Parts Spotlight: STM Powersports Miata Hubs


New hubs for Spec Miata and other Miata race cars add life and are rebuildable

STM-HubsPart No.: 0000-04-5HUB-ST
Racer Price: $379.00

The front hubs on a Spec Miata take a beating. SM racers know that the hubs need close monitoring and frequent replacement, and that even the heavy-duty hubs will sometimes only last 10 races. And when a hub fails, the consequences can be severe – a lost wheel that at best results in undercarriage and suspension damage, or a meeting with the wall at worst.
STM Powersports, owned by Spec Miata racer Mark Beyer, has come up with a U.S.-built solution that is sold through Mazda Motorsports and is approved by the SCCA Club Racing Board and NASA for Spec Miata, and can also be used in other classes (as allowed by the rules) where NA and NB Miatas compete.
STM-hubs-assembly“We utilize a tapered roller bearing on the hub,” explains Beyer. “The roller bearing has a lot more contact surface than the ball bearings used [on the OEM hub].”
The alternate hubs were tested last year, and held up well. “The hubs have undergone testing at multiple events, on different cars, with different drivers and multiple locations and tracks throughout the U.S. over the last year,” says Sean Hedrick, who is not only the owner of, but is also a member of SCCA’s Spec Miata Advisory Committee and was involved in the testing process of these alternate hubs. “The final test was the 25 Hours [of Thunderhill] in December. Each set of hubs on the 25 hour cars had over 30 hours each on them prior to taking them off of the cars and sending them back to the manufacturer for visual and microscopic inspection.”
The hubs, Hedrick says, held up fine.
Offering greater durability and longevity over stock hubs are only two reasons to upgrade; another reason is these can be rebuilt. “You can take them apart and put new bearings in them,” Beyer says. “They’re [also] the same offset, same everything as stock.”
Despite the advantages, there is still plenty for Spec Miata racers to consider before placing an order. “The hub is heavier than an OEM one by a little over one pound, and does have more bearing contact, so one could argue that it is a performance disadvantage due to the additional drag,” Hedrick explains.
Regardless, Hedrick agrees these alternate hubs are a solid option all SM racers should consider. “This hub was made as an alternative to the OEM hub for those who don't feel the lifespan on new OEM hubs is good enough or long enough,” Hedrick concludes. “It is a very, very nice piece for those who don't want to run the OEM hub.”