Finding my physiologically relevant maximum heart rate I've always believed my maximum heart rate was 198 based on my performance. I'm 24 years old, so 220-24 = 196, but I routinely hit 197/198 during hard efforts in many rides, and never exceeded 198. When I hit 198 I can barely sustain my level of exertion and have to ease off in short order.

Then one day I blew that number out the window when I sustained 202 for almost 20 seconds on a huge sprint effort. After the effort I had to get off the bike since I was dizzy and could hardly hold my head up and grasp the bars.

So, for the purpose of defining my heart rate zones, is my "max" 202 or 198?

The 220 - age (or any age based formula) is a myth that works well enough for roughly 60% of the population and puts the other 40% wrong. That it persists to this day with such ready access to HR monitors and reasonably accurate sub-maximal tests to determine max HR astounds me.  (I blew over 210 when I was in my early 30's and now over 50 can sustain 170 for a hour and can probably reach 190.)

Training zones based on  max heart rate percentages are based on average people and  well enough for most of the population, but they are guesstimates. You do not gain more accuracy from knowing max HR to a few beat per minute.

Presuming your HR monitor is accurate, your maximum is clearly at least 202.  For defining your training zones, use 200 - its a nice round number.


What are the risks of untrued wheels? I understand that wheels should be trued for efficiency. Are there any safety risks (or risk  of damaging the bike) in using untrued wheels?

Are the risks different between wheels untrued left-right and up-down?

My question is motivated by the following fact: I have an up-down untrued wheel and not much time to take it to the shop, should I keep using the bike?

It is important to understand that spokes work in tension rather than compression. What that means is that the spokes at the bottom of the wheel are not 'doing anything'. The load is shared by all of the spokes to varying degrees and, particularly with cross-laced spoking patterns, that load gets dynamically transferred to use the strength of the available spokes. You can actually knock out a chord of a dozen spokes on the cheapest of steel rimmed wheels and the wheel will still be able to support your weight and get you home, albeit with gingerly riding style with no kerbs or potholes attempted...

Therefore, even quite seriously mangled wheels that are as true as a poppadom are surprisingly strong when riding on paved roads in a straight line. As other contributors have noted the problem comes with the brakes and stability at speed. You really do want to make sure your brakes are not hitting the tyre or falling off the bottom of the rim. If you have the slightest doubt then you can ride the bike using the other brake as your primary, using the brake on the affected wheel for 'emergencies only'. This should not be a problem if the weather is dry and you know what you are doing.

Straightening out the wheel need not be something that you need to get the bike shop to do. Consider doing it yourself, with a spoke key on the wheel in situ. Here is a handy page on how to do just that:

http://www.kenkifer.com/bikepages/skills/spokes.htm

As for getting a spoke key, go into the bike shop with the bike and ask. There are a couple of common sizes and you will need to get the correct key for your bike.


Adjustable stem issue Hello I have a quill adjustable stem on a Raleigh Royale. (The bike is an absolute dream to ride, wonderful seat and great gearing) My issue is that the handlebars wobble, both front and back and side to side. They definitely don't wobble at the face  plate area. I'm certain it's at the adjustable part of the stem. The bike is a Raleigh Royale. I've taken as many pictures as I can. Thanks

Do the nut and bolt need to be removed to adjust the angle of the stem? If not I can't see how that will ever be tight. If yes then I'd say the design still suffers from a flaw which is that tension of the bolt does not engage those teeth.

All that to say that here is how you test to find the area of wobble (because the problem might be a loose headset): straddle your bike with feet on the floor and pinch the intersection of two parts with one hand while you hold your front brake with the other and use your weight to rock the bike forward and backward against the tension of the brake. You'll feel the loose part move. This test is often used to test for loose headsets by squeezing the headset top nut (that big black nut on top of the headset) and the bottom of the stem where it goes through the top nut. I recommend you do this just to make sure it's not the headset. (It looks like I see grease there - was the bike serviced recently?) If you don't feel movement at the headset try pinching the stem and do the rocking.
Whatever the verdict, that stem looks like an engineering short cut and probably will never get tight. I wouldn't be surprised if you sheer that bolt like so many seat tube bolts.


Using cycle with tube for long distance I'm having Ralson 26*1.95 Tyre with tube....
I have heard that tubes burst due to friction at high speed.
Can I use it for travelling a distance of about 200 Km continuously and slowly??

No, a tube will not overheat in those conditions.

Even riding very fast will not heat a bicycle inner tube. And even an under inflated bicycle tire will not warm appreciably.  An under inflated tire can fail or cause crashes but no it is not going to overheat as is the case with motorized vehicles.

Tandems descending 2+ mile steep (6% and greater) hills have been known to blow tires off of rims, but the tandems are 300+ pounds and the blown tires I'm aware of were all road tires 28mm or narrower AND the tandem had rim brakes. Tandems with disk brakes have no issues with overheating (blown) tires.

The larger the tire the more air volume so it takes more heat to warm the air and cause the tire to overheat.

The wider the rim the more heat will be dissipated. The air rushing against the rim & tire will cool the rim and tire.

A bicyclist simply doesn't have enough energy to appreciably warm a tire.


Sunrace 10 Speed 11-46T cassette rear derailleur compatibility I would like to know:

What rear derailleur (RD) was the "Sunrace 10 Speed 11-46T" designed to work with.

Is there a compatibility chart ?

Shimano 11 speed MTB rear derailleurs can officially handle up to 46 cogs and can be run with 10 speed trigger shifters since the pull and ratio are almost the same. I used to run RD-M9000/SL-M980 combo successfully. So you can use those with the cassette in question.

There's also Archer/XShifter electric cable drivers, these allow to run any RD given it can handle 46t cog, like RD-M9100 or SRAM XX1 Eagle.


Raising handlebars using a stem raiser on B'twin Triban 500 I've just got a second hand B'twin Triban 500. The seat goes easily high enough, but I've not used a road bike before and the handlebars are far too low for me, even with all the spacers in place. I understand that the bike has a carbon fork. I'm looking at getting a stem raiser so that I can increase the handlebar height to a more comfortable level while I get used to the bike, and saw this one on Evans cycles, but it says not to be used for a carbon steering fork; does this mean I could not use it on my bike, and why so?

Similarly, I saw this one too; it doesn't mention not being used with a carbon fork, but should I assume that given the previous one?

Thanks!

EDIT: Turns out that a carbon fork doesn't mean a carbon steerer tube; thanks for those who commented! Any general tips regarding the situation are welcomed :)

As mentioned in comments a steerer tube extender should not be user with a carbon fiber composite steerer tube. Less expensive CFC forks often have an aluminum steerer tube.

You may want to consider a stem with a greater angle that will give more handle bar rise before a steerer tube extender, that would be a stronger option.

Are you riding with hands on the drops of the bars, or on the higher brake hoods position? Most riders spend most of their time on the hoods. If you are riding on the  drops and that feels too low, try riding on the hoods.


Can a 7 speed Derailleur work on a 8 speed cassette Can a 7 speed Derailleur work on a 8 speed cassette I have a extra 8 speed shifters? and a wheel that has a 8 speed cassette.

8 speed shifter and cassette, 7 speed derailleur? You'll be fine. There's no "probably" about it.

6-, 7- and 8-speed gear is all cross-compatible in terms of chain width.

The only time you'd hit a problem is if the shifter and the cassette weren't made for the same number of gears, for example you could imagine a scenario (e.g. 7-speed cassette, 8-speed shifter) where you might click past the edge of the cassette. That would negatively impact your day.


Is the bike i'm using right for Mountain Biking? Im not exactly down with the terms used in MTB, I have recently bought a new bike. It was within my price range and its great for riding on the road and forest trails. Its a "Carrera Hellcat II Limited Edition" 29er. Its got 100mm of travel (front suspension only) So i was wondering if this bike would be any good for doing some mountain biking trails. I know of one near to where i live.

If anyone could shed light on this i would be very thankful.

I am 6ft and weigh approximately 165lbs

Thanks, Jack!

Looking at the component specs, its an entry level MTB, one better than a BSO.

80% of mountain biking is about the rider and his skills, not the bike. Shops won't tell you this, as telling you your riding skills matter most does not end in a sale of a newer season/more expensive bike.  Cashed up middle aged execs won't either - many just want you to see how much money they have to spend on toys and cannot ride to save themselves - a lighter/faster/more forgiving bike hides the lack of skill. Competitive riders care what they ride - they have expensive bikes because 1/2 a second here and there makes a difference to them.

Where it will let you down is weight (Makes it harder to accelerate and not as fast up hills), front forks (Likely to have poor rebound control and bounce a lot - pogo sticks) and gear shifts will not be fast and crisp.  Picking the right gears early will be critical to having fun, as will picking good lines in corners.  The forks mean you will not have room for cornering mistakes and will probably have to enter corners slower than other.  Being a hard tail, you will need better skills to ride fast, as they are less forgiving of mistakes than a softtail.  It will also need more maintenance and tuning than a better bike, and probably wear out faster.

As far as trails you can ride - if the trail requires air time, the bike is not great. It would be OK on trail that can be ridden without having to do jumps, but is better suited to XC style trails rather than all mountain or down hill.

In the end, you won't break it any quicker than a better bike, so go out and have as much fun as you can on it.


Bicycle noise when pedaling When I pedal my bike, it make a very loud noise.

I put a video so you can hear what it sound like:

https://streamable.com/e5jl8

Further info:   I tried all these steps to try to fix the problem and nothing worked:

degreased the chain with a degreaser and cleaned with soap and hot water.
lubricated the chain
replaced the bottom bracket with a new one
greased around the bearings
greased the pedals.

Do you guys suggest another thing I can do ?

Problem solved:
The noise was coming from the right pedal, i changed both pedals and the noise is now gone.
Thanks for help guys

If you can diagnose exactly where the noise is coming from, it will be easier to know what you need to service/replace. It sounds like the squeak is periodic with the crank turning around (as opposed to the chain or the wheel), so that would suggest that it is a problem with the crank, bottom bracket, or pedals. Try inspecting and turning the pedals and crank independently and see if you can narrow it down from there.

If the grease around the bearings washes out, the bearings can deform or break or become loose, and sometimes that will lead to a problem like that. Chances are the easiest way to fix it is to just replace whatever is making that noise.


