C: Clutch Honda Clutch

[Comet Rider]

Hi All,
The original clutches used by Conways were CB350, or CJ360 which have not been manufactured for nearly 40 years. I'm not sure what they are currently using, but I remember when I bought mine I paid for it with 3 cltches from breakers in my area.

 

[Peter Holmes]

The original Comet/Honda Clutch was a Colin Jenner product, I remember Colin saying he used to scour breakers yards to source the donor clutches, and they were only available when he could find them, but that is not the end of the story, the splined component is not a Honda part, but has to be manufactured and grafted onto the Honda Clutch after some machining of the Honda part, that is where problems can arise, I don't know if it was intentionally oversize to compensate for possible existing wear on the Burman splines, but they are sometimes a little tight on the spline and might require some careful fettling, I am not sure how Colin or now Steve engineer the spline, but I don't think it is what you might describe as precision engineering.

 

[clevtrev]

Ever seen a Burman spline that wasn`t worn, given the minimal amount of engagement ? Even more so when the nut has not been tight enough.

 

[Simon Dinsdale]

Hi All,
The original clutches used by Conways were CB350, or CJ360 which have not been manufactured for nearly 40 years. I'm not sure what they are currently using, but I remember when I bought mine I paid for it with 3 cltches from breakers in my area.

That number rings a bell. For a while Conways stopped the Honda conversion as they coudn't find any donor clutches. I managed to find one on eBay and it was off a CJ360T from 1974-78 and then sent it to Conways for conversion. They only provided the parts they made / modified and I used the springs that came with the clutch so they could be anything, but they do work.

Simon

 

[oexing]

In a typical multplate clutch you could set the spring preload as you like, just short of getting a slipping clutch. Some tests will be done each time but no big deal I´d think. You either apply some mild octite on preload screws or put spacers in between for experiments. No need to have excessive spring loads as long as no slipping is noticed. Be sure the outer plate lifts nicely parallel to get no dragging clutch.

Vic

 

[John Reynolds]

Going back to the original query, i.e. heavy clutch action with the Burman gearbox, I have recently had to replace the internal clutch lever (because I noticed, when rebuilding the box, that the old one had a surface crack - but that's another story!). The old one had been performing satisfactorily and I had got used to the weight of the clutch action. However, when the new one arrived I noticed immediately that the 'small projection that bears on the clevis fork' (Eddie Stevens description!) was at least twice the height of the one on the old lever. On further examination of the old lever I also noticed that there was wear on the clutch lever itself, indicating that it had been contacting the clevis fork rather than the 'projection' when the clutch was being lifted. While this was obviously providing the required lift, it would have been a dragging action on the side of the clevis fork rather than the intended sliding action of the 'projection' in the groove of the fork. The clutch action is now much smoother and lighter. The clutch lever assembly (PR50-175X) is very cheap and easy to replace - VOCSC sells them for around £30 - and, in my experience, well worth doing.

John

 

[Sakura]

Bovine Excreta ! Flimsy excuse for poor workmanship

If you want parts that fit straight on, buy a modern bike fitted with high precision CNC machined components. If you want to play with 70+ year old bikes either learn some engineering or pay someone who does know how to do it!