounds (even that worries me)

I recommend against doing this. You will be dramatically increasing your unsprung mass, which will play hell with your suspension's dynamics. You might want to consider a trailer instead, or see if you can carry the load in a frame bag and/or seat bag.


Do I need a chain guide or bash guard to convert to a single chain ring? I want to convert an old 12-speed into a 1x6 for urban commuting. I'm hoping to keep one of the existing chain rings at 42T and use washers on the chainring bolts or replace them with single speed bolts. When I remove the front derailleur, do I need to replace it with a chain guide? Do I also need a bashguard? Or is that more for downhill mtb conversions?

I agree with Batman.  You can disconnect your front shifter, and use the indexing screws to position the front derailleur to act as a chain guide, and you're good to go.

If you're not interested in doing that, I would recommend paying attention to Emyr's advice--chainrings intended to be used with a shifter have "ramps" on the gear teeth to facilitate shifting.  If you're not using a derailleur, these can make your chain drop, which is bad.  You might want to get a singlespeed-specific front chainring, they're not expensive.

But, if you keep your derailleur as a chain guide, you'll be fine.


Presta Valve Pin + Core Problem My rear tire Presta valve began giving me some problems this morning. I noticed that the top screw (typically unscrew/screw this to inflate/deflate) was screwed too tightly to the valve pin thread and subsequently to the core. With a pair of pliers I was able to get the screw off but with it came the thread from inside the valve. I know how to screw the core back into the tube thread, but can't figure how to get the valve thread to attach/stay inside the core so that I can put it all back together and inflate the tire?

Have attached a picture showing the tire stem, the vale core, and pin thread/screw so you can understand how things have come apart.

Any thoughts on how to get the thread back together with the valve core?

The brass rod (I believe its technical name is the "plunger rod") is broken. You can probably find the lower part hanging out in the tube somewhere. Getting it out may be tricky, but you should probably do so before replacing the core.


Why is low sprocket minimum 28t for a Shimano 105-GS? I have a Shimano 105 R7000 GS (medium cage) rear derailleur and would like to mount a 12-25 cassette. According to its specs, this should not be possible.

I am just wondering: why not? A GS-cage will manage a 25t sprocket fine in many cassette combinations and in reality go as low as 11t. I understand, there is a problem in the other direction and a max on how many teeth it can handle on the highest sprocket.

Would anyone know, why a GS derailleur cannot handle a 12-25 cassette?

Thanks
Morten

The key aspect of the GS cage is the length of the cage. The other key aspect of   derailleurs is the geometry of the parallelogram.

Because the design has been adapted to suit more modern gearing with larger max sprockets, it moves downwards at a steeper angle, with room to accommodate the larger cogs. Therefore if a tighter range cassette is fitted, the guide pulley is now further away from the largest cassette than older GS derailleurs on the same cassette.

This is going to reduce the accuracy of the shifting a little if you can't move the guide pulley up enough using the b-tension screw. In practice of course, Shimano are famously conservative and breaching the spec might not give any issues. The 12-28 cassette is guaranteed to work, the 12-25 is not.


wheel bearing pre load what is the average amount of pre load supposed to be on the front and rear wheels?? mountain bike. i know that if you leave just enough to barely feel movement in the wheel, then tighten wheel, seems like i'm constantly having to re adjust. if i put any load on it just past the no play area, it feels kinda ruff...but when i squeeze both ends manually like i'm installing it, it gets smooth...is the rufness correct before preload after tightening wheel?

Bearing adjustment is part science and part art. It is based on a sense of feel from trial and error. It should feel smooth when spun, with the least amount of play. If it feels rough it is too tight or dirty. I had the most difficulty with tightening the jam nut after I made the adjustment. It seemed that the cone always got too tight while I was locking everything in place. You may find it easier to have a helper hold a wrench on one side while you hold the other cone and tighten the jam nut.


Hybrid bike inner tube size The following images shows the tyre sizes of my hybrid bike. I need to buy an inner tube with presta valve. I can't seem to figure out which size I should buy though. Can someone please point me to the right tube size for my bike?

Your tire size is 700x38, meaning the overall width of the tire is 38 mm. Inner tubes are sold in ranges of sizes rather than for specific widths.

eg 700x23-25 - means this is suitable for 23 to 25 mm;
700x28-32 - suitable for 28 to 32 mm;
700x35-42 - suitable for 35 to 42 mm;
and so on.
So you need to find a tube has your tire width (38 mm) that falls within the range that's on the packaging of the tube you're looking at. And make sure that it is with a Presta valve rather than Schrader.

Edit: just to be clear, the above ranges are just examples. Different manufacturers may have slightly different ranges.


How do I remove old hockey tape from drop bars I used hockey tape on the drop bars for my bike and I need to remove it to replace the brake levers. Over time, the tape has become melted/fused together, and I used lots of layers for extra cushioning, and I can't just peel it off. Are there any tips or tricks for removing it that don't require a Delorean to undo my bad decision to use hockey tape in the first place.

A razor blade/knife/x-acto knife should cut it. Hockey shops have special knifes for cutting through hockey tape if you want a specialized device. This shouldn't be a problem for non-carbon bars though, if you're careful.

The residue can be removed with rubbing alcohol or soapy water or mineral spirits (again, for carbon, I'm not sure what you'd do).


Sigma bc 1609 kmh flashing but not counting I've just presented a new Sigma BC 1609 (wireless), assembled, put the sensor on the fork and a magnet on a spike, set the wheel size, looks fine.
But the speedometer does not work - it is just flashing?
Any hints?

Thank you.

update
replied the question

update After watching the installation video on the Sigma web-site, understood that the gap was too big between sensor and the magnet. So the sensor shouldn't parallel to the wheel, but pointing towards it -


What does this barrel adjuster do on the rear derailleur (SRAM Apex 1)? On this SRAM Apex 1 derailleur, what does this barrel adjuster do?

What happens if I turn it clockwise/anti-clockwise?

It lengthens or shortens the housing length to adjust the lateral position of the derailleur cage. It's used to adjust derailleur 'indexing' so that the chain sits properly on the cassette sprockets.

Mountain bike shifter units have barrel adjusters, road bikes use this one as well as having frame mounted or 'in-line' adjusters some where on the housing run.

This video from park Tool Company has a good visualization of how it works:


clincher wheel lifespan What is the typical lifespan of a set of clincher wheel rims? I know there are a lot of variables, but roughly? To be specific I am looking at a set of Mavic Open Pro rims with 2000 miles on them. I don't have them in person so I cannot judge the wear of the break surface.

Short answer: there is no typical lifespan.

The only way to know when your rims have exceeded their lifespan is by inspection.

Why? The wear on a rim is going to be due to a variety of sources: the miles, abrasion of the braking surfaces, corrosion, crashes, plus more.

Ignoring carbon, all respectable rims are made of aluminum, which does have a finite life, as aluminum does not have a fatigue limit. However, that fatigue limit could be reached at 1000 or 1 million miles, depending on the cross sectional shape of the rim and how heavy its loaded. Only way to know, is to inspect.

