mx_599

i am new to road riding and have not installed carbon forks before. am i supposed to be doing anything special?

i am having a difficult time getting the lower "bearing race" pressed on the all carbon stem and crown. i am using a pvc pipe and soft mallet as i have normally done in the past on mtb forks. i am afraid to hit too hard but it doesn't look like it wants to go. it is going on square and the pvc is hitting it square.

now i am not even sure if i can get it off. it is partially on. but i don't want to pry anything because i don't want to mess the carbon up.

did i do something wrong? was i supposed to sand the carbon seat down a little? how do you guys usually go about pressing the "race" on a carbon fork?

dekalbSTEEL

Take it to the LBS, that's what I did. you only get one chance to do it right.

Al1943

There is a special tool for "facing" the fork crown tube. Maybe your LBS can help.

Al

mx_599

i don't have a local shop

mx_599

you can face the carbon seat? doesn't seem like that would work like it does on metal.

i guess i might have to carfully take it off and lightly sand the seat. technically the instruction booklet never mentioned facing...but the did mention lightly sanding to remove paint, or in this case i think they mean more like resin

BoSoxYacht

What did you get for a road bike? Pics, please?

Patriot

I know it sounds odd, but I always use an inside mic to measure the race, and the crown to make sure the fit is within a few thousandths of an inch.

One way to get it on with more force without hurting it, is to use a long PVC pipe, and flip the fork over (upside down) with the pipe snug against the race, and hammer it with the pipe onto a concrete garage floor. I hold onto the fork with my right hand, and the pipe with my left. The inertial force of the fork into the pipe will press the race on. hoever, if the race is just plain too small, it may not go on, no matter what.

mayukawa

If I need to sand more than a quarter millimeter, I'll file the crown race instead.

Al1943

The carbon steerer forks I've seen have an aluminum seat at the top of the crown that the lower race slides over. This is the part that needs facing. If you're having trouble getting over the carbon fiber I would try wrapping some sandpaper around the tube and dressing it down. What kind of fork is it?

phantomcow2

It should be okay to sand down a bit, as the top layer is all epoxy anyways. See if you can get ahold of a caliper though, check the difference. You don't want too large of a difference. .001" is plenty. A lot of bearing press fits are among the lines of .0005", some even less for the outer race.

efrobert

I used a pvc pipe on the bike I just built. I held the forks in both hands, upside down. The pvc was on a cement floor and I smacked the fork down on the pvc. It worked fine, but it wasn't easy, it was hard to get on, harder then I thought.

mx_599

hey everyone, thanks for the great advice! i used a combo of all your ideas and made everything work with no damage to anything

here is what i did for future reference to those who might see this thread. nothing special...

first off, the fork is a Columbus Super Muscle fork and the seat above the crown is all carbon.

1) to pry the the halfway-on race off without damaging the carbon i slid a thin piece of sheet metal between the flat head screw driver and the top of crown and was able to pry the race.

2) it's funny it was mentioned about the masking tape because that is exactly what i did last night before it was posted. i wrapped tape above the carbon seat so the sandpaper wouldn't touch the steer tube. more of an aesthetics thing. i looped a strip of about 1" sandpaper around the race/tape and kind of twirled the fork. i did my best to do it evenly.

3) i sanded just a little on the inside of the metal race as well.

4) i knew the thick pvc pipe was making ideal contact with the race, so i tried the inverted technique on some concrete.

i only sanded a little and the inverted pipe whack seemed to do the trick. it was still a tight fit so i know i didn't take too much off.