EB3551

Hi,

I am building up an aluminum Litespeed frame with a Litespeed carbon fork (carbon steering tube). I've never had a bike with a threadless headset where I needed to cut the fork tube. I've read articles about how to do the actual cutting, but I'm looking for advice on how to make sure I wind up with a good fit for me -- before I make the cut.

I guess I can put on the wheels (when they finally get here), do a rough assembly of the fork, headset, stem and handlebars, and see how the layout feels. A friend suggested that I put on just the rear wheel and attach the bike to my resistance trainer with the fork in the trainers front clamp. This would allow for more stability while I tested the riding position.

Does anyone have any insights on how to get this thing set up to fit me? I'd rather not have to go to my local bike shop, since I bought this "leftover" frame, fork, etc. on eBay and not from him. (It's not a current model, but he's a good guy, and I'd rather not aggravate him.)

Thanks for your help.
EB

phidauex

This method isn't really recommended for carbon steerers, but it may be effective for giving you a chance to test the fit out before cutting the steerer:

https://www.sheldonbrown.com/handsup.html - Look down the page for the threadless headset without spacers instructions. On a carbon steerer I probably wouldn't go ride around a bunch on it, but I'd trust using that technique with the bike on the trainer to try out different heights. When you choose a height, mark your steerer, and cut away. When in doubt, leave a few spacers of height above the stem, its ugly, but it lets you change a bit later if you need to. You can always cut the steerer down to the stem a few rides later when you are sure.

peace,
sam

Raiyn

This is exactly what I did when I replaced my fork. It's almost always easier to find the right position BEFORE you cut than after

capwater

Cut it long and toss on a bunch of spacers on top of the stem. Play around with them in various combinations over the next several rides until you get the right feel. You can always trim it later but you can't add to the cut length.

EB3551

Thank you, Sam. Sheldon Brown's method is unconventional, but it should work to give an approximation of fit. I'm trying to be very cautious not to damage the fork steerer tube. It's amazing how many times the answer - or at least a thought-provoking article -- for a bike question can be found at Sheldon Brown's web pages.

I'm thinking of using about 50mm (about 2 inches) between the headset and the stem, as needed, but I'm concerned whether using too many spacers can compromise the safety or rigidity of the steering system. Is there a recommended maximum or a rule of thumb I should know about?

My Thomson stem has only a 10 rise (or drop), and was expensive, so I would like to keep it rather than have to buy another size/angle stem.

Thanks again.
EB

sydney

General recc for CF is 35mm for a 11/8 steerer,and 25 mm for a 1". Some fork makers are good with more.