Hot answers tagged

17

The idea used to be that a triple was just a double with an extra small, 'granny' ring (i.e. only grandmothers would need to use that one) so there was definitely some snobbery in a triple; that it was designed for those who needed a little more help. So on the club training run, you might be teased for it. (Google for 'triple granny ring' for various forum ...


15

If you are looking at the Biopace/Rotor/O-Symmetric relationship as similar due purely to aesthetics, or their similarity due to their lack of similarity to round chainrings then, yes, they are similar products. But, that said, from the RotoR website "The Q-Rings are elliptical; the Biopace and O.SYMETRIC chainrings are asymmetrical.". And Sheldon Brown ...


13

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


13

As the others have stated, there's nothing wrong with any various drive train types (triple, double, 1x, single, etc). Compact drivetrains and triples are becoming more common because they provide an easier set of options for casual riding. A traditional double for a road bike may be more than most people want for casual riding. For example, if you take a ...


12

Obviously, the simpler the better, and a triple is a little, er, "crankier" to maintain and use than a double. But on most bikes it will mean that you have both a slightly larger large gear and a significantly smaller small gear, in addition to having closer "jumps" between gears. Exactly how this all will work out depends on the manufacturer's choice of ...


11

This is actually a matter of the force multiplication that each chainring provides, and the size/mass of each chainring. Force difference Let's propose, only for a moment that you had a chainring as big that the radius of it is almost the same as the crank length. If the rider stood to pedal while using that chainring (and using simple platform pedals). ...


11

You have a couple different options. I think the cheapest would be to switch to a compact crankset which would change the front chainrings from 52-39 to 50-34. I'm pretty sure you could do this while still using the same shifter. Changing the front shifter is required if you want to go from a double to a triple, as is changing the front derailleur. If you ...


10

Those notches are used when shifting gears, as you move the derailleur, the chain moves and catches on a notch and switches from one chainring to another adjusting the gearing. You do not need a replacement bicycle, this is a nice bike and with proper maintenance (keeping the drive train clean and lubed) should last a long time.


9

Well, in 2010 there's the S1, S2 and S3. S1 is lower-end and has 50/34. In 2011, they dropped the S1 and there's only the S2 and S3. (based on what's up on their website right now) The lowest end of the line is probably considered something like "entry level" or at least "not for racers", so it gets the "slower" chainring setup. They've kept the ...


9

You'll probably need to replace the cassette as well. Generally once the chain has worn ("stretched") a little, it starts to wear down all the gears (front and back) that it touches. If there's enough wear that the front chainrings need to be replaced, it's almost certain that the gears on the cassette that you use most are also worn enough to need ...


9

UCI time trials are a class race contested in the tiny fractions of a percent, tiny differences in equipment become very important. Riders practice in wind tunnels to tweak everything from clothing to pedalling style, because a shift that gives an overall gain of 0.01% in speed can result in a win. Considering more than just the top gear, the jump from ...


9

50/34 makes more and more sense for most people. Especially as many cassettes come as 11-25 rather than 12-25. A 50x11 is the same ratio as 53x12. The 50/34 combination therefore offers great flexibility in gear ratio even for top level racers. I know of one rider whom finished regularly in the top 50 at the Etape du Tour and competes at Premier Calendar ...


9

Interesting question. Real world conditions are messy with multiple factors impacting any analysis, as such my answer will be speculative, but based on a number of sensible working assumptions. Chainring degradation as a source First lets consider how much material comes off a chainring. Generally speaking, if you replace your chain regularly before it ...


8

Drivetrain components tend to wear in this order: Chain Rear cassette/sprockets Front chainrings (and the teeth on your derailleur's jockey wheels may last, but the bearings may not) The chain is usually the culprit for wearing out the other two. As it wears, the distance between links effectively increases, and the mismatch between the links and teeth ...


8

7 speed systems use slightly wider chains, and the teeth on the chainring are slightly wider too. You might run into an issue with a ten speed chain not fitting over the teeth, or at least not fitting well.


