Hot answers tagged

41

If the aluminum is sufficiently stiff it makes zero difference -- the crank could be any shape (a disk, an S shape, etc), but the relationship between the two contact points would still remain the same, and that's all that counts. The only effect the crank could have is adding a bit of spring to the crank, which might be good or bad for effective cranking. ...


36

The pros of buying pre-built are the cons of building your own. Each approach is born of very different requirements. That is, the person who is actually likely to build their own is very unlikely to buy off the shelf and vice versa. (I assume that 'build from scratch' also covers getting the LBS to do it for you to your specification). I would caution ...


32

Economics of scale. For instance, when a bike manufacturer buys thousands of groupsets directly from a component manufacturer, they get a significantly better per unit price than a retailer can. The retailer not only must necessarily buy in lower volume, but also typically buys through one or more layers of middlemen, each layer adding their cut to the ...


27

Equipment/Accessories: Fenders — keep you dry if it's rained recently. I prefer the "full-coverage" kind with a mudflap, but anything that keeps you from getting a stripe up your back is probably sufficient. Regular platform pedals (or even better: BMX style pedals) - clips or clipless and frequent stops don't go well together and might mean needing ...


25

The comments on the Kickstarter project have a few good explanations of both why the design is effectively identical to a straight crank, and why the plan to make carbon-fiber versions is dangerous. Now leverage: if you tried to push down on the pedal (as shown in the video) when it was exactly top dead center and stopped, it doesn't matter if it is ...


24

Pedal Selection Pick a system that will work well for your current and future use. It's annoying to have different shoes for different bikes. My experience is limited to Shimano SPDs and Crank Brothers systems -- both of these work very well for road and mountain biking. The shoe cleat is similar for both systems and is fairly small, which means you can ...


23

Here I'll summarize everyone else's answers (because of all the Q+A scattered through in the comments), with some additional information that I got elsewhere from reading inspired by people's answers. Wheels+tires: 700 x (28 - 38, maybe ~30), tires; slicks or light treads, not knobbly. The larger wheel makes it faster (because of 'gearing') and the ride a ...


23

If you want to maximize your max. speed, go for an 11 tooth cog. If you want to maximize your average speed, unless you're a pro you probably are better off without it. Even cruising at 40km/h does not require and 11 tooth cog. For example, take a look at this table, showing cruising speeds for a 11- 21 tooth cassette: And compare to this table for a 12 - ...


23

Here's a little bit of information that's in contradiction to "higher end equals better" Lower end components can sometimes last longer and be less problematic than the higher end components. In order to shave off every single gram they sometimes have to skimp on materials. Also, the tolerances are much tighter, and high end components can often be ...


22

Other than the obvious fact that your better quality (and better handling) bikes tend to be lighter, there's no real correlation between weight and performance (other than a modest effect on acceleration and the obvious effect on hill climbing). But you can generally (with some exceptions) assume that a bike that is quite a bit (like 2x) heavier than others ...


21

Basically, they're harsh and hard on your wheels. A quick look at Sheldon Brown's site will tell you more: Airless tyres have been obsolete for over a century, but crackpot "inventors" keep trying to bring them back. They are heavy, slow and give a harsh ride. They are also likely to cause wheel damage, due to their poor cushioning ability. A pneumatic ...


21

You should not be getting multiple flat tires in such a short timespan. I commute on poorly-maintained roads in Atlanta, and have not had a flat tire in 4,000 miles. In order of estimated likelihood, either: your tires are not properly inflated your tires are worn or punctured and need to be replaced you have a sharp object embedded on the inside of your ...


21

This is just a rehashing of a very old and horrible idea. See PMP Cranks et al. Edited for additional information: RE: PMP cranks A moment's thought shows a straight crank and an L crank always have the same relation between pedals, chain, and bottom bracket. Thus, there is no advantage to L cranks. And an L crank always has more material than a ...


