cycle gearing

[Aub]

Hello,in the long distance past when I was raceing I think that in track -except motor paced (and roller) raceing the gear was restricted to 98" (number of teeth on chainwheel divided by the nuber of teeth on rear sprocket X dia. of rear wheel). I wonder what the restriction is today if any.
Aub

 

[when eddy ruled]

over here in oz the only gear restrictions are for the juniors. i dont know what they are coz im waaaay out of the junior ranks. 1 of the A grade trackies i know uses a 102 gear strong boy though

 

[rickt]

Gear restrictions only exist in junior racing and roller racing. There are no restrictions on anything else. Roller racing is limited to a roll out of 7.63m with a minimum crank length of 165mm. The 7.63m is roughly equal to a 95.6" gear when using tyres that are a true 27" in diameter. These days the tyre diameter ranges between 26.25" and 26.5" depending on profile. Therefore a 50/16 combination (96.43" gear) would achieve the correct gear with room to spare.

 

[VeloFlash]

Gear restrictions only exist in junior racing and roller racing. There are no restrictions on anything else. Roller racing is limited to a roll out of 7.63m with a minimum crank length of 165mm. The 7.63m is roughly equal to a 95.6" gear when using tyres that are a true 27" in diameter. These days the tyre diameter ranges between 26.25" and 26.5" depending on profile. Therefore a 50/16 combination (96.43" gear) would achieve the correct gear with room to spare.

If you changed the 50/16 to a 50/14 you would be right on the money.

A 50/16 is only 84.38".

 

[rickt]

Sorry about that, a mere typo, without checking after typing. Too cocky I guess. Goes hand in hand with the track sprinter mentallity.

 

[drewjc]

I know that on a couple of smaller tracks with inadequate banking there has been gear restrictions set in the past. It used to be something silly like 88" (46x14) at the old muswellbrook velodrome in central NSW. But on a 180m concrete track what do you expect! No restrictions that i know of apart from the ones you mentioned (ie. juniors, rollers, derny etc.)