How to do a bike fit? Here on bicycles SE I often read questions about right sizing of a bike, how you should sit on a bike, what to do when some part of your body hurts etc. I also came across the answer

  Go to a local bike shop and have a bike-fit

quite often.

I wonder how this "bike-fit" is done? How can I do it myself?

For an actual fit, you can't really do it yourself without extended riding and testing, usually with a powermeter or other method to measure performance, and someone willing to take video and still shots of you on your bike.

What a fitter should be doing is measuring your body morphology (shape and structure), and then using that to get you into a correct sized frame (whether it's road, mountain, time trial, etc), and then adjusting the fit using different length stems, handlebar widths, seat posts/seats, etc. to get the bike comfortable.

There are several different methods, including Fit Institute Slow Twitch (FIST, usually used for time trial/triathlon frames), GURU, Retul, eyeball and a few others. Many of these use fit bike mechanisms where the "frame" that you are sitting on can be lengthened, shortened, raised/lowered, etc. Some (Such as the Retul) also have cameras that can pick out and measure all the different lengths and angles and provide a printout.

A fit, however, is only as good as the person doing it. There are good and bad fitters, and if you really want a good fit, I would do some research on the local fitters and their experience/certifications and word of mouth reputation.

A "good" fitting will probably cost between $150 - $500 US dollars, depending on the type of fit, follow up sessions, and number of bikes being fitted.

Part of the reason for the variance is that frame manufacturers (Especially in time trial/triathlon frames) do not really follow a "standard" measuring convention, and a 54cm top tube bike from Trek may fit very differently than a 54cm top tube bike from Specialized. Also, someone that is 5'10" with a 34" inseam will fit a bike very differently from someone that is 5'10" with a 30" inseam.

If all the guy does is have you stand over the top tube and say "Yeah, that'll fit ya", I would definitely seek a different shop.


Determine Rotor and Caliper Size I bought a used mountain bike and it does not have a caliper or a brake lever for the front.  How can I go about finding out what will work on this bike and where is a good place to buy online?

The disc rotor size is 160mm as engraved on the rotor (160mm is a common size rotor).
The mount type for the disc brake calliper is Post Mount (which should be 74 mm spacing between the mounts, center-to-center), which is the most common standard for mountain bikes.
You can purchase a single Post Mount calliper and matching lever, separately or as a set.  My understanding is that 160mm is the standard size to be used without an adapter, meaning only larger rotors would require an adapter.  The selected calliper for purchase should have a  specification that confirms it is compatible with 160mm rotors.


Is it really necessary to loosen/unmount handlebar while packing bike? Reading multiple advice on how to pack a bike in a cardboard box for shipping, I have always read to "remove the handlebar" or alternatively "loosen it and rotate it by 90 degrees".

Since my bike has a straight handlebar (like this one)

I wonder why not simply removing the front wheel and turning the handlebar and the fork by 90 degrees?

Two reasons, one major and one a little more subtle.

Majorly, most adult bikes won't come close to fitting in a standard, non-oversize bike shipping box if you just turn the bars and fork as you describe. What counts as oversize and how much more it costs will vary depending on where you are in the world and the carrier, but you'll need a significantly bigger box and that will generally be more expensive.

Second, if you have the fork turned in the box, only one fork end will be contacting the bottom, which will prevent the fork from being able to sit flat on the bottom of the box and will cause loads on the box to have more of a tendency to side-load the fork, the direction it's weak in. The normal way of sticking a plastic fork block in the fork ends which then sits flat against the bottom actually does a lot to keep forks from getting crushed.


Win TdF without winning any stages? It's theoretically possible to win the Tour de France without winning any stages. But has this ever happened?

What about the other Grand Tours (Giro d'Italia, Vuelta a España)?.

Yes it has in fact happened several times, the most recent ones being 2017 (Chris Froome), 2006 (Óscar Pereiro after Floyd Landis was disqualified) and 1990 (Greg LeMond). Before that, the TdF was also won without a stage victory in 1922, 1956, 1960 and 1966. (see here).

For your second question, Wikipedia has a list for the

Giro (1913, 1946, 1951, 1961-63, 1969, 1971, 1999, 2002, 2008, 2011, 2012, 2015)

and the Vuelta (1955, 1965, 1971, 1976, 1990, 2001, 2009, 2010, 2015).

(To keep to the same format, here's the TdF again): 1922, 1956, 1960, 1966, 1990, 2006, 2017.

So, the Giro has been won 14% of the time by someone who didn't win a single  stage, while for the Tour this has only happened in about 6% of cases. For the Vuelta, it's close to 13%.


Why did my tire just blow up? I finished a 2 hour bike ride outside today, and I parked it next to the wall in my kitchen after I got home. 3-4 hours later... all the sudden the front tire just "blew up". What happened? Thanks!

Check the tire carefully for a split in the carcass. There may have been a small split starting to appear, and leaving the bike in a position where the sun could come through a window and hit the bike, may have caused the tire pressure to increase enough to extend a split in the carcass enough so that the tube was forced through the tire and it blew the tube. I had a bike in the basement do this same thing. I had changed the tube and didn't realize the tire had a small split in teh carcass. I aired the tire up to the maximum and set it aside. Apparently the sun coming in through a window had enough of an effect on the tire that it suddenly blew the tire right off of the rim!


Seatpost clamp bolt replacement I rounded the flats on the seatpost clamp bolt (it's an Allen bolt; i.e. I turn it with a Allen key) that came with my bike (2014 Fuji Absolute). I found a replacement for the bolt at a local hardware store, but it's a Philips screw, not a bolt. It's the same size and fits the clamp perfectly.

Is it safe to install? Is there any chance of damaging the bike?

My primary concerns are due to not really understand what torque has to do with seatpost clamps, and other bike repair forums insisting you use a torque wrench lest you damage things. But I think that might apply more carbon fiber bodies.

Philips Screw

Allen Bolt

As long it secures the seatpost I don't see how a screw instead of bolt can damage the bike. If it fails, the worst case would be a seat sliding down. You might find it inconvient if screw has head that requires tools not usually used for bicycles, like phillips screwdriver or a hex head.

New seatpost collars are cheap, so you can buy a replacement to feel subjectively safer.


How bike computer wheel circumference change affects speed I have a cateye stealth evo+ bike computer and have been using the standard 700/25 wheel circumference that is listed in the instruction manual "2096". The value has been changed to 2143 using the rotating wheel method(stem to stem) while on the bicycle. The  wheelset and tires are the same. Will this increase or decrease my actual and average speed.

Your actual speed will remain the same. The speed displayed by the computer will be higher by 2%, as Will Vousden says. Please note that this higher reported speed will probably be more accurate (closer to your actual speed) because you measured the true circumference of your wheel (which is what I assume you mean by the "rotating wheel method").


Chain skip on new chain. Cassette has only 3200 km on it I replaced a worn chain the day after the chain indicator check showed 100% wear. I replaced the 8 speed 52 full link chain with 52 + a half link plus a quick connector. The quick connector is fully seated.

Chain skip is happening on all gears under load. The bike is a loaded work bike and did not have skip on the old chain. The old chain was last checked at 2200 or 2400 km.

Why am I experiencing chain skip?

I suggest you change your cassette now, before you get accelerated wear on your chain.  At 1% chain stretch, the cassette was as worn as the chain.

Have a very close look at the cassette with your chain in the gear that skips the most.  I suspect that if you add tension by pressing lightly on the pedal by hand, that only one link is making good contact with cassette teeth, and there may even be light visible "under" the chain.

Of course this is based on rule of thumb.


What is the difference between folding bead and wire bead tires? I'm shopping online for some new tires, and see that some models are sorted by folding and wire beads?  What exactly does this mean, and do I need a special rim to support them?

Folding versus wire refers to the material within the bead or 'edge' of each side of the tire. Foldable bead tires use kevlar in most cases (I think) and tires with each type are entirely compatible with the rim size that the tire is designed for (in the absence of a manufacturing defect). Folding bead tires have a few advantages (in my opinion):

Somewhat lighter
Easier to store (can be refolded by flattening the tire and folding it into a bundle)
Bead has more stretch to it, so mounting the tire is usually less difficult

For these advantages, you will probably pay more for a foldable bead tire when a tire model includes both options. Also, wire bead's also appear more often as the OEM tires on lower end bikes.


Why are rear wheels dished? I know it's because of the space taken up by the rear cassette. But why not just make the hub narrower, and not make it asymmetrical? Sure, the drive-side hub flange must be moved inboard to make room for a big cassette. But why not move the other flange inboard as well?

The spokes must be at an angle to provide lateral stiffness to the wheel. However, the wheel must be in static equilibrium, so on a dished wheel with different spoke angles on each side, the drive side and non drive side spokes must be in different tension, or else have different diameter or spoke count. This is well known. But why go to the trouble? Why not move the non drive side flange in as well, and use the same spoke tension on both sides?

Suppose on the drive side, the spoke flange is offset 20mm from the hub centerline, but on the left, the flange is offset 40mm. Obviously, 20mm of offset is sufficient offset for the drive side, in order to impart sufficient strength and stiffness to the wheel. In fact, I postulate that the larger offset of the non drive side is unable to add additional stiffness vs. the 20mm offset of the drive side because the wheel must be in equilibrium. Any additional offset of the non drive side must be compensated for by looser spoke tension, anyway, giving no benefit. So why not just make it 20mm on both sides, and reap the benefits of a shorter, stiffer axle?

It cannot be true that dish provides a laterally or vertically stiffer wheel. The wheel must be in equilibrium, so the stiffness of a dished wheel should be the same as a wheel where both flanges were simply the same distance from centerline as the drive side. In other words, the drive side is the limiting factor. The only advantage I can see to dishing is that the lower spoke tension on the non drive side might allow thinner (but longer!) spokes and thinner hub flange, saving weight. But this seems unlikely to compensate for the weight savings that could be had with a shorter axle.

Another possible reason is an aesthetic desire for a laterally symmetrical frame dropout spacing. But in a world of Lefty forks, is this really a barrier?

I thought of this after seeing a heavy duty touring bike with an un-dished rear wheel.

