Differences in fork tube diameter of different years

If it's broken or just needs tweaked

Moderators: Volker_P, tidd650

User avatar
rob
Posts: 33
Joined: Mon Mar 13, 2006 6:09 pm
Location: Canada
Contact:

Differences in fork tube diameter of different years

Postby rob » Wed May 10, 2006 12:34 am

Hey everyone,

One of the fork seals on my 81 CB650C leaks pretty good. Got a quote from the Honda dealer at around $180 US to fix the seals last year. These are the air/oil forks which, to my knowledge, no one on either this forum or sohc4.us has sucessfully rebuilt themselves without other tools. I managed to pickup a pair of air/oil forks from another CB650 from ebay for $13 + shipping! what a deal! I've noticed that the forks are slightly different, my forks have an air nozzle on each fork, while the ebay forks have just one air nozzle.

So, I figured I would just swap the forks temporarily, allowing me time to dismantle my other forks, attempt to replace the seal myself, and if anything, go back to the dealer with already dissasembled forks so that the labor cost would be less.

I just can't get the ebay forks through the tripple trees! It seems like the diameter is a little bit too wide. The air cap is still on each of the forks, as I can't get them off. It doesn't seem like the caps are any wider than the diameter of the fork tube. Is it possible that different years of forks have slightly different diamter? Or is the cap just ever so slightly wider than the fork tube? If so, any tips for removing the fork cap without using the tripple-tree as a vice? My current technique has been a wrench on the cap and a strap wrench around the fork tube, only result so far is to break a strap wrench..

Thanks!

Rob
'81 CB650 Custom

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Differences in fork tube diameter of different years

Postby Volker_P » Wed May 10, 2006 1:23 am

The (EU)RC03 and RC05 forks look different, but I never tried to fit them as the only ones I ever had were heavily bent.
From my impression Honda seems to like playing around with stupid small changes which destroy compatibility. And are you sure the ebay guy really sent a CB650 fork?
I think the most straightforward solution is to check out with a sliding caliper if there is a chance to get them in. If it only should be the caps, I would carefully work them down with a file until they fit through. Might be time consuming but safe against subsequent destruction during opening efforts.

cb650
Posts: 2959
Joined: Fri Mar 03, 2006 7:20 am
Location: Denver CO USA
Contact:

Postby cb650 » Wed May 10, 2006 9:35 pm

I believe all the tube diameters are the same. Sounds like a aftermarket air system. Can you put them in a vise with protection?



Terry

User avatar
rob
Posts: 33
Joined: Mon Mar 13, 2006 6:09 pm
Location: Canada
Contact:

Postby rob » Wed May 10, 2006 10:42 pm

Be much easier if I had a vice. Let me refrase that, it would be much easier if I had a workshop or garage, with a bench to mount a vice, and a vice 8)

My bike is in the driveway with both wheels off the ground balanced on a suspect system of cinder blocks, mlik crates and rope. I gave up on trying to get it sorted out, I was more interested in getting the bike on the road, so I just changed the fork oil and air in my old forks with the leaky seal just get it riding again. I'll save getting the seals fixed for a rainy day or when there is little more disposable income in the bike repair fund :)

Rob

cb650 wrote:I believe all the tube diameters are the same. Sounds like a aftermarket air system. Can you put them in a vise with protection?



Terry
'81 CB650 Custom

cb650
Posts: 2959
Joined: Fri Mar 03, 2006 7:20 am
Location: Denver CO USA
Contact:

Postby cb650 » Sat May 13, 2006 2:37 pm

If you want to bring it over I'll only charge you a beer to use the vise here. But it might take a tank or two in gas. :lol:



Terry


Return to “Technical Discussion”

Who is online

Users browsing this forum: No registered users and 50 guests