Tyre Size

[Spikehaus]

I popped down to my local tyre centre today, but stumbled as i could not decide which size tyres to purchase.

I was looking at Toyo 195/50/R15 to replace the 195/60/R15 that is currently has. What is everyone else running for a good ride height?

[robo]

Spike is the toyo the tyre of choice for the roadster ? So much in the way of rubber out there its hard to know whats best.

Bob

[Spikehaus]

Spike is the toyo the tyre of choice for the roadster ? So much in the way of rubber out there its hard to know whats best.

Bob

Its mainly the size I was interested in to get a decent ride height

[alga]

I'm running 195/50R15 Toyos, and Sierra's speedo looks within limits (shows 70 km/h at 65 by GPS). The ride height is also fine, if I set the ride height to 11-12 cm everyone here recommends, the front lower wishbones are angled up a little bit (the wheel side is higher). Also note that with smaller tyres you get the gears shorter by several percent.

[alga]

Spike is the toyo the tyre of choice for the roadster ? So much in the way of rubber out there its hard to know whats best.

I think it's pretty well established that for track performance semi-slicks are best. Toyo Proxes R888, Advan A048, Avon has something similar, too. They have very soft rubber, meaty sidewalls, but are also driveable (carefully) in the wet. But they are noisy, bumpy, and wear fast. (Federal 595 RS-R are a good budget alternative if you can find it, I've heard).

[DRCorsa]

Just to add to alga's contribution, i would like to note the DMACK's DMT-RC tyre which is a "brother" of the brand's rally tyres but with DOT and E marking certifications.
It comes in 4 compounds and the available sizes are here: http://www.vitalequipment.co.uk/index.php?dispatch=products.view&product_id=29830
If budget allows it i will get a set when i finish my car.

http://www.vitalequipment.co.uk/images/detailed/0/29830_DMT-RC.jpg

[baz-r]

there is 195/55r15 inbetween thoes 2 sizes ;) and "track day" tyres are available in that size
no idea on tyres avialable or the price diffrence

[flyerncle]

To my way of thinking anything in a low profile usually gives a harsh ride given the fact that the sidewalls wont have a lot of give in them,its a trade of between handling and ride quality.

Change in profile height will also alter the rolling diameter,gear ratios and speedo reading.

[baz-r]

well no 13 or 14inch options with our rear suspension setup
a 195/55r15 works out exactly same cir as the 185/65r14 on my doner

195/60r15 will have 3.3% bigger and 195/50r15 3.3% smaller if your worried about speedo readings

[alga]

14 inch steelies fit, but only just.

http://locost.lt/pic/361

[alga]

there is 195/55r15 inbetween thoes 2 sizes ;) and "track day" tyres are available in that size
no idea on tyres avialable or the price diffrence

Yes, 195/55R15 is the Sierra standard rolling radius, but my impression is that 195/50R15 is by far a more popular size.

[baz-r]

14 inch steelies fit, but only just.

http://locost.lt/pic/361

you need to get a lock nut on there as well so its mega close and if you have a flat in the rim it will touch :mad:

as for ride hight i feel the need to point out that if you fit bigger/smaller rolling radius tyre/wheel combo's you want to ajust the ride hight figure the same amount just as if you put the std wheels on, set the hights then, changed the wheels over
i hope that makes sence