The Bicycle Wheel by Jobst Brandt touches on this:

Some rear hubs that have done a version of this include the Ritchey Zero or Z-hubs. The road Zero hub had a 21.3mm center-to-right flange measurement and 28.6 center-to-left, so combined with a 3.65mm or so offset rim it was dishless. (It didn't need an asymmetrical frame, but moving in the left dropout is secondary to whether this sort of idea can work.) These wheels do function and didn't seem to have any grievous reliability problems, so maybe they should have been copied more, but they also don't push the concept all the way to total symmetry.

I believe the deal with this is that there are some physical reasons why if you take the center-to-right flange measurement off a road hub and say, "Okay, if that's strong enough for lateral loads in one direction, then let's make the left one the same," you wind up with a wheel that buckles easily from lateral loads in either direction. In other words it's not just a matter of what bracing angle is good enough per side; in the highly tension-disparate wheels we have, the better bracing angle side is somehow making the whole thing more stable.

I haven't done the deflection tests that would be needed to test whether this is true, but what I have done is build a number of SP generator hubs with their dainty 23.5mm per side center-to-flange dimensions. Those wheels have the unlovely trait that when you do routine side-loading on them to reduce spoke windup, you can feel that they're extremely laterally flexible, and it's easy to induce a "column buckling" type failure if you're not careful, something I have no trouble with in other wheels. People ride them and they work, but from what I've experienced it's clear to me that once you're down to bracing angle numbers like that on each side, the wheel threatens to become too unstable.

Another piece of the puzzle is that, as with so many aspects of bike component design, competitive and sport use is the economic backbone of the industry and so what works there drives what gets made. How it applies here is that existent rear road wheels have been strong enough for competitive use under athletic riders, so doing anything about their lack of strength from being so heavily dished has never been seen as a priority by the mainstream, or worth compromising anything else to fix. Virtually no advantage is ascribed to increasing the strength of the wheel against vertical loads, so why sacrifice any lateral strength to get it, even if it were just in one direction? Were this not the case, offset rims would be ubiquitous, because they work against the problem in a manner that gives up nothing other than some additional costs (and have become common on prefab sets).


Chain Cleaning Frequency vs Cost I got myself a new 2019 Giant Trance 2. I am loving it and am doing lots of off road trails here in Texas. A typical ride for me is about 4-6 hours and maybe 10-20 miles depending on the inclines.

I've read plenty about how to clean my drive train, but not so much on frequency. I've heard that you should do it every 40 miles or so. At the same time, I can visibly see bits of dirt and sand attached to my chain. Not clumps of mud, but little grains you can see. My gut says to clean it again.

I get those bits of dirt and sand every single ride though. Is it really logical to clean it every single time? I mean, I make $70/hr and it takes an hour to clean the thing. At some point, the opportunity cost has to overcome the extra wear.

I am a noob, so I have no idea what a chain, the derailer gears, or the cassette, or gear on the crank, cost. I've got a Shimano SLX if that matters.

Should I be cleaning every time I see dirt and grit, even if that means every single ride?

The answer to the chain/drive train cleaning frequency question is pretty ambiguous. Allow your good sense to prevail as there is a fine line between meticulous and a psychiatric diagnosis. I ride daily using either mountain bike or roadie and in all weather conditions except ice or snow >6 inches. I use TriFlow (just a fact, not a product endorsement) to lube chain, derailleur pivot points, shifter & brake internals.  I find that every week to 10 days, the chain requires the full cleanse and relube, which, as noted in other answers, has many routes to the goal of a lubed chain free of contaminates.

As far as in-between these complete cleansings, here's some ideas:
--Compressed air. Clinging dirt and sand get blown away rather easily and quickly with short  blasts from the nozzle. I also hit the cassette and derailleurs.  The Teflon in my choice of lube helps matters as road grit is less likely to stick firmly, if at all, to the chain or components. This is quick and easy enough to do after every ride, though the conditions on every ride don't always create the need for cleaning. Like pressurized water, good sense and care must be used so that the contaminants aren't driven into bearing housing, shift and brake cabling, etc.  It's also possible to blow lubrication layer off the chain if one blasts a spot for too long. Overall, this works great.

--Take a rag, wrap around the chain and back peddle the crank to effectively remove much of the gunk collected on a chain. Related to this, one should wipe excess lube off the chain a short period of time after applying to chain and allowing it to penetrate the only place on the chain where it's needed: the internal aspects of the linkages where pin, bushing and side plates come together.

-- Excess lube creates an opportunity for more dirt and grime to attach itself to the chain. When applying lube, a couple of drops on each linkage followed by normal chain movement to assist it's penetration into the linkages is ample.  Allow the solvent carrier (if applicable to your choice of lube) to evaporate and wipe off the excess clinging to the side plates.

--I find that paying attention to the rear derailleur pulleys is a helpful indicator when assessing the contamination level. It's here on the pulleys where the gritty, chain-wearing paste accumulates and transfers to and from the chain as one rides along.  It's a simple matter to take a cloth or scraping tool and remove this from the pulley wheels.

--Some bicyclists like to run two chains, swapping the clean one in and gaining some flexibility with the dirty one, which can be cleaned at a time that's more convenient. The advent and success of Quick-links to break and rejoin a chain multiple times make this an easy way to keep the drivetrain fresh. Many report both cassette and chain have gained excellent longevity using this technique (more than can be explained by simply doubling the typical life of a single chain).

That was a Texas sized answer to say run two chains intermittently and utilize compressed air for quick cleaning between changes.


My rear brakes squeal like crazy, but not when they are wet! I am a new cyclist in Bonn, Germany. Someone gave me a free bike that is very nice, but the rear brakes squeal like crazy, and the weird thing is that when it rains and they are wet, they don't squeal at all, which is the opposite of what I have read, since often people's brakes only squeal when they are wet. What could this mean? Any ideas of how to solve this problem, other than pouring water on my brakes on purpose? Lol! The brakes are new and they work fine, just to give you more information. Also adding that they are rim brakes.

I know a lot of people don't care about squealing brakes, but I mean we're talking, if rode my bike past 11 pm I could wake up entire apartment buildings! And I seem to be the only person in Bonn with this problem, so I'm not going to lie, it's embarrassing. I definitely get looks too! I could just get a new bike but I guess I'm wondering if there is possibly a simple solution. I already asked a bike repair shop and they didn't think anything could be done, but that was also before I had this piece of information that they don't squeal when wet.

They are rim brakes.

You probably need to toe in your brake pads. That is, adjust them so that the end of the pad closer to the front of the bike touches the rim slightly before the back end of the pad.  There are plenty of videos on YouTube explaining how to do this, and it's not at all difficult. The quick summary is that you loosen the brake block's retaining bolt slightly, then apply the brakes with a piece of cardboard between the back of the brake block and the wheel. Then tighten the retaining bolt back up again, and repeat on the other side.

The squeal is caused by the reverse set-up, where the back end of the pad contacts first.

To see an example of what's going on, hold your hand flat, a few centimetres above a slightly rough surface such as a wooden table, and tilt your hand downwards so that your fingertips are pressing quite hard against the surface. If you move your hand away from yourself (so your fingertips are at the front), you'll feel a vibration as your fingertips alternately grip the surface and release from it; if you move your hand in the opposite direction, you'll feel it slide much more smoothly.  What's happening is that, as you move your hand away, your fingertips are being pressed harder into the surface, which increases the friction force until it gets too much and they slip and jump. When you move your hand towards yourself, the movement doesn't cause your fingertips to be pressed harder against the surface, so you don't get this alternate slipping and jamming.

It's this repeated jamming against the rim that causes the squeal.  Why are they quiet in the rain? Because the wet rims have much less friction, so the forces don't build up nearly as much.


Is a Roadie with wider tyres still faster then a MTB with slicks? I need a new bike, but I´m in a dilema on which too choose, because my rides involve 4 kinds of pavement: smooth cycle ways, cobblestone, ok city roads and rough city roads.

Was thinking just to keep doing what I have been doing till now, get a new MTB, a BTWIN rockrider 500(for those in the US, BTWIN is a brand sold in Europe that as nice groupset parts for the price) and fit it 26 slicks.

But then on the site saw they have some flat bar roadies: http://www.btwin.com/en/road-bikes/fitness-road-bikes/18701-triban-520-fb-road-bike-black-red-white.html

So I wonder...
If that roadie was fitted with 700x32 slick tyres would it make it rideable on cooblestone/cracked pavement without the risk of damaging the wheels?

And maybe the most important, would it loose much speed compared with the original tyres(700x25) on the smooth roads? Would it be just about as fast as the "slicked" mtb?

And please, no need to tell me to get a city bike. From what I have seen, they are even heavier then MTBs, and in my prices budget I can get a Btwin MTB with Sramx4 or Acera. While urban ones only have the tourney.

I'd recommend a Cyclocross bike (also called CX).  That's a robust road bike frame, configured to accept tyres up to about 40mm wide.  You won't need 40mm unless you're doing proper off-roading, but a nice 30-35mm file tread such as a Specialized Trigger or Schwalbe Sammy Slick will run nicely on smooth pavement, will handle cobbles and bad pavement, and will also handle mild gravel/dirt.

I have a setup like that, and the thing that I love about it is that I can ride pretty much anywhere from road to gravel to bike paths to rail trails to single track (except for MTB trails with lots of rocks!).

Have fun.


Why am I not seeing improvement in my bike split time? My training went up significantly between half-iron events.

There was improvement in the swim and run. But no improvement in the bike...

In fact I could say I did worse because there was little wind and I used aero-bars and saw the same time for the bike. Not sure why I would not see improvement on the bike.

In my first Half Ironman I did:

swim 43:00
bike 3:00:00(much wind; no aero-bars)
run  2:30:00

Training:

I biked only 5 times that year,
ran 3 times and
swam maybe once a week for a number of months leading up to this.

A year later(same event course):

swim 37:00 {6 min improvement}
bike 3:00:00 (no wind; used aero-bars) {no improvement}
run  2:00:00 {1/2 hour improvement}

Training:

Completed 5 full marathons between previous Half Ironman and this one.
Swimming was a little more and under good instruction.
Biked at least once a month and then some come this event.

