Sheldon Brown's
Bicycle Glossary Ri - Rz
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Rivets are commonly used to assemble derailers, fenders and saddles. They are also used to assemble low-quality pedals and cranks/chainwheels.
The links of a bicycle chain are held together by rivets (sometimes also called "link pins") which in most cases only have a slight thickening at the ends, rather than a seriously spread head. This allows chain links to be disassembled by partially removing the rivet, then driving the rivet back in with a chain tool. The narrowest chains used can not be reassembled with a chain tool, but rather, must be reassembled using a special replacement rivet or master link.
Usually, the term "road bicycle" is used to refer to a sport bicycle with drop handlebars and narrow tires. Sometimes the term is used in an even more restrictive sense, to apply to a road racing bicycle.
See my articles on English 3-Speeds, and my 1954 Superbe Roadster (pictured above.)
Most rod brakes use a "stirrup" which holds brake shoes that pull against the inner circumference of the rim. These are usually used with Westwood or Raleigh pattern rims, which have a ridge where the spokes attach, so there is no risk of snagging a spoke nipple with the brake shoes. These brakes are relatively trouble-free, but slight irregularities in rim radius can cause a brake to grab. Unless a rim is dented, caliper brakes that bear on the rim sidewalls are, on the other hand, very tolerant, because the rim's width remains constant even if the wheel is out of true. This is especially so with rims that have parallel sidewalls, including the Westrick rims used on higher-end Raleigh Industries three-speeds for many decades, and most aluminum rims made since 1980.
The Rohloff Speedhub has an unusually wide gear range.
also see our page about the Rohloff Speedhub and a user's report
Compared with a stationary trainer, rollers have the advantage of forcing a cyclist to ride in a very smoothly, and generally improve form and smoothness on the bike. For most riders, however, a stationary trainer allows a higher intensity of riding, since it requires no mental effort to stay balanced.
Mastering roller riding is tricky. It is helpful to start out with the rollers in a doorway, so it is possible to lean against the door frame to prevent a fall.
It is also useful to have a full-length mirror straight ahead, so that you can observe your form.
If you are having trouble learning to balance on rollers, make sure that you are looking straight ahead, not down at the rollers. It is much harder to balance if you look down.
It is also a very good idea to set up a fan to help cool you off, as the slipstream does when riding outdoors -- or to set up your rollers in a cold place. That is often easy to arrange, as rollers are typically used for winter training..
Roller bearings also are used in some pedals and for the planet pinions of some internal-gear hubs.
These brakes are prone to fading due to overheating if used in mountainous terrain.
I particularly advise against using a front Rollerbrake, because the front hubs made for these brakes incorporate the infamous and wrong-headed "Power Modulator " mechanism which reduces the effectiveness of the brake.
Also see the article about Rollerbrakes on this site.
Compared to cantilevers, roller-cams have the advantage of not protruding past the sides of the frame, which made them popular in the late '80's when there was a fad for placing the rear brake under the chainstays...you couldn't use conventional cantilevers there, because the cranks would bump into them.
Unfortunately, roller-cams are more difficult to set up than conventional cantilevers, and they make for more-difficult wheel changes.
Roller-cam brakes do not work on studs made for cantilevers, because cantilever studs are mounted inward from the rim, while roller-cam studs are outward from the rim. "U-brakes" are interchangeable with roller-cams.
With both roller-cams and U-brakes, there is a tendency for the brake shoes to strike higher and higher on the rim as the pads wear. If the pads are not checked regularly, they eventually start to rub on the sidewall of the tire, destroying the tire in short order.
The Odyssey "Pitbull" is a caliper-type roller-cam unit, popular in BMX and recumbent applications.
For more detailed information, see our article on roller-cam brakes.
In addition to eliminating the annoying "tick-tick-tick" of a pawl-type freewheel, a roller clutch has less slop when drive force is applied to it...drive begins as soon as forward motion of the pedals starts, unlike with a pawl-type freewheel which drives only once it has rotated far enough to let the pawls engage the notches of the ratchet ring.
Last Updated: by Harriet Fell
