CB77: early vs. late swingarm differences

[cfloren]

Quick question for anyone who might know the answer...will an early CB77 swingarm (tubular with cast ends) fit a later bike with no modifications?

My bike is a '65, and it originally had the later style, stamped/welded sheet steel swingarm. It was bent so I bought a replacement, but it's the early style made of tubes welded to cast end pieces.

It seems the early style swingarm is a tighter fit on the wheel than it should be. Is the later swingarm narrower at the wheel end? If so, did Honda change the spacers to match? Unfortunately I no longer have the original swingarm so I can't measure and compare the two.

Just trying to determine if I need to get another late swingarm, or modify the spacers, or if something else is wrong. Thanks.

[Goodysnap]

Looks to be no difference dimension wise .

Here ya go

http://www.honda305.com/forums/early-sw ... t=swingarm

[cfloren]

Thanks for finding that thread. I searched for swingarm info here on h305.com but didn't come up with that one.

Maybe my "new" (older) swingarm has been pinched at the rear. Last time I assembled the bike for mock-up, which was several years ago now, it was just a very tight fit getting the rear wheel, hub spacers, and adjusters to all live happily on the swingarm.

I'll take a rear width measurement and post it up...maybe someone with a later-style swingarm could be kind enough to do the same.

Thanks again!

-Chris

[cfloren]

I measured my early swingarm. Width between the axle mount plates at the rear is 9 1/8" (232 mm). It would be awesome if someone could measure the later style and let me know if it differs. Measurements from another early style swingarm would also tell me if this one has been pinched at all. I appreciate it!

[Goodysnap]

Near as I can measure with a tape my early cast arm yields the same width as yours.

The LH spacer is 1.5".

How much are you lacking?

I would say you should be able to squeeze 1/8" either way without any issues.

Goody

[Superchicken]

I just measured one, and it will be a hair lose, the modern on is like 9 3/16", should be doable.

[cfloren]

Thank you guys. I think my swingarm is just slightly tweaked. I reassembled the rear end and got everything to fit. It was a tight squeeze to get both spacers and adjuster plates in there, but not nearly as bad as I remember from a few years ago.

Thanks again - looks like I can run the swingarm I have. Sweet.