Replacing Forks

[lfmitchell]

I am on my first of hopefully many cycle tours with my girlfriend. Last week she crashed into a small boy on a bike and although both people were fine, her bike took some serious damage. So now we need to replace the front forks of her bike. Its a Cannondale t800. The local bike store is going to try to contact Cannondale to see if they can ship us a replacement. We are in Kathmandu and the chances of us finding a replacement here are nill. The problem is we are not sure if we can afford the replacement + shipping costs. do you think it would be possible to attach some non - Cannondale forks to the bike, and what information/sizes do I need to start looking for them. I am fairly certain that the headset is threadless.

-Thanks

[Joe_W]

It is (if google is to be trusted) a rigid fork, threadless, 1 1/8" headset. In general: to make it to the next bigger town any threadless fork with a 1 1/8" diameter steerer should work. However, handling depends critically on the rake / trail of the fork. Measure the fork (unless it was bent during the crash...). What is interesting for you is: where does the line running trough the steerer hit the road in relation to the spot the wheel sits on the road. http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_geometry
Try to find one that is as close as possible, otherwise you might end up with an unrideable bike. Maybe you can contact Cannondale for the specs?

[lfmitchell]

thank you for the information, I am learning . . . slowly. I have seen a set of Surly Long Haul Trucker forks, that I could get shipped from the us. The rake is 45mm, its 53 on the Cannondale. Do you think this would be a close enough match?
Thanks

[Joe_W]

Let's find out!
Ok, trail is calculated by:
t= (R * cos(alpha) - r)/sin(alpha)

R=wheel radius, r=rake, alpha=steerer angle
According to people more knowledgeable than I, a trail of 50mm - 70mm is (was?) considered ok. Reducing rake increases trail. I guess that on your bike alpha=73° (around that) and t=51mm in the "normal" config. An increase should not be bad.
However: I am not a framebuilder, could somebody else check the numbers? C'mon, someone has to have the Paterek manual (or somesuch)...

[lfmitchell]

Hi thanks for the help Joe_W. After hours online and after many emails later we have decided to go for some Kona project 2 forks, as they were a much cheaper option for us. We are just waiting for delivery then we can set off again!


Hope they fit ok.

Thanks again, Laurence

[Joe_W]

Awesome! Hope everything works out well and you enjoy the tour!