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R65LS Final drive

Posted: Sun Sep 11, 2022 6:48 pm
by MotoD
Hey all! I just wrapped up a 1982 R65LS with a 860 big bore. I love the get up and go but the gearing is a bit short. It currently has a 32/9 final drive. Ive got the double shock swing arm and drum brakes so would like to get something that'll mate up. Do any of you have an opinion on what ratio I should look for? Thinking something off an R80 or so...possibly 32/10 or 11. Thanks as always!!
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Re: R65LS Final drive

Posted: Tue Sep 13, 2022 2:42 am
by gspd
:o
I was waiting for someone to chime in but everyone seems at a loss for words.
So here's my 2 cents...
Fitting a larger diameter rear tire would be the easiest way resolve your gearing issue.
(You might have to relocate the petcocks.)

Re: R65LS Final drive

Posted: Tue Sep 13, 2022 7:22 pm
by MotoD
gspd wrote: Tue Sep 13, 2022 2:42 am :o
I was waiting for someone to chime in but everyone seems at a loss for words.
So here's my 2 cents...
Fitting a larger diameter rear tire would be the easiest way resolve your gearing issue.
(You might have to relocate the petcocks.)
Yeah…good stuff. Don’t want to change tires so I’ll figure it out. Thanks anyways

Re: R65LS Final drive

Posted: Wed Sep 14, 2022 6:01 am
by Rob Frankham
I would guess that a 32/11 would be too high for you, you'd trade too much of the 'get up and go' for top speed which probably wouldn't be too comfortable on a bike with zero protection. I would suggest that a 32/10 or a 34/11 would be more in keeping... but the only way to really know would be to do it and make your own decision. Incidentally, I would expect a R65LS to have a 31/9 rather than a 32/9... but then, you don't say that the current drive is original I suppose.

Assuming the current drive is a stock twinshock drive, any unit, smooth cased or stepped cased, from a twinshock is going to bolt up to the swong arm but you might have issues with the brake. Not sure quite what the differences are... the cam seems to be common to other models but the brake shoes are unique to the R65LS.

Rob

Re: R65LS Final drive

Posted: Wed Sep 14, 2022 11:28 am
by barryh
R65LS brake shoes are unique to the R65LS wheel being both wider and larger in diameter. As long as you keep the same rear wheel you will need to retain them. I don't know if the wider shoes means the same cam spindle or not but you would be able to transfer the old one if it's an issue.

Re: R65LS Final drive

Posted: Thu Sep 15, 2022 1:44 am
by MotoD
Thanks for all the tips. I have a standard R65 in the shop as well also with the stock 32/9 final drive. It has the snowflake wheels VS the LS style wheels. I’ll try next week to pull both wheels and see if the stock 65 rear wheel fits ok onto the Ls setup. The final drives look identical but I’ll be interested to see and measure the brake setups. Thanks again.

Re: R65LS Final drive

Posted: Thu Sep 15, 2022 5:47 pm
by MotoD
barryh wrote: Wed Sep 14, 2022 11:28 am R65LS brake shoes are unique to the R65LS wheel being both wider and larger in diameter. As long as you keep the same rear wheel you will need to retain them. I don't know if the wider shoes means the same cam spindle or not but you would be able to transfer the old one if it's an issue.
So are you saying I may be able to transfer over some of the LS bits to the possible donor drive? I found a good deal on a 32/10 setup from an R90s. The shoes maybe able to be swapped over which would be fantastic, I wouldn't be surprised if the cam spindle is the same across the board BUT could be wrong here...

Re: R65LS Final drive

Posted: Thu Sep 15, 2022 5:52 pm
by MotoD
Quick look @ calmoto parts fiche part number: 35211454836 for the rear brake shoe cam appears to be shared by most airheads including the R90s so that is a good sign. The LS also uses a 200x25mm rear brake shoe which does a lot of other years/models so once I get this all sorted I will report back with my findings!

https://bmwparts.calmoto.com/p/bmw__R65 ... 54836.html

Re: R65LS Final drive

Posted: Thu Sep 15, 2022 10:19 pm
by Seth

Re: R65LS Final drive

Posted: Thu Sep 15, 2022 11:21 pm
by MotoD
Seth wrote: Thu Sep 15, 2022 10:19 pm I thought all R90S had 33/11

https://bmwmotorcycletech.info/ringgears.htm
🤷 this is what one of the eBay listings I’m watching states

https://www.ebay.com/itm/234681069513?m ... media=COPY