Tyres, 100/90-10, 100/80-10?

[Treeman]

Hi,

I usually use S1 tyres, 100/90-10 but would like to try Michelin City Grip. I can’t seem to find them in 100/90-10 but can in 100/80-10. Therefore me question is will 100/80-10 be good on a Lambretta with normal and wide rims?

Thanks in advance,

Treeman

[Shaunbond]

The 80 Tyre has a smaller height than the 90 therefore it would reduce your gearing. I. E. 100/90 = 100mm wide and height 90% of width which is 90mm. Same principal 80% is 80mm height.

[Treeman]

Thanks for that Shaunbond, as I don’t understand what lowering the gear would do, what effect would it have on the performance of the scooter?

[Shaunbond]

Don't know to what degree but it would increase your revs. Higher cruising revs but maybe a bit better on acceleration.

[Treeman]

Thanks again Shaunbond. So how does a 100/90-10 compare to a 3.50 -10? Are they similar so they don’t effect over revving at higher speeds etc? I did some research and found something that suggests that the change of 100/90-10 to 100/80-10 maybe around 3%? I used to use back in the day 400-10, would that have increased the gearing so it would rev lower at higher speeds?

[mick1]

Don't worry too much about your gearing. I bought a 100/80 to try and haven't yet fitted it........it looks too small compared to the 100/90. I live in York if you want to see it and make a decision.

[Shaunbond]

Treeman - 100/90 is about 10mm Wider than a 3.50 but the same height. 90/90x10 is as near to a 3.50x10 in metric sizes.

Take Mick1 up on his offer so you can see.

[Timbo]

I would stick with the size you want, plenty of choice here..

https://www.lambrettaspares.com/search/Tyres.html

[Chris in Margate]

Fitted my City Grips last month. Nice tyres and they feel better than my previous S1's.

[mick1]

Fitted my City Grips last month. Nice tyres and they feel better than my previous S1's.

are they 100/80's ?