Mk.2a belt conversion alignment trouble

Previously rupert_girdlestone wrote:

I am having real trouble fitting a belt drive from RGM. The shafts just will not align. I have the RGM double adjuster and I have tried pulling the gearbox back with the left hand one. but it is still not parallel and the belt tends to walk off the pulleys toward the outside. I have tried forcing the box to rotate with the use of both side adjusters, but predictably it all binds up rather quickly. Is there anything else I can try, or should I box it up and send it back and go back to the chain?

Would be prudent to check the condition of your sleeve gear bushes, as any movement there, no matter how small,can exacerbate (good word, no?) the problem.....

Previously charles_claxton wrote:

Previously rupert_girdlestone wrote:

I am having real trouble fitting a belt drive from RGM. The shafts just will not align. I have the RGM double adjuster and I have tried pulling the gearbox back with the left hand one. but it is still not parallel and the belt tends to walk off the pulleys toward the outside. I have tried forcing the box to rotate with the use of both side adjusters, but predictably it all binds up rather quickly. Is there anything else I can try, or should I box it up and send it back and go back to the chain?

Would be prudent to check the condition of your sleeve gear bushes, as any movement there, no matter how small,can exacerbate (good word, no?) the problem....

Hello Rupert.... Remember the old steam fairs when a stationary steam engine powered a threshing machine with a long leather belt ??The pulleys were barrel shaped and the belt always found the highest point on the barrel. Can you visualise what I mean ? The way you are adjusting your belt could be the opposite of what is required.By adjusting the gearbox the opposite way would make the belt find the inside of the clutch drum pulley.Give it a try and let me know if it works !!!colin

Previously rupert_girdlestone wrote:

Aha! The reason I decided to fit the belt was that I suffered a catastophic failure of the layshaft bearing. I thought that whilst apart I would bung on the belt. I replaced the casing, all the bearings and all the bushes, exceptthe sleeve gear ones, because the looked too hard to do. Ho hum, looks like its all coming apart again to do the bushes. Any advice on pushing out the old ones and the new ones in?

I liked the post about the old staionary engines... I will give it a go if the bushes thing doesn't work, I might even try a half twist in the belt and see if that helps. Haha.

Thanks again all. I will let you know when its done.

Rupert

Not overly sure if the Mk2a sleeve gear is the same as the Mk3 but....

To remove mine (engineers look away now!)... having had a great time prising out the internal circlips... I split the bush with a wood chisel enough to get purchase with a pair of pliers (the chisel isn't hard enough to damage the gear itself) Then used the new bush to push the other old one out, then used THAT (old)one to drift the second new one in. BUT, used a piece of wood to 'persuade' them in, not a hammer!

As many have mentioned, belts don't have to be overly tight to work.

PS: On a 20,000 mile bike my mainshaft needed renewing too, ridges where the bushes 'supported' it....... not!

Previously rupert_girdlestone wrote:

I am having real trouble fitting a belt drive from RGM. The shafts just will not align. I have the RGM double adjuster and I have tried pulling the gearbox back with the left hand one. but it is still not parallel and the belt tends to walk off the pulleys toward the outside. I have tried forcing the box to rotate with the use of both side adjusters, but predictably it all binds up rather quickly. Is there anything else I can try, or should I box it up and send it back and go back to the chain?

It does sound like you are adjusting the gearbox the wrong way. Before you start knocking the sleeve gear bushes out with wood chisels and the like, try slackening the left adjuster and tightening the right one whilst maintaining the correct tension as per the RGM instuctions. If the belt still creeps to the outside of the clutch do it some more until it stops. Jim

The way I align my sprockets is to use two 12" rulers. If you put one each on the outside face of the two sprockets and then overlap the two rulers between the sprockets you can see pretty clearly if they are in line. The belt may still run off slightly due to play in bearings but it's a good starting point before fiddling a bit if needed.

Ian

Previously james_brierley wrote:

Previously rupert_girdlestone wrote:

I am having real trouble fitting a belt drive from RGM. The shafts just will not align. I have the RGM double adjuster and I have tried pulling the gearbox back with the left hand one. but it is still not parallel and the belt tends to walk off the pulleys toward the outside. I have tried forcing the box to rotate with the use of both side adjusters, but predictably it all binds up rather quickly. Is there anything else I can try, or should I box it up and send it back and go back to the chain?

It does sound like you are adjusting the gearbox the wrong way. Before you start knocking the sleeve gear bushes out with wood chisels and the like, try slackening the left adjuster and tightening the right one whilst maintaining the correct tension as per the RGM instuctions. If the belt still creeps to the outside of the clutch do it some more until it stops. Jim

That's what I suggested !!!