GS750 max tire size - 130 on rear?

[Chuck78]

I have a 110/90-18 on the rear now, p.o. apparently like to do a lot of burnouts... My wife's 77 GS550 looks so much better with a 130 on the rear, but i have read that the wider tire will balloon out over the rim and flex a lot in cornering, making handling not so nice.

I just measured the rear rim on my GS750, and it looks to be about 3-3/16" wide on the outside, so I'm guessing 2-7/8"+ inside width (not sure which dimension they are rated by). Am I best off sticking with a 120, or can I fit a 130 on there with no ill effect on cornering? Can I drop down to a 130/80 if that is even available, or is the taller profile better?

I will probably be going with Shinko 230 Tour Master tires.

My front is currently a Kenda Challenger 100, seems to fit with no problem over the stock 90.

[Chuck78]

I mentioned the rim sizes because I thought I had read specs posted before on this topic which mentioned much smaller rim widths on a GS750. This is a 1977 GS750B but I have no idea if the wheels are original.

[Nessism]

There are a bazillon threads about tire size in the archives. Your bike has a 2.15" wide rear wheel so a 120 is the widest tire you can reasonably use.

[Big T]

The 110 is closest to stock, a 4.00 is even better

Why do you hate your wife?

[Chuck78]

Are you implying that the 130 tire on the gs550 will make my wife wreck???? Uh-oh!
You say my 750 rear rim is a 2.15" width, but the one on the bike measures 3-3/16 outside width. Not sure how rims are measured or if this one is stock or not, but it seems far fetched that my current rear rim is. 52" thick on the sidewalls, as that is the difference split to both sides from the 3-3/16" outside dimension & the 2.15" you stated. Trying to understand rim sizing & get to the bottom of this. Maybe some size indication will be stamped in the rim itself

[Big T]

Yep, less rubber on the ground makes it easier to skid the rear in an emergency and distorted profile ruins handling

I didn't get the in the hate line, many people do the big tire thing and survive. Just put the correct size on next time

Yes, you will find 2.15 X 18 stamped on the wheel

Some manufacturers, like Avon, have a chart that tells you what size tire goes with a rim width.

[Rick Romero]

i have a 4.10x18 on my 78 750

[mrbill5491]

120/90-18 65H on my 750 rear, MM90-19 61H front pretty much stock size. I once had a 510 rear and a 110 front on it in the early 80's that was a mistake. Screwed up the handling big time. . Staying as close to stock on these bikes is what I found best.

[mrbill5491]

Tire sealant

Just found this. Anyone use this stuff yet?

http://www.ride-on.com/motorcycle-formula-mot.html

[Big T]

i have a 4.10x18 on my 78 750

Yeah, I went back to the stock sizes on my 78 (Avon makes them) and I just about went across into the other lane on the first left hand curve I hit. I forgot just how quickly the bike can turn as I was using larger tires.

A 120 rear will fit, but it's pretty large

120/25.4 =4.72, so almost a 5" tire

[mrbill5491]

Just found this. Anyone use this stuff yet?

http://www.ride-on.com/motorcycle-formula-mot.html

When I bought tubes, I saw this on the counter and asked them about it, they said they just started carrying it a couple months ago, now they can't keep it in stock. Their tire guy in the back said a guy came in with 4 nails in a tire, hardly lost any air. He asked when got the nails, he said 3 weeks ago, just got around to getting it checked lol.

[tkent02]

It is supposed to be good stuff, haven't used it yet myself.

[mrbill5491]

Guess I'm going to find out