As for the brake track and corrosion, riding around exclusively with clear skies in the summertime of California will have a much different impact on the rims and spokes than someone riding year round in Minnesota in the sand. Getting sand and other gunk caught in the brake pads can wear the tracks significantly more than in clean situations. Road salt and other substances can corrode the spokes and cause wheel failure through that.

In short, 2000 miles is not a lot of miles except for perhaps super-niche-crazy-expensive-pro-racer wheels that are only used for a few rides before being discarded. For the rest of us, 2000 is barely a drop in the bucket of what a good wheelset will be capable of delivering provided it is well cared for.


Highest gear "jumps" under load When I'm in the highest (smallest) gear and pedaling hard, it sometimes "jumps".  I'm not sure if that's the right word, but I feel a bump in my feet for a moment and then I continue pedaling.  It feels like I'm shifting gears, but I'm not.  I've spent some time today adjusting the rear derailleur, and all the other gears are good.  Could this be caused by a worn out sprocket?  I don't use this gear all that often, so I'm not sure why it would wear out faster than the others.  Pedaling moderately is fine, this only happens when I push hard.

This is a 9-speed Shimano Sora.

It wears fast because there are fewer teeth in contact with the chain, but that might not be the cause. Here are some other possibilities:

A stiff chain link is most noticeable with a small sprocket. It's also more annoying if not more noticeable when under load. This tends to cause an even rhythm under steady pedalling, about one every 3 pedal strokes depending on your chain length and chain ring.
The high limit screw needs a tweak for some reason and the chain is trying to change gear. Even the chain tension is a possibility.
The derailleur has taken a slight knock and isn't quite straight.

The first two of these are best checked on a stand, turning the pedals by hand and watching the rear mech.


Mixing different front and rear tires My used bike came with different front and rear tires. It appears to have some kind of Kenda commuter tire in the front, and Continental Country Ride in the rear. They are both the same size (700x28).

Is this perfectly acceptable or should a bike always have matching models (and/or size)?

My main concerns from mismatching tires:

Grip thresholds may be inconsistent
Ride comfort?
Wear rates (but rears seem to wear faster anyway)

It's perfectly okay to run different sizes, brands, and types of tires on the front and rear.  As you note, rears will wear faster due to carrying more of the load.  The grip threshold is largely irrelevant, since the front and rear will be exposed to different forces and grip requirements.

The main concern is keeping within the range of a single tube size if possible, since otherwise you'd need to have twice the spares on hand.

At the extreme end, there are 69er and 96er mountain bikes that mix and match 29" (622) and 26" (559) wheels on the same bike as well as Terry women's bikes with 24" (520) front wheels and 700c (622) rear.  By necessity those run very different tires front and rear.


How to improve braking with hands on hoods? I have gravel bike for around 3 months now with mechanical disc brakes and one thing I have problems with is braking. When I ride on drops (which I do rarely) I can brake well -- I pull the brake lever by its bottom end so I can even lock the wheel.

However with hands on hoods I cannot reach the far end of the lever so I have two fingers close to rotation axis of the lever. As the effect I can pull the lever slightly but not to such degree as riding on drops -- as the effect I am slowing down but not really stopping, I cannot execute emergency stop for example.

Which of course worries me. So is there some trick I didn't figure out? Or there some levers with different shape which help braking on hoods?

Braking is always stronger from the drops than the hoods, as you noted only your lower fingers have mechanical advantage when braking from the hoods, when braking from the drops you have much better mechanical advantage for all your fingers.

That said, when properly set up, you should have no problems locking up both wheels on gravel from the hoods. You should also have no problem locking up the rear on asphalt.

Ergonomics

There are a lot of factors that can affect brake effectiveness, how you set up your handlebar (ergonomics) can be one major component.  These include:

Brake hood position: if the hoods are angled down, or the brake hoods and bars are angled down, it will be harder to brake effectively from the hoods. You will however be able to brake effectively from the drops.
Handle bar reach: If the reach is set too far it can make braking difficult to get a firm grasp on your brakes from either the hood or drop position.
Bar height - If your handle bars are too low you may also find it hard to brake, raising the bars can improve your reach as well as making it easier to brake from the drops.
Brake reach adjustment: Many road shifter/brake (i.e., brifters) come with reach adjustments which can be used to shorten the reach slightly.
Brake hood ergonomics: Each brand has slightly different ergonomics, and at times slightly different pivot locations for the brake lever. The ergonomics has also changed over time. I personally found mid 2000 Shimano brifters never braked well from the hoods, newer Shimano ergonomic design has improved this greatly, but some of the lower tier models still use the old design and pivot point location.

Observing some pictures of your set-up and your set-up in use would help


U-lock stuck on a bike Some time ago, I stuck a U-lock on my bicycle for safe keeping, on the top tube below the seat. It's annoying when riding, and I'd like a way to remove it. I've lost the key some time ago, or I would have removed it that way. Preserving the lock is optional. What would you suggest?

I figured out a way to do it which was actually fairly easy. This only worked because it was in my garage, trying to steal someone's bike like this would be crazy...

I took a hammer, and pounded on the bar. The first thing that happened was the plastic broke away. I kept pounding on it, until the lock just fell apart. It took about a minute...

Note to self, don't buy a cheap lock next time...


Need help identifying adult tricycle I picked up an old adult tricycle to restore at a yard sale. It needs plenty of work and needs a bunch of new parts (spokes, fenders ect.), however I do not know anything about the tricycle except for the serial number that was found on the headtube. The numbers being HC0755083, I have seen no other identifiable markings, leaving me to wonder if it is perhaps a custom made tricycle. Any help would be greatly appreciated!

Most bike shops have access to parts for adult trikes, no matter who the manufacture was, taking the trike in is always a plus (I know it's a hassle) but call first to make sure your working with a shop willing to help you before you haul it in.
I've sent a message with the serial # to one of my vendors to see if it's one of their models (I'll respond later with an answer), no matter; adult trikes used pretty standard bike parts.
please upload Pics I'd like to see it.
later,

Sun trikes informed me that it's not one of theirs, and by seeing the pics
it's probably not a (professional) custom built.
you should be able to find parts for it, just make sure the frame isn't compromised or it's just not worth fixing, you can buy a new one for 300-500 US.
I hope this helps & if you do decide to get rid of it gift it to a local bicycle collective they maybe able use parts off it.


Commuting daily with an Expensive Bike, tips? I have been commuting to work daily for years now. Sadly I just switched jobs and there is no bike parking, so I have to leave it in the street. My main problem is that I'm riding a Colnago Single Speed, so I'm not a fan of that solution in the long run.

I just wanted to know if any of you have had a similar problem. Maybe the best solution is just to get a new cheaper bike to be safe.

I think that picking up a second bike is definitely a good approach. Not only does it allow you to not risk your more expensive bike getting stolen, but it allows you to  have a bike more suitable to commuting. You can put fenders and racks on your commuting bike.  Perhaps wider tires if you want something a little more comfortable.  Since you are good with a single speed, this can also be very advantageous on a commuting bike because they are extremely reliable as there are much fewer parts that can have something go wrong with them.


What to use to clean a derailleur? I'm not sure what type of solvent to use to clean a derailleur.

