Shiny hardware for the three piece wheels

TL;DR stealth on a shelf

My Ultralite wheels were actually configured with another car in mind. More precisely, they were supposed to be chef's kiss👌 on a carbon fiber-clad Caterham 170R with a Nardo grey body. A real thing of beauty; a bit radical. The black perimeter bolts (20 per wheel) worked really well with that livery.

On Firecracker yellow with black stripes, I did intent on having silver assembly hardware. It's a bit more subdued on a car that is already attracting a lot of attention. That to say those black bolts are bit much on my 170S.

A good thing with split rims is that the fasteners can be replaced at will. A better thing yet is that the bolts aren't screwed in the wheels centers themselves, but rather on nuts behind the rim sections. Those allow for a visual inspection and can be re-torqued if needed. This is also way safer than threading straight in aluminium : failing threads can lead to wheels that split while driving or even explode when mounting tyres.

Anyway, while I'm sure I could get all the hardware I need from Image Wheels, the message I sent from their contact form got no answer. 😑 For once I refrained e-mailing management and opted to order from a company that was willing to take my money instead. Note that on the same day I did also send a message to Caterham to ask for a replacement thermostat, and I got no reply to that either.

That's how I ended up placing an order to SRR Hardware. They have a large choice of wheel assembly hardware kits in about any colour/finish.

With the wheels in storage for winter, I was able to remove a bolt and measure that I needed M6 x 32mm bolts with flat (non serrated) nuts. 

Those bolts have 12-sides heads that I've never seen anywhere else. Any regular 8mm spanner (combination or ringed) does the trick here. On the inside the flanged nut had a standard 10mm hex head.

Not willing to mess around or gamble with the thread pitch or any other nonsense, I also bought a set of 80 nuts. I paid 90€ including the 15€ shipping offset by a 13€ discount (15% for "Black Friday"). VAT and bPost brokerage feed did add 40€ on top.

As SRR Hardware sells thread locker fluid and the bolts I removed had some blue on them, I did put a drop on the new bolts too. Image Wheels maintenance page says "Perimeter bolts are factory-torqued to 12–14 ft/lb.". Between 16 and 19 Nm then. I aimed at the middle with 17.6Nm.

For removal, I got a 10mm socket on the 1/4" ratchet with a long extension, and a long 10mm socket with a short extension on the 1/4" torque wrench to fit the new ones. I ended removing five bolts at a time, or one in four. It took about 45 minutes per wheel.

Loosening the thread locker took quite some effort with only one hand free to operate the (short) ratchet with its extension and the other hand holding spanner for the bolt on the front side. Tightening felt easier despite the similar tooling. It was confirmed when I read the instructions for my thread locker later on : that it takes 33Nm to break it, or twice the torque I was applying on assembly. Old dried thread locker left a lot residue on the ground.

I did split the work over two evenings and got the 3/4" ratchet out the second time. The longer lever helped loosening the original nuts, that were then removed with a 10mm socket on a screwdriver handle. 

Having 3 nuts blocked by balancing weights, it also took about 45 minutes per wheel. The best solution has been to hold the nut with an open-ended spanner while rotating the 8mm bolt a bit at a time, with little space between the shiny surfaces of the rim and polished permiter of the wheel center. Forcing the 10mm wrench on the nuts led to deformation of some sides, I do not recommend it. As there was no way I could get the torque wrench on those, they were tightened to what felt adequate. I assume a 12 sided socket would have been a good solution here, I could have gotten one from SRR with the kit.

With the job finished, I was left with 5 extra bolts and 9 extra nuts, they sure allow for some little accidents. 

Regarding weight : the new nuts and bolts are 60 grams lighter than the ones that came on the wheels, you wouldn't guess there was 1.1kg of steel in there. 

I'm really pleased with the result : the new bolts do blend in better while adding some bling. They also make the wheel centers appear smaller, that's nice too.