17

Yes, people still use them and swear by them. I've seen them for sale in most of my local bike shops. The breaking-in thing (that they mold to your backside over time) is the big feature that everybody who uses one seems to love. They're very popular amongst the touring crowd, especially the B-17. Yesterday, I was volunteering at a huge road ride event and ...


17

It protects the frame from the handlebars. The handlebars, unrestricted by brake or derailleur cables, can rotate freely to the point that they can smack into the top tube. This is particularly easy to do when carrying the bike.


17

In addition to economies of scale, you also have to consider the difference in price sensitivity and leverage between a manufacturer and a consumer. If Shimano told Trek that they'd start paying retail prices for their cranks, for example, your next Trek would have SRAM cranks. You can be sure they've negotiated the lowest plausible price, because it's very ...


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 ...


15

The focus is on the riders, because the bikes are just not so different from one another. The UCI (international cyclists' union) tightly regulates what shape and weight the bike must be, and what technical solutions are acceptable, so the sponsoring manufacturers can only compete on relatively minor features such as aerodynamic tubing or frame stiffness. ...


15

They are called Pegs. Pegs are mainly used by BMX riders to help perform various tricks. Flatland trick (standing with all of his weight on one peg, not damaging anything): Grinding a wall on the rear peg (imagine the forces when the rider jumps on the wall, still: no damage to the hub but of course to the peg and the wall): Images from Wikimedia ...


15

For me, and for many riders that come through my shop, the 11-25 is missing the critical 16t cog, which (at least for me) is the sweet spot. That is, the gear which I don't tend to spin out of, and that doesn't turn in to a grind fest. If I'm doing a Euro trip, then I will run an 11-28, with a compact front. But at home, for daily riding, a standard 53/39 ...


15

Flat pedals are great for lots of reasons, but I won't get into the virtues or pitfalls of platforms versus toe clips versus clipless systems (though I am a big fan of plain old platform pedals.) I will try to give information pertaining to the different styles and a few examples rather than an exhaustive list of specific brands and prices. There are lots ...


15

The purpose of such a steering damper is to stop the front wheel from turning when using a (two-leg) kickstand or while pushing the bike. Not much use otherwise.


14

Chains There's a lot of information here about why chains wear, how long they might last, how to tell when they need replacing, and what happens if you don't when they need it. 1000 km (cross-country, or all-weather abuse) 3-5000 km (well-maintained derailer chains) more than 6,000 km for perfectly groomed high-quality chains, single-gear, or hub-gear ...


14

There's no way to 100% secure everything, but there are things you can do to make it more difficult or time-consuming. Don't lock up your bike. Bring your bike with you instead of leaving it outside. Mine goes into my office. Choose a location where you or other people will see thieves messing with the bike. Not a super-high traffic area (in that case ...


14

Unfortunately this doesn't help. The example pictures demonstrate misunderstanding elementary classical mechanics and more specifically, statics. Moment, a.k.a. torque, is defined as M = F * d where F = the force applied d = the perpendicular distance from the axis to the line of action of the force. The shape of the crank has not effect on either. F ...


14

I assume that you're talking about road biking. I can give you my opinion after using these groups for a while: Shimano Sora, Shimano Tiagra, Shimano 105, and now a full Shimano Ultegra. All work, when properly adjusted and when shifting correctly. You have to do your homework and know how to shift smoothly, and adjust the gears. Whoever tells you that ...


14

The ball-end wrenches are really handy when there's an obstruction in front of the bolt, since they can be inserted at a slight angle. But since the contact area is smaller, you're slightly more likely to strip the hole. So I would use a regular wrench when possible.


14

They're trying to sell you stuff. More expensive stuff (have you looked at 11 speed consumable (chain+cassette) prices vs 10 speed?). I would not bother upgrading. As groups go to higher and higher speeds, the older stuff gets pushed down to lower component levels. So today's 11 speed 105 group will be next year's (or likely a few years later) Tiagra ...


13

You use a Torque Wrench. You set how much pressure, and when you tighten to that pressure, the wrench will "click" and not tighten the nut/bolt any more.



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