Step 1

Clean the derailleur pulleys by holding the blade of your screwdriver against the sides of the pulleys and turning the crank. You can do this with the wheel in the dropouts, or with the wheel removed.

Step 2

Brush the dirt off of your derailleur using a combination of brushes with bristles of varying length and stiffness, like the ones in the Finish Line Easy-Pro Brush Set.

Step 3

Degrease the derailleur using Finish Line Speed Clean, a powerful degreaser that dries almost instantly. You won’t have to wait before applying lube, or worry that the lube will be broken down by excess degreaser that didn’t dry.

This is also a good time to go over the pulleys again. First spray down the jockey pulley with Speed Clean while turning the crank, then take your rag, hold it between your thumb and forefinger, and pinch the pulley while continuing to turn the crank. Any dirt that didn’t come off on the screwdriver blade will come off on the rag. Repeat with the bottom pulley. This is most effective if the pulley is still moist with degreaser when you run it through the rag. Because Speed Clean dries so quickly, ensure this by spraying down only one pulley at a time, so that the bottom pulley doesn’t dry before you’re done with the jockey.

Step 4

Lubricate the derailleur by first spraying it down with Finish Line Dry Teflon Lube, then injecting Extreme Fluoro, a fully fluorinated grease, into all points of friction.


Very confused about the seatpost clamp I can't figure the seatpost clamp on my bicycle (maybe it's stuck?). I've had it for a few months, it's quite old. I hit a bump in the street and the force lowered the seat but now I can't figure out how to open/loosen the lever. I thought it was a standard quick release but it does not seem so.

Turning the lever will not tighten or loosen the clamp.

The lever is a handle to allow you to twist what would normally be a nut by hand - instead of using a wrench.

Using the lever as a handle twist push down on the lever and move the "nut" counter clockwise until it comes off.

Put just a tiny dab of grease on the threads of the bolt and re-assemble.
The grease will make it easier to get the clamp tight enough to hold the seat post - and protect against rust.

While you are there it would be good to remove the seat post completely and put a little grease on the seat post in a super thin coat and then re-assemble. This will protect the seat post from rusting to the inside of the frame.

If you have no grease a little oil is second best.


cars and scooters in a road bike race I see this a lot in videos from road bike races. A lot of rider team cars mixed with the road bikes doing the actual race.

What is the matter with that? What do they do? Also, don't the riders inhale all the fumes from the exhausts?

Motorcycles are mostly used for media (video and photos) and sometimes for support (they can have a limited number of wheels; I'm not certain if they are "neutral" or team specifics.

The motorcycles will be mixed in with the cyclists; the drivers are highly skilled.

The cars are for race support; there are team specific cars with spare parts and replacement bikes in case of breakage, and have team coaches and also used to transfer food and water bottles to the cyclists.
I think there are neutral cars with spare wheels (maybe dependent on the particular races)

There are also neutral cars with doctors and race officials and VIP.

Most of the cars stay behind the cyclists; if there is a breakaway a car will (as safely as possible) stay with the breakaway.

As for the fumes; at the speed they are going, it is not an issue; and since there are only a few motorcycles mixed in the cyclists, I don't think it is an issue in itself; and the majority of the cars are behind the cyclists.


Peugeot rear brake location I have a 1985 Peugeot P16 (mixte). The Weinmann 730 sidepull rear brake was located at the seatstay bridge.

Q: Is it safe to relocate it to the gusset plate located behind the seat tube and attached to the intermediate stays (because i don't know the name of the head tube to rear drop out twin tubes!).

The brake, with a spacer, will physically fit, but i don't know if it's the right thing to do. Seems this would leave the seat stay bridge for rack & fender mounting.

thanks

Yes, on my 1975 Peugeot UO18, the brakes are located on the intermediate stays and the seat stays are used for the rack mount.

The brake configuration is visible here.

(photo source: http://oldtenspeedgallery.com/owner-submitted/joans-1975-peugeot-mixte-uo-18/#.VWFRtmDDz88)


How would I find a LeMond head badge? Looking to buy a used LeMond frameset. The price is right but it's missing its head badge. Anyone have advice about how I'd go about replacing it?

Thanks in advance!

You could always keep an eye out on eBay for your LeMond head badge, or better yet create a "saved search" that will notify you by email when someone tries to sell one.  The other alternative is to search eBay, craigslist, the classified ads in the newspaper, and so on for another LeMond bike or frameset for sale, buy it, transfer the head badge or use the new bike/frame, and then sell the bike or frame that you don't intend to use.


What components are required to upgrade from a 14 speed to 24 speed? I made the mistake of buying a 14 speed bike... I live in WA so it's hills everywhere you turn, took it for a spin yesterday and while on flat surfaces it felt great, but taking hills or going down a massive hill, I was totally limited on my gear options.

What components are required to do this upgrade? I'm not looking to go all out, I'm just starting to train for my first sprint tri.

Here are my current components for my Motobecane Mirage S.

These are my specific questions

Do I need a new chain, or will this chain be compatible with an upgrade to 24 speed
I need new Cassette/Freewheel, right?
I need new shifters (I'm assuming 3X8... as its 3x8 is it pretty much compatible with any 24 speed upgrade?)
I need a new Rear Derailleur? (This should be an 8 speed correct?)
Do I need a new front derailleur? If so, do the front and rear derailleurs need to be compatible.

I just want to make sure I'm not buying these new components to install and find out it wont work because they are not compatible. I'm pretty new to this so I need some advice. We do all our bike work/upgrades ourselves to save money.

First, make sure your bike is fit properly - with a bad fit, your efficiency is likely lousy.

More sprockets is not necessarily going to make you go faster/easier - changing gear appropriately and becoming more physically fit will (along with better selected sprockets sizes - we went ages before the Gillette razor-blade increase in rear sprockets...). Most of the more sprocket drive trains are driven by hype.

You may need better choices of sprockets, but certainly, with a 2 x 7 setup, you have enough choices that it should be fine (for example, if you were touring, a 11 cog in the rear would be useless - you'd want a range of larger cogs so you could move the stuff you're lugging around). A 24 speed would need a 3 x 8 setup which means new crankset, new front derailleur, possibly new bottom bracket, new cassette and new shifters (these are the real killer if you want brifters; bar ends or downtube or friction shifters somewhere are cheaper) assuming you could get the chainline and what not right (the RD will be fine if you stay shimano). At this point, with a cheap bike like the Mirage S (400 dollars), you're better off just replacing the whole bike, since parts and labor will cost more than the bike is worth/costs (you will also need some tools you might not have, like a crank puller and cassette tool and cable cutters and what not).

If you're going for a sprint tri, you should be in decent physical shape, so I'd look at fit or just spend some time getting used to the gearing - whenever I haven't ridden my road bike in a while and I get back on, I feel like its geared way too high, but after a few weeks, I feel fine.

If you want to change something and you're sticking to this bike, your best bet is to just change the cassette to something with a wider range of gearing. This may necessitate a new rear derailleur (go wide range (marketed with a SGS code) from Shimano). I guess a new chain may be needed as well if you're using weird gear combinations. I suggest you go to your LBS and see what they'd recommend for a new cassette if you want something easier, given the terrain you're likely to ride.

