Dutch made twin primary cover for Newby belt drive

johnmead

Well Known and Active Forum User
Non-VOC Member
I have a couple of pictures of a twin primary cover made to fit with the Newby belt drive and clutch. I was told that it was made by someone in the Netherlands.

It looks like a new casting with the insides and attachment holes CNC machined. Also, it looks like it is one piece with no separate clutch dome.

If you know who is making these could you send me their contact information?

John Mead
 

timetraveller

Well Known and Active Forum User
VOC Member
There was such a device, made by one of our French members, at a rally held just south of Dieppe several years ago. It was made in one piece, of fibreglass, and it did cover the clutch as well. I do not remember who it was who had it on his bike but the French section members will certainly know.
 

johnmead

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Non-VOC Member
Thank you for Osman's name. I have contacted him and found out that the original CNC machined primary cover was a one off and he is in the process of creating a plug to be able to get his primary covers cast in aluminum. He said it would take 3-4 months to have finished covers.

John Mead
 

Tom Gaynor

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VOC Member
Search with no keywords for "categories", scroll down to "VOC sections", then highlight "Holland (Dutch)"

How does Osman "tension" the belt? My experience has been that a belt needs at least an inch of up and down play, but my "belted bike" is a Manx with a moveable gearbox. Once "tensioned" however, it never needs to be touched again.
 

Osman

New Forum User
VOC Member
Hi there, i am still building the bike. It's a Newby product. I trust his product (!).. I'll see how is goin.. I hope i don't need any tension adjusment. If so, it's (maybe) possible to use the kickstart hole to use an extra wheel or something..I'll post my riding experinences to this forum.
 

Tom Gaynor

Well Known and Active Forum User
VOC Member
Newby

I've raced with a Newby clutch and belt drive (500 Manx Norton) since 1993. I broke a belt once when a stone got in, and have had to replace the front pulley once. The ally pulley is fitted to a steel shaft via straight splines, eventually 52 bhp hammers the splines loose, and the more slack there is, the more effective the hammering becomes. But that's it. 16 years racing, well over 300 full power starts, and I've bought three belts (one spare), and one pulley. One bit of advice: buy two extra steel plates. Put one under the ally pressure plate, because otherwise the friction plate underneath will rip up the pressure plate. Weld a handle to the other plate, and you have a highly effective clutch locking tool.
No, two bits of advice: ignore instructions to tension the belt by twisting it. Make sure that when the motor is hot you have at least an inch (2 1/2 Dutch inches...) of up and down play. Too slack isn't a problem. Too tight, is.
Really neat job, Osman, congratulations. The cover is a work of art. Keep us all posted on progress.

Hi there, i am still building the bike. It's a Newby product. I trust his product (!).. I'll see how is goin.. I hope i don't need any tension adjusment. If so, it's (maybe) possible to use the kickstart hole to use an extra wheel or something..I'll post my riding experinences to this forum.
 

timetraveller

Well Known and Active Forum User
VOC Member
Roy Robertson uses a belt drive etc on his Egli racer. His engine is about 1175ccs and he is getting, or has got, about 103 BHP. Belt is about 40mm wide but I could check if needed. Lots of racing and lots of sprinting with no problems at all. Just a thought , and not wanting to interfere, but if one was to have a single piece primary drive and clutch cover then why use all those screws to hold it on. It no longer has to be oil tight and a single pillar on the back which lined up with the left hand kick starter tunnel would allow a single bolt fitting. Easy to get on and off!
 
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