Looking at your times, your times on the bike leg are below the levels you are setting in the other legs. But given that you are barely training for the bike leg, your times are pretty good.
This site says

How long does it take to finish a Half Ironman Triathlon?
The answer, based on our analysis of more than 67,000 finishers in 40 Half Ironman triathlons: about 6 hours, on average.  Swim 1.2 miles in 45 minutes, Bike 56 miles in 3:00, and Run 13.1 miles in 2:15.

In comparison, your swim time is better, your bike time is the same, and you run time is much better.
Your bike legs are 3 hour for 90 km; an average of 30 kph. Since the effort required for a given speed varies as the square (or some say cube) of the speed, riding 10% faster will take 20% to 30% more effort and energy.
To deliver that, you need to train your aerobic capacity to deliver oxygen for your muscles, and you need to train the muscles you'll use for the bike leg to deliver at that level for 3+ hours. These capabilities will not be improved by riding once a month - they will barely be maintained if you ride once per week.
Everybody will have their recommendations, reasons, and ideas. From my experience training with athletes of various levels, including one full Ironman competitor, here is a fairly conservative plan. For you own plan, work backwards from the race date. Work out how, and how much, and how long to taper. Work out what level of training you should be doing at the peak. Plan variation to keep it interesting. Set goals to measure you performance. Build up slowly to avoid over training and injury. And talk to a lot of people about it. A specialized coach would be best.
In the off-season, you should be riding a minimum of once per week for a minimum of 2 hours. About 4 months out from the race, that should step up to twice per week, with one longer ride and one shorter. Gradually increase the longer ride to about 4 hours at a lower intensity than your race pace to build endurance, and on the short ride warm up thoroughly before riding at race pace then cool down thoroughly. Gradually increase the period at race pace.
Two months out from the race, increase to riding 3 times per week. Continue the casual endurance ride as before, but increase the race pace ride gradually until the fast section is 2 hours. Six weeks before the race and 4 weeks before the race, push the race pace training ride so that you do the full course at race pace. The day after every race pace ride, do a short recovery ride. Be aware that people have differing opinions on the topic of recovery rides.
Be very careful not to over-train. Listen to your body. If you need a break, then do it. If you are getting injuries or feel jaded, back off. Assuming all is going well, 3 weeks out from the race is when it's time to get serious. A week earlier, you did the full course. This week do it again at race pace. The endurance ride becomes the previous race pace ride, and the recovery ride is also longer - there is more recovery to do. And now taper - reduce the length of the rides over the next week by 20%, by another 20% in the next week, and another 20% in the race week. Again, people have differing advice on tapering, so do your research - certainly some would suggest that another week of tapering would be better.


Which countries have employed rail biking in their armed forces? Can anyone tell me which counties have employed rail bikes in their armed forces? I remember seeing pictures of soldiers riding the rails on bikes, but cannot recall any details of them.

Rail biking on abandoned rail tracks!

A rail bike set to go!

From the Military History Journal (Volume 4 No 1 - June 1977) there is an article entitled BICYCLES IN THE ANGLO-BOER WAR OF 1899-1902, by D.R. Maree, which seems to fit this question.

The 'War Cycle' carried several men on the coupling-framework in addition to the eight riders,
 could be fitted with a Maxim gun, and was capable of a speed of over 48 kmh.
 Photo: Africana Museum

  A special 'War Cycle' was built for use on railway lines, and a prototype of this 8-man bicycle can be seen at Fort Klapperkop Museum. It was introduced into South Africa by the Royal Australian Cycle Corps and had a detachable rim which was fitted to the pneumatic tires, enabling it to be used on rails. When the rim was removed the bicycle could be used on normal roads. These cycles were used for reconnaissance, for carrying despatches, checking the railway line for demolition charges, and also for removing the wounded from a skirmish taking place near a railway.


How do I add pressure and adjust rebound on older mountain bike forks? It doesn't have design of modern forks and I can't find a tutorial online for a fork like this. Any tips?

You can easilly find the manual just by googling the visible words from your photo "Marzocchi Bomber 2001", for example https://www.manualslib.com/manual/1728712/Marzocchi-Bomber-2001.html  Adjustments are on page 10 and in detail from page 24. A schematic picture is on page 14.

There are air and coil variants.
What you can adjust in the air ones is the air pressure and the oil level, which in turn determines the air volume.

However from the picture on page 32 it appears to me you have the coil variant and that by getting out the dust cap on the left crown (on the right in the photo) you will get to the coil preload adjustment (use the Allen key). A flat screwdriver should then suffice to adjust the rebound cartridge.

Make sure which exact variant you have. The picture tells a lot.


Italian bottom brackets and modern cranksets - a compatibility guide? I have an Italian frame (presumably a Moser) which I chose to repurpose as a single-speed/fixie with parts from another Single-speed/fixie of mine, with the exception of the bottom bracket and crankset, due to the size difference.
I chose to go with a tapered / squared JIS axle, but the spindle length in relation to both the crankset and the chain line is still making me confused, being the first time I have to buy these parts, therefore:

what should I take in consideration when looking to pair an Italian BB with a crankset?
is my current chain line measurement (on the older bike) of any use when looking for these parts, since those same wheels on the old bike will be used on this Italian frame? (taking in consideration the wheel's axle length and how much the cassette can be moved using spacers)
is it better to buy a BB with a spindle length longer than the one recommended by the crankset manufacturer or shorter?

Spindle length and chainline are immaterial to it being Italian. The center of the spindle is at the center of the shell either way. If the chainline is good now and you're using all the same parts, get another JIS BB of the same spindle length in Italian.
If you wanted to tweak the chainline, it's the same process as any square taper crank. Use your existing crank and BB to figure out what length spindle puts the chainline where, figure out the chainline you want, and change the spindle length by twice the difference.


Minor but persistent saddle sore - Safe to continue riding? A few months ago I switched from a heavily padded saddle to a Velominati-approved one: http://www.velominati.com/the-rules/#61

It was very uncomfortable at first (even with padded shorts), but I quickly grew accustomed to it.

My shorts are of the cheaper type, and most of my weight is concentrated on a very specific spot on each of my sit bones. A little more padding would be better, but it's tolerable the way it is.

Three weeks ago I did a particularly long ride (7 hours), and it left a small saddle sore on each of my sit bones.

Since then I haven't done any long rides. Just my usual 20 minute commute to work (which I do in normal pants, no padding).

The sores haven't gone away. But even on my commute, without padded shorts, there's only a very mild (often unnoticeable) discomfort, and I'd rather sit and spin than ride standing.

By continuing to do what I'm doing, am I preventing the sores from healing? Am I risking an infection?

I'd perhaps look at your saddle again.  Padding isn't everything and there is a lot to be said for fit/sit bone width.  Consider getting measured/fitted.  I know what width fits me in the brand I buy.  Personally, I think every serious cyclist should know their saddle size as well as their frame sizing.  Keep in mind that all your riding up to this point (before saddle change) developed extra padding/tissue/internal callus (whichever) on the contact points of your old saddle.  Moving those contact points just a slight bit by getting a new saddle can make quite a bit of difference.

Not to be rude, but what is your hygiene like?  I would recommend making sure to always wash after a ride (commutes included).  Always ride in clean shorts.  Toward that goal, if you haven't cleaned/showered/bathed recently and go for a ride, you really aren't riding in clean shorts (your skin isn't clean, even though the shorts are).  Consider washing before and after a ride.  Are you using a chamois cream of some sort?  Part of the problem can be caused just by friction.  A good chamois cream can help.  Some have various antibacterial/anti-infective "stuff" rolled in and can help on multiple fronts.

If you are going to look for less padding in your seat, you may look for more in your shorts.  Seven hours for most folks goes past stage type training and into endurance riding/training.  Ultra light sometimes gets sacrificed for comfort.  You may look for touring or thicker winter padded shorts/bibs and opt away from ultra light race padded shorts/bibs.

I have done a fair amount of winter endurance riding (100 miles on snow) and sometimes you just forget your prep and end up with a sore.  I've lanced my own in the past to speed healing, but that's not for everyone.  Once you have one (I have my own set and recurring spots), it's kind of always a preventative fight while you are trying to train.  In the end, if all your equipment is properly fitted, proper hygiene and prep (wash before/after, clean shorts and chamois cream) just become a regular part of your training like bike maintenance and proper nutrition.


How is fat bike traction on icy roads compared to a mountain bike? From anything between black ice to 4 inches of snow (paved roads only, no offroad), how will fat bike tires compare to mountain bike tires traction-wise?

Please note since the bike has to be ridden on paved roads without any snow too, extreme forms of spikes or chains on the tires are not an option.

Having ridden both on a lot of ice for years, I'll answer that most of the fatbikes I have ridden tend to be more stable on ice than a MTB.  The wider your tires are (and at lower pressure) the less likely that the wheel will slip (side to side) easily.  Riding on snow and ice are very separate things.

Snow is actually very easy to ride provided it is either (semi)packed or not deep.  Fatbikes were to some extend perfected by snow riders since the main advantage they provide is not "punching through" packed snow on trails as easily as a narrower tired bike.

Ice can be very difficult to nearly impossible to ride on.  Flat ice (like a skating rink) can be ridden across in shorter sections with only good technique.  By maintaining balance and not turning or pedaling in a sloppy manner, flat ice can be travelled. Sloped ice (like overflow or an icy hill) requires studs; pretty much end of story.  There are many companies out there producing high quality (and some low quality) studded bicycle tires.  I have a narrower set (3.8 inches) I use on my fatbike for commuting or riding trails with longer overflow sections.


