Re-gearing a bevel box?

I’ve been after an R850GS bevel box for some time. These things seem to be practically impossible to track down at sensible money. A while ago I bought a spare 1150GS rear drive. Question is, can I take my spare 1150GS drive to bits and fit the gearing from an 850? If so, how tricky is this? Finally, and possibly more importantly can you actually buy just the bevel box gears?

Anyone got any ideas?

Thanks in advance

Alf

You can certainly buy the parts. For some reason, the US Based Max BMW On Line Parts Fiche doesn't cover the 850GS - I'd guess it wasn't exported to the States - but they show all the parts for the 1150 available individually (the crown wheel was priced at $365, to give an indication of price).

Steptoe will probably be able to give you guidance on the difficulties or otherwise of correctly shimming the drive.

I would have thought a gearbox swap with an Adventure might have produced a similar result, with the parts easier to find used just a thought...

Mike

you can fit the internals - so long as the gears are a matched pair -

they'll need shimming at the input , and the output end - special tools required

bevel swap

Just spoke to Rainbow,and you can buy a bevel gear kit at £193+vat.That will get you crown wheel and pinion,It will drop straight in,all the internal dimentions are the same 850/1150.Reading on the ADV site there is a thread as long as your arm on this subject 20 pages nothing negative.From what I can make out you gain about 500 rpm in E and it will lift the front wheel in 1st/2nd off the throttle if you want .I have been looking for a bevel from an 850gs for about 2 years now, and they just don't come up for sale,and simalar are £300 from breakers if they do.The only person to have done it on here is R.savage,don't know if he still posts!!!,but he posted on ADV when he did his and said it was the best thing he had done to his bike. Andy

Thanks for the info guys. Sounds very interesting indeed. It’s not going to be cheap but reading through all the info on Adv, it sounds like it’s going to be worth it. 2nd gear wheelies off the throttle hey

Just found out that wheelies in 2nd off the throttle are easy peasy with a spare bevel box in your topbox and no fuel

Please don’t tell anyone about the topbox though