TL;DR: Don't do this. Either get used to the gearing, put on a larger rear cassette or get a new bike. More speeds isn't necessarily better, knowing how to use them and picking the right speeds is far more valuable.


Can a (relative) beginner adjust spacing on a 501 cromo road frame? Have acquired a cheap old Peugeot road bike from ebay; nice cromo frame, but it needs a new rear wheel and unfortunately I didn't check the dropout size before buying.

It has an OLD of ~120mm, but I am finding it very hard to source any new or second hand wheels that would fit that, and most of those that do seem designed for fixed sprockets. There are plenty of seemingly 'cheap and cheerful' wheels with 135mm hubs that would otherwise be perfect.

Sheldon Brown's article on frame cold-setting makes it sound easy, but I'm worried it'll be hard to adjust each side to be exactly 7.5mm further out and keep the wheel central, even using the string method.

Has anyone got practical experience of this? In addition, will there be any other effects on the running of the bike I've missed?

If you're going to be respacing, I'd suggest an alternative method from sheldon's 2x4 method. Use a threaded rod with washers and nuts. It's far more controlled and easier to keep your frame aligned, plus you can keep it in the stand as you work.

See here

If you need to adjust the dropout alignment, you can adjust thusly


Indoor cyclist keeps popping out of clips I bought a pair of Shimano indoor cycling shoes with two hole cleats to wear during my spin classes.  Unfortunately, during my classes, I snap out of the clips.  I know part of it must be my form but I think another part is that the clip isn't held in like mountain bike shoes are.  Is there a way to buy an attachment to make mine more sturdy. I know there must be something, but I can't seem to find it!

On Shimano SPD pedals, you can sometimes adjust the tension for how tightly they clip in (likely via a hex bolt). If the tension is too low, your feet will be too easy to pop out, whereas if its too high, you won't easily be able to get out (which isn't a problem on an indoor cycling setup). Try playing with this setting to see if you stay clipped in (turning the bolt clockwise should increase the tension).

Also, there are two types of cleats  available -- single release (Shimano SH-51) which only release by turning your heel out and multi-release (Shimano SH-56) which release by turning in any direction. It shouldn't matter which one you use for indoor cycling (SH-56 is probably preferable for most people) but SH-51 might be an option if you're having trouble with SH-56.

If you can't get the tension to adjust and swapping the cleats doesn't work (if you're using SH-56), normally indoor cycling bikes have toe clips available as well. You may want to use those. And work on your form.


In the UK, is there any (legal or similar) limit on bike+trailer length? With a couple of miles of quiet lanes, and around 10 miles of fairly straight bike path that takes me right to a river I'd like to go kayaking in.  I've got a trailer that my daughter is too tall for and which I could modify.  So I wondered about towing my kayak by bike.  The boat in question is already 2.3m long; when behind my hybrid it would mean a vehicle of over 4m.  This is only as long as a normal car. I have to admit, this is more for curiosity than something I'm likely to do, as there are awkward bits of bike path even for a normal-sized trailer

We've already discussed the practicality of towing boats behind bikes, this question is specifically about whether it's permissible (i.e. not forbidden either by law or by "...should..." clauses in the Highway Code).  I'm interested in the UK situation; answers for other jurisdictions won't get accepted but should get upvotes from me

I can't find a legal requirement specific to bicycles anywhere.  There are width restrictions but not height or length restrictions for bicycles.

It would be "reasonable" to have a trailer no-longer than a trailer towed behind a motor vehicle so there's an existing precedent already set.

Basically length is governed by the corners you want to go around.  So a silly-long trailer combination becomes impractical on a bike path with chicanes or a small road.

Taking reasonable precautions with flags and additional lighting (even in daytime) will mitigate risk.

From https://can.org.nz/node/12541

From https://www.cycletrailers.co.nz/

(I know the maker of these trailers personally but have no other connection)


Difference between Road/Mountain Hollowtech II Bottom Brackets? Shimano sells Hollowtech II bottom brackets which are labeled for road and mountain bikes explicitly. I had no trouble fitting a Shimano Deore BB52 Hollowtech II Bottom Bracket into my road bike and so I wonder is there a real subtle difference that I failed to notice, or is this just marketing?

I'm going to limit this answer to Shimano Hollowtech II BBs as per the question. Some other brands do it a little differently.

Mountain external bearing crank spindles are longer than road spindles, and their respective bottom brackets are sized to fit one or the other. Shimano BBs have a plastic sleeve joining the two cups that protects the bearings from water dripping down from the seatpost opening and other contamination. That sleeve is a fixed length, so that if it's to be used the cups have to be that far apart from each other (give or take a tiny margin for variance from the exact nominal shell width, i.e. 67.95mm). This isn't the only potential problem with mismatching mountain and road, but it is the first one that will stop a bunch of the potential hack-type workarounds involving adding or taking away spacers from being able to work.

In the beginning, when external cranks came out, road bikes mostly (BB30 existed in nascent form) all had 68mm threaded ISO shells (70mm for Italian) and mountain had either 68 or 73. E-type (bracket-type in the nomenclature of the image below) front derailers and chain retention devices also have to be accomodated by MTB bottom brackets, which is done by keeping the drive side cup thinner than it could otherwise be and running a spacer if they're not being used. (E-type front derailers and many chain retention devices mount clamped in place under the right BB cup.)

Road external cranks and their bottom brackets don't use any spacers between the cups and the shell. Mountain external cranks have longer spindles and the bottom brackets generally come with spacers to accommodate both 68 and 73mm shells, each with or without an E-type front derailer or chain device under the cup. You're using some amount of spacers in all configurations other than 73mm + e-type FD or chain device, and the chainline stays the the same, regardless of shell and spacer configuration. (Complicating matters is that I believe there are some Shimano mountain BBs that don't have seperate spacers for e-type or chain devices, but still do use 2.5mm spacers to adapt for either 68 or 73mm shells.) And road chainline is a different, smaller number, again the same regardless of ISO or Italian.

(From Shimano service instructions for many external MTB BB models)

What can be made to work presuming a willingness to forego the plastic shield (which actually does a lot of work) and/or add spacers not supplied is another question.

To be clear, a 68mm shell is the same on both a mountain and a road bike, and, other compatibility issues such as chainring clearance and chainline notwithstanding, either type of crank with its associated BB can be installed on a 68, say for the purpose of putting a road crank on a hybrid to make it more "road" or a mountain crank on a road bike to make it more "touring". 73mm shells require mountain cranks.

To put it all another way: Say you've got a road crank, a mountain BB, and a 68mm shell. If you install the BB into the shell as intended, you'll find that the tip of the spindle poking through the left cup is inadequate to clamp the left crank onto, because it's physically shorter than a mountain crank. If the shell was 73mm, the situation would be exactly the same, although you would have used fewer spacers to get there. If you tried not using the spacers, the physical length of the plastic shield would keep the cups from being able to torque properly against the shell. If the situation were reversed, say a mountain crank, road BB, and 68mm shell, if you install the BB as intended than you have excess spindle sticking out of the BB. If you add spacers under the cups to take up the slack, the plastic shield becomes too short to fit inside and doesn't do its job properly.