Why do base kilometers help with time trials? Question:
If I want to maintain some objective measure of improvement by keeping track of the time it takes me to do a 40-km round-trip, why is it important to not do a time trial every time (riding every other day), but to vary the workout by introducing longer and shorter trips, and, particularly, to often do the 40-km round-trip at a leisurely pace?
Context and Unlikely Answers:
I have no intention of racing. I'm using time trials as a loose measure of progress mainly because other objective measures (maximum heart rate over the trip when completed in less than a given time; the much more complicated oxygen efficiency measurements) are not quite so straight-forward.
I don't see the parallel in other sports. For instance, 100m/200m sprinters would not practice by running marathons, nor even 1/10th of marathons.
A tennis player who wants to become a better player does need to play leisurely often (with less challenging partners, for example), but that's because the reflexes then improve, making tougher games more easily winnable (by instinct). Improving reflexes is important in cycling, for things such as avoiding falls, but it's unclear why they might help with time trials.
It would be nice to understand what exactly happens when one rides at a leisurely pace, that eventually improves time trials. Do, for example, glycogen stores in muscle cells become gradually capable of storing more (glycogen), hence enabling a more intense workout during a time trial?
Sequels:
Like all good answers, what Michael wrote generates many more questions to help us increase our understanding of the "why" part:

If you've gone to any aerobics class, you'll have noticed that it's a very bad idea to maintain your heartbeat at 170 and immediately leave the studio with a heartbeat dropping down to 70. The workout will take a heavy toll on your body. Instead, it's important to slow down gradually to return your body to the lower energy state. Is something similar happening with cycling? If true: Suppose, for example, that I aim instead for an intense 10-km round-trip (every other day), but do not return until I have cycled 30 more kilometers at a leisurely pace. Does this also count as "periodization"?

Is the idea to simply keep moving at lesser power? Suppose I have a rowing machine sitting unused, or suppose I dabble (also willingly) with tennis. Can I use these alternative activities as the "low power" activities—during rainy days for example? In other words, do the base kilometers really have to be cycling kilometers, rather than running on the court or (virtual) rowing kilometers?

What if I'm not at all aiming for a (yearly) race day? These Tour de France cyclists look like they're a different breed of humans anyway. I just want to maintain a regular, gradual, and possibly very slow, level of improvement. Can I set up my own monthly race day? Is that inherently sub-optimal than a yearly race day? (Or, really digressing, is one yearly race all that the human body can aim for? In particular, do TdF cyclists use the Giro and the Vuelta as merely practice rides? Do they save their real energy for the Tour?)

If you live in Southern Italy and are enjoying cycling year round, you may not quite appreciate the frustration of those of us who have a far shorter season during which to enjoy the thrill. You may not even fathom why we sometime have to think about other than cycling.

It’s all about maximizing the positive effects of training while minimizing recovery time and injury risk
You want to target different systems in the body as effectively as possible. A naive approach to training would be to (try to) train at race intensity and duration each and every day. However you’ll quickly reach a point where you can’t recover fast enough, suffer from injuries or reach a point where you don’t improve anymore. Different systems in the body also respond to different intensities.
Long rides are great to strengthen the heart muscle, improve oxygen uptake of the muscles and improve how fast you can burn fat. Training these systems mostly depends on training duration and less on intensity. Long and easy can even be done after hard training days and shorter easy rides can improve recovery because of increased blood flow through the muscles. Short, high intensity training is best to improve other factors like VO₂Max or pure muscle strength.
Apparently until a few decades ago athletes used to perform the same workouts, day in day out, the whole year long. Periodization was kind of a break-through. Now you generally start the season with a lot of long, easy endurance workouts and replace them with more and more relatively short, high quality, high intensity workouts the closer you get to the final race day.
Edit: I’ll try to answer the follow up questions:

I remember an episode on That Triathlon Show where an expert cited research that cool-down (i.e. continuing at very low intensity after a hard workout) actually doesn’t have any positive effect for recovery or training effectiveness. She mentioned that the only positive effect is that it prevents people from fainting after a race because it prevents the blood from suddenly pooling in the legs (I imagine simply lying down would achieve this as well). Not sure why people still seem to do it, maybe because it’s also a good way to calm down.
At least for running, Daniel Craig’s ”Running Formula” recommends to do running if you want to get better at running. I think he mentions that off-season activities like cross country skiing can have a positive effect but he doesn’t recommend it if all you want to do is get better at running. I think the same applies to bicycling though since it’s less dependent on form/technique it probably benefits more than running from exercise which targets similar muscles, endurance etc.
I don’t know about that one. I think your question boils down to if doing a certain type of workout for a few days or weeks in a row (e.g. several weeks of easy rides during base training phase) is more effective than simply throwing it in every now and then. Some training plans do have supercompensation blocks where you do high intensity workouts for a few days in a row (more or less intentionally going above the maximum recoverable volume). Not sure you could fit that in a monthly training cycle.


Replacing a cassette with a freewheel I am building an EBike. The motor manufacturer said I must replace the existing cassette with a freewheel. Why do I need to do this?

That does not make much sense.

A freehub/cassette combination has the same function as a freewheel. You cannot replace a cassette with a freewheel unless you replace the wheel hub as well.

The only reason I can think of is that the manufacturer thinks freewheels are stronger and can resist the extra torque of the motor better.


How to fix tyre issue - rubbery sounds when riding I don't know much about bikes at all. I have this bike which I was ideally going to use tomorrow for an journey but I think that I may have to use other transport now. I haven't used it in a while, and I know it had issues in the past with the chain slipping when trying to change gears.

I read online about how to fix this and then I noticed that the front tyre looked flat, so I inflated it, but when I rode on it to test it, the tyre makes this loud rubbery sound, I have no idea why. Its a mountain bike and I read that it was supposed to have about 1cm give when squeezing and it feels right. But this sound makes me think that something is really wrong. I have recorded how it sounds in this video. Please help. Is the tire broken? I have a photo attached too. Thank you.

It sounds like a combination of two things: your tyre is under-inflated (1cm give seems like a lot) and it's also pretty knobbly.

To solve the first problem, pump them up a bit more! There's normally a range shown on the side of the tyres (often it's hard to find, but it's nearly always there), so somewhere in that range would be a good start. If you'll be mostly riding on roads or paths like that shown in the video, towards the upper end of that range is best; if you're doing off-road, try a little lower. Don't be afraid to experiment. You will need a pump with a pressure gauge to get the best results (it's a good investment for the future anyway), but otherwise put some more air in both tyres, and see how that feels; normally you'd ride with about the same pressure in front and rear tyres. I ride a road bike with smooth tyres, and if there's any give at all, I know they're drastically under-inflated! One advantage of higher pressure is that it makes you less vulnerable to the type of puncture known as the "pinch flat".

The tyre itself has quite deep tread (ie, it's "knobbly"), so it will be noisier (and less efficient) than a smoother tyre. Whether it's a good idea to swap your tyres for something a bit (or a lot) slicker again depends on the kind of riding you'll be doing. Generally, the smoother the surface you'll be riding on, and the longer the distance, the smoother the tyre you'll prefer. For tomorrow's journey, you'll probably be fine with these tyres.


Performance Road Flat Shoe/Pedal combo My girlfriend is a keen road cyclist, but does not want to use clipless pedals.
She currently uses something similar to these shoes: Scott MTB
(with bog standard flat plastic pedals)

We've tried some Shimano XC5W but they didn't fit well. Also not sure how well they would work without cleats?

Any ideas for some shoes/pedals that are appropriate for road cycling without cleats.
Ideally something that is lightweight, moderately stiff and looks sleek.
(would need to come in size EU38)

What pedals would work well? Most MTB pedals are way too chunky and heavy.

The shoes and pedals that are appropriate for road cycling are the ones you feel comfortable using.

Almost all MTB shoes come with a "plug" over the screw-hole recess that you could just leave in place. Make sure that's the case with any pair she has her eye on, if she decides to go that route. These probably won't be ideal, as they're still designed to work with cleats, so there won't be a natural interface surface. Many MTB shoes are identical to road shoes except for the cleat attachments and the greebling on the sole.

If she wants to stick with flat pedals and no toeclips, look at downhiller pedals, which typically have a big open platform with studs for grip. If she is open to toeclips, there are platform pedals meant to be used with toeclips (mostly targeting commuters), so you get good support for flat shoes.

There are shoes meant to be used with DH pedals, that pretty much look like standard sneakers with flat soles. This will fail the "sleek" test.

AFAIK, there aren't a lot of straight-up road shoes not designed to be worn with cleats. They'll have hard, slick soles that will be a downright hazard on flat pedals. You might have some luck searching for bike touring shoes. That's a category of shoe we don't see much of anymore, but when they were popular, they had road-shoe styling with flat soles. There are still some throwbacks to that style if you look for them.


How to setup my 26er MTB for indoor MTB park There is an indoor mountain bike park along the lines of Ray's MTB park being built near me (though I also road trip to rays and rent a bike).  Most of the riding here seems suited for a dirt jumper.

I don't own a dirt jumper. However, I have a 26er setup for XC riding that I havn't really been using since I got a 29er.  It's an older specialized rockhopper with a rockshox suspension fork, bb5 disc brakes, mountain triple, and 9-speed cassette.  The frame is a bit small for me.

What adjustments or parts swaps should I do to make this bike more suitable to this style of riding which includes jumps, rollers, pump tracks, and technical skill sections with narrows, teeter totters, etc...

Convert it to a single speed and slam the seatpost. Those will be the biggest things. Add a bash guard up front too for when your rear wheel falls off the teeter-totters and skinnies.

A shorter stem would be a good addition too. It'll improve the steering for those technical sections.

You might also consider a rigid fork. Suspension isn't really necessary for that type of stuff and can actually be a hindrance. That's why trials and bmx bikes have rigid forks. Surly makes a suspension corrected fork. Even with the correction, your front end will sit a bit lower than it does now, but you get used to it.

You might want rim brakes too (if your bike is set up for either) for the same reason that you'll want a bash guard. You only have to land on a brake rotor once to really mess it up. You can true them to a certain degree, but they're never the same.

If you stick with the disc brakes, you could try smaller wheels. 24" perhaps. But if you're going to go that far it's probably a better investment to just sell it (since you haven't been using it anyway) and buy a bike that's built for that type of riding.

In fact, if you're going to be riding at this park more than once in a blue moon, you'd probably be happier doing that anyway.


Giant ATX 2 2017 axle size? I have a Giant ATX 2 27.5 2017 and I broke my rear axle .

I sent it to my LBS, a week later they told me their axle fitted the front wheel but the back wheel was a different size.

They haven’t got the axle for it but at the mean time how do I get the axle size and what’s it most likely to be?

