USAC Racing Forum

Hey all,

any one out there experimented with different rear axles? Titanium, hollow aluminum, carbon fiber vs. regular aluminum? What are your thoughts on them?

Hi Lyra,

I am surprise that no one has commented on your post. Here are some facts about the various axles you mentioned. Maybe this will help get the conversation started.

Just about anyone in racing believes that eliminating rotating mass and unsprung weight is beneficial. With that in mind, if you have a solid aluminum axle in your car that weighs between 4.5 and 5 pounds, you stand to benefit by replacing it with one of the other axles you mentioned. The debate is probably whether or not the cost of replacing the axle is worth the potential benefit.

Titanium: Titanium axles are normally 2.5 - 2.9 pounds. They retail for about $950. Titanium axles are strong. It is possible to bend one, but it takes quite a shot to do so.

Hollow Aluminum: Weigh approximately 2.5 pounds. We sell them with snap ring grooves for $59.99. They are surprisingly strong. We had them in multiple cars last year and didn't bend a single one. Of course, they are the most likely to bend out of all the axles you mentioned.

Standard Aluminum: These usually weigh between 4.5 and 5 pounds depending on the manufacturer. Our retail is $65.

Carbon Fiber: Carbon fiber axles are the lightest axles available. They weigh about 1.5 pounds, and they are very strong. They cost about $850. I know of a few used axles that would probably sell for half that. I have a new axle with a cosmetic blemish that I'd make someone a good deal on.

David

Thanks David. Great info.

I was interested in Carbon Fiber, but we also race QMA. Do you know why these axles aren't allowed there? I wonder if they'll revisit that ruling...

Also, on the used ones, any particular reason why they're selling those?

Lyra,

I honestly can't say why QMA made the decision they did about carbon fiber. I heard it was over safety concerns, but any claim that they are unsafe is unfounded in my opinion. Carbon fiber is used in much more abusive applications than quarter midget racing. Hopefully, they will revisit it at some point. It will take someone willing to submit an RCP in order to get it re-evaluated.

I know of 3 used axles. Two of them were purchased when carbon fiber axles were first introduced at the Columbus indoors a few years ago. When QMA made them illegal the family took them out of their cars. They were done with QM racing by the time USAC started .25.

The third was purchased by a guy that was going to run only USAC. He decided to run both USAC and QMA and didn't want to change the axle to go from one to the other all the time.

The rotating weight of the axle is so close to the center that it makes little difference except in the lowest horsepower, restricted, classes. I would spend money lightening everything else on the assembly first and worry about the axle last. We ran the solid aluminum axles and did not replace one for 3 years in Hvy. AA and WF. Previous to that we only replaced 1 due to damage.