The thickness of the external parts of the cups themselves, measured from the shell contact to the crank contact, is also not the same between mountain and road. Road ISO is about 11.2mm and mountain is 10.2mm. I believe the reason for the difference is that road handles its two different shell width (68 for ISO and 70 for Italian) by having the Italian cups be 1mm thinner in this dimension. Mountain handles the different shell widths (68, 73, plus the need to accomodate e-type and chain devices) by allowing different spacer configurations.

Some other companies, namely SRAM/Truvativ, work differently because the plastic shield slides within the cup, creating a situation where the same Truvativ/SRAM Team GXP for ISO is the generic replacement BB for almost all SRAM and Truvativ external bearing cranks for ISO threaded shells, mountain or road. It comes with two 2.5 mm spacers to be used in the case of a mountain crank on a 68mm shell.


Does riding on the sidewalk make it more likely to get a flat tire? I just started bike commuting, and the two times I've gotten flats were when I was biking on the sidewalk, and in both cases they seemed pretty random. I use a mountain bike. Is it just a coincidence or is there more to it?

There's almost certainly more debris on the sidewalk.

Sidewalks are swept less often, and vehicle movement pushes debris off the travelled areas. You can more easily see the latter on wet days - there will be wheeltracks from motor vehicles with much wetter areas between. The worst areas are the edges of major roads, where debris gets pushed into the bike lane by passing motor vehicles.

On my ride to work the most puncture-prone area is where the bike path crosses a major road - there's a shield wall between the road and nearby houses and at the break in that wall is a small space for people to wait before crossing. That acts as a dust trap for all the stuff thrown up from the road and is rarely or never swept. It's common to see broken glass, sharp metal fragments and even nails in this spot.

I often carry a pair of secateurs and a small hand broom in my pannier so I can clear plants and debris from the bike path. It's a small amount of extra work but it helps a lot, especially on Monday mornings when the bike path often has broken alcohol bottles on it from the weekend.

Sidewalk cycling is also much more dangerous so should be minimised.


What to look for in a (Cheap) MTB headlight for night trail riding I'm wondering what to aspects to look for when buying a mountain bike headlight is for night riding on the trails.

I have never bought one before, but I'm hoping to spend at most $50, is it possible to spend this amount and get a reasonable light, or would I have to spend more.

As already suggested by @Batman, have a look at this Bike Light Database write up.

What to look for ...
LED - with cheap lights don't believe the claimed Lumen, Look at the LED specification - a CREE XL-M T6 or U2 are probably the one you want. There's not much difference in them, you typically get about real 600 Lumen out of the cheap lights, more expensive lights with better drivers can get a bit more. IN the end, few people need more than 600 Lumen.

Battery
Lithium batteries vary enormously in capacity and price. If you buy cheap ones, expect 1/4 of claimed capacity. Buying off the likes of EBay is a crap shoot - if you want good batteries, buy locally from a reputable supply, otherwise buy cheap ones off EBay and expect to get what you pay for. Life time may be short for cheap ones, as some are known to be 'recycled' lap top batteries.  Make sure you get what is known as protected batteries.

Construction
Heat is the enemy of LEDs, some cheap lights have plastic cases, so don't get the heat away, others have good alumina extrusions. They do not need fins when riding as the airflow is enough to keep them cool. Most cheap lights are not particularly  water proof - if you ride in the rain you probably want to go for better quality.

Most cheap lights come with a Silicon O ring to hold them to the bars/head-mount. It works surprisingly well, but I wonder how long the O rings will last, and getting the light and battery pack on and off the bike is not a quick task.  They will not survive a big knock and a probe to breakage, and the wires are prone to breaking internally - fixable if you are handy with a soldering iron.

Optics
Expensive lights have vastly superior optics to cheap ones. Cheap ones often have a very bright center spot with little flood - great for seeing further than you car head lights, not so great in corners, especially if helmet mounts.

With the cheap lights on EBay (and sold in many shops), they lights may look identical, but be quite different in quality and optics.

For a budget of $50 my suggestion is to do what I have done - Buy a couple of cheap lights off the likes of Amazon/ EBay / Dx. One for helmet, one for bars, be prepared to buy a new battery or lamp every now an then. This gives you a spare light to get you home if one fails, typically a couple of hours each on full brightness (I run both mine on medium, giving 4 hours ride time). The major down side is optics could be a lot better. Many people live with the limitations of cheap lights and replace them as they break rather than buying some good quality ones at 10 times the price.


Trying to add an extra cog I am trying to use a multigear bike to make a pedal power bike. I am trying to add an extra cog to attach a chain to connect the motor to. See link.http://www.popularmechanics.com/technology/gadgets/how-to/a10245/pedal-power-how-to-build-a-bike-generator-16627209/
Is it possible with multigear or do I need a fixed gear?

You need a rear hub that can have a cog on both sides.

Some fixed gear hubs have threads on both sides, or a fixed thread on one side and freewheel thread on the other. The author apparently has one of these.

The multi-gear option is to use a disc hub and cog that has been drilled to fit 6-bolt disc brake mount. This trick is usually used to make fixed gear hubs out of MTB front hubs, but could also work here.


Shimano FD-M191 replaced with Shimano FD-M590 just replaced Shimano front derailleur (FD-M191) to FD-M590. And problem appears, on smallest cog chain rubs lightly on left side, and on biggest cog on right side.
Just can't lower derailleur more when chain on smallest cog, cant put derailleur higher when chain on biggest cog. I think just reached limits in both directions, any ideas?
Thanks

According to the data sheets for the FD-M191 and FD-M590, you should be able to run one for another provided the difference between the middle and largest cog is at least 12 teeth.

The first thing to check is if you've adjusted the front derailleur properly. Are you using a reasonable gear combination when its rubbing? If so, are you using a 9 speed chain?


Gitane Frame Identification Year Was wondering if anyone can verify year of the Gitane frame

Thanks
Damian

I'm going to point out the features that make it a 70s bike.

Cottered cranks.  They went away in the late 70s.
3-leg spider in the middle of the cranks - that's old looking, but the thin cranks imply a racer.  Do get it off the ground, you're damaging the big chainring like that.

And these are the aberrations:

The cable stops on the top tube - most bikes used a full brake cable housing with clips, not an exposed inner cable.
No lugs - at least none visible in the photo.  This looks like a smoothly welded steel frame.
Down tube derailleur seems to have a thing under it - is not overly clear in the photo.

The saddle is too new, and there appear to be no wheels, but its very close to being complete and rideable.  You need a new chain and new brake pads too.


Disc brakes and single walled rims - is there something to worry about? I know that the physics of disc brakes are different than rim brakes, but the differences are not intuitive to me so I want to double-check this. I understand that one fail point of single walled rims is the spoke hole; that they are prone to cracking. Will this tendency be exacerbated by a disc brake (compared to a rim brake)?

FWIW, this is the front wheel I am thinking of.