Changing Campy index downtube shifters to 'only' do friction shifting How do you change Campy down tube C-Record indexed shifters to be friction shifters? I don't like index shifters as they limit your options with the cassette you can use.

Mine are Campagnolo Veloce.

I'm not familiar with those shifters but perhaps this will be of assistance: Campy Syncro 2 shifters

The left/front shifter is a standard friction shifter.
To convert (the right one) to pure friction, you can actually just remove the springs and optionally the boss collar -- the springs are all that is required to (re)move.


Buy cheaper bike and upgrade Can I change group set of this bike from Tiagra to Ultegra 8XXX without changing wheel? If yes, does it depend on geometry of rear fork?

I am asking because I would like to know whether it is cheaper to buy a new bike like this and occasionally change group elements (with used) Ultegra and you will get after some months one pro bike :).

Thanks for your time

More about what I want to buy here

You can do it, but it will be much more expensive to buy the Tiagra-equipped bike and then buy Ultegra parts piece-by-piece. Bike manufacturers get the parts much more cheaply than you can, and that price difference is reflected in the price of the bike.

Also, consider this: Ultegra is an 11-speed group. Tiagra is 10-speed. This means that you will need to upgrade the cassette, rear derailleur, and shifters all at once anyhow.


Does Campagnolo have a groupset model number system? With Shimano it is easy to find compatbile parts in a groupset because they will all share a model number system.

For example, Shimano 5800 series will consist of:

FD-5801 Front Derailleur
FC-5800 Crankset
RD-5800 Rear Derailleur
etc.

Does Campagnolo have a similar system?

It can be quite confusing since names such as "Chorus" are recycled between years; "Chorus 10 speed" is not enough to indentify a groupset.

If compatibility is what you're after, you should know that it's not always necessary to use the same group. Many times, you can mix and match different groups,  even different manufacturers.

As far as I know, all 10-speed Campy geartrain components should be compatible with each other. You have to consider the capacity of both derailleurs relative to your gearing, but you have to do that even if using the same group for everything.


What should I look for when buying a bike from an auction? I'm going to an auction to look for cheap gems. Each bike is shown only very briefly and the bidding starts immediately. No hands-on inspection is allowed.

What should I pay attention to when trying to decide how much / if to bid? Are there some immediate signs that I should look for that either hint to the high or low quality of a bicycle?

I don't know brands very well and the brands here in Finland might be different from other countries. However, brands I should look for or avoid are welcome, but any other more general external indicators for quality would be better.

I know this is similar to What should I look for when buying a used bicycle? but I think the situation is different enough to merit a separate question.

Just like with any other area of expertise, there is no substitute for years of experience. If you need a simple heuristic though, brand recognition in combination with a general knowledge of groupsets and their quality can go a long way.

At the very least, know how to tell forged components from stamped. Learn Shimano's and Suntour's groupset lineups. Groupsets are generally a good indication for the overall quality of the bike.

Know about the different qualities of steel (hi10 < 4130 chromoly < branded {reynolds, columbus}). Learn about the qualities of good steel lugs (some framesets are worth money that won't have any parts on them).

Back all this up with a smartphone and you should be good.


Front derailleur feels "disconnected" in cold I've got a Shimano Deore 3x front derailleur and it works perfectly fine while warm.

But after a ride in cold (about -10..-15 C) there is a problem in shifting up: first time I pull the lever it goes without any tension - like the cable is torn - and nothing happens. The second time it works fine.

Downshifting is ok, and rear derailleur works well too. So: do I need to worry and what is the reason for this?

There are three places to explore: the shifter, the cable housing or the front derailleur.

Given that you can't shift up (to a higher/bigger front chainring) and that the shifter feels that it's disconnected, my guess is that it's the shifter  (#1 below) that is frozen since the symptoms of #2 and #3 are that shifts down to a smaller chainring are slow/harder; and/or that the shifter feels hard/stuck when shifting up, not loose which is what you're experiencing.

If you have an indexed thumb shifter, then these are known to have lubrication problems and will eventually freeze up in the way that you mention (shifting up doesn't work, it feels like the cable is disconnected). The simple fix for this is to shoot some WD-40 or other light lubricant into the thumb shifter body and to work it in while shifting up and down. If you can, taking off the top of the housing will work better. This is only a partial fix as eventually the lubricant will stiffen again. You can then do an overhaul of the shifter, or just get a new one from your local bike shop. There are numerous intertubes videos on how to do this, just youtube "[name of shifter] DIY fix"
The simple fix for housing freeze is to try to use an injection of WD-40 (water-displacing formula #40) into the cable housing to expel all of the water and leave a thin film of very light lubricant. I would try to do this when it is warm (or your bike is inside the house) to give yourself the maximum chance of expelling the water. They sell cable lubrication widgets to put on your WD-40 straw, but I find it's sufficient to take the housing nipple off, aim the straw at the raw cable, spray, and then work the shift lever in and out -- keep repeating until you're either tired or there's some lubricant coming out the other end of the cable. This is very messy. Do not wear your favorite shirt and lay down newspaper or cardboard over your spouse's favorite rug before doing this.
If that doesn't work, then I would unhook your front derailleur from the shifting cable and leave it overnight to "freeze." In the morning, I would dry shift the cable and see if it is moving properly. I would also pull and push on the front derailleur shifting mechanism to see if that is also moving correctly. This is step #3 since steps #1 and #2 doesn't require unhooking, hooking up, and readjusting your front derailleur.

a. If it is the cable that is stiff, I'd replace it since the WD-40 in the first step didn't work. Replacing derailleur cable is relatively easy, the hardest bit is measuring the housing and cutting it to the exact length without leaving burrs. Your bike shop can do this for you.

b. If it is the derailleur that seems 'frozen' then it requires a good cleaning and lubrication. There's numerous instructionals on the intertubes on how to do this.


Long sleeves for safety? I took @Jason's and @Neil's advice and practiced wearing clipless pedals in cold weather. I fell three times (nearly four) last week, all at very low speeds: twice because of ice, and twice because of having my shoes clipped to the pedals and not unclipping in time.

Falling didn't hurt: at all. At the time I was wearing a short-sleeve shirt, and a long-sleeved uninsulated Gore-Tex wind-and-rain-proof anorak (and jeans and gloves and a hard hat). I bruised my hip slightly, one of those time; never any cuts or abrasions.

The weather is getting better (it's above freezing, this week). Eventually, it will be hot. I commute and I don't know about specialist bike clothes. I expect I might wear, I don't know, summer shorts and a T-shirt in hot weather (and shoes and a hard hat and maybe gloves).

Ought I, for safety, to wear long sleeves or something, even in summer, in case I come off again? I can't see myself wearing a wind-proof anorak in sunny summer when the temperature is in the +10C to +25C kind of range.

Should I have something though, to protect my arms if I fall? Would long sleeves make a difference? Is there a fabric that's protective yet cool?

I don't see myself wearing armour just for commuting. On the other hand, my fear / worst case scenario is that I might fall, leave bits of elbow tendon behind on the pavement, and then people say "what a fool: didn't he know he's supposed to wear XXX for, you know, basic safety when cycling?"

Unless you're out derbying or have a complicating balance issue I wouldn't worry about it.  Falling off a bicycle when commuting or recreational riding should become an extremely rare experience with practice.  Tank tops and shorts are perfectly acceptable bike wear in the summer.

Ice is of course a different beast; the best advice I have for ice is that you should be prepared to fall and do not have anything in your pockets that you don't want embedded in your leg.


Using Rohloff with a thicker chain I have a Bosch/Rohloff bike that currently uses a 3/32 chain. Seems like that's the standard for Rohloff hubs. Problem is, I'd much rather use a 3/16 chain, i.e. a chain that's exactly twice as thick. Are there Rohloff sprockets designed for this? And if not, how difficult is it to manufacture a 3/16-compatible Rohloff sprocket?

Update: even though I'm still sticking with 3/32 chains, I'm now using the stupidly thick (8.8mm pin length) Connect 7R8 chains.

This maybe late but KMC now manufacture a 1/2" X 1/8" splined sprocket for Rohloff hubs https://www.kmcchain.eu/webshop-sprocket

With a matching 1/8" chainring you can now use a 1/8" chain no problem.


Help understanding effect of Crankarm length on gear ratios Trying to learn more about bike fit and gearing, and having trouble understanding the effect of crankarm length on gearing. In an article on bicycling.com it states

"The relative jumps between gears stay the same, but the overall range will feel slightly easier to pedal, or smaller, with shorter cranks and harder with longer ones."

It makes sense to me that crankarm length would have an effect on how hard it feels to spin a certain ratio, but instinctively I would assume the opposite effect described here -- that a longer arm would give more leverage and make the overall range feel lower.

https://www.bicycling.com/bikes-gear/components/what-you-need-to-know-about-crankarm-length

I think the article you reference is in error. Obviously a longer crank arm gives more leverage, requiring less pedaling force to move the bike but requiring a faster pedaling cadence the pedal to moved faster around a larger circle (same angle/unit time, more distance/unit time). The rider's leg must therefore extend further and more quickly.


How do I adjust my 7-speed Shimano SIS indexed shifter not to miss out one of the cogs? I have a 7-speed indexed twist-grip gear-shifter, but it was set up incorrectly: it has eight positions, the fourth is where the numbers start showing, and while it hits the top and bottom gears, it has an 'empty' click that takes it from top gear to top gear and it skips from ring 3 to ring 5 with just one click.

I've read the response to How can I adjust index shifter so it doesn't skip the second chainring? but this is a 7 speed shifter (masquerading as an 8 speed and a 6 speed), not a 3 speed, so I don't believe the answer there applies here.

It seems that the twister is giving too much cable for each click (like a 6 speed shifter) and has its own position limiters which allow extra travel (like an 8 speed shifter). I've fiddled with the top and bottom limit screws on the derailleur, and with the [barrel] that simultaneously changes where ALL the indexes locate, but while I can get it somewhat aligned for all sprockets, it still does the 'not quite engaging properly' thing for a few of them, and I still have extra clicks at top and bottom.

How do I reduce the amount of cable each click gives? There's an intriguingly yellow 'c-deck plus' sticker on the twist-grip that looks like it's hiding a screw, and a couple of tiny Allen key looking things that I'm guessing are holding the unit together.

