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Micha
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Posts: 277

It is stamped:
596
251/1 – 35x8

What can I conclude here? And is it the correct one for my R51/3 1952 solo bike?
Mark Huggett's site does not mention these sizes/numbers.

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Michael Steinmann
R51/3 1952
Engine Nr. 529466

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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The part number you provided

The part number you provided shows up in RealOEM for a 35:9 ratio. Phil Hawksley's site also shows 35:9 was the spec for the R51/3 solo.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Micha
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Sorry Kurt, I was not clear

Sorry Kurt, I was not clear enough. I provided the p/n just to help understand what I mean by crown gear.
I know that the p/n is the correct one. Thank you.
I would like to know what are these stamps refer to, in order to be sure that this is the correct part installed in the rear drive.

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Michael Steinmann
R51/3 1952
Engine Nr. 529466

stwilliams
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Posts: 87
Depends on your final drive housing

This crown wheel and pinion set is a sidecar ratio. Does it match what is stamped on the top of the final drive housing? Its fine to use if the gear teeth are in good condition.

The 596 number can likely also be found on the smaller pinion gear. Generally they matched up the gears based on fit, then ground a matching number into them. 35x8 refers to the number of teeth on the crown wheel and pinion.

I would strongly suggest, as others have, getting the Betjeman book. May be expensive, but will help you avoid a costly mistake, and will pay for itself very quickly is saved time and frustration.

The Plunger
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From the manual R51/3 solo

From the manual

R51/3 solo 35:9
R51/3 sidecar 32:7
R67/2 solo 32:9
R67/2 sidecar 35:8

So you have a R67/2 sidecar set

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Brian
'52 R67/2
'63 R69 S
In what space, sir. In what space!?

Micha
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Posts: 277
Wow. Is this good or

Wow.
Is this good or bad...?
I understand that it is not the correct one, but what are the effects on a solo 51/3 having a 67/2 sidecar set?
Can I go on with it or will this be a bad idea?
Appreciate your time guys.

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Michael Steinmann
R51/3 1952
Engine Nr. 529466

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6652
A 35:8 rear end provides for

A 35:8 rear end provides for quicker rise in speeds when shifting through the gears. 35 divided by 8 is 4.375 while 35 divided by 9 is 3.888. Typically, there was a different transmission 1st gearing as well, but it appears that the later R51/3 didn't have that. With the 35:8 rear end, you would likely not be able to reach the highest speed for the engine as you would "run out" of gear at the top end. For most, that's not a big concern.

Another thing is that the speedometer should be matched to the rear end to display speed properly. For R51/3 and a 35:9 rear end, the small numbers on the speedo face would be 0.95 for a kilometer setup; for 35:8 it would be 1.15.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

The Plunger
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Since you seem to be on a

Since you seem to be on a tight budget, I would use it if it's in good shape as one pinion tooth less won't affect performance too much. As Kurt said, you just won't get to wrap her out. Make sure your final drive case is stamped to match or you'll forget what's inside! That said, how much is a good used pinion gear?
Brian

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Brian
'52 R67/2
'63 R69 S
In what space, sir. In what space!?

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