EDIT: if the answer to the question is no, what do I do with the various yes answers that I find? For example from Park Tool's website:

  A similar torsion or twisting load is applied through the spokes by
  rotor disc braking.... The rim caliper brakes, however, do not apply
  braking force through the spokes in the same way.
  http://www.parktool.com/blog/calvins-corner/wheel-tension-balance-web-app

Am I confusing the discussion of load with the forces that cause a spoke nipple to crack the rim at the hole? Or is it, as @Rider_X says, that the forces are different but the differences are negligible?

Well, let's compute the forces. For example's sake, I'm assuming 80kg of bike + rider, all braking force on front wheel and deceleration of 5 m/s^2 (extreme, but possible). This equals 400N at contact surface. The radius of 559mm rim and tire is something like 320mm, giving 128Nm of torque. The spoke hole is at 22mm radius, and cross 3 lacing places the spokes roughly tangential to hub flange. Using the axle as pivot and spoke attachment to hub as lever, we can calculate that we need force of 5818N to produce the torque.

Spread over 32 spokes, that is 181 newtons per spoke. Since spokes in a properly built wheel are already at 1000N or more, the increase is around 15-20%. This requires a rim with stronger spoke holes, but not by that large margin.

Keep in mind, that in many double wall rims the spokes attach to outer wall. In this case, the extra wall doesn't help at all.

The case with radial spokes on both sides is different: The spokes exit the hub at zero angle, there is no leverage and if the spokes wouldn't stretch and let the hub twist, the force would be infinite. Calculating the actual force is left as an exercise to the reader :)


Is it annoying to carry a backpack when riding a road bike? I plan to buy a road bike for my daily commute but I need to carry my PC with me as a well-equipped engineer. My daily commute is around 5 km plus intermittent city tours. I afraid after some kilometres, it might make my back ache. Do you think it will be painful after a while? Do you prefer something like a trekking bike for this example?

Backpacks have a number of drawbacks when riding.

They can make your back sweaty.
The can interfere with your helmet/head posture depending on bike geometry and backpack size/design.
They increase the weight on your hands.

In general most people I know that complain about riding with a backpack "feel" the extra weight as pressure on their hands, not in their back.  Obviously your bike geometry and anatomy may vary.

Backpacks also have some advantages.

Their weight can be moved dynamically by your torso.  The extra weight is on you and moves with you.
You have less to do at your destination.  The backpack is attached to you and doesn't need to be removed when you arrive.
You aren't required to alter your bike.
The backpack can be used for other things besides cycling.

My personal opinion was that for short commuting (30 minutes or less of cycling) I prefer a backpack.  It's less to deal with and a short enough time that the extra weight on my hands didn't matter to me.  For longer rides I would not wear a backpack because the extra weight becomes noticeable.

Road bikes tend to have "longer" geometry and stretch you out.  This means you are holding your head up at a higher angle.  I would test your setup out before I committed to a road bicycle/helmet/backpack combo.  Many of the backpacks I have tried come up high enough that if you lean far enough forward, you can't actually raise your head all the way up with a helmet on, which isn't safe.


Why is it common for cheap bikes to have the frame sawn in half below the saddle? These days cheap bikes often seem to come with the frame sawn in half below the saddle.

What does the manufacturer gain from this design, and why is it associated mostly with cheap, low quality bikes?

What disadvantages are there to the bike rider? I assume that it's not a great feature since quality bike makers don't seem to opt for this design.

The seat tube is split because it has rear suspension - the rear of the bike rotates around a pivot located just in front of the bottom bracket.  Several early full-suspension bikes used a similar design for the rear pivot; this design was then knocked off by the lower-end manufacturers looking to cash in on the popularity of mountain bikes.  It's extremely simple and gives the bike the expensive "full-suspension" look.  Unfortunately it mostly just adds weight, pedal bob, and complexity to an already heavy turd of a bike.

Most modern full-suspension bikes use more expensive rear linkages and advanced suspension designs, so this older design has almost entirely been relegated to department store bikes.


What can my Shimano BR-M445 caliper be replaced with? I have a Shimano BR-M445 disc brake caliper that has decided to give up on life, so I need a replacement. It seems like the BR-M445 is no longer produced, so are there other calipers that can replace it?

Seems like the BR-M445 and BR-M446 are the same/interchangeable, while the BR-M447 uses some different parts, but still has the same hose, so I assume that it is compatible as well.


Tried to tighten the brakes, won't grip at all I have a big problem. I know I could get this fixed with a mechanic, but really want to learn how to do it myself. I tried to fix (fool around) with my brakes a little the other day. The brakes are Shimano Nexave BR-IM70-R rollerbrakes.

I loosened the "thing" that connects the cable to the actual brake pads, but when I tried to fasten it again the brakes don't grip at all. That is to say, when I pull the lever at the handle, the cable is pulled, but doesn't grip the brake at all.

I have tried watching videos online, but none of them seems to deal with this problem. Also, I have tried to find the name of the brakes, but I am unsure where to look at the bicycle. Hope that someone would be able to guide me on the right path

Here are some pictures:

On the first picture, if you look closely at the cable right to the bolt at the center, you will see deformation marks from the previous clamping. The position where you have clamped the cable seems to be too slack. That is, too much cable is left between the lever and the pinch bolt.

To fix it, loose the cable, press the "thing" that rotates when you press the brake lever clockwise, and clamp the cable again at the new place.

You may end up taking up too much slack, permanently pressing the brake pads against the rotor or drum; in this case, find a compromise position between too slack and too tight. It can be done by using the adjustment barrel at the lever, if you have one there.


Mysterious case: chain falling off large chainring, how to fix? On my commuter bike I decided to rid myself of the small inner chain ring (which is almost never used) and front dérailleur (now redundant). However, I have come across an unusual problem. Whilst cycling the chain is coming off of the outer chain ring and falling onto the crank arm. This usually coincides with a shift of the rear dérailleur onto a smaller sprocket, although notably not onto the highest gearing - it has happened shifting from the 5th to 6th scrocket on the 12-27 cassette for example. Furthermore, I am not exerting abnormal force on the crank, just sitting and riding as normal. This just happens out of the blue and as you can imagine is quite disconcerting/dangerous.

I have considered and checked the following so far:

Chain length - tension is good so no obvious problems there...
Chain dirty - it most certainly is not, it has only seen 200 miles and its lubed up a treat ;-)
Chain ring to cassette alignment - Hollowtech II BB and Ultegra 53T 6600 crank in 68mm shell, standard setup afaict, no obvious problems there...
Lack of front-dérailleur - I removed this since there is only one chain ring - could this be a factor that prevented me noticing the problem before (surely not...)
Chain ring worn - the chain ring looks in pretty good shape to me

I experimented briefly, turning the crank and applying a very slight outward pull (away from frame) on the chain and it promptly fell off onto the crank. Frankly, I was surprised how such a small misalignment could cause the chain the fall off...

My question: Has anyone else encountered this problem before?

Any comments on the things I have checked (why I may be mistaken in my assessment of the problem)?

Other possible causes I have missed would be gratefully received - this is spoiling an otherwise nice bike and I really do not want to go back to using the double crank configuration if possible.

Yeah. A modern double chainring is ramped and pinned, in order to be more easily shifted from one ring to the next. Simply put, the chainring "wants" to pass off the chain to the next cog. Without a derailleur to keep it in place, the lateral pull of the chain shifting across the rear, combined with some road jostling, can make the chain fall off the front.

