Best way to lower 82 cb750 C forks?

[davidgwells]

Hey all, i have an 82 cb750 C with the ridiculous longer stock forks. Ive slid the fork tubes up in the triple trees 2.5" and with the air assist fully deflated im at the height i would like to be at. Ideally i would like to loose the air assist and get progressive springs. If i get the tubes cut down by forking by frank, what do i do about springs? Can i just replace the air assist fork caps with regular caps? If so, what caps would fit? Thanks!

 

[my-79-750-k]

What size are the forks, 35mm or 37mm? Honestly, I wouldn't go the route of cutting forks and then finding springs that would fit and then finding fork caps etc. But, if you do what to do all that, just find out which non air assisted cb came with the same size forks and get some fork caps. Ideally the better/cheaper way would be to grab some shorter forks from a junkyard, craigslist, etc and swap them over, but it can be done either way.

 

[roadandtrack]

Can lower those internally with spacers.
But it can be a pain to get them to work right unless you know what you are doing.
If you just want to lower them and don't care about anything else just make spacers, but that is up to you.

 

[roadandtrack]

Where do you get the 90mm trail from?

 

[nashbuilder]

I have an 81 CB650C and found out that the air shocks that we both have can not take spacers to lower. I contacted www.progressivesuspension.com that this is not possible. I agree with finding shorter forks to replace. That is what I am going to do with my bike. There is a guy on here that put CB450 forks on his 81CB650 and it looks great. As far as the trail I am not sure how that all works. Someone explained it to me once but I really hate math!

 

[roadandtrack]

Yes you can.

 

[legendary_rider]

I feel your pain bud. I just bought a pair of 750 forks for my cb350 cause some guy recommended them on one of these forums for the 35mm upgrade. He forgot to mention the 2.5" height issue. Not to mention I got a '79 triple tree for them instead of '78 and the neck bearing sizes don't work!

I'm looking at buying a set of cb550 forks now. They apparently have same height and bearings match. We'll see.

I called around to different machine shops to see about getting the threads extended down the 750 forks and chopping off 2" or so. No one was willing to do the job. Anyone want to buy a pair of rebuilt 1979 cb750 forks with new seals in them?