Update: the shifter declares itself to be a 7-speed shifter on the front, and the part number bit towards the back reads 'Shimano SL-RS43-7 Singapore 22.2' which mentions '7' so... presumably it's a 7-speed.

I don't know where to find the serial number of the rear cogset..?

The Park Tool web site is generally the first place to go for info on how to do different bike repairs/adjustments.

But adjusting a derailer is fairly simple if you understand the basic principles.

First, you sorta ignore the shifter lever/handle and observe the derailer.  On it are two "limit adjustments" -- a "low" and a "high".  These are generally setscrews of a sort.  One limits how far derailer can sift in the direction that the spring pulls it, while the other limits how far the cable can pull the derailer in the opposite direction.

You first need to get the cable slack (twist the cable "barrel adjuster" a bit if needed) and adjust the stop that the spring pushes against.  This stop should be adjusted so that the derailer centers the cable over (usually) the smallest cog.  Then use the shift lever/handle to get the cable tight and pull the derailer all the way in the other direction, against the other limit screw.  Adjust that screw to position the derailer over the large cog.  (You may need to adjust the shifter slightly as you make this adjustment, to keep the derailer tight against the limit screw.)

Only after adjusting the limit screws do you attempt to adjust the cable.  If you're lucky simply adjusting the "barrel adjuster" in the cable will get everything working right, but it may be necessary to loosen the cable clamp at the derailer and slide more/less cable through it, if the barrel adjuster doesn't have enough range.

Having done all this you'd generally ride it around a bit, then go back and recheck all the adjustments, fine-tuning them.


How tight should I screw my thru-axles? I have a new road bike with thru axle and disc brakes (Ultegra). I noticed that depending on the how tight I screw the axle in the frame, the brake disc will be closer to either side of the brake pads. I didn't pay attention at first, so now the rear left pad is much more worn that the right one.

Is there a way to find the perfect torque to make sure that the disc is perfectly centered?

You should screw your through axle according to the manufacturer's specified torque value range. The torque applied to the axle is not meant to be used for adjusting relative brake/disc position, even if you observe such effect. Keeping the axle under-torqued is dangerous, and over-torquing it might damage the fork/frame dropouts.

A proper solution would be to adjust the position of the brake caliper itself relative to the disc. One possible way to achieve that:

Screw the wheel's axle to manufacturer's recommended torque.
Loosen both bolts that attach the caliper to the fork/frame. Do not unscrew them too much; you should just be able to wobble the caliper by hand.
Squeeze the brake lever so that both pads hug the disc. If the pads were symmetric, then the caliper would become centered relative to the disc. In your case, you should probably do this with a new pair of pads.
Keeping the lever pressed (by using a rubber band, rope etc.), tighten the caliper bolts so that the caliper will stay in the new position. Make sure to tighten these bolts to a proper torque as well (typically in a range 7-9 N×m, but it may be different)

Now, when you release the brake lever, the distance between pads and disc surfaces will be equal (given that both pads move at the same rate, of course).


Tektro brake bleed block size? The bleed kit for my Tekro HDC 330 hydraulic brakes did not come with a bleed block. I've seen a 15mm ring spanner mentioned as a suitable alternative, but would prefer to make/buy the correct tool.

What size/thickness of block is needed?

This model of Tektro brake uses a Shimano M575/M505/M445 brake pad - so I ordered the Shimano bleed block for these brakes (p/n Y8FZ05000) which did the job.


Changing 7-speed Shimano cassette to 10-speed I have a bike with a 7 speed cassette. My question is can I swap it to a cassette with more speeds (like 10). I will change the derailleur to a compatible one.

EDIT As ojs points out in the comments below, the freehub's width of 7-speed systems mismatches those of 8- to 10-speeds. This means the rear hub/wheel has to be changed as well, in addition to everything listed below. Clearly a cost of such change now would exceed the price of a half new bike.

It would require changing the complete drivetrain and the rear wheel.

However, the good news are that a freewheel coming with 7-speed Shimano cassettes is compatible with 10-speed systems, so you won't need changing the rear hub/wheel.

The reason why the complete drivetrain has to be changed is that the front chainrings may not be working well with a narrower 10-speed chain.

The rear cassette has to be changed for obvious reasons to have more cogs
The rear derailleur has to be changed because of a different cable pull, range and tolerances required by a 10-speed system.
The rear shifter has to be changed to have 10 indexed positions and matching cable pull
The shifter cables/housings might be preserved, but they are cheap and it is recommended to change cables periodically to have better shifting experience, so it is highly recommended to get new ones.
The chain is to be changed because 10-speed chains are narrower, and a 7-speed one will be too wide and will jump all over the cassette.
The front chainrings are spaced to match a wider 7-speed chain. There is little possibility it will work nice with a narrower chain.
The front derailleur matches the front chainring spacing.
The front shifter goes away together with the derailleur.

What you need for drivetrain parts is called "a new groupset" — a name that encompasses all the parts I've mentioned.

Converting the rear wheel to a new hub would require a complete wheel rebuild. Oftentimes it means that buying a new complete inexpensive rear wheel would be cheaper.


Valve Extender for Kids Bike I can't seem to fit my bike pump onto my son's bike. The tires are too small, and there isn't enough of a gap to put the head of a bike pump on the valve.

Are there any valve extenders (not permanent) that I can use when I need to inflate his bike tires?

Yes. Slime makes some valve extenders for Schrader valves

, and if you have a Presta valve you can use a Presta to Schrader valve adapter (and if you really want, you can attach a Schrader valve extender to that, since you can buy the Schrader valve extenders at Walmart or whatever)

.

Some companies (like Topeak) make Presta valve extenders as well:

That being said, you can also use a little hose attached to the pump to better access the valve like the ones offered with some Lezyne hand pumps if the chuck is too big.

An example of a bendy extension hose is .

There are also 90 degree extenders which you screw on:


From the perspective of a cyclist, what is a common way to hydrate throughout the day? A couple of nights ago, I went for a ride. My destination was only about 4 miles away from my house, and it was a downhill journey. Of course, I had to ride back up many hills to get back home, and didn't stay at my destination very long. The total journey was 8 miles. My bicycle is also a single-speed bicycle, so I didn't don't have the luxury of gears which resulted in a challenging ride.
Anyway, I woke up with a headache and nausea the next morning; this was about a week ago. According to the posts I've have read regarding headaches after cycling, I've come to the conclusion that I must be severely dehydrated because I'm still feeling the symptoms today, just not as much.
I'm just not very disciplined when it comes to sufficiently fuelling my body. I really want to take steps to prevent this kind of issue from happening again. I used to drink 4 litres of a water per day, but the regular trips toilet gave me the impression I was overdoing things when trying to consume 4L in a couple of hours, and so, I got into the habit of drinking when I felt like it which resulted in me drinking much less than 2L per day.
I'd really appreciate some input. Drinking water should be a straight-forward process, but regularly taking small sips like many people have suggested has never worked for me; I end up not drinking as much as I should for my weight of 175lbs/12.5 stone.
I should add that I'm probably in a calorie deficit due to eating 2 small meals per day rather than my usual 3-4 medium to large meals per day. I experienced this issue in the past (many years ago) after weight training (squats and dead lifts) on an empty stomach. A bottle of Lucozade and lying down for a couple of minutes fixed the issue. However, I'm sure many other factors were at play e.g. breathing technique and so one because I trained on an empty stomach years after that and it never happened again.
If the issue has nothing to do with dehydration, then it could be something to do with me not eating enough.
Main question:

What is a common way to hydrate throughout the day at home, but also prior to/after a ride?

I have some additional questions:

After becoming dehydrated, would it be best to rehydrate with water, or use some special kind of energy drink?

Does repeated trips to the toilet when I consume water throughout the day mean I'm hydrating myself incorrectly? I definitely don't have a weak bladder.

Should I be including the water I use in food, i.e. oats, as part of my daily water intake measure, or should I only be measuring water I drink directly?

EDIT

This was in London
I consume very little salt. For example, breakfast consists of oats (made with water), crushed almonds, and fruit. The second meal I've been having is eggs, yams or potatoes and various vegetables. Very bland indeed, and definitely lacking salt from what I can see.
I've been riding regularly since December 2019, and prior to this, although I drive, I used to ride a lot. This is my first single-speed/fixed gear bike though. All of my previous bikes had gears, and riding up hills was easy, however, it's a totally different experience with a single-speed bike. It's much more work, especially with my gear ratio.
At the start of 2020 I was about 187lbs/13.5 stone, but the change of diet and reduced weight training caused me to lose a lot of weight. I wouldn't say my diet is a ketogenic diet though, but I'm starting to believe undereating was the cause of it. I had 4 meals yesterday, a lot of water, fruit and a glass of juice and the nausea and headache have gone. Looks like I really need to pay close attention to my diet.
I've been lifting weights a long time and I'd say I'm quite fit. Even when I take time off training, it doesn't take me long to get back in shape, and although the ride up the hills was challenging because I didn't really pace myself, I wasn't knocked out. I recovered quite fast, but the headache and nausea the next day concerned me.

Very unlikely you were dehydrated from such a short ride. If you were dehydrated post ride, you almost certainly started out dehydrated.  Humans evolved to the top of the food chain by drinking when thirsty, the advent of the '8 glasses a day, drink all the time' has been popularized in my lifetime (First references appear to be a 1945 FDA recommendation), is controversial and largely debunked.
Worth a read.. but this is just one of thousands saying the same thing .
(https://www.med.umich.edu/1libr/Gyn/ObgynClinic/8GlassesWaterMyth.pdf)
What I believe has happened is some people have lost the ability to listen to their body and know when its time to drink, and are so used to drinking a measure amount to a clock they now mistake the sensation of thirst for dehydration.
So how much to drink....
Drink when you are thirsty.  Use the color of your urine to tell you if you are drinking too much or too little.  Personally, if I am about to head out on a long event then I preloading a day or two before - Buts thats mostly because I tend to not drink enough, so the conscious effort is need to ensure I do not start out thirsty.
With all that out the way, say you really were dehydrated, not just hungover (which is mostly dehydrated with toxic by products of metabolized alcohol), had Covid19 or one of many other medical conditions that cause headaches, what to do...
Rehydrate with water if its mild. If you want to rehydrate quicker, or it is moderate, rehydrate with an isotonic drink. Do NOT consume energy drinks, they use more water than they provide.  Drink until you pee, then drink another litre is a reasonable point. You are recovered when your pee returns to normal color.
If the dehydration is severe, then you need medical intervention, likely a saline drip (Speaking from experience, magic, but like any medical procedure, negative side effects are always a possibility so should be avoided whenever possible)


How do I change the rear tire on old Raleigh "Tourist" 3-speed Never changed the rear tire on this bike. How and what is loosened to remove the rear wheel so the tire can be changed?

