Centerlock wheels

I recently installed a set of centerlocks on my SLC, and thought I'd share the details, as it a relatively rare option, and most SLC builders have probably never seen them in the wild.

As most people know, centerlocks are the choice in motorsport where they are allowed, and where pitstops are required. That's largely because it's so much faster to change wheels that have just one large nut, instead of 4 or 5 small ones. Most all of the IMSA GT and prototype class cars have them. The Le Mans P1 cars all have them, as on the current Audi, Porsche and Toyota prototypes, as do all Formula 1 cars, and most all other formula cars, for that matter. Of course, the Porsche 911 Cup cars have them, and they are an option for some of their other cars as well.

So there's a motorsports theme to them that is consistent with the Group C look that our cars have.

The setup from Superlite is, as you'd expect from them, lightweight, strong and well-engineered. The main adapter and nut are actually machined in house, from steel and aluminum billet, in order to meet quality and delivery requirements.

Even the wheels are machined in house. In fact, though the Superlite centerlock kit uses Forgestar wheels, Forgestar doesn't have or sell a centerlock wheel. Superlite gets un-machined wheel blanks from Forgestar, and does final machining on their Haas CNC machining centers (each of which is about the size of a minivan, for those who haven't been to the factory). Each wheel is bored to have the correct center hole, machined for the correct backspacing, and carefully machined for the pins in the adapter that actually transmit the torque. Any of the standard Forgestar wheels Superlite supplies can have this treatment- mine are the CF5s.

Here's a pic of the steel hub adapter, and the large aluminum nut:



The wheels, adapter and nut are surprisingly light. Detailing, including the threads, is typical superb Superlite quality, with the nuts in particular a thing of beauty.

Here's a picture of the adapter bolted to a hub:



The stainless steel pins are actually a kind of lug nut, serving to locate and lock the adapter to the hub, as well as fit precisely into the corresponding holes in the rear of the wheel. They are beveled on the adapter side, to fit matching bevels on the adapter. This serves to precisely locate the adapter on the hub to maintain concentricity.

Once mounted to the car, the adapter looks pretty motorsporty:



Once the adapter is mounted on the car, the wheel is easy to slip on the adapter. Aligning the wheel on the pins is easier than I thought it would be, and once aligned, the wheel just pushes on the adapter and allows the large aluminum nut to be installed and tightened.



The pins are tightened just like a regular wheel nut (the pins use a 5/8" socket), but the actual centerlock requires a 3" socket- and no, that isn't a misprint. The socket is massive, and so is the torque wrench required to tighten it to the 330 ft lbs it needs.

Once installed, the wheels are like any other wheel on the SLC- except faster to change (assuming you have the John Bunyan-size torque wrench and socket). And cooler.

Here are a couple of pictures of my car at the recent Carlisle Import and Performance Nationals last weekend, showing how the centerlock wheels look on a car:







I'm really happy with the look, and the quality of the individual pieces. The setup isn't inexpensive, but these are special cars. :)
 
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I have shared this on Facebook. At least 2 and 1/2 more people will now know about the Centerlocks! :)
 
Very nice. Would need a wheel retention system such as a locking pin or the like to be used for motorsports, I would say. I'm sure the SLC race car uses something different.
 
Looks good. I assume most any wheel blank could be used, that atleast had the hub depth for the pins in the design. I have entertained doing this myself.
 
They look great!

It looks like the new wheels fixed your rear back spacing problem as well.

Wow, 330ft/lbs for the center locks. You'll have to add a trailer hitch just to carry the 8 foot lever needed to tighten/loosen the center locks:shocked:

Could you share a PIC of the 3" socket and lever?
 

Scott

Lifetime Supporter
$3,295 if ordered with the kit
$4,295 if ordered separately

When ordered separately you get a new set of Forgestar wheels
 

Julian

Lifetime Supporter
They look great and that has to be the prettiest SLC I've seen yet. Do the center locks come aright hand thread for the left side and left hand thread for the right side to prevent coming undone? As mentioned you really should consider a safety pin, either drill and use an r-click or these;

T/A Wheel Nut Safety Pin

Julian
 
They look great!

It looks like the new wheels fixed your rear back spacing problem as well.

Wow, 330ft/lbs for the center locks. You'll have to add a trailer hitch just to carry the 8 foot lever needed to tighten/loosen the center locks:shocked:

Could you share a PIC of the 3" socket and lever?
I use a 5ft long torque wrench and breaker bar .... only another $1000 in tools to remove/install rims, lol



 
OP,
I run those on the gt40 with BRMs.
They are cool, but are a LOT easier to get off with a one-inch drive impact!! Once you drive the car a bit they are VERY tough to get off with a breaker bar. (lots of guys with cobras and 40s get tired of the seized 3-ear knock-offs) Use plenty of anti-seize on the threads..... S
 
I think Mike has hit on something here. Need to justify the cost with your significant other? Honey, just consider it an investment in physical fitness!
 
Question:
Pit crews obviously use some kind of air ratchet to take theirs on and off.
Are they calibrated somehow? No torque wrench to get it 'just right'.

Never seen a wheel fall off during a race, so whatever they do seems to work.
 
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