Bicycle Mechanics - Building a rigid mountain bike up -- already have a fork, will it work?

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TurbineBlade
09-07-10, 05:50 AM
I don't have pictures up yet - but am thinking of getting a steel or Aluminum mountain frame and using parts I already have to build it. I built up my Surly LHT and had no issues with it, but it already came with a proper fork that I simply had to cut a bit.

I already have a mountain fork (steel - rigid) but was wondering how you go about checking to see if it will work with a different frame..? It seems that some measuring is necessary in case the head tube of the frame is too long, thereby making the fork too short.

Thanks for any tips or advice to avoid pitfalls! :)

TurbineBlade
09-07-10, 05:51 AM
Side note: If anyone knows a good source for cheap mountain frames let me know! I'm eyeballing Nashbar mostly because it's all I really know.
dabac
09-07-10, 06:46 AM
..am thinking of getting a steel or Aluminum mountain frame and using parts I already have to build it. ..I already have a mountain fork (steel - rigid) but was wondering how you go about checking to see if it will work with a different frame..? It seems that some measuring is necessary in case the head tube of the frame is too long, thereby making the fork too short.


You've identified one already, steerer tube vs head tube length.
Then there is steerer tube diameter vs head tube diameter vs headset size and type.
Then there is the trickiest one - head tube angle, which influences what axle-to-crown length you should be looking at(and rake too, to a lesser degree)
Then there is compatibility with the braking system of your choice.

Can't think of anything else.

HillRider
09-07-10, 07:54 AM
A couple of years ago I wanted a replacement fork for my old Trek 7000 rigid MTB when the OEM Tange threaded headset went south. Trek had cut the factory steerer to EXACTLY match the headtube and stack height length with no slack at all. Newer decent threaded headsets were too tall and it was an excuse to go threadless.

I went to my LBS and could choose from a huge variety of take-off rigid forks from MTBs that had been upgraded to suspension. I was able to find a 1-1/8" threadless Cr-Mo fork with the correct crown race to dropout distance and an uncut steerer for $40. All I had to do was rattle-can it to pretty much match my frame's color.