THSCC Forums

Could you measure the treadwidth of a mounted tire?

Decided I will be doing 15x7.5in Rotas this year - only question is whether to go with the Bridgestones, or take a gamble on the new Toyo R1R's in 225/45-15.

Thanks!

PS - if I do go with Toyos, I'll trade the chance to try them out for a little coaching at the first test and tune or events.

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

Kendt,

Tire Rack says that the maximum wheel width for the 195 is 7 inches. Not sure how they would work on the 7.5"


Tire Rack Linky

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Todd Breakey
STS 42 - 1992 Sunburst Miata
Dammit!
"You souldn't play leap frog with a porcupine. You might get hurt." - Eliza

Im sure a majority of the grid in Topeka were on 195's with 7.5" rims

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02 Focus SVT
STF 9

I personally wouldn't take a "gamble" on the Toyos. They have never produced a "leading" tire (at least not that I can remember) and there isn't much reason to think they would do so now. I'd love to be wrong and have another great option out there but I have a feeling it isn't going to work out that way.

Seriously, you need to quit worrying about a few mm's and either make a choice now or let some others find out if the new Toyo (among others) is worth running.

As Ryan said, the majority of the grid in Topeka was on 7.5" rims and nobody had an issue with them. I'm almost positive my car was the only one in the top 10 on 7" rims but there are a lot of deficiencies with my car compared to the top cars-- no surprise there.

Kendt, I really believe you are over-analyzing the situation a bit. I can measure my mounted 'Stones when I get home if it will really help with your decision but I tend to think it is a data point of relatively little value.

Jim

Thanks Jim - decision made.

I was always keeping your advice in the back of my head - if the potential performance of the 225 Toyos is higher, but I can't drive to more than 75% of the tires' performance, while the 'stones let me get 90% of their potential because they are easier to drive, then I'm ahead anyway.

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

Sure. I'll be curious to see how your car performs with the slightly better gearing. When I drove it last month, that was really the only thing that stood out to me. Your car has enough length in 2nd gear to make a Z06 driver blush.

I finally went and looked at the results from that event and your car was quite competitive overall even on the clapped-out Azenis. Considering the HP-intensive nature of that course (it was much worse than our last Sanford event in that regard, IMHO) and the fact your car was pulling out of some of those slow turns at nearly idle in 2nd gear, it did really well. If it wasn't for a few 'Vettes and 1 Elise on Hoosiers, your car could have taken FTD. Not bad for an overweight STS car!

Jim

Great - no pressure for me to run well this year

Sorry I never got back to you with a video - the camera only caught your first run. I'll get it to you at the meeting if you want.

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

Think of it as motivation!



No problem. With only the first run captured, I wouldn't worry about it. I'm sorry it didn't capture more for you. I shouldn't have started it so early but I didn't know they were going to take forever and a day to get us organized in grid.

On the bright side, there is no evidence of me rifling through your glovebox looking for a tool to adjust your shocks. On an even brighter side, there is also no evidence of me rifling through your wallet looking for gas money to get home.

Jim

FWIW, there will be at least one new Toyo-shod car running at the upcoming Dixie Tour next month. I'm not sure how useful that data point will be but it is a start. At the very least, it means that the tires are definitely in the country and some people already have them.

Jim

Ah, but there is now solid evidence of you driving a FORD !

Give me back the money and I won't post links of it everywhere

I've changed my mind yet again (surprise!) - 15x7.5in Rotas require a 5mm spacer, and change the offset to 40mm - I don't think I'd be comfortable with that without longer wheel studs. I'll also be too low to drive on the street or track.

I'm going to go with Enkei OR52's in 16x7 with a 42mm offset, and 205/45-16 Bridgestones. I can run these on the track, drive to the closer AX's, etc. If I really think I need crazy-light AX wheels I can always get them down the road.

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

Those 16" Bridgestones are barely taller than the 15" if you're concerned about scraping stuff with the bottom of the car FWIW. I haven't looked at the published stats but I've seen the tires side by side and there isn't much difference. You might have to go with the taller 16" but that would kill obviously your gearing gain from the shorter tire(s).

Jim

Ah - thanks alot for that info. Might as well go the smallest/cheapest/lightest route then. 195s are $50 less per tire, and the Rotas are 11-12lbs I think.

_________________
One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!