Tire Size Advice Needed - New Cafe Build

[gibbsnbits]

So I'm tearing down a 1980 XS400 to turn into a cafe bike. I'm going from the stock 18" spoke wheel on the front and the 16" spoke wheel on the back to a 19" alloy both front and back (working on the aluminum rear conversion spacers now). I was wondering if anyone has an opinion or some experience with the tire sizing for this type of conversion. I'm thinking 100/90-19 for both the front and back (looking to maintain the symmetry of the matching 19" wheels). Thoughts? Also any brand experience would be helpful (I'm considering Shinko 230 Tour Master 100/90V-19)

 

[Wolfe_11B]

Can I ask why 19's?

Normally 'cafe' bikes use 18's. Plenty of nice preforming tires in that size due to the popularity.

 

[gibbsnbits]

I purchased a set of mags and was under the impression they were 18" but it turned out they were 19". Deal was done so here I am with 19's.

 

[Wolfe_11B]

Well honestly you are kinda screwed. Your only option is going to be putting a front on the rear, and I would not recommend that at all.

A 100 on the rear is too small for these bikes.

 

[Wolfe_11B]

If you are dead set on the 19's, go with Avon AM26's. They make a universal that will fit both front and rear.

 

[esmith87]

Does the embossed rim size show 19" on the rim or did you just measure the overall diameter? They may be 18" from bead to bead. Just a thought. Stock 18" alloy rear wheels for xs400's actually measure 19" overall.

 

[gibbsnbits]

Confirmed, they are both 19" mags. If 100/90-19 is too small for the rear how about 110/90-19 on the rear and 100/90-19 on the front? I've seen this setup on 18" wheels before on the forum.

 

[Wolfe_11B]

Whats the rim width?

100/90-19 on the front and 110/90-19 on the rear will work. The only real issue you run into is that if you are doing spirited riding in twisties, you won't be able to get as good of lean angle as you could with say a 120. So long as you know the limitations of the tire size you will be okay. A benefit of the small rear though- it will turn in quicker and feel more 'flickable'.

 

[Wolfe_11B]

Also get a good idea of the overall diameter of the tires on a 19" rim. You may run into some clearance issues with the fenders.

 

[gibbsnbits]

Not going to run fenders on this build, clearance will not be an issue. Thanks for all of the advice Wolfe_11b, much appreciated!