1981 GS550T Tire Size

[Mr Toga]

I am very reluctant to post this question but after using the search feature, I'm even more confused. I've got a 1981 GS550T with either original tires on it or tires from 1991. Either way, they need to go. The manual lists the front as 3.25H19 and the rear as 4.25H17. I figured a 100/90-19 would be okay up front. As far as the rear is concerned, I've had mixed reviews. 4.25 inches works out to 107.95 mm so technically a 110/90/17 would be best on back. However, I've heard some go up to a 120 or 130. I tried to compare the sizes to a 550L from the same year but the manual gives the rear size as 130/90-16 (weird how they change from inches to mm). I would like to run a 130 on my rear so I can get a matching set of Shinkos but I don't want to have an unsafe configuration. What say ye?

[cowboyup3371]

Currently I have the same bike with a 120 90/18 on the back and a 100 90/19 on the front. Both tires are Dunlops and I hope to see how good they really are in a week or two.

[Nessism]

A 130 is to wide for your rim. The L model bikes have a smaller diameter wheel, but wider.

120/90-17 is a good fit but somewhat rare. Bridgstone BT45's come in that size, but they are more expensive than Shinko's.

[Mr Toga]

Has anyone had any experience with the Duro HF261A tires? Seems like I can get both tires for under $100.