This is where a 60 second Youtube  video is worth 1000 words. The adjustment takes less than a minute. There are a couple methods. If it is shifting ok now, mark the threaded rod where the cable attaches. Place the shifter in gear 3. Loosen the jam nut 1/4 turn, just enough to allow the cable end to unscrew from the threaded rod. with the cable disconnected, remove shifter chain guide nut. It may be separate or part of the axle nut. Remove the wheel as you would any other nutted axle. Reinstall the repaired wheel. You can reattach the cable screwing the cable end up to the jam nut. Tighten the jam nut. To check the adjustment. Place the shifter in 2nd gear. If you look at the shift chain guide you will notice two observation holes on the sides. If properly adjusted you should see about 1mm of the straight rod exposed. If more than 1mm is exposed loosen the jam nut on the cable end and expose a less of the threaded rod and tighten the jam nut. If less than 1mm is exposed loosen the jam nut and screw the cable end to expose less threaded rod.


What are Clarks 2P and 4SP cable housings? Lots of websites stock Clarks cable-outers. Lots say which type -- but I can't find what that type means. Can you help?

I suspect 2P is a fairly standard brake cable outer (5mm, spiral-wound, nylon-lined) and 4SP is a fairly standard gear cable outer (4mm, straight-wired, nylon-lined). Is that correct? Are there also other types?

I recognise those numbers so yes that’s right, but don’t ask me to explain what they mean! Buying housings nowadays doesn’t require overthinking, just buy from someplace you trust like anything else.

You can get compressionless brake housing, used for example for longer cable runs where you might otherwise get a spongy brake feel. It’s similar to gear housing, which must be compressionless, but obviously larger diameter and is a more expensive upgrade option so will get filtered out if you’re searching by price.

Shimano make a coiled gear housing called OT-RS900 a length of which comes with new R8000 rear derailleurs and probably some other models. Very slick, cuts like butter, but also a bit of a luxury item which you wouldn’t often use.


What frame does my mountain bike have? I'm trying to work out what my frame is, and what size bottom bracket it needs (68/71/73 mm), and the recommended spindle length. I've attempted to measure both and it seems to have a 68/115 bottom bracket.

I can't find any serial number on the frame, but someone told me, circa 2002 that it looked like a Marin.

Complete bike

Yoke

Rear

Rear wheel hub, note the unusual markings

Rear from top

Crank

You  probably will waste more time trying to identify the bike compared to just replacing the BB.

Two options - Easy but likely more expensive - take the to a bike shop have them supply a BB of the correct size, if they supply the wrong size, they should be prepared to swap it.

Or buy one cheap off the internet (probably 68x115) and if its the wrong size, well you have a spare the wrong size for you current bike.

Its unlikely a spindle length of a couple of millimeters too short or long (i.e. one size up or down) will make a major difference. The worst happens is the front derailleur rubs when cross chaining. BB are cheap - $10 for a cheapy, $20 will get a reasonable quality one for that bike. So it won't break the bank if you buy the wrong size first time.


Freehub comes free from wheel with cassette attached I was cleaning my bike and a gust of wind knocked my wheel over which had been standing up against a wall. I found the cassette/freehub detached from the wheel. The end caps don't appear to have a thread and I wonder if this is okay, as everything would be held in place when the wheel is placed on the bike. Could someone confirm?
For reference, the wheel is a Reynolds AR62.
I've uploaded a demonstrative video to Imgur, here

You usually can't remove the freehub body on most hubs by hand, as is probably obvious. However, on at least some hubs, the freehub body does slide right off. Mountain Bike Rider mentions this about DT Swiss star ratchet hubs in general, and I am able to do this on a DT Swiss 370 hub (a lower-end hub with pawls). Consider that while you are riding, the hub is under some compressive force from the thru axle or quick release. The freehub should be unable to just back off out of the hub.


Can I fit rear panniers to a full-suspension bike with a dropper post? I'm looking at the Whyte T129s and have seen that there's a couple of options for fitting panniers to the back of a full-sus bike.

Topeak

Freeload - see link

Any suggestions whether either of these would work for (occasional) off-road touring? Concerned that the dropper post on the 129s might not take a rack (like the Topeak) bolted on.

The main issue is the load limits on those racks, and the second one is why those limits exist.

The Thule Pack ’n Pedal Tour Rack is claimed to take 25kg, the Topeak seatpost mounted racks will take 9kg. Thule seem to be selling rebadged Freeload gear? I have seen a Thule rack fail with significantly less than 25kg on it, and while being ridden fairly gently (very gently by full suspension MTB standards - think hiking track rather than singletrack), when the rider twisted the bike from side to side. None of the solutions of full suspension bikes are robust enough for harder mountain bike routes, and none will carry their full weight rating without really affecting the bike's handling.

The reason for that is that full suspension frames and components are not designed to take the extra force of the load, and often not designed to take much force at all where the racks attach. Ideally the rack will attach to a point that's designed to take a load but isn't being used for that load - V brake posts on a bike with disk brakes, for example. But regardless, if you have a lightweight bike and you load it up and ride it hard, something will break.

If you look at designed-for-touring bikes they usually have heavy frames, built in points to attach racks, and are sold with heavy wheels and beefed up components. At least compared to a fun bike or racing bike, which is what most full suspension bikes are. There are full suspension touring bikes, like the Bike Friday, but they are built very differently to mountain bikes.

The usual compromise is a hardtail - that gives you a solid place to attach a rear rack while getting some benefit from the front suspension.

How much gear you carry depends on what you mean by touring. To some people touring is accompanying a tour bus and support crew on short daily rides, to others it's riding the Canning Stock Route without a support vehicle. In many ways your weight budget will determine where you can go along that spectrum. You can also spend your way out of some of the problems by using ultra-light hiking gear to cut the weight you're carrying. As an example, I normally carry about 20kg of gear on month-plus tours, then another 10kg-20kg of food and water. For a weekend I'd not take cooking gear and minimise everything else to take about 15kg total assuming there's water en route, but that means accepting that if it rains I sleep in wet polypro and if we're delayed a day I go hungry (ie, trading weight for risk).

I suggest looking at some of the touring questions to get an idea of what exactly you want to do and what gear you're likely to need to do it.

Note on risk: if you're touring off road you need to keep an eye on your escape routes. Specifically, remember that you go much faster riding than you do carrying a broken mountain bike. If you break the bike late on the first day of a two day ride you might have to spend three days walking out (assuming you're unhurt). On-road touring is usually less risky because you can flag down a passing motorist and get a ride (or call a taxi).


Presta valve problem new to the Presta valve game, I just replaced my tube and the valve tore in less than 10 mins of riding. My bike tire is 26x1.9 the tube the got was 1.7-2.4. I have both the same rims and the front is also running a Presta valve. Not sure if I did something wrong or just a faulty tube.

A picture of the damage would tell for sure but 90% of the time tearing a valve - presta or schrader - is due to under inflation.
Low inflation pressure allows the tire to slip (during acceleration and/or braking on the rear, braking on the front) on the rim. The slipping tire rotates the tube. As the tube moves the valve is torn off as it moves against the valve hole in the rim.
It is possible to have a faulty tube. Usually defects (imperfections in molding etc.)look very different than forcibly tearing or cutting the valve on a tube.


105 11-34T Cassette Compatibility I purchased a Merida Speeder 400 a year back. This came with Shimano 50-34 teeth and Shimano CSR7000 11-32 teeth 11-speed cassette which I replaced with Shimano 105 R7000 11 Speed 11-34 Teeth Cassette. Since then, the ride is not quite right. It feels like the chain is about to break sometimes especially in certain gears. What am I doing wrong?

Shimano's published method for establishing chain length is based on adding links to the length that will wrap around large/large sans derailleur. When a bigger cassette is swapped in on a chain sized that way, the chain will typically be too short, and breaking your chain, derailleur, hanger, and/or frame may result.
The alternative is to do the technically wrong thing and size to allow the RD's entire total capacity to be used, which allows any cassette the RD would otherwise be compatible with to be swapped in. (The b-tension would need to be adjusted for it to work right, but typically things won't blow up even if that step is skipped.) There are those of us who feel sending riders out with a chain sized this way is doing them better service on average than giving them whatever marginal upside there is with fewer links. This practice can really save a lot of pain. And, if you're a mechanic, you have to think about who the finger is going to be pointed at when a 25 or 27 gets swapped on when the chain was sized for a 23 and someone's race/bike/life gets messed up because of it.
It's possible what you're describing is from not adjusting the B screw, but more likely it's from the chain being too short.


Am I too heavy for my road bike tires? I am wondering if bike tires have a weight limit.  I have to admit, I am a large guy at 6'3" 250lb (190 cm, 113,5 kg), and I have always had issues with my road bike's tires getting pinch flats.  I could never seem to put enough air in the tire to keep the rim off the road on bumps, etc.  I ride a mountain bike now and I haven't had the same issues.  Though of course they are a lot knobbier/thicker.

The tires are 27 x 1.25

Pinch flats are due to under-inflation of tires.  On a road bike you should be inflating your tires to 120-130 lbs.

Also, you need to check and re-inflate your tires every time you ride.  I just keep my pump right next to my bike, and wind up adding air every 2nd or 3rd day.

I see you added tire size - those are older bike tires, they don't inflate as high as road bike tires, I'd try pumping them to 65 lbs, and if you are still getting pinch flats, go up 5 lbs at a time until it stops.

You can tell a pinch flat because it will look like a snake bit, 2 small holes close together.

If you do not get any pinch flats at 65 lbs, you can try going down 5 lbs at a time until they return, then you know the range your tires need to be at to be properly inflated.

