Electric start and belt drives

Hi Rob, Every month I put a few ounces of oil into the primary and it very slowly leaks out. .I renewed the chain last year as the old one was from the 1960's and it seemed a good idea. Can't say the system is foolproof as its only done about 40k over 58 years ,time will tell. Would really like an electric start ,but don't fancy a sprag . I think you are right to go for the steel re-enforced belt.

I would have thought the Alton electric start would put less strain on the belt as the starter is acting directly on the crankshaft so only load on the belt is to turn the clutch. A lot more load on it when kick starting.

Ian

Previously Rob Bradley wrote:

I fitted a Steve Maney belt drive to my Commando nearly twelve years ago, and an Alton starter kit three years ago.

The belt snapped last weekend after 4000 miles use with the Alton kit (19,500 miles use in total). I wonder if an electric start puts more shock load on the belt than kickstarting?

I think the belt Maney uses is polyurethane and fabric (Optibelt Omega 912 8M-A 912mm long x 30mm wide).

I have an RGM belt drive on my Dominator which is still going strong after nearly 26,000 miles. Not electric start, of course. The belt (980 x 27mm) is steel-backed.

Maybe a steel-backed belt kit is a better proposition with an electric start?

As for running an Alton starter in a dry primary case, the chain drive to the sprag clutch from the starter motor is only in use when starting, so a light spray of chain lubricant lasts a long time. Every so often I spray a little grease into the sprag clutch through the extractor holes whilst rotating it by hand. So far, so good, though I realize 4000 miles isn't much.

a 30 mm belt is a bit too wide for the alton kit. The chain is so close that it can catch the edge of the belt. Once the edge is damaged failure is inevitable.

Best to fit a 27mm ATP10 gen 111 Synchroflex timing belt with steel tension cords from Belting online. It is supposed to be 25% stronger than the older belts

You would of course need to reduce the width of the pulley accordingly.

Yes i have 32mm RGM belt drive and a Alton Ekit. It fitted with just a round 1mm needing to be removed from the area were the motor pulley interfered with the Alton inner primary case casting. The area is as cast an un machined so i removed it by hand with a sanding disc an angle grinder a little at a time. The issue is caused by the size of the tapers affecting the position the pulley stops at relative to the crank case so yours may not have the same issue. It is one of the reasons for the shims on the gearbox mainshaft to adjust the position of the clutch relative to the engine sprocket in the original manufacturers arrangement. Also it did in my case give a little more clearance between the belt and starter chain so not necessarily a bad thing for me.