Author Topic: Drive belt for 1913 2-3/4  (Read 4438 times)

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Offline phil_h

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Drive belt for 1913 2-3/4
« on: 11 Mar 2013 at 13:56 »
Mine is running a 5/8in top width belt and I think it should have a 3/4in one.
Its a linked belt, and I prefer the idea of these on the grounds of easy repairs.
Can anyone advise if I am correct about the size please, and where a new one is best obtained.

ps I can also only find metric sizes of 17mm and 22mm top width for Nutlink belts which doesn't help.
« Last Edit: 11 Mar 2013 at 14:04 by phil_h »

Offline Black Sheep

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Re: Drive belt for 1913 2-3/4
« Reply #1 on: 12 Mar 2013 at 07:02 »
17mm is near enough 5/8" and 22mm close enough to 3/4". My 1913 2 3/4HP has a rather well-used linked belt and I would be very interested to find out where I can obtain a replacement, ideally before the current one fails. 

Offline Chris

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Re: Drive belt for 1913 2-3/4
« Reply #2 on: 13 Mar 2013 at 10:53 »
Hi Phil
   You are correct in saying that you believed 3/4" to be the correct size of belt for the early machines. Now and again an original length of 3/4" "Brammer" linked belt can be found. Linked belting might appear to be attractive due to ease of repair but the amount it can stretch has to be experienced to be believed. Old hands will tell you that before fitting they would hang it from the rafters with a great weight attached. Modern linked belting is currently being manufactured in all sizes including 3/4" and can be found with one well known supplier at major autojumbles but in my opinion is of very inferior quality compared with original Brammer which can be identified by a capital B on the head of each rivet. In terms of life and reliability I have achieved the best results with genuine "Optimat" belting made I believe in Germany. This can be obtained from good transmission specialists but as noted above is only available in 17mm and 22mm sizes. 22mm is in fact 7/8" as makes no difference and is the preferred size for the later belt drive machines although it rides a bit high in the pulleys but the 17mm is probably the best for the earlier veterans. Do not be tempted by the polypropylene "T" linked belting which is not very original in appearance quite often in garish colours but is also much more prone to belt slip. Chris.   

Offline Ian

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Re: Drive belt for 1913 2-3/4
« Reply #3 on: 13 Mar 2013 at 22:14 »
Chris - agree re the modern T link belts - as soon as they get oil anywhere near them its terminal belt slip. Kevin uses one on his 2 3/4 with no problems though. I have found with bigger engined veterans (particularly singles) thet the belt does not survive long either.

Over here they seem to all be orange. Quite a few people have died them black and they look pretty good if they survive on your machine.

Most of my belt machines run a belt with holes in it and a single joining link - not sure where that is available now. I got a lot of it a while ago but almost all used now.

Offline cardan

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Re: Drive belt for 1913 2-3/4
« Reply #4 on: 13 Mar 2013 at 22:57 »

I have had great success with modern V belt on my belt drive machines - in C size/section which is 7/8" (22mm or so)

When I can, I use endless belts. They are cheap and last for ever - almost - but can only be used on machines where the rear frame can be unbolted to fit it in the first place. No big deal: you might need to do it once every 5 years if you ride it a lot. The only tricky bit is to get the length exactly right; on a Douggie neither the rear axle nor the gearbox pulley is adjustable. The length required will depend on your gearbox position (tension the primary chain first!) and the pulleys fitted. Here in Australia the belts come in 1/2" (1.27cm) increments, and are still readily available at transmission specialists for less than $50 or so. Fit and forget.

The green Varifit(?) belt (pre-punched holes every 1/2") and a joiner (with a hinge in it - don't use the two flat plates they try to give you) is OK but delaminates after a season or so. We bought a spool of expensive black belt from the US and it was much, much better. It was designed to be used with a joiner - if you cut an endless belt and try to fit a joiner it often just pulls out.