The most important thing is to check tire pressure every time you ride, as bike tires can lose up to 5/lbs a week from just sitting.  These are high pressure tires, so they lose air much faster than low pressure car tires.

Cheers,
Mike


Pedal that stays horizontal Sometime when I step on the pedal my foot slips off because the pedal is in vertical position, not a horizontal position.
I used to own pedals that always stayed in a horizontal position, but I forget the brand name.
Do you know a platform pedal that always stays horizontal?

I don't know of any current pedal with those properties, but an old example is Shimano's Adamas AX touring pedal, which you can often find for purchase used. These pedals are weighted on the underside at the spindle so that they remain horizontal. Here is a view of the underside where you can see the weighted portion:

I have seen plastic copies of these pedals, but I do not know what brand they were. I suspect there are other similar variations out there.


Installing Schwinn Vestige frame LED cable I read a post (Daniel and Jennifer) from a couple of years ago explaining that the Vestige frame LED should be replaced if it is no longer working.  Thanks for that. Now, I'm seeking tips, a guide or a manual on how to install the new light string so it will work properly.  Mine is not. Dynamo has been tested and works fine.

I do a lot of bike repairs but this one is a big challenge.

I would start by pulling the seatpost, fork and the bottom bracket. Use a small mirror similar to a Dentists type to try to see if the wire is attached in the frame or just passes thru. You may then be able to remove it. If possible attach a string to the end of the cable. You can then use the string to pull the repaired light cable back through the frame.


Free Spirit "Brittany Te12" Part Identification/Upgrade i found this old 12 speed basically attached to a neighbor's back porch by vines, and aside from some superficial rust on the chrome, it seems to be structurally intact. the decals read as stated in the title and also indicate that it was sold by Sears Roebuck and made in Taiwan.
a photo album of the bicycle and closeups of parts is available here.
i can't find any reliable documentation specifying the parts currently installed, but as far as i can tell from googling, it appears to have:

a very noisy, threaded, adjustable cup-and-cone BB. resource
a cottered crank, which was loose, and upon tightening, became crooked. resource
a "Falcon XT" rear derailleur with little remaining spring tension.
a "Falcon" front derailleur with little remaining spring tension.
a 126QR bolt-on, drop-out rear hub, based off of ~126mm measurement. resource
a bolt-on, drop-out front hub that i could not identify (nothing found with ~88mm measurement).

i would like to replace most of these with modern equivalents that fit with minimal/no modification. (e.g., a non-cottered crank, quick-release hubs, common derailleurs, etc.)
the only resource i could find with something specific was this Reddit post where someone claimed to replace the BB with a Shimano UN-55.

tl;dr: knowing the parts is useless. You have a caliper, now you just need to remove everything and measure everything. You will learn something just by disassembling this bicycle and not focusing on brands, just on dimensions and "mechanics" of the parts you are removing.
Then, about reassembling it, it will cost you 5 times the money and 50 times the time+effort with respect to a bicycle shop.
Disclaimer: I do not own a bicycle shop.

The parts currently installed have no value and will provide very little information on their own.
You can still disassemble them and try to understand a thing or two on how they are assembled and maybe how they work, especially about the derailleur (springs, limiting screws and so on).
Bottom bracket and cranks are good to be recycled (=scrap metal), as well as the chain and whatever is installed on the rear wheel as a cassette.
New bottom bracket and crank ---> most likely new chain line. Which is not that bad considering that the wheels will almost for sure need a good clean (greasing the hubs and so on) and you may discover that they are in bad conditions, so counting them temporarily as scrap metal as well, the new chain line is less of an issue (you have a lot of freedom once you have to replace bottom bracket, crank, rear wheel).
So remove the bottom bracket, check whatever size is relevant.
Then check the fork. Remove it, give it a thorough clean and a good examination, check for cracks in the fork or for deep rust. You do not want a fork that breaks in half while sprinting across an intersection, nor while you are just coming up/down from the curbs.
Check and note wheels size.
Save the frame, maybe the fork, then you have a lot of freedom in how to reassemble this bicycle.
I forecast something on the order of at least 3/400 USD/EUR/GBP, only for the parts (assuming you have all the needed tools for cassette, bottom bracket, fork, etcetc).


Is there a cycling equivalent to Naismith's rule After doing some training rides on courses without bigger ups and downs where I didn't make significant elevation gains, a recent ride was in more rough terrain. Of course, the relief changes the average speed one can achieve and I was wondering, if there are some rules of thumb to estimate the influence of the relief.

From hiking I know there is Naismith's rule which allows to calculate the time needed for a certain route based on distance and elevation. I am aware of the fact that with cycling the rule would be less general and require more calibration depending on

mountain vs. road bike
different surfaces
greater difference between uphill and downhill speeds.

On outdoors.SX.com also someone presented a slightly different approach that translates different parameters (elevation gain, trail conditions etc.) into distance travelled, which could be another useful approach here.

So my question is, is there some rule of thumb or a set of rules of thumb for cycling as well?

As you have noted, the problem is slightly more complicated for a bicycle since aerodynamic drag is a larger component. However, one can combine two rules of thumb which are given in these two bicycles.stackexchange answers (How do I calculate power to climb a hill and How many miles of riding are equivalent to one mile of running) to make an estimate of either speed or power on the flat and on climbs.

If you are only concerned about climbing the rule of thumb is simpler: on a steep hill, multiply the hill's gradient by your speed in km/h, then by ~ 3. If you measure your speed in mph, multiply by 5 rather than 3. That will give you a ballpark estimate of the watts/kg you need to produce. Since you're trying to calculate riding speed, just "solve backwards" given the equivalent power (in watts/kg) for a given slope. For flat roads where aerodynamic forces predominate, you will need to have a ballpark estimate of your "drag area" which mostly depends on your position on your bike.


Reusing SRAM 10 Speed PowerLock? According to: http://www.sram.com/sram/road/technologies/powerlock

"SRAM chain engineers developed PowerLock as a tool free, sure and consistent way to connect our 10 speed chains. While PL does not require special tools for install, the especially tight tolerances of 10 Speed drive trains mandated that each PowerLock is good for a one-time application only."

According to: http://www.competitivecyclist.com/sram-pc-1051-chain

The SRAM PC-1051 Chain is compatible with both SRAM and Shimano 10-speed drivetrains. Please note that while the PowerLock installation can be done tool-free, it's recommended to be used only once due to the extremely close tolerances required by the narrow 10-speed design. So if you must break your chain for maintenance reasons, a new 10-speed PowerLock link will be required to reassemble it.

Two questions:

Why is this the case?
Have people hear observed or seen tests about what happens if you re-use?

I use the Park Tool Master Link Pliers to remove master links. I have a hard time believing that doing it that way stresses it significantly.
Related, from http://www.bikeradar.com/us/mtb/gear/article/trail-tech-mastering-master-links-36757/:

"According to SRAM, the ridge that joins the two plates of the PowerLock together can be damaged when unlocking it, increasing the risk of failure if reused. So yes, if you choose to reuse a PowerLock there is an increased likelihood of if failing, according to SRAM."
I know a number of professional and team mechanics who routinely reuse PowerLocks on their own bikes, but replace them with a new link when dealing with a customer or athlete, so it’s a bit of “do as I say, not as I do.”

It's not so much that reusing the link increases the chance that the pins or plates that the Powerlock is made up of will fail, but rather that it increases the chance that the link will come apart the same way it was put together. Each time you remove that link it wears down the "ridge" that snaps the pins in place on their opposing plates. This increases the chance that the link can undo itself in unusual circumstances. It may also slightly increase the chance of the link failing in the case of shifting under heavy load, which should be avoided anyway.

SRAMs 9 speed quick links were notorious for coming apart on the trail as they are reusable- some of this had to do with improper removal which damaged the relief that held the pins in place. It's probably easier for the company to just say "don't do it" than to say "do it this way" and folks don't adhere to the manufacturer's recommendations, leading to failures.

TL;DR version- if you only remove the link on occasion, its good for the life of the chain. Don't reuse an old quick link on a new chain.


Correct inflation pressure for old road bike I have an old Fuji road bike that I got a garage sale a while back. It's probably from the 70s or 80s. This summer, I've been trying to fix it up into good condition for some longer-than-usual rides (maybe 10+ miles, as opposed to just 4 or so). The old tires (27 x 1/8, hooked rim) were very worn, so I took the bike to a shop where they replaced them with new ones (32-630, 27 x 11/4 to fit schwinn s-6 or k-2 tubular rim).

The new tires say "inflate to 90 psi", which is what I was planning on doing until one of the bike mechanics told me that I was running them way too high. He said the tires and tubes could handle that 90 psi pressure, but that my rims (which are the original aluminum ones I think) couldn't take 90 psi. Instead, he advised that I keep the tires at 60-65 psi. I tried his recommendation, but the tires definitely seemed to bulging out a lot where they contacted the road as I rode it around. I feel like the tires should be more inflated, but I don't want to damage the wheels.

So, I thought I'd get some advice about the matter. I'm 165 lbs, and my rides won't be too serious for now at least. Just riding around mainly on some wide walking/bike paths we have in the city. There may be a few mile-long stretches of sidewalk, however. Any advice is very much appreciated!

I can't see your specific rims from here, but plenty of bikes back in the 70s and 80s had rims that width capable of handling 90-110 PSI.

And I definitely wouldn't run a 1-1/8" tire at 65 PSI.  I'd imagine that the rims, if designed for tires that narrow, should be able to handle 80 PSI or so.


Gear 5 and 6 got slower in bike? Yesterday I pedaled reverse (one circle) while getting on my bike, I heard a sound at the chains and after that the bike speed on my 5th and 6th gear got slower. Before I used to pedal less and the bike would go faster but now I have to pedal alot faster for the bike to move ahead. What is the problem? Should I visit the cycle repair shop for fixing or can I fix it by myself?

Sounds to me like your derailleur is not properly shifting (to the smaller cog) in those gears you mentioned.

First thing to check (imo):
Put the bike in a bike stand or position it upside down, shift onto smallest rear cog.
Watch the cassette/chain whilst pedaling with one hand and shifting with the other hand. Check if the chain properly shifts each time you press the shift button with your hand. Do some shifts require more than 1 'click' of the shifter before the chain moves? Are any cogs being skipped? Are the outer most cogs (biggest/smallest) on your cassette ever reached by the chain (if you cannot shift into these (biggest/smallest cog) your derailleur limits will be improperly adjusted or (for biggest cog) cable tension may be too low.

