Competition Tyre's and Steel Rims?

bowie

Member
1000+ Posts
Evening Brains Trust.

Have just been reading some regs from the VIC Alfa club, they are running a 12h regularity in October at Winton and I reckon this might be the one to take the POS-12.

The 12h regs refer back to the AROCA Sprint regs in regards to vehicle stuff, and along with "metal valve caps" that must be fitted, they prohibit "R" type competition tyres with steel rims.

Ke?

Whats the issue / history of accidents with steel rims being used with slick and other competition rubber?
 

Bustamif

Member
There is no specific data comparing the history of failures using various compounds of soft and hard slicks, sticky road tyres, hard road tyres alloy wheels, composite 3 piece and steel wheels. You will find it is a rule made by a committee of experts. It is likely based on the experience of the club at the particular event.

It was not until I did a compliance project for CAMS (Motorsport Australia) that they began to apply risk management methodology to the decision making processes on safety issues. That process has now been applied to the racing harness expiry date extensions and medical assessment processes for competition licences.

The only failures I have had were an alloy wheel at Amaroo, front left at Mazda corner end for ended the car at 170kph and a right rear BBS mag at Sandown coming onto the back straight in 2nd gear. I have seen centres pull out of steel wheels at Bathurst back in the 1970's.
 

bowie

Member
1000+ Posts
Ah I see. Yes the first I've seen a direction like that.

Well I look forward to asking someone in the club what happened to so and so's beloved Alfa.

There is a lot to be said for first hand experience, but I'm certinally glad there are some frameworks in place, in some organisations, to guide the decision making process.
 

PeterT

Member
1000+ Posts
Bizzare. I ran R spec tyres on steel rims for many years at CSCA Supersprints. First I've heard of it.
 
Steel rims tend to flex more than aluminium alloy so more potential for metal fatigue & R-spec tyres would increase the amplitude of that flexion. That said, I would think that much depends on the particular wheels & their history. Such blanket rules are simply reflecting probabilities & are "a good thing" I think.
 
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