Bridgestone RE71R wear

[NickST]

Would you consider a 225 on a 7" wide rim as stuffed 

I wonder if 225 ZII's would be gripper than 205 RE71R's

[Reijo]

Would you consider a 225 on a 7" wide rim as stuffed 

I wonder if 225 ZII's would be gripper than 205 RE71R's

Not at all. Earluy S2k's have a 6.5" wheel that I run 225's on....not stretched at all. Wider is better!

[PedalFaster]

Would you consider a 225 on a 7" wide rim as stuffed 

Not at all. Earluy S2k's have a 6.5" wheel that I run 225's on....not stretched at all. Wider is better!

A 225 would work on a 7" rim (that's what I'm running on the front end of my car), but I would consider it slightly "stuffed".

I wouldn't say wider is better either. Two years ago I tested both 245 and 275 Rivals on the 8" front wheels of my then car, a BMW M3. Much to my surprise, there was no discernible difference in either feel or times. Another M3 driver, thinking I was crazy, repeated the same experiment on his car with the same result.

Last year I tested both 255s and 275 RE-71Rs on the 8.5" front wheels of my Corvette, and again the results were inconclusive. Many other national-level drivers did the same test on their Corvettes -- some found the 275s to be faster, some found no difference, and one found the 255s to be much faster.

This year I tested 225s and 195s on the 7" rear wheels of my Mini, and was flabbergasted to again notice no discernible difference.

This is all a long-winded way of saying that I don't think you're going to notice a significant balance change from putting 225s on your rear wheels. Putting that much tire on a 7" wheel is definitely into the range of diminishing returns, and potentially in the zone of no benefit at all. (I'm going to test 205s on the front end of my car next.)

I wonder if 225 ZII's would be gripper than 205 RE71R's

No. Rubber compound trumps width.

[Reijo]

That is really interesting Stephen.  Thinking back on it after your comments, it just occurred to me that we "are" talking about street tires rather than Hoosiers which /can be a different story.

Great input!   

Thanks!

Reijo

[Mkelder]

I think as you go bigger in width you have to look into suspension setup and camber curves. If at full compression you only have enough ability have the outside 2/3 of the tire in contact with the surface then your added width only applies to that one side of tire so your adding only half the width. 

As Stephan noted, tire compound matters the most. My 265mm re71r's are quite square on my 9.5 rims, even slightly stretched. I could have fit at least 285mm on that rim but had to pick the sizes available for the bridgestone. I was hoping this year's availability would be better but it was rather skimp. Perhaps next years run will have more tires out their door.

[NickST]

Very eye opening insight, thanks guys!   

[Terry Johns]

I moved from 205 to 215 in terms of grip I noticed no difference in gearing I did

[Reijo]

Some/thing that has not been mentioned much here is heat cycling of the RE71's.  I experienced this first hand at the Tour this past weekend.  During practice on Friday the tires/car were behaving good ... balanced handling ...fully prepared STR S2000 (Penske shocks even).  Saturday morning the car pushed ... and I went wide on corners.  Sunday, it became worse by the run despite our best efforts ... including softening the front sway bar, softened the rebound and compression on the front shocks and even stiffened the rear shocks once we ran out of adjustment at the front!  None of it availed at all.  The car pushed worse EVERY run ... very frustrating.  Lewis from Vancouver also confirmed that they cycled out for him/them at about 150 runs.  In this case it was just the front tires ... and the backs seemed to hang in there .... could not get on the gas until lined up straight at the end ... It was bad.  Now I don't know if the fronts had suffered some abuse in the past via overdriving etc.?  They were just about down to the thread bars incidentally.  Have to look into this some more ...

And, of course our times sucked big time.  On Friday I took a few runs within a couple tenths of Kevin Dietz on the practice course but when the tires went off we were completely out of the game ... sucked.

[PedalFaster]

Does anybody have experience with the Falken Azenis RT615K's?

I am also tempted to buy 2 Dunlop Direzza Star Spec ZII's in 225/45R16.

Saw a relevant post by a Tire Rack guy on another forum that was relevant:

Tires included in this test are: RE71R, slightly updated RT-615, Nexen and ZII Star Spec.

My personal results from today's TR test on the stock BMW 3-series:

Falken - 29.48 clean
Nexen - 29.37 +1, cone brush at the slalom exit. Excellent braking grip, steering response is a bit behind the RE71R and ZII SS.
RE71R - 28.84 clean (ran a 28.86 last year, Woot!)
Z2 Star - 29.23 clean

As you can see, there's a huge difference between the RE-71R and the earlier tire generations.

[NickST]

Yeah it is hard to ignore that kind of a difference

Thanks for posting that up!