Tire Size

I know Commandos came with same size tires on front and rear: 4.10X19. So I recently purchased my '71 in Surrey, BC (the exchange rate is amazing right now!) and the guy had installed brand-new Dunlops: the 4.10X19 K81 Roadmaster on the rear, but he installed a 3.25X19 K70 Dunlop Gold Seal on the front. So my questions are: Is this a problem? Does it affect handling in any way that one would notice? So what? Feedback would be helpful.

Should not be a problem, I run a 90/90 19 on the front and a 100/90 19 on the rear, the smaller front quickens the steering.

The stock 41.0-19 is essentially a 100/90-19, or, 4.00/3.75-19. The 3.25-19 will turn in a little easier, but there's the concern of reduced footprint on the front end. I'm currently running that size on mine in the Avon Roadmaster, and, with a small-diameter master cylinder and Ferodo brake pads, the tire can be made to squawk during panic stops. 'Not very re-assuring... I'll be going back to the 100/90-19 once the current tire wears out.

Nathan

Nater_Potater said:

The stock 41.0-19 is essentially a 100/90-19, or, 4.00/3.75-19. The 3.25-19 will turn in a little easier, but there's the concern of reduced footprint on the front end. I'm currently running that size on mine in the Avon Roadmaster, and, with a small-diameter master cylinder and Ferodo brake pads, the tire can be made to squawk during panic stops. 'Not very re-assuring... I'll be going back to the 100/90-19 once the current tire wears out.

Nathan

Click to expand...

That is not correct at least for the Avon tires many run and stock rims, they do recommend the 4.10-19 AM9 Roadrunner for the stock WM2 rims but do not recommend the 100/90-19 AM26 Roadrider and if you mount one the profile will visibly be wrong...that being said many do run them and live to tell the tale but they are definitely too wide for a WM2 (1.85") rim. FWIW they do sell a 90/90-19 AM26 that is OK on a WM2 rim but it is front wheel only.

http://www.avonmoto.com/products/classic/roadrunner

I find the skinnier front tyre works better in the corners than having both tyres the same size, so no problems with running what you have.

Ashley