Wider rims, but stock hubs. How wide can I go?

[odbuffalo]

New guy here, just bought a 74 GT750 and am considering getting some newer aluminum rims. Im thinking about getting a set of Moose, Excel, something along those lines, new spokes and using my original hubs.

How much wider can I go, especially in the rear and will it cause any problems with clearance with the chain?

Thanks

[Suzsmokeyallan]

Its been said a 215 can be mounted up front and a 250 out back. I have them but have not tried any retrofitting yet. The ones I got were from Moose for the KTM model as it had the right spoke count but you will need a plug from a Honda XR to block one of the rim lock holes.

[tz375]

215mm or 2.15"????

Seriously though folks, I have a 2.5x18 on the front of mine and 3.00x18 on the rear. rear tire is a 130 and there is clearance.

140 on the rear requires some clean up of the inner flanges of the swingarm and starts to run into chain clearance issues.

How wide were you thinking?

[odbuffalo]

As wide as I can go without running into any issues. 3 inch would be nice.

Thanks

[tz375]

3" rim is what's on mine with a 130 tire, so I know that works.

[Buffalo-guy]

My hotrod has a 4 inch Excel shoulderless rim with a 140 tire on it, and it barely clears the chain. It's laced to a GS 1000 disc rear hub, on a GS 1100 swing arm. It looks totally cool, but a 130 tire would be a far better fit, and would handle better. The power output of these old devils doesn't warrant any more tire than that, even in tuned condition. A 100x19 front is all that is required, and prevents most clearance problems with fender stays, and brake calipers. A 110 is do-able, I think, but not necessary. Brigestone BT45's, or Metzler Lazertechs are my choice of rubber. They far out do anything the old girls can throw at them. My two bits worth. Cheers.
Fred

[Suzsmokeyallan]

ok then 2.15x19 front and 2.50x18 rear rims to be specific, this is done to unwrap the shoulder sections of the 100 front series and 120 or 130 rear series tyres and to allow them better profiles towards the edge for more stable cornering.
Its been noted these tyres are too wide for the 1.85 and 2.15 stock width rims.

[tz375]

Allan, that's correct. Those wide tires would be horribly pinched on stock rims. I wanted to run a 140 on the Phat Trakka but with a 3 inch rim that I already had, that wasn't feasible.

fatter than stock tires on stock skinny rims look bad and usually handle worse that the right widths. Glad you made that point.

[odbuffalo]

Thanks guys! Anyone have photos?

[odbuffalo]

I did a couple searches here looking for the answer but does anyone know the axle diameter for the GT750?

Thanks

[odbuffalo]

20MM or something like 0.78 inches.

[evol02]

I've always read that the axles were the same for the T500 and GT750s (I have a T500), which makes sense since I'm swapping front drums at the moment. The Suzuki T500 is a 15mm axle.

[tz375]

Are you asking about front or rear axles or both?

[oldjapanesebikes]

Front is 15mm and rear is 17 mm.

[odbuffalo]

Okay, so I have narrowed it down to the front at 2.15 X 19 and the rear Id like to go with a 18 X 2.5 or 3.0 in the rear.

Other than the spoke count is there any other criteria I should be concerned with?

Thanks again.