Wheels

[sam.gibbs]

Hello,
Can anyone give me some guidance into the perfect size of wheel for a FSAE car. We currently use 13" formula ford wheels which weigh in at nearly 8kg per wheel, what would be advantages/disadvantages of using smaller or larger wheels? Any help would be apprieciated. Cheers, Sam.

[racingstuff]

Our Formula Ford, 13"X5.5" wheels, weigh in the 7.5 - 8 Lb. range, here in the US. At 8Kg, you have a weight disadvantage for sure. But, because the FSAE car is a unique size/weight, in the motorsport market, and with the tire/compound choices available, it is probably your best choice. Wider tires take longer to heat up, are more camber sensitive, smaller wheels allow less brake rotor diameter to be used.
Keith

[syoung]

Warwick's wheels are 10", as are those of many teams running single-cylinder engines and a few other four-cylinder teams. It can create some major packaging headaches and some compromise, but of course the wheels have that much less moment of inertia.

Do a search on this forum and you'll find pages of argument on 10" vs. 13". I have a strong feeling the "perfect" wheel size for many of the design directions taken by many of the FSAE teams would be somewhere between 10" and 13", but nobody seems to make soft racing tyres for anything in between. You've got to make an either/or choice and stick with it really.

[sam.gibbs]

Cheers guys,
I did a search of the forums and found some useful information. I'm new to fsae but felt that at 8kg per wheel we were at a bit of a weight disadvantage, especially in unsprung weight. I think due to wheel packaging issues we'll have to stick to 13" but can anyone tell me what a reasonable weight per wheel without tyre would be that we could buy? and where could we source them from in the UK? Cheers,
Sam.

[rjwoods77]

average 5-7 lbs for good rims including centers.

[jonno]

Sam,

Brunel Racing's BR5 (2004) wheels were purchased from Jedi and were quite (very) expensive £1000 for 4 rims. They were 3.96kg each. For BR-6 and FS 2005 we're dropping down to 10's from Keizer (http://www.keizerwheels.com). we had to import these from the states but after shipping and tax 8 rims set us back a bit over £600. They weigh 2.14kg each and have the pcd and offset we stipulated

[Andycostin]

We design our wheels as we need, at the moment they're 13" with 4 stud three piece wheels. Centres are cast Magnesium and inner and outer are spun aluminium.

[ozzy]

Andycostin:

How much do they weigh?

[Andycostin]

Roughly 7kg with a tyre on, not sure without, as we're setup for testing at the moment.
Hope that helps