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transmission sidecar gearing

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haroldson
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Joined: Sun Sep 16, 2018 7:02 pm

transmission sidecar gearing

Post by haroldson »

Can anyone tell me what is the difference in the gears between the /2 solo and sidecar transmissions? I know fourth gear is the same. Is it just the spur gears on the output shaft that are different or is it also the intermediate shaft?
Thanks
Trig

Daves79x
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Re: transmission sidecar gearing

Post by Daves79x »

As far as I know, the intermediate shafts are all the same. The first three spur gears are different. The are the exact same gears that the R26/27 came with and will interchange.

Dave
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haroldson
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Re: transmission sidecar gearing

Post by haroldson »

Looking into it further I find I need the first three output gears and the R26/27/50/60 intermediate shaft.
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Trig

Daves79x
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Re: transmission sidecar gearing

Post by Daves79x »

What other intermediate shaft is there for the Earles bikes?

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Flx48
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Re: transmission sidecar gearing

Post by Flx48 »

From the Salis site-
40027 countershaft R26 27 50 60
1st-19T 2nd-15T 3rd-10T

40028 countershaft R50/2 50S 60/2 69 69S
1st-20 2nd-16 3rd-12

Think that means the earlier twin standard trans, with the shorter 1-2-3 gearing, countershaft was shared with the singles; while the later sport trans, with the taller 1-2-3 gearing, was shared with some R69 and most all post '61 trans.

All new to me, thanks for bringing it up.
Best-
George

Daves79x
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Re: transmission sidecar gearing

Post by Daves79x »

Looking at the various parts books, up through '59, there is only one part number shown for all models' intermediate shaft, including the R69. Then in '61, there are two part numbers shown, as described above, one for the R26/27/R50/60, and the other for the R50/60/2, R69 and R69S. The teeth on the shaft did change slightly, did the very last of the R69 models have this - who knows. But I think replacement sidecar gears on the output shaft will work with either intermediate shaft, as BMW offered the sidecar transmission through the '60, as far as I know.

I can tell you after researching this topic, and the sidecar topic in general, there is very little out there concerning the specifics about any of this. The guys that know this stuff are long gone and/or are not talking.

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Flx48
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Re: transmission sidecar gearing

Post by Flx48 »

When I got the '60 R69 (pictured to the right) in the early '70s, it came equipped with the sport trans, marked so on the case, and showed no signs of having been r&r, (though of course it could have been) it had been a one owner, low mileage bike.

When the s/c was found a couple of years later, same year/color as bike, and the last year for both, I believe, (yes- bike, s/c, and myself have all aged gracefully together, thank you very much [smile emoji]) the sport trans was swapped out with its stable mate, a '56 R69, which was equipped with the standard trans, and had the lower 1/2/3 gears, which has worked out much nicer for hauling the s/c, and has also been nicer for the solo '56 as well.
Just another piece of datum.
Best-
George

dellatorre6708
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Joined: Fri Oct 27, 2006 3:00 am

Re: transmission sidecar gearing

Post by dellatorre6708 »

I have a sidecar trans on my rig. The first two gears are lower but 3-4 seem the same as a standard unit.
Frank. NYC.
Frank,
NYC

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