The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: mrclubike on September 28, 2014, 07:33:13 PM

Title: 4.00-18 VS 120/90 -18 Metzeller
Post by: mrclubike on September 28, 2014, 07:33:13 PM

Hello all
I am getting a new tire for the back of my R65
Is switching from a  120/90 to a 4.00  going lower my overall gearing.
   I need to get as much speed out of  4200rpm  that I can get .
I could not find any specs on outside Dia on the Metzeler site
If someone has a 400-18 mounted  could you measure the outside dia or the radius for me  (from ground to center of rear axle)
Thanks for the help :)

Title: Re: 4.00-18 VS 120/90 -18 Metzeller
Post by: mrclubike on September 28, 2014, 10:29:02 PM

I did find a size chart on Avon tires and it less than 1% difference in a 400 and a 120/90
not enough to worry about  ::)

Title: Re: 4.00-18 VS 120/90 -18 Metzeller
Post by: Barry on October 02, 2014, 05:19:12 AM

Here is something I put together a while back for different tires.  Let me know if you have some new info and I'll add it.

Title: Re: 4.00-18 VS 120/90 -18 Metzeller
Post by: mrclubike on October 02, 2014, 10:11:28 PM

                                                                wide    tall  
Avon Roadrider AM26 (rear)      4.00-18       116        671        

Avon  Roadrider AM26 (rear)      120/90-18       129    675        

Title: Re: 4.00-18 VS 120/90 -18 Metzeller
Post by: Barry on October 03, 2014, 03:08:57 AM

Thanks

I'll update the table