Who has Chain Rails?

[justscootin]

Can any one explain the difference between the different numbers/stages? I was told by BMW that I need to change the chain rail to #2 but not sure what the differences are

The difference of the numbering is from 1-4 the arc increases. At 75000km I was not able to fit #4 as over time the chain is stretching less.
One last tip if you do your own work, don't buy a gasket for the crazy money just buy a silicone gasket cement.
Easy to apply just run a bead on the casting where the gasket was.

Peels off when you open it up a a later date.

I have not had any leaks after 50000 km on the rear drive.

About $7

When I restored my isetta I did the same thing on the rear drive (yes it is a chain in an oil bath) and transmission

When I worked on my K75 same thing

Never had leaks

 

[moodleman]

Just did my own, not hard or complicated, you'll need 740ml of synthetic 75W90, the 2 dot (#2) rail, possibly a gasket, long torx bits and about 1 to 1 1/2 hours. I removed my rear tire so the catch pan was under the rear drive and super cleaned the wheel while it was off. Expect your first change to be really dirty (chain assembly lube that gets washed off in the gear oil), also checked brake linings and cleaned everything I can't normally reach due to tire. I purchased chain rails from Ben, 2, 3 and 4, you'll need to keep the rails you take off as they can be re-used with a new chain. I cheated and bought the Harbor Freight motorcycle lift so it's much easier now (after both kee replacements, a rebuilt shoulder, neck and back surgery and foot surgery I needed to get off the floor).

OK, no.1 comes already installed on the bike. When it's time to add rail no.2, do you simply add it, or take no.1 out at the same time?

 

[Ceesie76]

Mine came with a no. 2 rail new from the factory (to my surprise) so don't assume it has a no. 1 currently.
To answer your question: you take out the one that's in there now and put in the next size up.
I decided to get the whole series so have 1, 2, 3 and 4 with no. 3 currently in there. Because once you're done with no. 4 you get a new chain and go back to no. 1 (or maybe no. 2 in my particular case).
Good to order a new gasket for the cover and replace the oil 'while you're in there'.

 

[moodleman]

Thanks Ceesie76. I have checked the chain for slackness - not quite half an inch of play in it, so the bigger rail will be needed but not just yet (bike has 22,000 km on the clock). And I will hold off ordering a new rail until after I have made certain it has a no.1 installed - I would never have imagined it could have anything else! Thank you for drawing my attention to that possibility!