5 replies [Last post]
Bruce Frey
Bruce Frey's picture
 Offline
VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574

In the reference books that give engine and frame numbers, there are notations that the R62 shared engine numbers with the first series R11 and the same with the R63 and R16.

All of the R62 (and 52) I have seen have the engine number on the on the right (kickstart side). All the R11 I have seen have the engine number on the left (driveshaft) side.

Does anyone know which side the engine number is on for the "shared motors"?....or were there different motors given the same numbers?.....or were there different motors using the same numbering sequence?

I will pose this question to Fred J if no one knows.

Bruce

[Bruce, I am happy to help you move this to its own posting. — ed.]

Darryl.Richman
Darryl.Richman's picture
 Offline
VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2185
Have you seen a real series I

Have you seen a real series I R11? (I haven't, so I can't say.) I bet it's a real R62 motor (and transmission). BMW changed the motor housing in a dramatic way somewhere along the line, because on the R52/.../R63 bikes, the motor housing is a clam shell around the flywheel and clutch, which means a clutch job requires splitting the cases. Somewhere early in the R11 series, they got rid of the clam shell set up and added a plate that fit in the back of the motor housing and to which the transmission bolted. When they changed to the R12 and added the 4 speed transmission, the plate became incorporated into the transmission case casting.

If I read the R11 parts book right, the Series I is really an R62 motor, with a clam shell. There's no separate plate listed for that Series. Series II-IV had one kind of plate, and Series V had another. Also, there's no oil filter cover listed for Series I, but Series II-V do have one. Also, the hold down arrangement for the magneto spannband changed in Series II, from a drift pin to a screwed in holder. So they changed the engine castings a great deal when they came out with the Series II.

My guess is that, as is typical with BMW in general and specifically in this era, they spent one year working on the new pressed steel frame, and then went to work the next several years adapting their existing drivetrain to make it work better in the system.

__________________

VBMWMO Webmaster,--Darryl Richman
http://darryl.crafty-fox.com

Bruce Frey
Bruce Frey's picture
 Offline
VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
Thanks for moving my post. I

Thanks for moving my post.

I have never seen an R11 (or 16) with the engine number on the left, so I have probably never seen a Series 1. My "fluency" is better with bikes from 1935 on and I don't have an R11 Ersatzteilliste.

Motorcycles from Munich says the R62 and R11 Series 1 both have an M56 engine where the R11 Series 2 has an M56S2 engine. The situation is the same with the R63 and R16 Series 1 having an M60 and a M60S2 for the R16 Series 2, so I think you have it right.

Since I will never have "one of each" bike, maybe I should aspire to have "one of each" Ersatzteilliste and Handbuch. Even finding one of each original Ersatzteillist and Handbuch would be a daunting task.

Cheers,

Bruce

Darryl.Richman
Darryl.Richman's picture
 Offline
VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2185
Ersatzteillisten

I started picking up the books (as repops; I'd rather spend the big money on bikes and parts!) because I found that they answer a lot of questions -- some I didn't know I wanted to ask until I started looking. I had heard -- and it's quite true -- that the R11/R16 book indicates parts for each series separately. There is a column on the right side of each page that indicates how many of each part are required for each series. So you can find a part and then see what series they go to. Not everything is pictured, however, and especially the series I stuff, but that's ok, I think, because you can find it in the R52/R57/R62/R63 book.

I bought myself an R5/R6 book, too, because I wanted to know more about BMW's development of the telescopic forks. It looks like they threw out much of what they developed for the R12. I know that for the postwar plungers, the forks are again very different (and, I think, quite elegant). I'll have to get the prewar plunger frame book to see what happened in the middle of the story...

__________________

VBMWMO Webmaster,--Darryl Richman
http://darryl.crafty-fox.com

Bruce Frey
Bruce Frey's picture
 Offline
VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
I've managed to collect

I've managed to collect original Ersatzteillists and Handbuchs for my prewar bikes (R12, R5, R6, R71) and it has gotten really expensive, so I would not attempt originals for the bikes I don't own.

The R5/R6 forks are a bit "fiddly" with the adjustment mechanism and not terribly robust. The R51-R71 forks were used almost unchanged in the postwar plunger bikes, so you will need to add an R51-R71 Ersatzteilliste to your collection!

I will look for repops for the older bikes at Veterama in October.

Thanks for the insights on the R62/R11 engines.

cheers,

Bruce

Darryl.Richman
Darryl.Richman's picture
 Offline
VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2185
I was surprised when I got my

I was surprised when I got my R5/R6 manual and looked at the forks. It looks like they deleted about half the parts from the R12 forks. I guess it doesn't surprise me to hear that they're more delicate, because the R12 forks are very robust. No wonder the Wehrmacht liked the R12 better than the R71.

The postwar plunger frames have forks where the damping is completely separate from the alignment/steering forces. When the forks expand, it operates what is essentially a leaky oil pump. No internal baffles or other weird stuff. The leaky part is what determines the damping rate, and it's based on the profile of an angled slice on the operating rod. Cut the rod with a different angle, get a different response. Seems very clever to me.

__________________

VBMWMO Webmaster,--Darryl Richman
http://darryl.crafty-fox.com

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.