Changing fork rake
 

I'm overhauling a bike for a friend's son. The CF fork has some bad nicks in it where the carbon weave has been compromised, and I'm recommending replacement. According to the manufacturer's specs, this bike has a fork rake of 50.

Here's the problem - all of the budget forks I've found have rakes of either 43 or 45. I've done some Googling, but am still a bit confused. Will reducing the rake from 50 to 43/45 increase stability, or make the bike livelier/twitchier? Or, is 5mm difference really not worth worrying about?

I don't want to make the bike hard to handle for the youngster.

Going from 50mm rake to 45mm will increase trail and improve stability.

Forks also vary in length. Less rake will make the bike turn slower, but a change in length could double the effect or cancel it out, depending on whether the fork is longer or shorter.

Look for the largest rake and hope that the fork is not longer, if you want to retain similar steering response.

Is this a very small frame, say 50 cm or smaller? Some small frames are designed to accept a larger fork rake to reduce toe overlap with the front tire.

It is a smaller frame - 48cm.

which bike is it? Whats the fork's length?

Remember fork-length is not measured along the blade, but rather in a straight-line from the crown to the dropouts.

Or more accurately, from the crown race seat along a straight line to the center of the front axle at it's midpoint between the dropouts.

Here's a good website, linked from sheldonbrown.com http://www.phred.org/~josh/bike/trail.html

Ideally, you would replace it with a fork similar in dimensions as your current fork. Most road forks have the same axle-crown measurements. A 45 will make it a bit more stable, not sure if you would really notice.

It is a Raleigh Cadent 1.0

A quick measurement from the center of the dropout to the crown race seat (in a straight line) reveals it to be about 37cm.

I agree - ideally. But if the 45mm will yield acceptable handling and, as you suggest, not have a noticeable effect, I think this is what we are going to go with - a 45mm budget CF fork with aluminum steerer. 50mm's are a bit harder to find, and are about $100 more. Many places have 45mm's in the $60-$80 range (Performance, Cambria, Nashbar......).