A couple solutions:

install a singlespeed chainring without ramps or pins, with "straight" teeth.
use an outer chainring guard and inner "dog tooth" chain keeper
combine the two (which is the best solution).

The free and easy way to keep it on while looking at other solutions is to reinstall the front derailler and adjust the limit screws so it keeps the chain in place.

This is a pretty common concern with cyclocross. Racers often use a single-chainring setup for the sake of reliability, and either or a dual chainguard or chainguard-and-chain watcher setup for just such reasons (also because they keep picking the bike up and putting it down whilst running and jumping over stuff), so you get stuff like this: http://www.bikeman.com/CC-SRAMS300CX.html.


Shifting direction is different for front and rear shifters I have been riding singlespeed and 1x setups for decades. The last time I had a front derailleur was over 30 years ago, and the shifter was on the downtube then, and I don’t have any memory of how it all worked. So I’m experiencing a time warp of sorts when it comes to multi-geared bikes.
Recently I bought a cargo bike (Mongoose Envoy) with a Shimano 3X drivetrain. I love having the extra gears, but I’m totally shocked that using the thumb lever on the right shifter gives a downshift, but using the thumb lever on the left shifter gives an upshift. And vice-versa for the triggers…using the trigger on the right shifter gives an upshift, but using the trigger on the left gives a downshift. It’s completely counter-intuitive to my brain and I can’t imagine the reason it would be this way.
First of all, is my bike assembled right? Is this the normal way all bikes are? If this is the “standard” setup, how did this convention ever arise in cycling? Is there some advantage to the controls being opposite that I’m not able to appreciate? And lastly, can I change the cable routing somehow so that the front derailleur both shift the same “direction”?

The reason why shifting is arranged this way:

Shifting to a larger chainring at the front gives a higher gear ratio, shifting to a larger sprocket at the rear gives a lower gear ratio.

Shifting to larger chainring/sprocket requires positive pulling force from the shifter whereas shifting to smaller chainring/sprocket can be done with derailleur spring tension. It's intuitive that getting the chain to  climb up onto a larger chainring/sprocket will takes more force than letting it fall down.

Its easier to get positive pulling force from the thumb shifter lever then the finger lever, there's more room for a longer lever and a longer lever throw. The thumb can travel on longer distance without the  hand losing grip.

The exception is of course Shimano's Rapid Rise rear derailleur which use derailleur spring tension to shift to larger sprockets. THis obviously didn't work as well as 'normal' derailleurs as the type has disappeared.


How do the adjustment barrels on a gear cable work? I have a Shimano Sora derailleur on the bike I just bought with a triple chainring in the front. Right up by the shifters there is a sort of barrel adjuster on the cable. It doesn't seem to do anything when twiddled. When I was fiddling with the adjustment at the other end, and disconnected the whole cable by accident, this adjuster was separated from the cable covers on each side. I couldn't figure out at all how it was supposed to work. There didn't seem to be any threads, or screw mechanism to make it grow or shrink when adjusted. Yet it clearly does something. Can anyone explain what, and how?

Your basic barrel adjuster is a tube with a thread on the outside of one end.  The threaded end fits into a female threaded piece, either the shifter itself or another tube.  (If you have this second type, where the female end is another tube, it's necessary to hold that second tube stationary while turning the first tube.)

The cable passes through the tube, and the cable housing "bumps into" the end of the adjuster barrel (which generally has a sort of "cup" sized to accept the housing and keep it centered).

The adjuster works this way:  As you UNSCREW the adjuster, it pushes the cable housing farther out, effectively tightening the cable.  The cable is held in tension by the spring in the derailer, so this adjustment moves the position of the far end of the cable relative to the derailer.

[Note that some adjusters have a thin "jam nut" on the threaded portion of the barrel, and this is tightened against the female piece to keep the adjuster from turning.  It's often necessary to unscrew this jam nut slightly before working the adjuster.]

Note that once you've unscrewed the adjuster beyond the end of the threads it won't tighten the cable anymore, but will just spin.  If this occurs (before satisfactory adjustment is achieved) it's necessary to screw the adjuster all the way in, loosen the cable clamp at the derailer, and pull it a hair tighter.

Also, if some jackleg in the past decided to "tighten things" with a pair of pliers they may have broken off the threaded portion inside the female portion, rendering the adjuster completely ineffective.


Painting a bike with minimum cost I bought a used bike but I hate its color and I want to repaint it. I saw some videos on youtube on that. However I found the stuff too expensive. I went to Amazon and I found a black matte paint spray for 5 euros and my idea is to clean the bike and then just spray the frame.

So my questions are:

1- What happens if I simply do that without removing the rust or removing the old painting? Wouldn't the new painting simply cover everything? Bascially the steps on youtube is to first remove the old painting and remove the rust and then spray a coat (I don't know what a coat is but I think it costs extra 7 euros for the bottle) and then spray with the black matter paint. So what is the effect of not following those steps and directly use the black matter spray? Because the youtube steps would cost me 24 euros or so.

2- The Crankset also lost its color, so I'm thinking to spray that too with the black matte. Is that wrong or bad in anyway?!

Here are the pics of my bike:

So yeah I actually want to spray all of that with simply the black matte spray paint that cost 5 euros because I'm a poor student. (I hope that wouldn't make it uglier!)

I did a cheap paint job once. I'm mechanically inclined, so for me it was not a problem to disassemble the bike. Used 1000 grit sand paper to remove the gloss (opening pore) from the paint and then washed the frame with kitchen soap. Let air dry without touching it too much.
With clean hands, tape any piece I didn't wanted covered, because I didn't completely undo the bike. At this point, One complete can of spray paint was enough. I finished the job with stickers that I had printed myself at home.
Sanding is laborious, but completely necessary. Opening pore in the paint creates a better surface for the new paint to adhere to. Washing is crucial to remove grease and dust, both of them prevent paint adhesion. For a strict budget project it is better to conserve original paint because it is already well adhered to the frame and it works great as a base coat. It is easier for new paint to adhere to porous, clean paint than to bare metal. Do not sand too much, since factory paint is really thin, and some times you wont find a different color base to guide. Use a flashlight (torch) to check if you removed gloss and that's enough.
Masking any part that should not be painted is highly advisable. For a start, paint should not get into any pivot, bearing, axle. But second, correctly masking the bike before painting gives the final work a better look (it can be so good it doesn't look cheap nor even home made). I recommend removing wheels, cables, derailleurs, handlebar, stem and crank set. Bottom bracket can be masked. Also mask fork bearings (headset) and seatpost. Leaving the seatpost is advisable to have a "handle" so you can move the frame while painting so you don't damage the paint job.)
The trick to paint a bike (or anything) is to use several light coats instead of a single thick coat. Start moving the can before you press the nozzle and use quick, consistent movements, continue moving the can after you release the nozzle. If you watch any car restoration shows or similar, you'd see that they do this with their paint guns.
The first coat must be so light that the original color easily shows through. You should be able to give the frame and fork 3 coats from a single paint can. Let dry each coat before applying the next. The can label should tell the drying time.
It is absolutely necessary to let completely dry the paint before reassembling the bike because the paint may be "touch dry" but still not completely set. If you handle the frame at this time you will smear the paint or cause finger print marks on it.
Finally, some stickers can help to make the bike look better. In my case I used inkjet printer on plain paper, then I used clean vinyl paper to cover and adhere it to the bike. How ever It may be cheap enough to have them professionally printed. At this time (2014) in my country they charge around 1 euro to print a sticker the size of a letter size (A4) sheet of paper.
For reference, in my country (Honduras) a can of paint can cost the equivalent from 2 to 4 Euros, a sheet of sandpaper costs cents, and a roll of masking tape is like half an Euro. So the hole project is around 5 to 7 euro, plus your workmanship.
I really advise you on being patient and not paint several parts with the same paint and not letting over spray fall on anything not intended to be painted, because that usually gives a bad, cheap look, and you may end up liking the bike even less than you like it now.


