How to measure fork rake?
 

What is the easiest way to determine the rake of a fork? I am looking at replacing the Bonty RXL fork on my Lemond Tourmalet and a friend has a spare '05 Specialized C3 fork I can use. How do I determine if this is an acceptable replacement. Uh and I don't care that I'd have a Specialized fork on my Lemond bike.

Thanks for your help.
Nick

I'm not sure there's a really accurate method other than looking at the specs for the fork.

The only other way I can think of is to use something long and straight (meter stick maybe?) and line it up perfectly with the steerer tube. Then take another ruler and measure how many mm it is from the "extension of the center of the steerer tube" to the front drop-out.

That's gonna be really hard to do accurately though. And the differences in forks are only about 5 mm, so it matters a lot.

Just look up the specs.

Rake is the angle, from vertical, measured from the attachment point of the frame, to the axle of the wheel.

I think he meant fork offset. Nobody talks about rake angle. You can't even find angle numbers, just offset, which is what matters. You could figure out the angle from the offset if you know the length, but it's trivial.

Are you now talking about "trail" >

Does your manufacturer have anything like this http://www.specialized.com/bc/SBCBkM...icross&eid=123 then click on geometry.

They used to before Trek yanked the website.

Go here http://www.trekbikes.com/us/en/bikes...inox/equinox7/ and click on geometry

No. Trail is a combination of head tube angle and fork offset. Fork offset is how far from the imaginary line of the head tube the axle is. Trail is how far the imaginary line is from a straight down line from the axle.

Nobody really discusses fork rake angle. When people say "fork rake" they mean fork offset, which is a distance, in mm.