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3.5” tires With 25/8 final drive
3.5” tires With 25/8 final drive
My question comes from the fact that I have changed the final drive from the original 33/11 to a 25/8. The lower gearing works MUCH better for me because I live at 8000’ and ride regularly to 10 and even 12,000’.
I’m not sure it really matters, but the speedometer seems to be very accurate now with the 110 on the rear. I guess my question is, is the 3.5 tire the appropriate size with the 26/8 final drive?
Thanks
- schrader7032
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Re: 3.5” tires With 25/8 final drive
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
Re: 3.5” tires With 25/8 final drive
I have the original owners manual, I’ve been through it twice, and I still can’t find a recommendation on tire size. It must be there someplace.
Barrington says 3.5.
Thanks for the input
Re: 3.5” tires With 25/8 final drive
Re: 3.5” tires With 25/8 final drive
Barre, MA USA
1963 R60/2 w/ 1955 Steib S500
1973 R75/5
Re: 3.5” tires With 25/8 final drive
You're probably correct and I’m remembering it wrong. The original drive is packed away or I would take a look. 32/11 is likely. What's on it now and working very well for my situation is the 25/8. Is there a way to tell if a speedo matches a certain FD other than how it reads against a GPS?niall4473 wrote: ↑Thu Feb 09, 2023 4:02 amAre you sure that you mean 33/11?, which I believe was used later on /7s but not before that, the original rear ratio for the 1956-60 R60 was 32/11 (2.909:1), while the contemporary R50 and R69 used 35/11 (3.18:1), which was replaced by the 25:8 in 1961, if your R60 has the original speedo, it should be quite in error.
Re: 3.5” tires With 25/8 final drive
Thank you. Great article. I’ve had a 4.00 on the back ever since I’ve owned the bike. I’m excited to try the new tires. It’s -17 F here this morning, so It will be several weeks, but it’s something to look forward to.weh8127 wrote: ↑Thu Feb 09, 2023 9:02 amYou may enjoy this article, https://w6rec.com/bmw-motorcycle-neutral-steering/ . A great deal of handling is related to tire size.
- schrader7032
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Re: 3.5” tires With 25/8 final drive
The July 2005 issue BMW VMCA News has an article listing typical final drives and speedometer matches. If you can open it up, it's here:
https://vintagebmw.org/vmca/v2n3/index. ... 1676042273
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
Re: 3.5” tires With 25/8 final drive
Great. Thank you.schrader7032 wrote: ↑Fri Feb 10, 2023 10:18 amThe July 2005 issue BMW VMCA News has an article listing typical final drives and speedometer matches. If you can open it up, it's here:
https://vintagebmw.org/vmca/v2n3/index. ... 1676042273
- wa1nca
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Re: 3.5” tires With 25/8 final drive
Volune 32 issue #3 page 15schrader7032 wrote: ↑Fri Feb 10, 2023 10:18 amThe July 2005 issue BMW VMCA News has an article listing typical final drives and speedometer matches. If you can open it up, it's here:
https://vintagebmw.org/vmca/v2n3/index. ... 1676042273
54 R51/3, 55 R50/Velorex 560 sidecar, 64 R27, 68 R69US, 75 R75/6
Ashfield, Ma
USA