Tires (Size and Compound)

[Kink]

Hello All,

 

Yes, another, what tire should I use. However, I'm not 100% clueless, I just need some opinions to help make my decision.

 

I currently have a lightweight set of three piece 13x10 wheels front and rear that I have 20x9 Hoosier 25b compounds mounted for autocross use. I also have a 15x7/15x8 setup with 195/225 R1Rs used mainly for street but did track days with them as well. All of this is on a 2016 Birkin XS build with a built Duratec 2.0.

 

I'm moving more toward track work with the Birkin and plan on at least 5 multiple day NASA track weekends this summer. I'm competitive with everything I do and would prefer if I buy another set of wheels that it be a set that can progress with me into Time Trial and maybe SCCA wheel to wheel.

 

Now to the question. I'm wondering if I should run smaller width Hoosiers on my 13x10s all summer(will they hold up?), say maybe 22x9 and 22.5x9 25b (Those of you who know the Bias Plys know that the 20x9 I'm currently running is really 10" wide, and the diameter is too small for track work).

 

Or, buy a set of 15x8 wheels and run R888 225/45s.

 

I'm leaning toward the R888s but I hate buying another set of wheels (Had 3 sets of wheels for my S2000).

 

It all comes down to preference and budget but for you track guys who have tested more than I have, what say you.

 

Thanks all,

Brad

[yellowss7]

Hi Brad, I autoxed on the 20x9 hoosiers at all for corners and used them on track for a year. You are correct, they are too short and hurt the top end and shift points in all gears on track. IMO

 

I ran the 22.5 x 9 inch ones in the 25B compound and love them. They stick like glue and wear fine. I could fit them in on my yellow car with the Clams but on the Orange car, with cycle wings they won't fit unless I run without the front wings or have new wingstays fabbed up that give more room. I miss them badly. :svengo:

 

The R888's are fine and wear like iron. but compared to the Hoosiers they are like wagon wheels. I'm running Michelin Radials now and they come up short of the Hoosiers by a mile, but do wear a lot longer Tom

[Kink]

Thanks Tom, I appreciate your feedback. I have some adapters for the cycle wings that allow wider tires to clear so I'm good there. Why the switch to the Michelin Radials if the Hoosiers are so missed? Wear and budget? I know nothing of the Michelin Radials, should I consider them on my 13" wheels?

 

Sounds like I should stick with my 13x10 wheels and sacrifice autocross gearing, which I'm 100% ok with.

[yellowss7]

I bought the Orange caterham 2 years ago and it came with several sets of used Michelins which at that time were a Euro only spec. I ran through those sets and last year I found that they were now being imported into the US so I bought a new set. After running the old hard used ones for two years, the new ones were better but not as good as the Hoosiers iMO. I'm working on having the car set up with new rear spring rates and having it recornerweighted and all the other suspension settings reset.

 

I'll see how it feels and then if not to my liking, I'll take the wingstays off and try it on the hoosiers. I'd be interested in knowing how your wingstay spacing works. Any photos?

 

The Michelins are also a lot pricier than the Hoosiers, around $400 a tire. :ack::ack::ack:

Edited February 15, 2017 by yellowss7

[Kink]

http://www.usa7s.net/vb/attachment.php?attachmentid=12243&stc=1

 

It raises the cycle fender just enough. I'm not sure if the Caterham wing stays are similar to the Birkin and if this photo helps you visualize anything. It's an old photo before I installed them.

[Roger Rabbit]

I have the same problem trying to raise the front wing fenders a bit more ( say 2cm ) on my Birkin S3. Any idea where to get this ?

 

 

Sent from my iPad using Tapatalk