It has joytech hubs 32 spokes and has 27.5” wheels.

The info I have gathered on line suggests your bike is equipped with a 3x7 speed drive train. If that is the case the most likely axle is a 9mmx135mm QR (quick-release). You have apparently discovered the weak link in 7 speed freewheel drivelines. The issue with using a freewheel set-up is the drive side axle bearing is about 1.5 inches inboard from the edge of the frame. Unless you modify your riding style the axle is likely to break again. You can try to locate  a used 27.5 wheel with  an 8 speed cassette. Cassette wheels use a freehub not a freewheel. Freehub wheels mount both the bearings at the ends of the axle. You can have the rear derailleur adjusted to use only 7 of the rear gears. This will save the expense of buying an 8 speed shifter.


Balance bike: fitting smaller wheels I'm building a balance bike for a daycare kid. He is tall so I have a longer frame for him, but I think the tires might he too big.
Can I put 12.5" tires on forks for 16" tires?

Assuming:
- the axles are of a width that they will fit the dropouts and can be tightened down enough to prevent the wheels from falling off
- You don't have brakes or a drive train to consider (which you said you didn't in the comments)

...then why not? The bike will look a little funny, but the kid will dig it.


Winter maintenance before putting bike in winter storage? What kind of maintenance should I do before putting my bike into storage for the winter?  Are there any special considerations for storing it?  Does temperature matter?  If it's hanging on the wall from the rim all winter long, will that affect the shape of my rims?  Any other winter storage advice would be nice to hear.

Wash it. Dry thoroughly. You can even wax it if you truly love your ride...
Lube the chain
Lubricate all pivot points (derailleurs, brake handles, etc)
Loosen the tension on the cables and put a small amount of grease on the cable ends.
If the hubs haven't been overhauled in a while you can do that.
Remove the seatpost and if metal apply a light coat of grease and re-insert but leave the seat clamp a little loose.  If carbon fiber, remove, clean and re-insert (no grease).  Remember to tighten again in the spring.
Inflate tires to full recommended pressure.

Store your bike in a warm place and check the tire inflation periodically. If they deflate and it's cold your sidewalls are likely to crack when you pump them back up in the spring.

If hung, you may want to periodically take it down and spin the wheels (and the crank) and then hang it again. While it's unlikely that hanging the bike will result in pitting on your hub cones, spinning them a couple of times over the months can't hurt.


Compare optimal seated riding postions for different "fields" in mountain biking I remember seeing an illustration, in some article, of different riding positions. The cross-country guy leans low and forward, while the enduro rider was close to standing straight up. Both were represented riding seated at level ground.

Is this true? Are different mountain bike types characterized by specific height of the handlebars, relative to the saddle, and specific length of the headtube + stem? What motivates such design decisions?

The position does change from one discipline to another. There are no fixed values or ratios, but, at least until recently the differences were significant.

In the early day of mountain biking racing cross country was a long race (almost 3 hours) with few technical sections. Since these races were flatter, it was thought that aerodynamics could play a bigger role. Therefore the rider's frontal area was reduced with narrow handlebars seat much higher than bars, and longer effective top tube. Long stems came naturally to make up for short bars to make steering less nervous.

Then came the big split into numerous disciplines and different frame geometries came up for cross country, four cross, dirt jumping, enduro, downhill, freeride etc. Disciplines such as enduro required better bike handling and safety on steep slopes, therefore handlebars are wider, top tube is shorter and head tube is longer. This plus the fact that enduro was often defined as relaxed riding on mountain paths (it's still an arguable definition) caused rider's trunk to be almost vertical, which is more comfortable on a long trip.
Note: there are way more differencees in geometries for various disciplines, but we're only talking about rider's upper body position.

These days as world cup XC courses become more technical, cross country bikes get wider bars and a position safer on downhills. Tarmac/gravel sections are now much shorter so aerodynamic drag isn't an issue anymore (has it ever been?) and while top tubes on XC bikes are still longer (for better ascents) we can currently see more and more similarities between XC and gravity-sport bikes.


carbon frame chipped today while I was riding I lost control of my bike; it was nothing serious, I even fell "standing", but my bike fell on a rock and the carbon frame was chipped.

Should I worry about the damage?

I read posts about using nail polish to "cover" the damage, would you advice that?

Thank you a lot!

The damaged part is the top tube, close to the handlebars.

Here is a photo of the damage:

As far as I can see from your photo, the damage to your bike caused the paint to fleck but the underlying carbon fiber looks intact. Doing anything anything abrasive would risk damaging the fibers. If your bike is under warranty, I'd ask the manufacturer. If not, I'd carefully paint over the chips so as to seal it back up and prevent further damage (physical and UV) to the underlying carbon fiber.

If your bike is of recent make, the manufacturer or your local bike store (LBS) can get touch up paint in the right color. Again, you might want to inquire with the manufacturer what you need to do to maintain your frame warranty.

If you can't find the exact color through your LBS or the manufacturer, you can go to an auto parts shop and look at their array of touch up paints and get something near enough. This might be difficult as the chips are in an area where the color is fading to black.  A color that is too light will generally be less noticeable than one that is too dark.

While you're at the parts store, get some clear coat as well.  The little touchup paint bottles should cost about 3-8 Eurodollars each and come with their own little brushes.

Now, with metal frames and when you have an exact paint match, you want to sand down the metal so that you can remove any oxidation and lay down some primer. But you have a carbon frame, the damaged area is so small, and sanding may cause more fibers to abrade so I wouldn't risk sanding it.

Instead, I'd clean the area with some isopropyl alcohol and then apply the touch up paint very carefully. The area is so small that you likely won't need primer either but if you got some, it wouldn't hurt. Thin layers applied multiple times with time in between to dry is better than a blob of paint.

After the final layer had dried, apply the clear coat.

Ps. Don't use clear nail polish lacquer as it yellows under UV and age and is quite brittle. It's only designed to last a few weeks at most and then its removed and reapplied.


How to relate wind chill, temperature, and cycling I'm interested in how wind chill and temperature come into play while cycling.  If I rode on one day with the temperature at 15°F (-9°C), but the wind chill was 1F (-17°C), how would that relate to a day where the temperature is 10°F (-12°C) or 20°F (-6°C) with the same wind chill?

Ok, let's start with wind chill.  The faster the wind, the more chill Wind Chill chart from the National Weather Service Read along the top for the temperature without wind, then down for wind chill at different speeds.  So, for example, at 15 degrees Fahrenheit (-9°C) in a 15mph (6.7 m/s) wind, effective temperature is 0 degrees Fahrenheit (-18°C). (chilly!) That chart only works up to 40 degrees F (4°C), but it gives the idea! This Wind chill Calculator allows you to put in any value, and speed of air

Of course, that's if you're standing still.  If you're cycling you almost always have a headwind, Here is a link to a page with masses of detailed information about headwinds.  The faster you go, the faster the effective windspeed, and the lower the temperature felt.  This can be really helpful on a hot summer day, or really chilly in a cold winter!

When cycling you have to take this into account - in the winter, layer up (and find a wind proof jacket if possible.)  In the summer, it means that you can actually go up that big hill without totally overheating! I remember one hot day, on a steep incline, I rounded a bend, and came straight into the lee (wind shielded) side of the hill - in seconds I was feeling way too hot, without the cooling breeze.


Is it really going to damage a bike to wash it with a hose? I was chatting to the guys at my LBS the other day about how they get my bike so clean when I take it in for a service. They said they use compressed air to clean it.

They warned I shouldn't use any high pressure water because it can get into the sealed bearings and cause damage. I also noted on the user manual for Campag cranks (right at the end) that you should "Never spray your bicycle with water under pressure".

How much of an issue is this? Rinsing the bike with the hose is such a convenient way to wash off loose grit and then the soap after washing. How do you clean your bikes?

Yes, pressurized water can damage your bicycle, specifically by washing the grease out of bearing areas. Note, this is pressurized water.

Using a garden hose without a sprayer is unlikely to do damage. Using a garden hose with a shower type sprayer is unlikely to cause damage. Low pressure, so that it doesn't break the seals, is the point. (I avoid the risk, anyway, because I can't afford to be wrong, and how much pressure is OK depends on the strength of the seals on your particular bike.)

A car wash, or any other pressure washer, is pretty much guaranteed to do damage.

Washing by hand, with a bucket, a car wash brush, a toothbrush or gear brush, and some non-detergent based soap is the safest way, and with a little practice and preparation, can be done in half an hour.

Some detergent based soaps react to aluminum, and can cause serious damage to an aluminum frame or parts over time. Make sure you use an aluminum safe soap.

You can make things easier by using a repair stand to hold the bike, and removing some parts, if you have the tools and knowledge, but that's a bonus.

Other than that, it's just elbow grease.


How do I make a mountain bike go faster (commuting) I just began biking around 4 months ago, and due to lack of experience I bought a Diadora Orbita Mountain Bike. I've staring commuting to work recently (about 14 km daily) but I'm not exactly happy with my speed (around 17 kmph with no traffic) that is after inflating my tire and cleaning the chains on regular basis... Would changing the tires into thinner ones make my any bike faster? Are there any other modifications that I can apply to my bike to make it go faster? Or would be easier to just buy a road bike instead?

 (generic image)

I started commuting the same way about 8 months ago on a 29'er mountain bike, 2 things made the trip faster and more enjoyable.

Firstly tyres, I changed from knobblies to slicks and it made a BIG difference both in feel and actual speed.

Secondly I got a lot stronger from biking every day.

I eventually got a lighter cheap touring bike which is faster, and better in many ways, but I still prefer the mountain bike for fun.


What's the performance difference between a front-load and top-load bike stem? I recently bought a bmx and after doing a few tricks on it, the front-load stem became loose enough for the bars to slide forward (they rotated towards me about the point the bars were connecting at the stem.)

After tightening every bolt on the stem and adjusting the bars upright, I encountered the same problem after a few more tricks.

I was looking into buying a new stem and wanted to know what the major differences were between a front-load stem and a top-load stem.

