tommyg

Just saw these on CL if anyone is interested:
http://tampa.craigslist.org/pnl/pts/2685103799.html

ca993twin

275x35x18 tires on 18x11" wheels? Really?

BLT4SPD

Yeah, I thought the same thing, but it's also a narrow body, so they almost have to be 10s and not 11s.

nile13

Steve, why would this be an issue? 275mm is about 11". If we are assuming that the mounting thread is about the same as tire width, that's a perfect wheel for that size tire.

ca993twin

I have 315x25x19 on my 19x11" wheels, and THAT is a perfect fit. 275 is a bit too narrow for a 10" wheel, but workable. I have 255x30x19 on the front which is also a great fit.

nile13

Steve, I still don't see why 275 would be a problem unless Sumitomo has exceptionally narrow mounting width. So I'd like to understand what a perfect fit would be.

Take a look here: http://www.hoosiertire.com/rrtire.htm at R6 tires. 275/18 has a section width of 10.9 and recommended rim width of 9-11". These are Hoosiers, but the rule of thumb of 2"max difference between tire width and rim width is generally universal. If it's good for a racing tire it's good enough for me on teh street. BTW, I run these Hoosiers in 255 on 8.5" rims on my appliance.

I'd worry more about putting a fatter tire on a narrow rim.

Falcondrivr

****in'A those are local....Damn you tommyg

ca993twin

Mike,

I'm far from the expert, but if you look at some of the specs in tire rack for 275 width tires... yes the tire can be stretched to fit on an 11" rim. But if you look at the rim width for the size they actually use for the measurements, its is 9" or in some cases 9.5". That would be the optimum width. For my 315s, its is an 11" wheel. Tires specs DO vary by manufacturer.

dave morris

Be sure to check the weight of those bricks before you go too far.

max911

I'll bet a dollar that those wheels are 8.5 inch and 10 inches wide.

nile13

Steve, I agree with you on the variances. My experience is mostly with what's run at autocorss and considered the optimal for both race tires (essentially Hoosier A6 and Kumho V710) and street tire classes (more applicable here, the most common tires today are Dunlop Direzza, Hankook R-S3, Toyo R1R, Yoko A08).

For street tires, especially 'Kooks, the modern thinking is at least 9" wheel for 225 tire, for example. They almost don't start working until 9" rim is used and I've experience that first hand. And even though 9" wheel is much more expensive and, more importantly, heavier, fast people run them instead of common 15x7 wheels just to get the tire to behave.

I personally will be putting 225 and 255 R1Rs on my 8" and 10" 993 wheels next year more than likely. I also currently have 265 and 285 rears on two separate sets of 10" rear wheels on my 993, so there's some base of comparison.

Specific to Sumitomo HTR ZIII: http://www.sumitomotire.com/assets/p...e/htrz3_sm.pdf Sumitomo seems to be a bit confused showing that thread width on these is only 10" while mounting width is 10.7". It's probably the other way around. Otherwise, why the hell call them 275, that's a bit of cheating. They also say that 9" - 11" rim range is OK while the "designed rim" for this size tire is 9.5". I'll buy that and it corroborates both our views

In short, I believe that having mounting width and wheel width about the same works very well in both autocross and street applications. Sorry for the long "analysis", but this topic comes up pretty often.

PS. I don't believe for a second that these are 9 and 11 wheels. As Max above said, I'll also put my $1 on them being 8 and 10.

Arena993

Not that it amounts to a hill of beans, but the seller of the wheels is the guy that bought my Rivi Blue Cab when I sold it a year or so ago. He is a Rennlist member that has never posted, or only posted a few times. I had two transactiuons with him and he was a straight shooter, very honest and extremely accomodating. A real good Joe. PM me if you want his contact info

Mike

Spidey 993

I tried to contact him by replying to the CL ad. I said I was ready to buy assuming he is willing to ship to CO.

Falcondrivr

I'm happy to go get them and ship them to you if that's his hangup.

Arena993

I've dealt with him twice. He's a stand up guy. I will be happy to call him for you. Shoot me a PM if you need any help

Mike