What tire sizes, front/rear, are compatible with stock rims? Wider is bettter?

 

For 1987-1988:
Rear: 140 (stock) or 150 wide fits. The profile gets to pointy if you go any wider.
Front 110 (stock) or 120 is OK.
To fit wider tyres you have to fit a 1989 or newer rim.

 

I am looking for later rims for my 88 you Carnotuse full powerthrough a 140

 

Of course you can use full power with a 140 tyre. Just choose right type of rubber/brand/model.

 

I think you can go for a good rubber and you will be able to use full power on a 140 but I am privileged enough to have 91 model with a 170 on the back and a 120 in front!!!

 

Does the "Good Rubber" come in the 140 110 sizes? Using the Bridgestone Battlax on an 87 with decent results.

 

I run a michelin 120/70 pilot activ on the front it seems to be better than the 110 i had before you can turn sharper. At 8000k it is showing wear both sides 2cm off the centre not from low air 43 psi. I think it is a good tyre .On the back is a michelin 140/70 macadam 50 it has good grip 2 up or loaded but just me it will spin when you power out of a corner.

 

what mods to an 88 swingarm do you need to do to go to a newer rim (89 or newer)?

 

It seems like you need to remove the hugy chain guard and make up a new spacer for the caliper mount.