Racing wheel sources

[sdcat]

I'm still waiting for my new car, but thinking about getting some rims for track tires in the mean time. I had 7x13 panasports with 4.25" backspacing on the previous caterham, with kumho V710 215/50 tires all around. This was a good, balanced setup for that car, but with the higher powered engine I would like to go wider in the back.

The R500 comes with 6x13 and 8x13 rims, which are not quite wide enough for the rubber I'd like to use. As far as I can tell, the tires are 175/55 and 205/55 CR500's.

I asked Caterham Cars about their 7x13 and 9x13 CSR rims, and they said the backspacing for the CSR is different because of the suspension setup, and that those rims will not work on the other cars. Too bad, because their prices aren't too bad, and the rims look nice. They also said that they don't recommend going wider than stock on the R500. But based on available tire options, I would like 7x13 and 9x13 rims.

I was just wondering what other wheel sources people have used for 13 inch rims, and what backspacings/offsets you've used. The other key issue is clearing the AP racing brakes in the front. I've researched it a bit on blatchat, but found variable recommendations, and wheel sources that weren't available in the U.S.

I suppose the wise thing to do would be to get the car, take some measurements, and then order rims made to fit. But I've got to do something while I wait!

Thanks,

Justin

[GWise]

Justin,

I've never used them but I've heard good things about kodiak raicng wheels. They use 6061t on the wheel shells which can be made thinner than 5052t which is commonly used. The weight on the outermost diameter of the wheels is the most important.

What size tires are you planning to run on the rear? You can go considerably wider than the 205/55 on an 8" wheel, the question is clearance with the fender. The nice thing about sevens is it is pretty easy to adjust the fender if the wheels don't fit.

You may also want to consider the weight of the tires you're using. I believe the CR500's are pretty light and again that's weight on the outside of the wheel.

[moosetestbestanden]

I'm a fan of the Barnby wheels that used to be supplied w/ Caterhams. Barnby is

here

Stokes uses them too, although he's cracked a couple (accidents in all cases but one). He has ordered from Barnby more than once so I know they will ship here. They're notoriously slow and can be unresponsive, which is probably one reason why CC stopped sourcing wheels from them.

They're super light. I have the CC 8 spokes as well and the difference in weight is huge. I keep the 8 spokes for street tires and use the Barnbys only for the track.

Jon actually went to a smaller tire in front and found the car better balanced. My own opinion is that a 9" rear is too much tire. 8s are plenty. Personally I've found that CC has done enough research and experimentation to know what size wheels and tires work best.

The German guy at Westermann sells (he won't ship product to US customers) Rials, in a variety of sizes. Look here. I got some CF from him by going there and buying direct. Hey, you said you needed something to do.:D

[JohnCh]

Another option is Image Wheels in the UK. They offer both cast (cheaper) and billet (lighter) centers in a number of designs. Their 13x7 billet center wheels reportedly weigh about 8.5lb ea, so similar to a Kodiak.

-John

[Rod]

Kodiak

I have a 15"and 13" set of Kodiak wheels. I like them and would recomend them.

[sdcat]

Thanks for all the suggestions! I'll check out some of those options.

You are probably right, Chris, that the stock sizes might be the best for balance in this car for road courses. There really aren't that many choices for DOT-R's in 13 inch sizes. I would like something wider in the rear than the front to keep the car balanced. I loved the Kumho's but they only come in the one size, and even with my last Caterham I was able to break the rears loose easily with 100 less HP.

After looking at different combinations I am considering the Hoosier A6's in 255/40 rear and 225/45 front. That's just slightly too big for the stock rims. The other option would be R6's in 225/50 and 205/60 which would fit on the stock rims, but I'm not sure the fronts would come up to temperature on a light car like ours. And I think the A6's would last plenty long. I put a lot of miles on the Kumho's and they hardly looked used at all.

My plan for the fenders is to get wider fronts from Carbon Mods for track days:

http://www.carbonmods.co.uk/Products/Track-Style-Carbon-Fibre-Cycle-Wings__CMCWTRACMD01.aspx

Thanks again for all the suggestions,

Justin

[sdcat]

BTW, do any of you have offset/backspacing numbers for the rims you have?

Thx

[moosetestbestanden]

and even with my last Caterham I was able to break the rears loose easily with 100 less HP.

It wasn't the throttle or the power or the tires. It was the foot. Read this

here

Then, watch the idea illustrated at the ultimate level

here.

I'll sniff around for the wheel data and get back.

[Doug Liedblad]

Justin

You can try my Kodiaks.

I don't know the offset but do know it should be a bit more than I have. With some tires I need to use a couple of 1/8" spacers to be sure they don't rub on the Watts linkage.

It doesn't seem to be an issue if you don't have the Watts linkage.

Doug

[sdcat]

Chris, I suggested this to my foot, but it insists that it's doing everything right, and given just the right tires I would be the fastest driver on the planet.

Doug, Thanks!! Do you recall what the offset is on your kodiaks?

On a side note - Which of the Caterhams have Watts linkages? Is it an option on any DeDion Caterham? My '98 Superlight didn't have it, and the R500 does.

Justin

[Roll a 7]

My SLR has the Watts linkage. Barnby wheels are incredibly light. Kodiak are very well made.

[Doug Liedblad]

Usually the DeDion equiped cars have the provision for the Watts link. M. Murhpy's car is a '99 and has it. I don't know if they have always had it or it was added later or when.

You just need to buy the optional parts. See the assembly guide and it will show you what is involved.

It's reported to reduce rear wheel steering. I think it improved things but then I payed good money to upgrade so would never admit otherwise.

My Kodiaks are about 10 lbs each. 20 lbs with an ACB10 mounted. I really notice the difference from my street wheels and tires.

Woody Harris spec'd and sourced my Kodiaks and I don't know the offset but can measure it.

On second thought - I recall that newer Caterhams have a sligtly longer DeDion tube which may mean the offset I have will work fine. We'll need to check.

[sdcat]

Thanks, guys. Brad, have you been autocrossing this year yet? I won't be there this month. I'd come watch except that I'm out of town.