Originally Posted by
w1gfh
The 18T sprocket on my Twenty feels a bit "too low" for my taste. I may swap it for a 15T.
Also, being new to the Twenty, I'm getting a little confused by wheel options:
• Stock wheels: Steel rims, 20 x 1.75, 36H, 451mm?
• 406mm alloy Option: more choices? Stock brakes must be replaced?
• 451mm alloy Option: fewer choices? Stock brakes can be used?
Hi, I'm with you on being new to the Raeigh Twenty (aka R20). Here's the scoop. In the UK this bike came with 451 bsd wheels and the tires will have fractional numbers such as 20 x 1 3/8". When exporting to the US, Raleigh decided to go with the 406 because it's standard with BMX bikes. Those tires will read, for example, 20 x 1.75". You will find far more rims and tires going with the 406. However, the 406 rims require long reach brake arms, and the 451 can go with shorter brake arms because of the height difference (won't explain the math). Sheldon Brown shows how to make a drop bold to essentially lower the mounting spot for a modern brake to work.
In order for us to help you tell us what your wheel and or tire size is.