3.5 inch front wheel

[Bones]

I know the benefits of having a 5.5inch x 17 rear wheel regarding tyre selection etc... But what benefit is there having a 3.5 inch front wheel over the standard 3inch x 17. You'd still only put a 120/70/17 tyre on it wouldn't you.
                                                            Tony.

[stua1959]

Hi Tony.
I am pretty sure that 120 radial tyres were designed for 3.5" rims. Putting one on a 3" rim pulls the sidewalls in and gives u less useable tread. Looking at it from above the tread extends right down until it is almost vertical and not even Marquez could go there. On a 3.5" rim it would be a flatter profile and u would have more rubber on the road. When I did the trackday at Lakeside I still had huge chicken strips on the front so I am really only using half the tyre. My next tyre will be a 110 michelin radial which will suit the rim better

[FJmonkey]

The profile of a 120 on a 3.0 wheel is too pinched (reduced contact patch), a 120 should be on a 3.5 wheel. You should have a 110 on a 3.0 wheel. I cannot link the page but on the Avon site I chose a 110/70/17 and the recommended wheel width is 3.0/3.5. A 120/70/17 is 3.50/3.75. I think Dunlop has similar info posted.

Looks like stua posted first with some practical experience...

[~JM~]

3.5" wheel?!?!?

Wouldn't that lower the front end excessively? 

~JM~

[red]

Just information:

On a 120/80-16 tire,
120 is the "correct" rim width needed, in millimeters (4.75" here).
80 is the "aspect ratio" (profile height, as a percentage), and
16 is the rim diameter in inches.

3.5" would be ~89mm.
3" would be ~76mm.

Cheers,
Red

[rktmanfj]

Just information:

On a 120/80-16 tire,
120 is the "correct" rim width needed, in millimeters (4.75" here).
80 is the "aspect ratio" (profile height, as a percentage), and
16 is the rim diameter in inches.

3.5" would be ~89mm.
3" would be ~76mm.

Cheers,
Red

More information: http://faq.ninja250.org/wiki/Tires_101:_An_Introduction  Pay particular attention to the last paragraph.

http://www.mechanical-shop.com/frontend/files/userfiles/files/ISO_norm_velgen.pdf