R50 to R69 frame differences

[RipperFarms]

Does anyone know the differences between a R50 and R69s frames.

Thanks ... Dave in Central IL.....

[marchyman]

Does anyone know the differences between a R50 and R69s frames.

There is no difference. The parts book is good for answering questions like this. The frame (with sidecar lugs) is part number 46 51 4 000 043 which is used by R50, R50/2, R50S, R60, R60/2, R69, and R69S.

[20774]

Marco -

Weren't there minor updates over time? I thought that early frames, even R69S frames were lacking some gussets, especially at the back of the rear loop where it meets the bottom rail.

[marchyman]

Yes, there were changes. But the changes affected all models and I don't think the part number changed. You could use a later frame on an earlier bike. The only change that resulted in a different part number was the "without sidecar connections" version of the frame.

I believe the "no part number change" holds for the modifications made to the Earles fork, too.

[20774]

As I thought, there were production changes over time. I wonder if a first generation Earles fork would fit on the later model engines with the damper bulge. I think they fit, but under some heavy front braking, the cross brace touches the front cover.

Not sure what the OP wanted to know. I would think that one would want a later frame whenever possible if one had the choice and needed a frame.

[RipperFarms]

Thanks so much..............I believe that answered my question. I was running under the asumption that all of them were alike and I guess I was right.

Thanks again for helping me. ........ dave in Central IL.

[monsondm]

1955-1960(or so) frames were the same and 1961-1967 were the same (added gussets 68-69 were w/o sidecar mounts in the US and possibly the fork angle was changed, tho I have never seen specs. verifying the angle differences. In 68, telescoping forks were an option with earles standard and in 69 the telescoping was standard with earles optional. Personally, I think the angle is the same for both forks. The Germans didn't change things much.

This is not something I have seen in specs, but info form a quality BMW mechanic I knew in the 70's.

Dale