There should be no difference, other than the quality of the materials and workmanship.  One can clamp just as tightly as the other, and both will be apt to produce the same symptoms if the bar is slightly undersized or too flimsy at the mount point.  In both cases, if you do have a slightly-undersized bar you want to keep you can grind down the faces of the clamp a hair (though it would tend to deface the upper unit more).

I suspect the main difference between the above units is weight and "sex appeal" -- the upper unit appears likely to be a few grams lighter, and it's that cool black color.


Can I move one bike with a second bike with a QR and carrier-rack attachment? I thought of drilling a hole in a rear rack then put the quick release in, therefore securing the bicycle on the rack and making it possible to move a bike with another to another place that seems like a good idea.

I just didn't find any post anywhere confirming my theory. I'd like to know what you think about this idea?

Would not recommend

I have tried this - and it works well up to where it all went badly wrong.

So I had an old front wheel hollow axle with a QR skewer through it.  There were two locknuts and two old cone nuts set at a distance of about 100mm, duplicating the OLD of a front wheel.  Sorry no photos available.

This axle had been clamped onto a rear parcel rack as far aft as possible - since it was a test, there were jubilee/hose clamps and some packing.  Effectively there was no movement on this part.

The towed bike had its front wheel removed, and the fork dropouts in the towing QR.  The towed bike was angled upward like it was pulling a wheelie.  I also strapped a couple of red blinky lights to the towed bike to make it more visible, despite this being a well lit summer evening.

I also fitted a secondary safety rope through the towed bike's frame and to my seat post.  Car trailers must have them, seemed like a good idea.

The front wheel was strapped to the rear bike's chainstay and left pedal crank, the top tube and under the saddle to give three points of securing.  Strapping was done with some reusable velcro cableties, which worked well.

Riding straight was fine.  The towed bike was clattery and made a bit of extra noise.  Reversing didn't work because I'd clamped down the pedal crank.  That was not a problem.

Slow speed manoevers were okay - they felt really weird but turning at walking pace worked.

It all went wrong after about 10 mintes, when I was getting confident.  I took a sharper turn at faster speed, perhaps 12-15 km/h when the back wheel lost all traction and I almost fell.  I thought the towed bike had come loose or something.

On inspection everything was secured correctly.  So what happened?

When leaning to turn, the third wheel (back wheel of towed bike) follows a shorter path than the front wheel and probably the middle wheel.  But the QR was not able to rotate much, so that clamped on the towed fork, combined with the headset angle of the towed bike, lifted the rear wheel of the front bike.  Unweighted it rose perhaps 2cm clear of the ground on a 15 degree lean.  If the weight of the rider was there it would have risen less, but height doesn't matter once its clear of the ground.

The fix would be to either

build your towing mount so it has freedom to rotate in the same plane as the wheels (ie, the towed bike's back wheel can move up and down relative to the tow bike)
Set the tow mount lower, so that the effective angle of both head tubes is the same (or closer)  Being ~10 degrees different was enough to cause this problem.  You can't fit a front fork over a rear wheel because the OLD is different, but you might be able to suspend the tow fitment just aft of the front bike's rear wheel, or to somehow lash the towed fork dropout at the same place as the rear axle of the front bike but beside.  The towed frame should clear the rear wheel, but keeping it straight might need extra thought.


Cube bike cassette wobble Recently I have bought a used 2012 Cube CLS LTD PRO hybrid bike in a good condition . The only thing was the rear cassette a little wobbling. I asked a mechanic about this and he told that almost every bike has this problem . After riding about 300 km I noticed that the cassette is wobbling more than it had been. Today I took the rear wheel off and saw that the cassette had a tiny backlash on the wheel . Can I fix the wobble simply by tightening the cassette , or should I buy a new one ?

Wobbling cassettes should be absent from, not present on, every bike. It is possible that the wobble is caused by worn splines on what might be a soft (aluminium, as opposed to steel) freehub. I myself recently blogged about such an issue at http://bit.ly/HubTrouble .

The wobble might instead be a result of an incorrectly seated lock-ring, or a missing spacer from behind the cassette (in which case you might find this link of interest: http://bit.ly/CassetteIssues)


7/8 speed quick link on 6 speed chain? I have a 6 speed freewheel with a chain which says HG on it. Can I use a 7/8 speed quick link on my chain?

"HG" indicates that this is a Hyperglide chain, but it doesn't tell us how wide the chain is, which is the critical question to answer—Hyperglide is a Shimano technology used on drive systems with different numbers of gears. Although you have a 6-speed freewheel, you might not have a 6-speed chain, and outer chain widths are different depending on the number of speeds, although you can use (for example) a 7-speed chain on a 6-speed freewheel.
The safest thing to do would be to replace your chain so that you know exactly what you have (if you don't know when your chain was last replaced, it's overdue anyhow). You can also try fitting this master link, and if it works, it works. If it's a 6-speed chain, I don't think it will work.


Replacement for discontinued Schwalbe Tyrago Schwalbe appear to have discontinued their Tyrago range of tyres from what I can tell.

The rear tyre on my Boardman CX Comp needs replacing as it's showing wear and has little tread left for grip. What supersedes it as the closest direct replacement or a good alternative? (I cycle on-and-off road, nothing too serious; the Tyrago seemed to cope well unless it was particularly muddy up hill.)

Do you mean a CX tyre having similar tread to your Tyrago? Do you mean performance-wise? Same brand? Why don't you just buy a new tyre of same brand and model (Tyrago supersedes Tyrago)?

The question's a bit vague. Most CX tires produced recently are pretty much well-performing and supersedes Tyrago (or even better than it), though it depends on its specializations.

Anyways, I'll hand out some examples of CX tires with similar, angled treads/knobbles: (might give you insight on what you want)

Michelin Protek Cross - very fast rolling (road) but slippy in muddy conditions.

Michelin Cyclocross Mud 2 - fast rolling (road), more traction, a bit mud-clearing

Bontrager CX0 - pretty fast rolling (road), okay traction, not that mud-clearing, side knobs for cornering

Maxxis Mud Wrestler - okay rolling (road), nice traction, very mud-clearing

Continental Cyclo X King - meh rolling (road), mud-biting traction, mud-clearing

Hope you can sort that thing out. I myself use something like the Bontrager CX0 as I both go on long road tours and off-road sessions.


Installing modern Deraileurs in an Old type mountain bike Frame Found my old mountainbike(steelframe) and i saw that its Rear Deraileur was worn out, was wondering would i be able to install a modern deraileur on a bike frame like this? I'd also like to ask if deraileur hangers shown in the picture with be compatible for this frame? Pls i badly need some advise about this as i want to restore this old bike

Also! Can all deraileurs be fitted to ANY bike hangers or frames? (Do they all have standard bolt size and holes)

Yes and yes. The "everybody else" hanger adapter does indeed fit all screw mounted derailleurs except Huret. The size, thread and location of the mounting hold are all copied from the first Campagnolo derailleurs. The only complication are direct mount derailleurs, which usually come with adapter for frames with standard mount and can be used with the claw mount adapter too.

Of course, you can still buy a modern-ish entry level derailleur with claw mount.


How to repair a twisted Presta valve? On one of my old bike, I have a twisted Presta valve:

Unlike this user, I can't put glue on my valve because the air is leaking at the tip of the valve (where it is twisted). So, I want to know if I can change only the tip of my valve or if it is possible to just change the valve without throwing the tube.

As noted in this old question there exist Presta tubes from which the valve core can be removed; in this case it might be possible to replace the valve core.

However, yours appears to be a single piece valve (non-removable core).

Since the valve is otherwise trash, I would try gently bending it straight using a pair of pliers.  If it breaks, or doesn't straighten you're no worse off, since you'll have to discard it anyway.


How do I tell if a loose chain is because of the chain or the ring wearing? My chain looks as though it's 'stretched' - by the time it's fed around the large front chainring it appears to be 'longer' than when on the other chainrings.

Therefore I'm trying to work out whether the chain/links have stretched, or whether the teeth on the chainrings have worn.

How could I tell which I need to address?

Measure the chain. You can use a chain gauge, or just a metal ruler.

Sheldon describes it in detail, but assuming you have a ruler with inches (and fractions of an inch), you can just measure 12 pins' worth of the chain (under tension). If it it's 1/16th past the inch mark, he recommends changing it.

That linked page also has some information on checking for a worn sprocket: if the chain is new (or you measured and it hasn't stretched), and the sprocket is worn, the chain rollers won't sit evenly between the teeth when under tension.

If you can see light between the sprocket and chain, it's probably time to replace.


Replacing crank and bearing on cheap Murray Murray Cross Canyon. The pedal crank is all one piece with regular bearings. What would I use to upgrade this? Is there a bottom bracket that i can use. The outside diameter of the bearing is 43mm.
I'm converting this to an e=bike so it doesn't need to be high end, just better than the junk it came with.

There are many levels of "upgrade". To be "better than the junk it came with" there are at least two options with many shades of quality level.
1. One piece crank upgrade
There are different qualities of one piece cranks / bearings / cones / races. Murry, Huffy etc. come with the lowest quality.
Back when Schwinn bicycles were made in the U.S. Schwinn bicycles with one piece cranks came with good quality crank parts. "New Old Stock" (NOS) Schwinn bearings, races, cones, and crank would be an upgrade to the parts you removed and they will fit your bike. Other sources for quality one piece crank parts would be made by Tioga, Tange or some other name brand maker.
As with anything there are advantages and disadvantages to a one piece crank. They are easy to maintain, they are very strong - they are also very heavy. This would be the least expensive upgrade.
Sheldon Brown has a nice over view of one piece crank types and interchangeability.
2. Three piece crank
The video Argenti has posted demonstrates how to replace a one piece crank with a very nice three piece crank and sealed bearing setup. There are a variety of solutions offered by different companies to accomplish this with a wide range of quality and prices. They will reduce weight but I would argue that a good three piece crank is no stronger than a good forged chromoly one piece crank.
As you convert your Murry into an e-bike remember that the quality of crank parts you removed are relatively equal to the quality of parts on the rest of the bike - including the frame.
Murry designed the bike to be affordable and to do that they compromised on the durability of the entire bike, not just the crank parts.
Adding an electric motor to a bicycle introduces forces the bicycle was not designed for. Using a low quality bicycle as the basis for an e-bike is especially problematic and could be dangerous.


