Tire Size for 1981 xs400


XS400 New Member
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I recently bought a 1981 xs400 from a buddy. I need to put new tires on it. I've been looking at other threads on here and everyone suggests that I need to get 120/90-16 for a 16" rear tire on a '81 xs400. I would like to get the Avon Roadriders because I like the look and have seen good reviews. My problem is that I can't seem to find the Roadriders in the 120/90-16 size. However on MotoSport.com they have the Roadrider MKII with a 120/80-16 size. Would this slight change in size still work? Also, I plan on getting a 90/90-18 front tire.

This is my first build so I have a lot to learn. Any advice is welcome!

Thanks in advance!

tire sizes motosport.com.jpg
With tires, there is usually always a little wiggle room for the sizes up or down value. The 120/80-16 will have a slightly shorter sidewall and less overall diameter from the 120/90. A 130/90-16 would also probably be fine. The biggest factor is the space in the swingarm for the tire width. Again though, usually one size either way works out OK.