8

The crankset you have is actually held together with rivets and not bolts. Some manufacturers of some low-end cranksets make the rivets with a hex head on one side. The easiest way to remove it is with a hex key and a drill. Select a drill bit that is slightly larger than the core of the rivet. Being sure to hold it steady with a hex key, drill enough ...


8

In theory they are more efficient. Throughout the pedal stroke your leg doesn't give an equal amount of force - ideally you want to spend most of the time pushing down with the big thigh muscles and a minimum time in the horizontal movements at the top and bottom of the stroke. Elliptical front cogs give you a more up-down leg motion, so more time with ...


8

Presumably with 12K+ km, and never having bought new chain rings, you have a very high cadence. You should get a new chain every time you change your cassette, btw. If you are doing the work yourself, I don't see any reason to change the chain ring immediately. Try the new cassette and chain and see how it works. If it isn't broke, don't fix it. If it ...


8

Yes, this should be possible. Though there are several things you need to check to ensure it is compatible: Number of bolts, and bolt circle diameter (BCD). Count the number of bolts, and measure the distance between the centre of two bolts. Then check Sheldon Brown's Bolt Circle Diameter Crib Sheet to see what the BCD is. Common sizes are 110 (mountain ...


8

Possible causes: There is "play" in the bottom bracket bearings, this could also explain the clicks. Usually this is quite noticeable, and you can check it by grabbing the crank-arm and trying to move it sideways. Usually this is not the cause for variable chain tension on singles; The chainring is "eccentric", either because of haveing been tightened ...


8

Here are some points taken from the literature: Mechanical efficiency is usually 88-98% for majority of deraileur systems (when clean,lubricated and new) Drivetrain efficiency decreases with smaller rear cogs, Highest efficiency can be reached at high torques and low cadence, Chainline effects are negligible, imposible to note with measurement apparatus, ...


7

This is a common setup for many freeride bikes, as it allows uphill peddling and a bash guard. However only certain models of chain guide support this, and the one your son has doesn't officially (though it wouldn't hurt to try if you have crankset to test, might affect derailleur...). The DRS is eThirteen's 'official' dually chain guide.


7

You may need to change your cassette with your chain due to damage, but only if your bike has missed out on some previous maintenance. If you ride one chain beyond the point of wear, it will damage both cassette and chain rings to different degrees. Your chain is a consumable component on your bike. For most people, 1200-1500 kilometers on a chain is a ...


7

I would consider changing your crankset to a true compact, 50t/34t, and running an 11/25 rear cassette. Campy actually made a specific derailleur for running a compact front, because they said that the 50t doesn't work well with the standard front derailleur (that may be a function of the tooth differential, so it may not apply if you leave the 39t in ...


7

I think Shimano integrated shifters ("brifters") for the front derailleur on a triple normally have 5 indexed positions: 1-3-5 are the main positions that match the chainrings and 2-4 are intermediate spots to avoid chain rub for some chainring+sprocket combinations. If you give the front shift lever a short pull it will click once and the front derailleur ...


7

Depends on your budget, your requirements, and your mechanical aptitude. Plus how far down the slippery slope of knock-on upgrades you want to do on a BSO bike. Since the crank is riveted together, its unlikely to accept any bolt-on replacement chainrings. Though its possible the makers used rivets instead of bolts but used normal bolt chainrings. You'll ...


6

If you only know the pitch of the chain (standard for most bicycles) and number of teeth, then you can fully describe the circle (and n-gon) through the pin centers only. I will do my best to do the math formulas in a readable way with text, but I will fully describe each of the four circles/n-gons: Let: n = number of teeth L = chain pitch (link length) ...


6

You should always install a new chain (or have one that's pretty new already) when you install a new cassette. But you can go through 5 or so chains on a single cassette.


6

Good question! There are a couple important reasons for the differing materials: Wear: Steel lasts longer than aluminum, plain and simple. So why not use steel on all the rings? The larger rings have ramps on the sides that facilitate shifting and cannot be flipped as the ring wears. The granny ring can, therefore it can last a lot longer. Flexion/Bending: ...



Only top voted, non community-wiki answers of a minimum length are eligible