Stationary bike calories Could somebody give me an idea of how to figure out the number of calories I'm burning on a stationary bike?

The bike I'm using is a cheap Pro Fitness magnetic bike from Argos (http://www.argos.co.uk/static/Product/partNumber/9237386.htm), and it comes with a digital readout of speed, distance, pulse, calories, etc. but the calories stay the same no matter what setting I ride on.

In other words, if I do 45 minutes at 30 kph on setting 1 (extremely easy), the calorie readout will be the same as if I do 45 minutes at 30 kph on setting 8 (around 200!). Obviously this cannot be true.

I've been using this site (http://prod.bicycling.com/training-nutrition/training-fitness/cycling-calories-burned-calculator) to get an estimation of my calories, and the calculator says I will burn about 750 calories for a 45 minute ride at 30kph, but the calculator is for bicycles and not stationary bikes.

Are there any guidelines or info for stationary bikes only?

Since you say you have a heart rate display, you can use one of the various online calculators to convert heart rate to calories.

Such calculators can only give you an approximate answer, but they will be better than nothing. And they're free.

Be careful not to overheat using a stationary bike.


How to tell if a hub uses sealed bearings or loose ones? My rear hub is dead. Tt has tons of play and I'm planning to replace it with  a  new Shimano  one. Everyone suggests me to  get one  with sealed bearings,  how can I tell if a hub uses sealed or  loose bearings? For example I'm planning to buy this one:
Link to Shimano  hub

is there any naming scheme so I can tell by the  name?
where can I verify that?

I presume you mean loose vs cartridge bearings.
They are both sealed. High grade shimano hubs are actually pretty well sealed.
I can see cone nuts in that picture, so its loose bearings.


There is a grinding feeling at the end of my pedaling at high speed I bought a road bike about 6 weeks ago, but I just only realised it now that at the end of my pedaling (when either foot pushes down), I can feel a bit of a drag/friction/grinding on either pedal. I don't know what's the cause. It just feels unsafe, like something's about to come lose.

The closest thing to describe this friction/grinding feeling is if you imagine going on to a grated bridge. It feels like that.

I noticed that I only feel this at high speed and high gear (about 20+kmph and ~50 cadence). I can't pin point what's causing this because I can only feel it when I'm travelling at high speed and so it is really hard to try to look to see what's the cause.

Is it "normal" to feel this "friction/grinding" at high speed. This is my first road bike so I'm not too familiar on what's "normal".

Could it be due to low/high tire pressure? The tire says 130 PSI... but my pump gauge is broken so I just put as much air as I can and as much as the tire can take before it won't take anymore (using my body weight to pump the last few inches of air into it).

What should I be looking for to troubleshoot this problem?

Update

I've put the bike on an indoor trainer. I took off the pedals and then apply pressure to the cranks by hand. I can still feel a "grinding". So not the pedal.

I then took the chain off to see if it's somehow related to the chain tension. I spun the crank slowly, and I can feel a slight grind - not very noticeable, but it has the same rhythm of the grind when pressure is applied. So it's not the chain tension, it has something to do with the crank.

That is, the grind is more noticeable when pressure is applied to the crank. It might have something to do with the bearings of the crank. But because this is a new bike, I'm questioning if this is suppose to be normal and whether I should put up with it?

When you spin the crank should it be completely smooth without any noticeable grind? If so then I need some tips to rectify this problem because I've never worked with a bike before.

More update

After weeks of inquisitively monitoring the bike, and doing bits of adjustments. I re-greased the pedal bearings, which helped. I can only feel the vibration slightly at high speed and when applying pressure. Not as bad as before. It appears that the pedal bearings were either too tight or too loose which caused a vibration when pedaling. Now the problem still persist, but slightly less so than before.

I cannot regrease the bottom bracket bearings because it is a Shimano Hollowtech and so would mean I have to buy a new bottom bracket if it is the cause.

However, I've done more research and found that the wheels can be out of "true" and cause a wobble/vibration when riding at high speed.  I spun the wheels and monitored the brake calipers. My back wheel is definitely way out of true. It appears to be rocking from side to side about 1mm apart. So I've ordered a spoke wrench which should arrive in a week or two in hope to "True" the wheel to fix the problem. Will update when I've trued the wheel.

BTW, I've learned my lesson not to buy anything bulky/expensive online, because it's hell when something goes wrong.

I would say: pedalbearings? Seems that when you apply pressure, the bearing gets pressurised, causing this "rough" feel.


Adjusting road brake levers Recently I got my bar tape, brake cables and brake levers changed, but when I picked up the bike I noticed that the brake levers were to low (at the tip of the drops) is there any way I can put them in the right position without damaging the bar tape or the brake cables?

Answer: No - you can't just move the brake levers up the curve of the handlebar drops.   If you did this, the bar tape would be bunched up above the hoods and skinnied-out below the hoods.

Tools: You'll need a 5mm hex driver (maybe 4mm or 6mm, maybe a philips if its old, or flathead if its ancient)  Some tape to finish the bartape wrap, and sharp scissors to cut the tape.

Method: Unwind the bar tape carefully, reposition the brakes, then do up the bar tape again.  You'll probably put one, maybe two turns of bar tape below the brake hoods that were above the hoods when you started.

The brake cables should move okay - you might need to remove and refix some temporary tape.


Upgrading to new hydraulic brakes - should I put same sized rotors on front and rear wheel? I would like to upgrade brakes on my bike but I have a dilemma / question - currently, on my front wheel there is 180 mm rotor and on back wheel there is 160 mm rotor. Is there any reason why bike manufacturer did this (is it assumed that bike doesn't need that much stopping power on rear wheel?). Would I gain anything by installing same sizes rotors (180 mm) on both wheels and is there any risk to bikes frame?

This is a common set up, as the majority of your stopping power is assumed to come from the front wheel, and many frames, especially older frames, had less clearance on the rear triangle of the frame, so often the 180mm  rotor wouldn't fit.

You can change it if you like, but there is little necessity to do so.

If you choose to change it, you will only need a rotor, and the appropriate adaptor for you brake caliper type.


Add-on Aero Bars to an Already Aero Handlebar I've recently upgraded from a Specialized Allez to a (3T Strada Pro Force).  I took it on its first long ride (56 miles) and my, already bad, wrists really suffered.  I changed hand positions as often as I could, but it was still an uncomfortable ride.  On my Allez, I have a set of Profile Airstryke aero bars which have been great because being in an aero position takes the pressure off my wrists.

The 3T Strada Pro comes with Aeronova Aero Handlebars.  With them having a flatter shape, I'm not sure if there are any add-on aero bars, like the Airstrykes, that can attach to this handlebar.

Although I enjoy riding in the aero position, I do it more for comfort and hand position options than I do for aerodynamics.  Are there any add-on aero bars that I can purchase that will fit this type of handlebar?

Most clip-on aero bars attach near the stem, where the handle bars have a round profile, not where the bars have a flat profile. The elbow pads are outboard of the mounting point, which will put them over the flat portion of the bars.

As an aside I would try to assess why you are experiencing wrist issues.  You may simply need adjust your setup. It is also possible that on the new bars you are twisting wrists. Ideally you want to keep your wrists straight as possible. You may need to adjust the position of shifter/brake on the bars to help facilitate.


What size cone wrench am I likely to need for a Trek 1.5 2011 Compact rear hub? Unfortunately the manufacturer's website, and google don't appear to hold this information. The only thing I've found is that the hubs are aluminium which doesn't really help.

Is there a common size of wrench? If I get the size wrong I can always send it back but I'm guessing people who deal with road bikes a lot will know that there's a common set of sizes.

Any suggestions? :)

I had a 2008 version of the 1.5 bike and the rear wheel took a 15mm cone wrench.

It's possible that Trek changed this, but I think 15mm is a good bet.

I agree with @alex; anything other than 13, 15, or 17 would be considered uncommon.


Plastic ring on new Shimano crankset, toss or keep? I just got a new Shimano crankset and it has this plastic ring on the "inside" of the small chainring.  I'm thinking that this just some packing material.  Am I right and can I toss it, or is this a real part?

I haven't seen one of those before, but it looks as though it could stop the chain dropping between the bottom bracket shell (the bike frame) and the crankset if you ever drop the chain off the inside of the small ring. When that happens it can be tricky to get it back out, and if the chain is oily you end up with that oil everywhere (mostly on your hands and clothes). This is something I see occasionally, as I stop to help people standing next to their bike looking helpless on my ride to work. On some bikes it's possible to get the chain wiggled in such that it's still movable but you can't get it out without taking the crank off (I've seen that in the bike shop).

I would leave the plastic ring in place just in case is stops that happening. It's one of those "5 grams stops the once in 10 years problem" things.

It might also reduce damage from the chain rubbing on the frame if the chains falls off as above.

Edit: after Batman found the part (Shimano EV-FC-M410-2465A), here's a diagram of something very similar via this pdf link


Brake levers for Dia Compe centre pull brakes I'm looking at replacing the brake levers on an older road bike and was wondering if the cable pull ratio for the old Dia Compe center pull brakes pictured below is compatible with new road brake lever like Tiagra or Cane Creek SCR-5. Also do these brake levers fit the old thinner drop bars seen on older bikes? I will eventually be replacing the brakes as well but was hoping I don't have to replace everything at once.

I've used Cane Creek levers with old MAFAC racers which are pretty similar. However,
the MAFACs allow you to adjust the length of the cross cable which allows you to tune the brake force.

It's my understanding that all road caliper brakes use roughly the same cable pull so that all "standard" caliper levers are interchangeable. Where you need to be concerned about the cable pull is caliper vs V-brake levers. This question covers
that difference.

Direct Pull (V-Brake) vs. Center Pull Cantilevers (pros and cons)

As always Sheldon Browns site contains lot's of useful information for older bike
technologies.

http://sheldonbrown.com/calipers.html


How should a bicycle fit? What are the characteristic features of a bicycle well-fitted to its rider?

Are there a standard set of "rider positions" that we talk about in bicyle ergonomics?

What are the standard tolerances and variances of these heuristics in practice?

