Comparative Anatomy - Frames

I haven't been able to get a lot of information on the frame used on the R51RS. Clearly it was based on the R51 frame. From photos, the frame an additional brace in front of the rear fender, under the seat. Unlike the brace that was used in R51/3 frames, the brace was centered. The R51/3 brace was off center in order to accommodate the battery. I have some pictures of a couple of frames I own; 1938/1939 frame and a 1954 frame.

First the R51 frame:

 Simple gusset around the steering head

The frame had no bracing in the "interior" volume. Looks to be very flexible, not in a good way.

There is a spot for the battery right in front of the rear fender, on the right side

The R51/3 frame:

 Brace on the across the down tubes, right below the steering head (a little hard to see) and a second one that is easy to see

 Brace from front to the seat post, just as with the post-55 /2 frames

 Brace from top to bottom. Note that the battery box on the '54 frame not only had a "floor" but also a "back". Prior to '54, the battery only had a floor.

Don't mind the bandages. 

I will add that I weighed the two frames, both powder coated. The '54 frame is 5 pounds heavier that the '39 frame. The price of stiffness.

Timing Gears

I want to share some photos from JH who is also recreating a R51RS. From the photos sent to me from JH, he appears to be much further along than I am.

JH took some photos of the timing gears from a generous owner of R51RS who was willing to show what is behind the cover. I really have to thank JH. I spent many months searching the internet for photos of the the R51RS timing gears. The picture I have on an earlier post is the set that Josef Heft sells. I hope to get my set from Josef in the next month or so.

 Copyright JH

 Copyright JH

In the blog post Weiss und Blau, it was noted that in the 1950s, one could have bought the timing gears from Ernst Hoske (known in the /2 world for his tanks). I'm always surprised by the number of R51RS replicas that are out in the world, given that only 17 were only produced and only about five original are know to exist today.