How much of a speed improvment on new tire?

[islandbayy]

Hey all, quick q, how much of a speed improvment will I see if I go from a near bald back tire, to a brand spankin new one?

My back tire is in good condition, no dry rot or anything, it's the orignal also, but the tread is just gettign near nothing in the dead center. Front tire has all it's tread nearly, but is starting to form some dry rot.

[slowaero]

I'd be more concerned about its age and whether I'd fall at 30MPH when it lets go or gets fishy on a turn. Does it have cracks and is over 5 years old? Tires are also about 70% of your suspension system - so most of the improvement will be to handling. Bald in the middle also means an edge so the scooter tire is unstable as you turn and lean over as it goes across the squaring edge. Gives rear end a squirelly feel for a second as it goes over its edge on turns.

I'm replacing what must be 10+ year old tires on an Aero. Tread is actually good depth since its low milers but the sides have cracks as deep as the tread. I'd quess you'll get .15 inch ( 5/32) of new tread if you stay the same size. That is about 2 % increase in diameter and theoritical speed. Most of the speed will come only if you oversize the new tire.

Here's diameters of spree, aero, elite 50 tires.
size diameter width rim load rating
2.50 TT 15.3 inch 1.5 inch 209
2.75 TT 15.6 2.8 inch 1.5 -1.75 209
80/90 TL 15.6 Vino tires 3.1 2.15 353
90/90 TL 16.2 3.3 2.15 419
3.0 TT 16.2 Metropolitan 3.3 2.15 331

On mine I am ordering at least 80/90 to increase the load rating and vino tires are usually the cheapest. The 80/90 and 90/90 are tubeless design but its ok to use tubeless tires with tubes on a tube rim.

My Aero has a 1.5 rim and I'm sure Sprees do too.

[islandbayy]

Thanks, the front tire does have cracks in it, but the back tire is like brand new. Reason they lasted this long with so many miles is that I treet them to a spray of silicone tire protectent once/week during the summer, and heavy coat before putting away for the winter.



Now, if I oversize the tire, will I need a new rim? My rims are mint, have a we bit of spray pain on em, as I oncee (Long long time ago) spray painted my tires yello, then red, then black again. I have since scrubed it all off the tires, but a but on the rim

Thanks again

[noiseguy]

Good info.

The widest tire you can fit on the rim is probably the largest you can run without hitting the forks/engine case. So keep your stock rims, and hit them with some paint instead.

On Spree, 2.75 reportedly fits, while 2.5 is stock. Not sure on the Elites.