Front Brake caliper Titanium bolts.
BrilliantB8
New Member
Pro Bolt USA. Have them on mine and love them. Amazing quality and saves some weight
Hi Brilliant, are you sure about that ? M8 x 70mm Pitch 1.0 is not something that PROBOLT carry. Can you send me the link of what you have please ?
stevieboy
Member
Your wallet will lose more weight than the bike!
BrilliantB8
New Member
Just from the RC390 section on the Pro Bolt USA website. Direct replacement for the OEM bolts. I also have the 320mm rotor but why does that matter?
BrilliantB8
New Member
This is my bad, lol. I just re-read the post and realized you are talking about the caliper bolts. For some reason I first read it as rotor bolts....
That is correct, I haven't been able to find them for the caliper unfortunately. Just drilled and safety wired the ones that came with the 320mm rotor kit.
That is correct, I haven't been able to find them for the caliper unfortunately. Just drilled and safety wired the ones that came with the 320mm rotor kit.
Just to remind folks, before starting Formula390, I was a Machine Shop. I can honestly say I HATE threading titanium, but I can knock out that part, or whatever else you may need machining for. 
OK, so just to update everyone. I've had two folks express interest in this (Leandro and Maddog Reynolds) and have an estimate put together for making the custom bolts. The basic costs are materials (plus material shipping) for some 1/2" titanium round bar stock billet. It's easier and cheaper to make the bolts from round stock than machining an existing bolt and having paid someone to have previously machined said bolt to then be turned into a different bolt. There is some tooling cost, as cutting threads on titanium requires some special geometry and needs a specialty cutter. Plus the labor to actually make said bolts, which is estimated that it will take me about 23 minutes per bolt to face, turn down, thread, cutoff, mount in a 5C collet, make the head, and drill for safety wire.
So what's the cost... well, it breaks down to a cost of ~$63.91 per bolt. The labor is the kicker. If more members are interested, costs will go down, as the shippin cost of the material and tooling costs could then be distributed across the whole run. So it might be less. This would be for a custom M8 x 70mm x 1.0 bolt, which will be drilled for safety wire.
If anyone else is interested, speak up, and we can get a group buy organized so I only have to do one production run.
So what's the cost... well, it breaks down to a cost of ~$63.91 per bolt. The labor is the kicker. If more members are interested, costs will go down, as the shippin cost of the material and tooling costs could then be distributed across the whole run. So it might be less. This would be for a custom M8 x 70mm x 1.0 bolt, which will be drilled for safety wire.
If anyone else is interested, speak up, and we can get a group buy organized so I only have to do one production run.
Maddog Reynolds
New Member
If this is the real design (without a flanged head) then we should allow a wee bit extra length for a flat washer
If this is the real design (without a flanged head) then we should allow a wee bit extra length for a flat washer
To make them with the flange would have required going up to 3/4" stock. Titanium AIN'T cheap, and that's a lot of material that would have just been turned into chips, so I made a cost vs EXACT replica call. Figured a stainless washer under would have been acceptable if it meant 2/3 the material cost. I'm planning on using .500 grade 5 6Al-4V material.
Maddog Reynolds
New Member
That makes perfect sense. No need for waste. If I get the chance I'll check how many threads engagement we'd have with 70mm. Chances are a flat washer will leave plenty of thread engaged.
