Handle Bar CB 650 RC08

[Justsu]

Hello from Franconia, Germany.

Currently I'm trying to customize my old '82 CB 650 RC08.
For a better look and handling I wanted to mount a different handlebar.
But as you know the RC08 comes with this terrible handlebars without the usually used riser (see RC05).

Using a forkcrown of RC05 is impossible because of the diameter.
I just thought about using the whole fork of a RC05....is this possible ??

Has anybody an idea , how to use and mount an ordinary handlebar on the RC08.!

For any suggestion , I would be pleased.

Greets
Patrick

[Volker_P]

Welcome here, Patrick!

Never tried swapping forks but I won't like to have the weaker fork (and possibly also the single piston calipers) just because of the handlebars.

[jcasey007]

Hi Patrick

is this the sort of thing you are after?

Bolt on custom risers, 1 inch drag bar on a 1981 CB650

[Justsu]

Welcome here, Patrick!

Never tried swapping forks but I won't like to have the weaker fork (and possibly also the single piston calipers) just because of the handlebars.

You're right. Choosing a weaker fork won't be a good idea...!

@jcasey007:
Yes...that's what I am looking for. But with the original RC08 fork it would not work...!

Patrick

[jcasey007]

Hi Patrick

sorry, by RC08 is that a 650 Custom? Then mine is (or was the same)

I modified the upper tree, took off the standard mounts, welded in the dimples on the underside, and drilled out the M12 holes for the risers

here's a close up

[cb650]

Its the nitehawk. Completely diff fronts.

[Justsu]

[quote="jcasey007"]Hi Patrick

sorry, by RC08 is that a 650 Custom? Then mine is (or was the same)

Hi!
It's a 650 SC ! Nighthawk...with a 37 mm fork diameter

New idea . I will remove the original bars and install a bushing with 7/8" risers. Just tested it with 1" risers.
To install the bar , I have to remove the ignition lock and probably the fuse box.
Another issue is the clamping (marks) of the bar. Because the distance of the riser (middle to middle) is larger in comparison to my other bikes.
We will see!
If it will not work, I will keep the original handle bars. I adjusted the originals like a straight bar. So it nearly looks and feels like the way I want.
Greetings

[MiGhost]

Using the triple tree (steering stem, top bridge) from the 83-85 CB650SC should work to replace the funky handle bar on the 82 CB650SC with a more normal bar.

[Justsu]

Using the triple tree (steering stem, top bridge) from the 83-85 CB650SC should work to replace the funky handle bar on the 82 CB650SC with a more normal bar.

I just looked at it....perfect, but I think the fork diameter of 83-85 model is 39mm. So it won't fit??!!

[cb650]

Yes the dohc has bigger forks. I'm thinking on my nitehawk to just swap in a front from a 80 custom. Will look original and have most all the parts.
Or make a upper myself and use clipons.

[MiGhost]

Using the triple tree (steering stem, top bridge) from the 83-85 CB650SC should work to replace the funky handle bar on the 82 CB650SC with a more normal bar.

I just looked at it....perfect, but I think the fork diameter of 83-85 model is 39mm. So it won't fit??!!

My bad. I missed the 39mm fork dia.

Here is another option.
Honda CB-750F (81-82)
Keeps the 37mm fork
Same front wheel as the 81 cb650C. So the fork spacing is correct.

The only minor issue would be the steering head bearings

...........ID....OD......H
Upper: 26 x 48.5 x 15.2
Lower: 30 x 50 x 14.4
Honda CB650 (79-82), CB650C (80-81), CB650SC (82-85)

...........ID...OD....H
Upper: 26 x 47 x 15
Lower: 30 x 55 x 17
Honda CB750C/F/K (80-82)

As you can see. The ID on the bearings is fine, but the height on the lower is 2.6mm larger. This would require a shim under the bearing. If the steering stem lengths match. It should be a bolt on using the cb650 steering bearings

This will change the gauge mounting, ignition switch, and fuse holder also. Those are other things that will need to be looked at.