Forks 33 into 31?

[CB360]

I thought of putting 33mm forks into a triple tree made for 31mm.

Do you think it would fit in by opening the braces a bit? Would it be safe to ride or should I forget about it?

Thanks!

 

[Big R]

Just a bad idea. Opening up the clamps that much can cause them to crack, and even if they didn't, the mating surfaces would me even.

What bike exactly? Swapping out the triple tree is usually very possible.

 

[CB360]

I'm thinking of putting a front disk brake on my CM250. Since I have two CB360 front ends I was wondering if I could use one on the CM. According to the list found here my CM have 31mm forks and the CB have 33mm.

 

[Big R]

Check the list for steering stem bearings. The trees might just swap over. If not, you could look into swapping just the steering stem.

 

[CB360]

That's what I was doing at the moment!

Bearings are not the same. So I might be looking for a CMX250 tripple tree (same bearings with 33mm forks instead of 31mm). The CB360 forks would fit in I guess...

 

[DrJ]

Forcing 33mm tubes into 31mm trees will be nearly impossible and will probably crack the aluminum top tree. You should be able to get away with boring it out 2mm.

 

[VonYinzer]

Take the original bottom tree, and a 360 bottom tree to a local machine shop. Ask them to swap the 250 stem into the 360 tree. Bolt the 360 trees (with the newly swapped 250 stem and bearings) to the bike. Ride happy. MEASURE THE FORK LENGTH FIRST THOUGH!!!!! If the 360 forks are much longer (they shouldnt be) you'll need to shorten them. Thats no biggie though.

 

[CB360]

Thank you for the suggestions guys. I'll see what is the cheapest solution!