4.25 tire is what in metric speak?

[hikermikem]

My '82 GS650G has the following tire sizes listed in the owners manual:

Front - 3.25-H19
Rear - 4.25-H17

Currently, what's on the bike is:

Front - 100/90-19
Rear - 110/90-17

I'm having trouble finding a 110 width rear tire. Also, most of the tire places I've talked to say the 4.25 converts to a 120 tire. However, if i do the actual conversion (25.4 x 4.25 = 107.95) it seems to get me back to a 110.

Sooo...... what is everybody running on 17" rims taht call for 4.25 tires?? I want to run 120's because it opems up a larger selection og tires, but I'm concerned about how it will fit on the rim.

Any thoughts??

Thanks,

mike

[paco13]

It converts to a 110.
What is your rim width? it should be embossed on th rim somewhere.
120 can be fit on 2.15,2.50,2.75 width wheels, which happen to also be the recommended rim width's for a 4.25/110. i don't see you having any issues with a 120.

[hikermikem]

Thanks - going to a 120 tire opens up a much better selection.

[Nessism]

120 will fit nicely on your rim. There are not a whole lot of selection though in 120/90-17. I bought Bridgstone BT-45's for my 550's and they seemed like nice tires.

[hikermikem]

120 will fit nicely on your rim. There are not a whole lot of selection though in 120/90-17. I bought Bridgstone BT-45's for my 550's and they seemed like nice tires.

I ended up buying an Avon AM26 Road Rider for the rear (120/90-17). I can match the same tire for the front later.

[spokexx]

id like to jump right in here, I really want to get a 110/90 17 tire for the rear of my GS650G since thats what the bike was designed for. I know many people say its ok to use a slightly larger size (120 or 130) but I just want to keep it all the way it was meant. Ive felt the difference on other bikes when a larger size was used instead factory spec. So in my searching Ive found some 110/90 17 's but they were listed as front tires, specifically the IRC RS310. (funny how today's front tire sizes are what was being used as REAR tires back in the day) Would this be a bad thing to use a front tire in the rear?

drew

[Nessism]

id like to jump right in here, I really want to get a 110/90 17 tire for the rear of my GS650G since thats what the bike was designed for. I know many people say its ok to use a slightly larger size (120 or 130) but I just want to keep it all the way it was meant. Ive felt the difference on other bikes when a larger size was used instead factory spec. So in my searching Ive found some 110/90 17 's but they were listed as front tires, specifically the IRC RS310. (funny how today's front tire sizes are what was being used as REAR tires back in the day) Would this be a bad thing to use a front tire in the rear?

drew

Some tread patterns go both front and rear - Avon Roadrunner has some tires like that. As long as those IRC's are universal, I think you will be fine running it in back.

BTW, the 650G has a 2.5" wide rear wheel. Tons of members here are using 130's on wheels that wide. Using a 120 would be conservative, so no worry if you decide to give that a try.

[duaneage]

IRC makes the excellent Durotour RS 310 in every incremental size from 110 to 140 for the 17 inch rim. They are reasonably priced and offer great all around performance. I have used them for 5 years and recommend them highly.

The 110 tire is a bit small and the RPMs are a little high at 60 mph. Going to a 120 drops the rpms about 250. The 130 is as large as practical while the 140 is a mistake, too wide for the rim.

I think I went with the 120 last time. My bike came with a 130 on it and I didn't like the handling personally.

[doug g]

spokexx has a 130 on the rear of his 650G and the handling is no good. the bike does not want to turn. you really have to give it a good push on the bars to steer. I think once he installs the 110 the bike will ride soooo much better. If you were to go oversize it has been my experience one size over is the limit.