How do these features vary by domain (eg. road, mountain, grocery-getter)?

How do these features vary by application (eg. racing, touring, recreation, practical)?

Related (but not duplicate):

How to do a bike fit?
(This is similar but different because it's about doing a bike fit, versus what a good bike fit is.)
How should a bicycle helmet fit?
How is bicycle fit affected by switching from a riser bar to a flat bar?
Bike fit: Adjusting stem angle vs. height

To distil an entire field down to a short answer....

  The bicycle should be comfortable to the rider and for the rider's intended use.

How you go about getting to that state of comfort is a slightly longer-answer, and too big for this space.


What does double and triple gear shifters mean? I am looking at these components and am wondering what does double and triple gear shifting mean?

Shimano R221 Double Gear Shifters 8 Speed
http://www.chainreactioncycles.com/Models.aspx?ModelID=38724

Shimano R221 Triple Gear Shifters 8 Speed
http://www.chainreactioncycles.com/Models.aspx?ModelID=38725

Double and triple refer to the number of chainrings (front gears) that you have.

Here are the detailed service instructions, which allude to this fact:

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/NonSeries/ST-R221-R225/SI_6LU0A_En_v1_m56577569830606213.pdf


Replacing Trek front suspension fork I have a Trek 26" Y-frame with beat-up, hardly functioning, yellow generic front fork. I'd like to replace the fork with a Rockshox Yellow Quadra or a Judy. Will they work on my bike? Thx

In short yes.  I had a Judy on a 1997 Trek Y Five-o many years back.  80mm version if I remember correct.  That frame and fork used a 1 1/8 headset steerer which I assume your frame will also have.

Just make sure the steerer tube on the fork is compatible and aim for form travel between 80-100mm

Specs on the bike I had are here:

http://www.bikepedia.com/QuickBike/BikeSpecs.aspx?year=1997&brand=Trek&model=Y+Five-0

I did not have the Manitou fork as indicated above I used a Judy


Good substitutes for WD-40 in emergency situation? I broke my bike in a poor location where I can only find poor rusted bikes. I am switching to one bike with rusted screws, I am trying to get things such as touring back rack and water-bottle holders to the new bike. I cannot find WD-40 here to take the screw out. The comment here speculates Kerosene and Naptha as the ingredients of WD-40.

So how can I substitute the WD-40?
How can I find some physical way to remove the rusted screws in the bike?

Edit: I have solved the problem with time and Coca Cola in one screw. I let the screw to be 2 hours in Coca Cola and I got it off later. I am still unsure whether this is the best solution, at least it tastes good and it is easily available. More this kind of solutions?

I have a multitool with a file, saw and knives.

Actually, WD40 is a poor penetrating oil -- Liquid Wrench, et al, are better.  But the Coke trick works, supposedly because of the phosphoric acid.  Another one is to heat the part -- eg, get a piece of iron hot in a fire and then hold it against the fastener for a minute or two.  Works best if you can actually heat the female part of the connection, but tends to work even if you must heat the male screw.  Sometimes heating and then dousing with water will break a part free, if heating alone doesn't do it.

Of course, be careful of any plastic parts, and avoid overheating bearings.


Replacing old brake blocks with modern pads I'm looking to freshen up a 60's Raleigh Sports that has the old standard brake blocks on it.  If I able to put modern pads (http://www.koolstop.com/images/ks-bmxdl_art_lg.jpg) from a cantilever brake on it, as long as they physically fit the rims, will I run into issues with braking forces causing extra stress?  Any issues with performance?

The bike is all stock with side pull brakes and levers on it.  Wheels are original steel and seem to be true (not checked in a stand).  Fork, frame, and wheels are in great shape.

Side note/discussion:  Koolstop carries the blocks (http://www.koolstop.com/english/continental.html) as well marketed for such a bike, recommended or not?

Those long "mountain bike" Kool-stops work fine on my modern skinny wheel road bike with side-pull calipers. If the modern Kool-stops fit (and don't see why not), I'm sure they will outperform those vintage looking ones - the contact area is much greater. I'd even bet the long contact patch results in less torque on the caliper arms, but I doubt it's an issue either way.

Those Kool-stops are nice, the mounting hardware allows fine adjustment of the plane of the brake surface. You're supposed to adjust them with a little toe-in (toe-out?) so the inevitable torque when applied straightens them out (we're talking a very small amount of inevitable torque twist - but the Kool-stops are designed to account for that). That little bend on the tip of the red side helps with the setup for that.

Take the bike in and ask the bike shop, but my guess is they'll work fine on 60s era calipers/skinny wheels.


Require seatpost size of Dahon Vitesse D7 I have a Dahon Vitesse D7.. Have lost the seat post. Can you let me know what is the size of the seatpost  will fit to the mentioned model

Go to a bike shop and get it measured.

They'll have some seatpost measuring tool like this:

You basically stick it into the seat tube and it tells you what size seatpost you need.

Alternatively, you could use a vernier caliper to measure the seat tube diameter on the inside (this is key!).

Note that the seat tube diameter is only one dimension; you also need to know what length tube you need. Most seatposts have the same clamp type as well, but you may want to get one with extra fore/aft adjustment or whatever. So, going to a shop and buying one isn't a bad idea if you don't know what you need.


Can I replace the eccentric bottom bracket in my Salsa El Mariachi with standard BB? I have an older Salsa El Mariachi with a Bushnell eccentric bottom bracket with 54mm O.D.

Do I have any options to replace the EBB with a non-eccentric bottom bracket?

The current bottom bracket has threaded openings to accept a standard 68mm English thread BB, currently running a standard GXP bottom bracket and crankset in the Bushnell EBB.

I've never seen something like that, an eccentric to concentric conversion BB. Even if it existed it would have all the issues of an eccentric, so the only benefit would be if you really wanted that otherwise unattainable chainstay length. If you really, really wanted this, just having one made would be pretty easy. If you're having creak troubles you could try a Niner eccentric, which has been known to solve the problem.


Specialized Cycle Computer? I'm in the market for a cycle computer that runs in cold weather. Does the Specialized SpeedZone Sport Double Wireless ANT+ work in the cold (eg down to 20 degrees F or hopefully lower)? (I just got off the phone with Specialized "rider support" & they didn't know. (Yikes!).)

I could not find the SpeedZone Sport Double Wireless ANT+ manual on line but I did find the SpeedZone Sport Manual on line and here are the spec's

I would expect the SpeedZone Sport Double Wireless ANT+ model to be similar.  A agree with the comments that say a bit below should work fine but too much below and you will likely lose the Liquid Crystal Display until the unit warms back up to within the specified operating range


Is the use of wide fatbike tires problematic with 100mm BSA bottom brackets? Fatbike frames typically come with 100mm or 120mm BSA BBs. Does the 120mm BB help anything, though? For example, if I have a 100mm bottom bracket and a 5" tire on a 100mm rim, and I switch to the largest cog of an Eagle 1x12 setup, will the chain start scratching the tire? Or will there be adequate clearance?

The math is easy to do.

According to Sheldon Brown, fatbike chainline is 66 or 76mm for dropout spacings of 170 and 190mm respectively.

Assuming a 100mm BB is used with a 170mm dropout spacing and 66mm chainline: a 5" tire is approximately 127mm wide so the tire would extend 63mm off the centerline of the bike.

That's only 3 mm clearance if the chain is running parallel to the centerline of the frame. With the chain on the largest ring it's conceivable that the chain would hit the tire.


Restoring Aluminum Cranks Is it all right to strip and then anodize (at a shop, I suppose?) aluminum cranks?

I'm trying to build a bike and I saw second-hand cranks on eBay. They look like they're fine except for the scratches/abrasions they have. They're fairly cheap too compared to new old stocks so I'm wondering if it would be a good buy if I can restore them to look brand new again.

So would stripping, sanding, anodizing, etc. the cranks have any negative effect on them?

Well, from the comments, I guess it is all right to strip the cranks and re-anodize them. There wouldn't be any serious effects on the material itself. The only downside is the process and the cost, which would probably cost close to, if not more, buying a new set of cranks.


I need help on how to make my bike faster Hi Just wanted to ask how to make my bike faster.

Do I change the front chainring to a larger one, if so do I have to get a whole new drive train or can I just get another shimano large ring. Can I get a smaller cog at the back, will that make my bike faster?

Please take a look at my bike. here are the specs

Shifters: R660 Shimano trigger, Front derailleur: R453 Shimano, Rear derailleur: Shimano Sora, Cassette: FAC MICHE 9s 12X26 Bottom bracket: FC453 Shimano 50/39/30, Chain: KMC Z9000

here's the site with more information
http://www.btwin.com/en/fitness-road-bikes/3856-b-twin-forme-5.html

I just want to know if I can change anything to make it faster but I don't know what to change. thanks

Thanks

David

There's a nice gear calculator at Sheldon's site. I did a quick calculation for you, and at 50/12, at 90 RPM, you should be going 47.4 km/h.  If you upgraded your front chainring to a 54, and your back cassette to go down to 11, at the same RPM you could go 55.8 km/h, which is a significant increase.  You can play around with different options on the calculator to see how much it would help to get different gearing combinations.

You might find that you won't get much extra speed out of bigger gears as your bike has a somewhat upright posture and therefore you'll be quite limited in what kind of speed you can get.  I think that 50 km/h is plenty fast for a bike and that you should just focus more on going faster on the flats and uphills.


Roadside / Temporary fix for skipping chain Recently I was out riding when my chain began to skip in the big ring due to heavily worn components. The situation worsened surprisingly quickly such that within a few miles I couldn't practically pedal in the big ring (i.e. the force required to keep moving exceeded that which causes the chain to skip over the cogs).
Fortunately, the small ring was less worn so I was able to make it home using that. But it got me wondering whether there are any quick fixes or tricks to overcome a slipping chain, if only temporarily, if this does happen out on a ride.
One thing I tried was to move up/down the rear cassette in the hope that a different tension might alleviate things, but this had little effect.

The only ''quick fix'' is to find a gear combination that works and hope for the best. Spending a few pounds on a chain wear checker will save you ever having to be in this position as you can check once a month or whatever and change the chain before it starts eating the rest of your drivetrain.