question on gearing

[medved]

just been seeing a few bmxs locally that have very small chaninrings (25t) and extremely small freewheels (9t)

are these just on freestyle bikes or are they used on race bikes as well (adult sized)

if any, what is the benefit of the gearing and the drawbacks?

[HEYWOOD BMX]

  Gearing that small is mainly restricted to freestyle bikes.As well as weight saving in both sprocket and chain,a smaller sprocket is less likely to hang up or flex on any impact as much as a larger chainring..I`d guess a disadvantage is that you still have the same power going through a shorter chain resulting in more chain breakage,though modern chains tend to be much stronger than the OS ones..

[Jon The Bassist]

...and some good advice here: http://www.bmxtalk.com/viewtopic.php't=4075

[TwoBobRob]

Not really used on race bikes, more of a freestyle thing. I'd say the main reasons for running small gears are fashion and weight reduction.