► The final drive on the single-side bikes allows the rear wheel to bolt directly to the final drive with lug bolts. So although the single-side final drive housings look similar to yours, the ring gear found inside is completely different and would mandate the additional purchase of another rear wheel. I also believe BMW changed the design of the single-side wheels, so besides the additional issue of rear brake mismatch there would also be the aesthetic issue of mis-matched appearance. I also believe there are a host of other minor differences blocking or at least impeding your progress. So IMHO forget about using a final drive from a single-side bike.

► I believe if not for your rear disc brake, any final drive from a /5, /6 or /7 bike would directly bolt onto your bike and solve your issue. Since your bike is one of a very few models (only 3 years ??) with rear disc brake, that complicates the issue. At a minimum, you'd need to remove the posts and spindles from the final drive housing used to support the brake shoes. In the end, you might find it easier to simply convert the rear brake to drum and find a double-sided rear drum brake wheel.

► That leaves the simplest, most direct choice as sending your final drive away and having the 2 gears replaced within your existing housing. This is not home mechanic type work and probably fairly costly.

Thanks you have been very helpful at least I know what to look for now.
Even if I can't find it.
Peace
Kent

> On further reflection, the truly "simplest" method might be to do nothing except to stop using 5th gear, except on down hill sections. 😛

> The easiest way to spot the 2 basic types of final drive housings is by the presence/absence of the rear axle hole.

> On further reflection, the truly "simplest" method might be to do nothing except to stop using 5th gear, except on down hill sections. 😛

> The easiest way to spot the 2 basic types of final drive housings is by the presence/absence of the rear axle hole.