I got a leak on my shimano 105 R7020 STI My caliper rotor push oil back in the STI. All of the sudden mineral oil started leaking.
Do you know SKU of this part?

According to the ST-7020R exploded diagram at
https://dassets.shimano.com/content/dam/global/cg1SHICCycling/final/ev/ev/EV-ST-R7020-4341C.pdf
That part doesn't exist as a removable part, hence why you need to confirm your exact shifter part number.

For completeness - the dealer manual is at https://si.shimano.com/api/publish/storage/pdf/en/dm/RADBR01/DM-RADBR01-07-ENG.pdf
and a browse through shows no mention of removing that plate.


Why is it important to keep bearing sets when greasing a campagnolo hub? In almost all cases where hubs are regularly serviced, bearings don't need to be replaced. The general consensus though is to replace bearings after so many thousands of kms. Many posts on the web say a grade 25 bearing is fine to use in a hub.

I have a Campagnolo Record hub with loose bearings (not in retainers). The races and cones are fine and yet the wheel drags slightly at points. Backing off the tension leaves the hub very slightly loose and mostly solves the courseness of the hub. This is what I expect with normal wheels, but not a Record. Why should my Record hub need some slack when the races are precision ground and hardened, and Campagnolo selects bearings to within 1 micron, or about grade 25?

Did the other people who serviced this hub in the past use just any general bearing? New bearings have been introduced by many bearing manufacturers as high efficiency, where they select bearings to within 1 micron. But, in a bicycle hub, it's not so much a matter of efficiency. It's about smoothness and road feel, and loose-ish hubs just don't deliver that.

It seems the answer to my problem now is to either buy a 9+9 set of matched Campagnolo hub bearings or to buy grade 3 Si3N4 ceramic bearings which are manufactured from the same lot. Even better would be if I could size my own bearings to within 1 micron.

Any other suggestions or ideas?

EDIT --------

Just to clarify. When I talk about drag from this hub, I mean when I spin the wheel and rest the axles on my index fingers I can feel and see some movement. On the other hand with a Mavic 500 with sealed cartridge bearings I can lightly tension the bearings and feel no movement when spinning the wheel.

With either wheel mounted on the bike there's no play (without load). So, when I say I backed off the tension of the Record hub it's not something you would normally notice in a setup for a bike, but I've found in riding I prefer my hubs set a little tight. Maybe it's because I tour and carry an extra load on the rear. I tend to push my cornering hard on downhill switchbacks and I find tighter hubs give me more of a sense of hugging the road.

In almost all cases when servicing a hub the bearing DO need to be replaced.

You may not be able to see it without the aid of a microscope, but the bearings will be slightly pitted after any appreciable period of use. As one user points out, high grade ballbearings in case hardened steel, even grade 25s are very cheap - why cut the corner?

Case hardened are preferred as they are less brittle, BTW.

Bear in mind that in correct bearing design, as it's difficult to get an exactly consistent rate of wear on the three components, you will generally find that the balls (being the cheapest and easiest to replace part in the assembly) will wear first. Then the cones. Last will be the internal bearing surfaces (in the case of the hub) as these are the most difficult to replace. Cones and cup wear rates may be the other way around if the cone is integrated with another component or part of the assembly that is difficult to access or change - not normally the case in any conventional cycle application.


Hard and noisy Shimano ST-EF29 front shifter with brake lever I bought brand new Shimano ST-EF29 (3x8 Speed) Shifter + Brake Lever (both left and right) for my MTB which I installed some 3 months ago. But it is very noisy (especially when shifting from 3rd to 2nd chainring on the left shifter).

It changes super smooth and beautifully quiet from 1st to 2nd speed (chainring), a litle bit harder from 2nd to 3rd speed (chainring) but still satisfactory. The chain is not touching the front derailleur cage at 1x1 Speed and also not touching it at 3x8 speed).

But the noise is quite loud and annoying when shifting backwards from 3rd to 2nd and then from 2nd to 1st speed (chainring).

I noticed a small screw with the spring on the bottom side of the shifter and checked Shimano Tech website. It is called Reach Adjusting Screw and Spring (see photo). But it seems this screw is for brake lever adjustment so I didn't touch it at all.

Is there a way to fix this? Is there a screw on the shifter/brake lever that needs to be adjusted? The cable tension seems right when changing from 1st to 2nd speed but when changing from 2nd speed to 3rd speed it is a bit hard. The thing is that when shifter is in 1st speed (smallest chainring) the cable is completely loose) so I am not sure if loosening a cable tension (at front derailleur) furthermore would cause shifting problems.

The right shifter (Speeds 1x8) is working perfectly.

I have no clue how to solve this. At first I thought it's because the shifter is new so it will become better/quieter with the time but it is 3 months already and the noise is the same.

My initial suspicions would be either the indexing is slightly too far outboard, so that the cage is not quite moving far enough to push the chain positively down to the smaller rings; or friction on the shift cable within the housing is delaying or impeding the inboard movement of the cage on downshifts.

Try adjusting the indexing. Front derailleur adjustment is a bit tricky so I always follow Park Tool's front derailleur process.

Check the shift cable is running freely. Detach the cable from the derailleur, pull on it to provide so tension and work the shifter, the cable should pay out easily and smoothly on downshifts.


Replacement from 3x Sugino cranks to any Shimano 3x Specialized Sirrus with carbon forks, 9s peed Tiagra rear, 3sp front.

Alloy frame Sirrus has a threaded bottom bracket shell, square taper cartridge bottom bracket.
You can pick any any 3x9 crank from Shimano's Altus, Acera or Alivio ranges. Most cranks are '3-piece' for square taper bottom brackets, however, different crank models require different specific bottom bracket axle length to achieve the correct chainline. You'll need to look up crank specs and check that your existing bottom bracket has the correct axle. if not you'll need to replace the bottom bracket also. If you are replacing the bottom bracket you might wish to upgrade to a '2-piece' crank with external threaded bottom bracket bearings.
Note that special tools are required to remove and install bottom brackets, and a crank puller is needed to get crank arms off square taper axles. Bottom brackets and crank arms should also be installed with a torque wrench. It's especially critical to get square taper crank arms tightened properly.