Probably a cable issue (a cable in bad condition (even though it might look like nothing is wrong with it) can cause issues similar to the one you are describing). Especially when downshifting (to a smaller cog) this can cause issues since when up-shifting you 'pull' the derailleur to the next cog using the cable (you can determine the force on the cable with your thumb so even with a little more cable friction you'll likely be able to up-shift just fine) and when downshifting you are relying on the derailleur spring to move the derailleur into the desired position.

The issue could be with your shifter also but it's less likely in my experience.

A few things to check:

Remove cable from rear derailleur by undoing the cable clamp bolt, then pull the cable taught with one hand whilst shifting with the other hand. See if the cable moves smoothly through all the gears (both in up-shifting and in down-shifting). If the cable is not moving smoothly in either direction, remove the cable housing from the shift cable and check again, if the problem (cable not moving smoothly) is gone without the cable housing you know the issue lies with said cable housing.
Check the cable housing for any exterior damage (cuts, sharp bends etc.). If you have a lot of spare length (cable housing) and if the damage is near the ends of the housing you could consider shortening the housing to remove the damaged length. If that is not the case replace the entire piece of housing which shows the exterior damage. If the cuts are not deep enough to cut through the plastic/rubber of the cable housing then the cuts might not be a problem. As soon as the cuts result in exposed metal they will rust (if they are not stainless steel) which could very likely cause (undesired) extra cable friction.
Remove the shift cable from the housing and check it for any fraying/rust/loose wires sticking out etc. If the cable is rusty you could clean it with for example steel wool and lubricate it but your best option is to replace it (preferably with a stainless steel variant). If the cable is frayed or damaged in another way definitely replace it.
Check the condition of the cable housing end caps, are they bent/deformed in any way? If so definitely replace them.
Check (without shifter cable attached) the rear derailleur, check how smooth it moves (by pushing it from side to side with your hand), lubricate the linkage pins.
Whilst the shift cable is removed from the rear derailleur, move the derailleur from one side to the other side of the cassette by hand (whilst turning the pedals with your other hand), check if the chain can reach all the cogs (if the limits are set incorrectly the chain might A: not move far enough to reach the biggest/smallest cog or might not move onto said cogs far enough causing it to 'fall off' (jump to the cog next to it) when putting any pedaling force on the chain or B:move too far causing the chain to fall off the cassette (in between frame/cassette or in between hub/spokes and cassette). You should be able to move the derailleur by hand (when the chain is on the biggest/smallest gear) such that the center of the upper jockey wheel of the derailleur is approximately 1-2mm further than the biggest/smallest cog itself. (please check the Park tool video -linked below- on derailleur adjustment for more info on this)

Cable end caps:

I would personally suggest replacing the following:

inner shifter cable
shifter cable housing
shifter cable housing end caps

The cable housing and end caps shouldn't cost much, especially when bought in bulk (10+ meter). You can also buy sets which are meant to replace the cables on just one bike, but they are much more expensive and I have not personally noticed a difference in quality.

There are special pliers for cutting cable housing which are great but you can work with normal side cutters also, just have to make sure the cable is cut straight and when cutting brake housing cables make sure the 'spiral' (metal spiral that runs through the core of the cable housing) doesn't have any sharp pieces sticking out after cutting (you might have to cut a few times to get it perfect).

You can definitely do it yourself. Derailleur will have to be readjusted (cable tension) after you've replaced the cable, there are a lot of tutorials online on how to do that.

Some tutorials you might find useful:
Replace shift cables:

Adjust derailleur:

Note: when replacing the cable you'll only have to re-adjust the cable tension after having installed the new cable (assuming all (other) prior adjustments were correct), it can't hurt to check the other adjustments whilst your at it (how to do that is shown in the video :) )

https://www.parktool.com/blog/repair-help/rear-derailleur-adjustment

Adjusting derailleurs is very doable as long as your cables are in good condition, if they are not then you might be adjusting for an hour and you won't be able to get it to shift correctly (similar to your situation now).

Alternatively:
Your derailleur or derailleur hanger could be bent. You can check this with a derailleur alignment gauge (or in very severe cases it can be seen with the naked eye). On steel frames you can usually bend the derailleur hanger back if it's bent. On aluminum frames you'll have to replace the derailleur hanger (separate piece) if it's bent. This seems quite unlikely based on your description of the cause (backpedaling) but I thought I'd mention it just in case..

Here is some info on derailleur alignment:

Derailleur hanger alignment: https://bit.ly/2TVoYUJ

DIY derailleur hanger alignment tool: https://bit.ly/2RRvbyz

Align derailleur hanger without special tools: https://bit.ly/2TTF6Gj

How to straighten a bent derailleur: https://bit.ly/3aL3VdQ

Some more useful info:

https://www.parktool.com/blog/repair-help/front-derailleur-adjustment
(thank you for the suggestion @Argenti Apparatus )

Hope this helps, let me know if you have any questions.


Anyone able to ID and provide information about this mountain bike? (DK, Club Roost, FSA) I've had this bike for several years but I don't know anything about it. It would be interesting to find out the exact model and see what comes up on the internet about it. Everything is exactly how it was when I came into possession of the bike, with the exception of the gear-shifter and saddle that were both replaced. I also added a basic speedometer and bell.
On the front it has the DK logo and it also says Club Roost on the handlebars. The headset thing says FSA Orbit and the top-cap above is an FSA Conix. On the side of the frame is has a letter that looks like a backwards Z. I believe the wheel size is 26". There are 8 gears in total. Would anyone happen to know specifically what bike this is, and what modifications has it had? I assume the pedals are different to the ones that were included initially.

It’s a custom bike.

It’s a Saracen team M.A.D frame from late 90’s early 00’s
with as you correctly say dk stem and club roost bars
The Rear Mech looks like Shimano Deore.
The Forks: RST - most likely, Cranks - Gusset pigmy perhaps? And Pedals are Tioga
Shimano Stx RC brake levers
And that looks like a Mavic D521 rim on the rear.

Hope that helps.


How do I properly install pads into a Shimano BR-M365 disk brake caliper? I've been an idiot. I took them off the bike this morning, and there's nothing left - the springs have been bent back and stripped off, and that strange 'rubbing' noise I've heard from the back wheel? Yes, it was...

I've bought some new pads, but I don't want to mess things up any further.

How do I properly install pads into a Shimano BR-M365 disk brake caliper?

Any hints, clues, do and definitely don't?

Just because you let your pads get too far worn down does not mean you are automatically going to screw up replacing them.

Hydraulic disc brake pad replacement is reasonably simple:

Check you have the correct pads for the calipers.
Look up Shimano's installation instructions. I just googled 'shimano BR-M365' and found the product page. Pad installation instructions are in the dealer manual found on that page.
YouTube is replete with bike maintenance videos. Park Tool has a excellent channel, Global Cycling Network has some good maintenance videos, here is their hydraulic pad replacement one.
The big 'don't' is do not pull the brake lever when the disc is not in the caliper, and especially don't do it when the pads are removed. The pistons will be pushed out to far and do not retract. They can be pushed back in to the caliper (you have to do this when installing the new pads), but over extending the pistons with no pads in the caliper can result in fluid leakage.


Smartphone mount: stem mounted vs top tube For those of you that have tried these, I'm wondering if the stem (or even bar) mount is preferrable over the top tube mount? Seems like having the top tube mount means you have to look further back (and down) to glance at the screen.

I regularly use a stem-mounted phone mount for navigation on my tourer, and occasionally on my hybrid.  I have tried my phone in a toptube bag, and don't get on with either the bag aspect or the position.

One benefit I find is that mounting it further forwards means I can mount it more upright, which shields the screen a bit against both rain (waterproof phone) and sun. I've just made a little wind/rain shield for my stem mount, which I'll take on its first long ride tonight. It would be nice if someone made something like this.

On the MTB I occasionally use the toptube bag, but I'm more worried about knocks and more willing to stop for the map, and it's easier to move the toptube bag between bikes than the customised stem mount.

Edit: some pictures of the mount I use, more details on the windshield.

It did a good job of keeping the rain off the screen while moving, but I didn't have to navigate stop-start traffic in the rain so that's still untested.

This is about what I see when riding (if on the drops I can still see enough of the map, but not my stats). The toptube bag holds snacks, keys, and battery pack if needed, as well as the cue sheet/backup navigation.

The mount from the side.  It's a cheap one from Tiger (emergency purchase), with the smoked Perspex windshield hot-glued on (there's not enough plastic on the mount to screw into without killing the adjustment).  It needs a bit of anti-vibration (more hot glue, and a strip of old inner tube as a rubber band).  Ideally I'd have got my hands on some thinner Perspex (this is 3mm, and a bit hard to bend cleanly using just a heat gun and scrapwood), but it wasn't available in time.

Update: That particular plastic phone mount didn't last very long after those shots were takendue to a broken adjustment mechanism. Its replacement couldn't take the weight of my phone, which is essentially armoured - just as well as it hit the road at 30 km/h.  I'm currently using a metal phone mount on the aero bars and need to remake the wind/rain shield to fit it.


Rear hydraulic disc sticking My 2012 Model Scott Sub 10 has recently been experiencing issues with the rear disc sticking on my daily commute and getting so bad that I have to stop, wait for it to cool and then push the disc a bit to give it some space. I believe this has been caused by the terrible weather that the UK has experiencing, perhaps with some debris becoming lodged in one of the pistons.

I decided to take the pads out this evening following the guide that came with the bike and cleaned any dirt around the pads but there is still some friction there.

I am debating pouring warm/hot water over the whole brake system in an attempt to remove anything that may still be lodged.

What advice would you you suggest aside taking it to my local bike shop?

