Honda CB350 Clutch Worm Drive Modification?

This thread is continuing on a tangent from an old discussion about Honda CB350 clutch levers. Charly once said:

It appears that several racers over in the UK have modified their Honda CB350 sprocket covers with Suzuki GT250 worm drive mechanisms. I don't know details but it seems this setup provides eliminates the potential for over travel. I'm curious how they deal with the two bolt flange and the offset lever arm? Any ideas on the best way to tackle this modification?

Suzuki GT250 clutch worm drive lifter mechanism









Stock Honda CB350 ball & ramp clutch lifter mechanism and sprocket cover

 

I believe the Yamaha XS650 also uses a similar clutch worm drive lifter mechanism but I don't know how suitable it is for use with a CB350.

 

Kyle, properly adsjusted, the original ball and ramp work fine. I've only had an issue with it overramping (popping) during adjustment.

It took me a few times to understand the adjustment, but with good solid parts, the correct lever (?), lube, etc, it works great.

I did have a bent pushrod once.

Dang man, its almost like you are building a MotoGP bike or something.

 

Yep, a MotoGP racer with cable operated controls! I do have Magura levers though. Because forged Made in Germany. I know most all racers in the US manage with the stock setup but this worm drive mechanism intrigues me. Must be the mechanical engineer in me.

 

ive got nothing to add except that i love that laminate you have. ive been trying for years to find it new.

 

I hear ya Kyle, its fun to be intrigued!....But learning when to say when and stick with the "known factors" is a skill aquired over the long haul testing and developing some of the best fighter planes in the world.

I have a "development plan", and have a few things you are trying on the list....but ya gotta get the plane in the air sometime!....or every media outlet will start squawking about cost and downtime....oh wait, sidetracked, sorry...

Cant wait to see the bike man. :up:

...And yeah, what Joe said, that is some cool laminate. what is that an old countertop?

 

Joe, that countertop is wicked, eh? It's almost cool enough to trigger some spacey flash backs!

Roger that Charlie. This is an idea that is on my radar for future development. My big push right now is to get the bike up and running for shakedowns at some track days this summer. We're very close to the end of the tunnel. All will be revealed soon.

 

That being said, one possible solution I thought of is to machine a two-bolt flange adapter that gets pressed onto the bore for the clutch lifter. A press fit wouldn't require any welding but I suppose it could be tacked into place. Or maybe I can use tiny M3 screws to secure it to those two posts (from the casting process?) adjacent to the bore. This would provide a means to secure the two bolts for the Suzuki clutch lifter mechanism.

 

How are the guys in the UK doing it?....a picture would be worth 10,000 words, IMO.

 

I don't know how they're doing it, hence my question. Jon Sunter in the UK offers to fit one to your sprocket cover for £112 ($185) but I'd rather figure out a way to do this myself and save the associated expense and hassle.

 

Geesh....yeah I agree with you.

 

My question is " why " ?

 

Why are you asking me Mr. Alek.....Smart Alek that is?

I asked that question in a different manner, and Kyle answered....OK, so now I'm interested in how that thing would fit in there!

 

There's plenty of room in there, just stick it in there and go on.

 

Is that what she said?

Or is that what Bowie said?

 

Looks like Suzuki TL1000, GSX-R600, DL650 V-Strom and perhaps others use a similar worm drive clutch lifter. Makes me wonder what it unique about the GT250 setup that makes it particularly suited to the CB350 conversion. I'm thinking I'll pick up a couple of these and play around with them.

 

If you're looking for bikes with that clutch release setup pretty much all the Kawasakis in the early 70s did. G3,4&5s, F5,7,8,9s, H1 & 2, S1,2&3, etc.

 

kyle- do you want to make it to the track or just keep fiddling with it
I am not sure that we can wait much longer to see this thing take to the tarmac!

 

I replaced my XS 650 ramp setup with one from a GS 500. The XS would never seem to stay in adjustment. Leave home in adjustment and 15 min. into the ride it would be draggin' or slippin' . I made an adapter plate out of steel and had to shorten the pushrod a bit but with the steel ramp and ball bearings from the GS worm drive the problem was solved and made the clutch action a lot smoother. Sorry no pics.

I did have to move the point where the clutch cable entered the casting. Using the GS clutch cable also gave me cable adjustment at the bottom of the cable.

 

Soon....