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Mar Wheel Bearings

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If you are to trial the bike fit the non dished sprocket mod with the extra bearing, otherwise the spindle can bend wrecking the bearings and making the wheel difficult to remove.

There is another swinging arm variant which has two bolt holes so you can change the position of the bottom damper mountings. This was fitted to both 250s and 310s at some time late 74 on.

Or there used to be an aftermarket replacement spacer that doubled up as a 4th bearing carrier for use with the dished sprocket. Can't remember who made them, may have been Keith Horsman, who sadly died a few years ago now.

Never seen a swingarm that allowed different shock positioning. They were experimenting with shock position on Evertson's works bike, moving the bottom mounts forward for more travel, but that never made it to production as the swingarm would bend / break (don't think they reinforced it at all) They settled on laid down shocks for the next bike, the MK3.

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  • Many thanks amo and woody, sorry but I`ll be asking quite a few more questions in the near future. I was told by the previous owner that it was a 1972/3 bike but not registered until 1976. The engine

  • Just curious, what should they have said ?

  • Hi Basketcase, it can be frustrating but sometimes there is no easy answer. Tryed to buy a cam shaft Bush for a B40, ended up ordering 3 and returning 2 !

Yes, they're still available here for the flat sprocket conversion but there used to be one for use with the dished sprocket as well, different from that one. I think I might still have one somewhere, it was 'put away' after the dished sprockets were no longer available.

If I can find it I'll post a picture but it may be long gone now.

Yes, they're still available here for the flat sprocket conversion but there used to be one for use with the dished sprocket as well, different from that one. I think I might still have one somewhere, it was 'put away' after the dished sprockets were no longer available.

If I can find it I'll post a picture but it may be long gone now.

Not sure if this is the same type as woody refers too but here is a spacer/bearing carrier for use with dished sprockets next to a flat sprocket spacer...

013_zps11b88b8f.jpg

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Changing the subject, not the bike, what`s the extra bracket for under the seat and the circular bit on the rear silencer?

The dished sprocket is/was an elegant solution that failed to solve the problem of a too narrow but otherwise nicely designed rear hub which self destructs with use due to the flexing & bending of the 12mm dia. spindle.

MarliMar OSSA/Steve Sell who should be at the Telford show next month produces a well engineered twin bearing sprocket carrier for the MAR type rear hub which takes the modern 4 bolt sprockets fitted to all the current Beta & GG bikes.

He also makes a stainless steel rear spindle that is much stronger than the original and is a direct replacement.

The bracket under the seat is for I believe a horn, the silencer ring is so you can pull off the silencer against the spring, re-hang same on middle box tailpipe then run her on open pipe.

Edited by trialsrfun

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