The advice I have seen for a stuck piston is  a) hot soapy water, followed by Isopropyl Alcohol, followed by a small amount of brake fluid (Use the same that is in you brakes - mineral in your case) to lubricate the piston. If you google for "Stuck Bicycle Disc Brake piston" there is quite a lot of useful advise

Warm soapy water on it's own cannot hurt. Although I have never needed to do this, I would use a syringe to direct the water at the pistons to waste away as much crud as possible. Move pistons out (being extremely careful not to drive them out too far - put a pair of old pads in before squeezing the lever... When pushing them back in, do it gently) Watch for a piston moving more than the other. If one is not moving, hold the other in to get it free.  Then squirt water over them and wipe them off with a clean rag.

If the crud contains too much in the way of oils, the water may not be enough  - resort to the IsoP.

Wipe a clean rag soaked in a small amount of brake fluid over the pistons. If desperate, a normal mineral oil, but what every you do, don't use too much. You need just enough to put a thin layer over the piston, and more and you risk getting it on the pads (very bad for them).

Finally, and most importantly, get a clean dry rag and wipe the whole assembly down as clean and shiny as you can. Install pads and see how you got on.


Does sunlight damage helmet? Lately I am wearing my helmet also on my daily commute to work.

Of course I don't wear it while sitting at my desk, and it sits on a drawer next to the window, where in the afternoon it is exposed to sunlight with little or no air flow.

Can this lead to long term damage of the helmet? The helmet shell is white.

I was able to find one study that comes close to addressing this: Age Does Not Affect the Material Properties of Expanded Polystyrene Liners in Field-Used Bicycle Helmets. You'd need to pay to read the whole thing, but the abstract and title are clear enough. It's not clear from the abstract whether the helmets tested had been exposed to UV or not.

According to the Bicycle Helmet Safety Institute, UV exposure is not a big concern because helmets are treated with UV inhibitors, and unless there's visible signs of cracking, talk of replacing helmets on a regular schedule is marketing hype.

The EPS foam makes up the bulk of the helmet, of course, but it's not the only part, and if the shell, pads, or straps are damaged or degraded, that might be a reason to replace it.


How to use Windstopper gloves most effectively? The Cold hands due to cold/wind question had a number of good recommendations, including using gloves with Windstopper branded material. My ski gloves are worn out so I purchased this silk weight Windstopper pair of gloves (WARMER - not WARMEST or WARM) last week to see if it could measure up to ski gloves.

http://www.amazon.com/gp/product/B002VN86J6

They did not even come close. Commuting between 17-25 MPH on an electric bike in pedal assist mode (high cadence, low effort) at 50 degrees or so for 20 minutes, my hands are cold, and do feel the wind a little. My 10 year old thick ski gloves are much warmer. The upside of this pair of Windstopper gloves is that my fingers are fully mobile, as compared with my thick ski gloves which reduced finger dexterity to the point where it reduced reaction time for shifting and ringing the bell.

This morning I tried using regular bike gloves worn under the Windstoppers, and that at least kept my palms warm, but fingers were still cold.

What is the best way to use Windstopper-based gloves. Do they require liners to be effective?. If so, which brands/models are appropriate for which temperatures?

They'll never provide as much insulation as ski gloves, on their own - they're not designed to.

They're intended to block the wind (so minimising the convection heat loss due to high airflow) but still allow you to breathe (which implies you still get the heat loss due to evaporation).

A wicking/insulating liner underneath will add some straight insulation too; if it isn't wicking or fairly open weave you'll lose breathability, but on the other hand an open-weave glove the wind would otherwise cut right through will actually be useful with these over the top.

For comparison, I sometimes wear a windproof shirt for running, usually in the winter: if I wear it over a singlet and it sits against bare skin on my arms, it doesn't add much (or any) warmth. If I wear it over a baselayer, it adds lots, while still being lighter than an equivalent softshell and more breathable than a hardshell.

tl;dr - use a thin, breathable insulating liner. Wool will probably work well.

Oh, and pay attention to the cuffs and your sleeves: any part of your arm not covered, even if it doesn't feel cold itself, will be losing heat that should be reaching your hands.


Upgrade compnents to fix "Everest" brand BSO/MTB so after a month of research,i've come to a conclusion that this might be an everest brand mountain bike.its a unified rear triangle and its frame is made out of steel.since i'm not gonna just let this bike stay one side collecting dust,with a budget of about maybe a 100 bucks,what could i possibly upgrade to make it a good ride? please just give me tips,any will do.and don't tell me that i should just trade for another frame

From some quick searching, it seems that "Everest" is a department store brand. Most upgrades that you would really notice would probably cost a significant portion of the value of the bike. Other than making sure it's in good mechanical condition, I wouldn't recommend putting much money into this bike.  Make sure the chain is oiled and there is the correct air pressure in the tires.  Make sure the gears and brakes are adjusted properly and work well.  Even something simple like a set of tires or new brake mechanisms could easily cost $50+.  Just ride it and have fun with it. Save up your money for a better bike.


Can I take my bike on the New York City subway or buses? Do I need a folding bike to do this? What are the rules? Also, even if it's allowed, is it practical to do so? Subways get pretty crowded during rush-hour, and it's hard to imagine taking a bike there even if it's allowed.

Bicycles are allowed on the subways at all times, but the MTA suggests against taking your bike on the subway during rush hour.

  Bicycles are permitted on Subway trains at all times. However, we strongly recommend that cyclists avoid boarding crowded rush hour trains.

Folding bicycles are permitted on all trains and busses except for express busses. Once folded, a bicycle is really no larger than most other luggage.

When taking bicycles on the train, be courteous and use common sense. Don't bring a bicycle into a car that's too crowded. Let people out before getting in. Don't block the doors, keep control of your bike so it doesn't roll into anyone when the train starts or stops, and be aware of when people need to get by. I only ever take my bike on a train if there's enough room for everyone to sit; if it's crowded enough that people have to stand, it might be getting too crowded for a bike.

For more tips, see the MTA Bicycle Safety tips and the detailed rules on when you can bring a bicycle on the train.


Can cycling adversely affect male fertility? Is there any evidence to suggest that cycling adversely affects male fertility?

Most scientific studies on cycling and urogenital problems are written with clinicians in mind, to make them aware of possible symptoms that they will encounter. Often these studies get summarized into review articles. One such article (Leibovitch and Mor, 2005), reviewed 62 relevant studies. They say:

  The reported incidence of bicycling related urogenital symptoms
  varies considerably. The most common bicycling associated urogenital
  problems are nerve entrapment syndromes presenting as genitalia
  numbness, which is reported in 50–91% of the cyclists, followed by
  erectile dysfunction reported in 13–24%. Other less common symptoms
  include priapism, penile thrombosis, infertility, hematuria, torsion
  of spermatic cord, prostatitis, perineal nodular induration and
  elevated serum PSA, which are reported only sporadically.

When examined individually, many of these studies have limitations (small number of study subjects, no followup, etc.), but when taken as a whole, they are pretty conclusive that an association exists between cycling and urogenital problems.

The only study that I could find that was population-based, i.e., included men with a range of cycling durations, was Marceau et al., 2001. Their data on 1,709 men come from the Massachusetts Male Aging Study. After controlling for potentially confounding factors ("age, energy expenditure, smoking, depression and chronic illness"), they found that men who cycled more than 3 hours per week were 72% more likely to have erectile disfunction than those who cycled less than 3 hours per week. They are cautious, however (emphasis mine):

  Bicycling 3 h or more per week may be associated with ED. Data
  revealed that there may be a reduced probability of ED in those who
  ride less than 3 h per week and ED may be more likely in bikers who
  ride more than 3 h per week. More population-based research is needed
  to better define this relationship.

The last sentence is key. Granted, there are drawbacks to population-based studies like this. One major problem is that the data are self-reported. Another drawback is they their sample probably does not include elite or high-level sport cyclists, who might have better equipment or better technique.

Does this mean that your experience may vary? Absolutely.


What is the correct back position on an MTB? While searching for my lower back problems I come across the suggestion that you should have a straight back on your bike to avoid pain, one example:

But on the internet you find a lot of "professional riders" that sit with a pretty rounded back and on a short frame, for example:

Ok, she is climbing and this is maybe just a temporary position.

source: https://www.orbea.com/img/blognew/in-text/Pendrel%202012%20en%20baja.jpg

source: https://hips.hearstapps.com/hmg-prod.s3.amazonaws.com/images/slides/still-going-0-1440612429.jpg?resize=980:*

source: https://www.orbea.com/img/blog/large/PENDREL_WORLD_CUP-20140906164951.jpg

Looking at their elbow bent they are all on pretty short frames, haven't checked the dates of the pictures. But a "straight back" sounds like a good idea even though frame geometries change over time.

Question: what's the right back position?

A straight back might avoid pain there, but it's going to create quite a lot somewhere else.

In your first rounded back/straight back comparison pictures you can see that the rider's pelvis is upright and the ischial tuberosities of the pelvis  - the 'sit bones' are on the saddle. In the second picture the rider's pelvis is rotated forward putting pressure on the soft tissue of the perineum. That picture makes me wince just looking at it. Chronic pressure on the perineum can lead to all kinds of complications, including numbness and erectile dysfunction (if you are a male).


How to assess safety of carbon frame after crash? I was recently hit by a car which pulled onto a roundabout.  The driver hadn't seen me.  The car hit me hard enough to actually snap the rim of my rear wheel.  The bike has a carbon fibre frame and fork.  It looks OK but the rear wheel is totalled I can't ride it.  How should I assess whether to rebuild or replace the bike?

The first thing is to clean the entire frame and fork very carefully and look for cracks or irregularities. I like to use something like a squirt bottle silicone cleaner/polish for this, along with a microfiber finishing rag, because it kind of normalizes the surface and makes things easier to pick out. Look extra carefully all around the joints, particular of the chain and seatstays, which is a place where rear end impacts are particularly likely to cause cracking on carbon road bikes in my experience.

If you find anything where you can't tell whether it's a crack in the frame or just the paint, chip away the paint to look underneath.

Presuming you find nothing, you're faced with an ambiguity that is best considered to be part of the cost of admission to carbon bikes. In other fields there are ways of using x-rays to look for unseen damage to carbon fiber structures, but it's considered impractical for bikes cost-wise and is not done. All anyone can do is guess.


How to choose pedals with 1/2 inch axle (single piece crank) for a non-bmx? Me and my daughter use a tag-along, and her pedals are slippery. So I'm looking for a pair of metal pedals. Due to the axle size, most of them are advertised as BMX, are too wide and long (10x13 or so). Cheap ones (£10) spin poorly. I would appreciate if you could suggest a model or a price range or an ebay/amazon search query that could help me find what I'm searching for.

