A7 Rigid Belt Drive

[maaseyracer]

I am sure this has been asked before and I am struggling to find an answer through search here. I have an A7 in a rigid frame. Engine is a 53 frame is a 48. I am getting the sense as I look at photos and engine cases that the Rigid and Plunger frames have a different primary set up than the swing arm frames. Will a newby or NEB belt drive fit the rigid frame engine? Is there a belt drive still made for the rigid frames?

[KiwiGF]

I fitted a Bob Newby kit to a 56 GF and B31 rigid, best thing is to ask Bob if he has supplied one before. B31 rigid is a non standard fitment.

Both my Newby clutches were for a taper mainshaft fit, your bike might have a splined mainshaft? Is so the worst case is fit a different mainshaft from s/a box?

There is a choice of teeth for Newby engine pulleys, also belt width (which affects number of clutch plates).

Your bike could probably use the narrower belt, the gearbox moves to get the belt tension right on my bikes, if your bike has a tensioner the belt would have to exact length, or a new tensioner arrangement fitted.

I run the cases dry, not sure if thats an option with the plunger, what oil seal if any is there on the engine? My b31 crank seal drips oil into the primary so I leave the oil drain plug off and get a few drips still 

[muskrat]

G'day Eric.
As Kiwi says your mainshaft is (or should be) splined, swing arms are tapered.
Why bother, the rigid/plunger clutch is great, a twin row chain would be stronger than a belt (3 row SF even better).
I've heard there's a Notrun clutch that fits the spline.
Or as Kiwi said swap the mainshaft for a later s/a and fit a Newby.
Cheers

[Swarfcut]

 Belt tension will be your problem. Rigid and Plunger engines use a slipper running directly on the chain, unlike the S/A version which uses the conventional method of moving the gearbox. All things are possible, but the time and effort are not worth it. Duplex, or if you can find it a Super Flash Triple set up would do the job far easier.

 Swarfy.

[maaseyracer]

My main concern is petty. I want a dry case to mitigate places oil can leak from and because I kick the bike and the bike sits for long periods I would prefer not to have a sticky clutch. Additionally the chain has let go on these cases. I am not fully opposed to a chain either, just look at options.

[muskrat]

G'day Eric.
Pulling the clutch lever and using the kicker frees the clutch, I do mine every start up.
It's not like your going to ride her for hours on end. The chain with a little chain lube will last quite a while. A squirt through the inspection hole will do. It's more the clutch rollers I would be concerned about running dry!
My A7SS ran a dry chain primary. One squirt before each race. A chain would last a whole season.
Cheers