[bmwr60]

Dear friends,
I'm from Turkey and the cafe racer style is not so popular or known in my country. So I need your valuable suggestions for my cafe racer project. I just bought a 1977 BMW R60/7. Original tire sizes are 3,25 S19 Front, 4,00 S18 Rear. I wanna replace the rear tire with bigger size. They says that (service guy) I am not able to install bigger tires. But I saw a lot of bikes on the internet, without any modification. I would like to ask that is there anyone who has some information or suggestion to me about the biggest rear tire size that I can use ?

Thank you in advance.

Goktug.

 

[Geeto67]

Why would you think the Internet is smarter than your service guy? He is right, in order to properly fit a wider tire you need a wider rim. If you put a bigger tire on your existing rim it will pinch the tire and change the profile. It will not give you a bigger contact patch.

 

[bfd]

A bigger one also will not clear the driveshaft. There is a factory spacer to push the wheel over a little but you can't go over much as it reduces the contact between the hub spline and the rear drive spline.
Listen to the tech and enjoy it the way it is

 

[drgonzo]

I am sure you are after the 'look' of fatter tires but if it were my bike I would run Avon AM26 in the original sizes or you could go with the
metric sized 100/90-19 and 110/90-18(4.5 inches wide). Bridgestone S11 and BT45 are also good choices.