If you can't find 1/2" pedals then you're looking in the wrong places.  They certainly exist but because they're normally a kid's size then quality ones are more unusual.

Check the eco-recycling at the local dump - many kids bikes get chucked out when the child outgrows the bike.  Upside, cheap!  Downside, they tend to be low quality and have been abused.
Repair the existing pedal - try squirting some penetrating oil/lube into the sides where the pedal body meets the axle.  Lay the tagalong on its side to let gravity help.  Spin the pedal by hand to help work the oil into the bearing/bushing.  Repeat a couple times.
I had some brand new pedals that were rubbish, and ended up spinning them with a 6mm hex bit in a drill press while adding lube.  After 10 minutes they got a lot more free.
Make something - if you're competent with tools, consider stripping down the existing pedal and build a new platform.  Its absolutely possible to make one from wood, using cartridge bearings at each end of the axle.
Modifying new pedals is possible too - the plastic body is generally adaptable.  If its too wide you can file or cut some off.


How would you recommend securing a pannier rack on a bike without braze-ons? My bike has lugs for mudguards/rack down by the rear drop-outs, but not in the usual places at the top of the seat-stays.

My two options seem to be:

use P-clips around the seat-stays
fashion a single bracket extending from the centre of the rack to the bolt-hole on the rear brake bridge

The first option seems easier and less fussy, but perhaps there's another way.

The two options you mention are widely used.

Another option is a seatpost clamp with rack mount points
There are a variety of makers and styles, here is one example.


Comparable Alternative to Messenger Bag Hunting the internet for months for an alternative of this bag (which unfortunately isn't available for purchase anymore): http://www.alkr.com/urban-messenger.html

I searched on Amazon, Ebags, Google, Codura Corporate Website, but can't seem to find something satisfactory.

Requirements:

Solid "Codura" fabric or comparable (no leather, black, low key design)
Not a dedicated messenger bag
Structured, thoughtful compartment design (not one big compartment, fits 13" laptop somehow, medium sized)
No floppy bottom

Any suggestion are welcomed and please don't recommend the common choices like Timbuk2 Messenger. Violates at least points 2), 4) ;-)

There are so many options for this I can't list them all, here are a few good ones.

 Mission Workshop has very refined and expensive bags, very full featured multi purpose bags.

Rickshaw Bagworks has several commuter bags you may want to check out.

Chrome Bags  has lots of laptop bags in addition to their standard messenger bags.


Identify bike brand to fit gear hanger! I have bought a new used bike, I got it very cheap since it was pretty broken up. I have replaced most of the parts and repainted the bike so it looks fine. The only thing I have a problem with is the gear hanger. When I got the bike it was broken of and I have a really hard time finding the right one. The bike frame is made of aluminum.

On the bike frame before I repainted it said "Peak Pt Arlington". But I can't really find any bike with that brand. The closest thing I got was this.

But there isn't any info about it.

Here is a picture of the broken hanger:

Can anyone help me? Thanks!

Here are some more pictures:

https://image.ibb.co/fTCvXU/IMG_20180925_151050.jpg

https://image.ibb.co/jTA4Rp/IMG_20180925_151228.jpg

https://image.ibb.co/dCY2CU/IMG_20180925_151243.jpg

Many bike shops have charts (posters) which they can use to match derailleur hanger to suitable replacements which they can order from a place like wheelsmfg.com.

I'd suggest taking the piece(s) you have to a bikeshop with such a chart and trying to use the chart to find a suitably matching hanger. This is likely easier than trying to search the varieties of hangers online on your own (since there are a lot that look the same, and if it doesn't come up in their search by manufacturer, you're going to have issues).

There are also various options for adding hangers to frames which don't have hangers if you really must; For example, the Problem Solvers Universal Derailleur Hanger replaces one side of your quick release. But a fitting hanger is probably better.

Looks like the brand is from Sweden, possibly, based on google image search. So you may want to look at something like wheelsmfg for Europe.


Can anyone help me identify this bicycle frame? I recently bought this frame from a gentleman who bought a closed bike shop and builds and sells bikes from his 10 or more sheds full of parts.  He teaches his church youth kids to build them as a way of staying out of trouble, I love that.  I acquired 90% of the parts I would need to put a bike together.  He was 100% sure this frame is a Cannondale frame (maybe 1987), but there is no serial number or marks at all that we can see. The fork reads Tange TF-R.

I need help from the experts.  Thank you.

I managed to find a couple of similar frames on web search that suggest the 1987 Vintage Cannodale identification could be correct. The really unique way the top-tube intersects the downtube before the head tube makes me think this is a very small frame. I would suggest it's a 1987 SR600 in 48cm


Accessory to raise handlebars (on a bmx) I just bought a used bmx bike and after raising the seat to a level where it is semi-comfortable to pedal while on the seat, I now find that the handlebars are too low.

Is there any sort of an after market accessory I could buy that could raise the handle bars up several inches?

UPDATE:
Here are some photos:
http://imgur.com/a/c55Mv

I'm presuming you've already raised the handlebar as much as the obvious adjustments will allow.

There are solutions, but precisely which one depends on the style of the of the headset.  If you have an old style threaded headset then you need to replace the quill/stem with a new, taller one.  You can often, at the same time, get one that changes the "reach" of the bar, if you wish.  (But unfortunately the available selection of different old-style stems is small and getting smaller daily.)

For a newer threadless headset, you can get an extension to go on top of the steering tube to allow the stem to be mounted higher up, and/or you can replace the stem with one that rises at a steeper angle.


How do you evaluate a chamois (padding in shorts) before buying? Stores only allow you try out shorts with an additional layer of underwear because of the hygiene issues. While this is great for public health, it seems to make it impossible to evaluate whether a pair of shorts is comfortable before buying. While it may be possible to return merchandise at some retailers, it would be nice to be able to compare different shorts before buying. The only usable advice I've heard is to always avoid gel padding.

What can I do to "kick the tires" on a pair of bike shorts to get a sense of whether or not the chamois will be comfortable? What should I look for either when looking at a chamois in person or when reading the marketing techno-babble on manufacturer websites (e.g., what the heck is a four-dimensional chamois)? Do more expensive shorts always have better padding, or are there certain styles of chamois that work for some people but not others?

Related questions: What should I look for in a good pair of cycling shorts?, Tights, Shorts, and Padding

I have bought my last few shorts by direct experimentation at stores, and had the same doubts as yours.

Mostly, what has worked is: you dress the shorts, and stand right up with feet in the normal position. In this position, the shorts should not produce a "bulk" between the thighs. Shorts that produce the bulk tend to be too uncomfortable either while on the bike or while walking.

Also, raising each foot alternately while flexing the knees should not produce a rubbing sensation against the inner thighs, which would mean skin irritation.

I have noticed that the padding should not be flat, that is, it should have a saddle shape. That means you cannot easily fold the short to put it in a drawer, for example, and when you hold the shorts by the waist, the short keeps like "inflated".

At last, the overall compression of the fabric should feel "fine" and specifically the elastic bands around the waist and the thighs must feel "right": a gentle compression, not a tight one.

I think that's it, hope it helps!


Is it possible to repair a dent on an aluminium frame? I have Centurion Cyclo Cross 4000 bike. Recently I got into an accident with a car door. As a result I have a significant dent on my frame(see the photos below).

I have two questions:

Is it possible to repair the frame?
Is it safe to ride the bike after this?

In the near term it's reasonably safe -- the dent is not sufficiently deep to seriously weaken the tube (though one does need to be concerned about the integrity of the welds on the rest of the bike, given it's been in an accident).  In the far term (10s of thousands of miles) there's danger that the tube will fatigue and become weakened at the dent.  (The thing to watch out for is growing cracks in the paint around the dent, or at frame joints, though some paints will hide cracks more than others.)

As to repair, about the only thing I can think of is to have an experienced frame builder cut out the section and weld in a new one, or fashion some sort of sleeve over the dent.  But those solutions would also be subject to long-term fatigue issues.


What is the max weight an MTB bicycle with a freewheel can handle until it starts putting high stress on the rear axle? Of course the riding style matters. How hard you go on jumps etc.
I don't drive my bicycle that hard. Sometimes i do when im in the mood. My issue is that i am constantly braking my rear axles. It all started a year ago while i was getting heavier and started going off road. I weight 95 kilos (210 pounds). So far i've broken 4 axles and my current one is bent. I don't get the hollow ones with the skewers(quick release). I get the solid ones. I've heard that bikes with cassettes have more durable axles. But i am not planning on buying a new wheel.
So what is the max weight an MTB bicycle with a freewheel can handle until it starts putting high stress on the rear axle?
Is there any way to reduce the chance of braking and bending axles?

Axles break for various reasons - weight is only one of them. Miss aligned dropouts, flexing in the frame, tension of the QR all play a big part. Different axles with slightly different materials will also have an effect - some are stronger overall, some more brittle, some more prone to fatigue.
As you identified, riding style also affects the axle loading.
While the manufacturers probably put a number on this for their axles, I suspect its very conservatives and more reflective of there policy around warranty and brand value.
As far as regularly breaking freewheel axles, they are known to be weak compared to other options. A freehub wheel will probably solve your problem, but also check your frame dropout alignment.


How can I merge two GPX files into one? On a recent ride, my GPS stopped functioning about half way through. From other sources I have approximate times for the missing data and I know the route, so (in principle, though I'm really not sure how) I could manually create a track for the second half of the ride. But how do I combine this data with the GPS data from the first half of my ride?

Is there a way to take two separate GPX tracks and combine them into a single one? What issues arise in "syncing" overall times, speeds, etc.? Are there tools that assist in reconciling them?

GPX files are XML files, which means you can edit them in a text editor. I use Notepad++ on Windows and TextWrangler on OSX, but you should be able to use the built-in Notepad or TextEdit. Don't use a word processor like Word or OpenOffice.

Open the second GPX file in a text editor. Copy all the stuff between <trk> and </trk> inclusive.
Open the first GPX file in a text editor. Paste the copied stuff after the </trk> line near the end of the first file and save.
If you have more files, repeat.