If he is currently running a Force/Red 8bolt which would be DUB, he will need a new bottom bracket. Rotor doesn’t offer DUB spindles. Not a huge deal, but is a factor at play.
Rotor offers 24 mm Shimano spindles and 30 mm spindles. I thought when you remove the spacer with the DUB BB, the 30 mm axle will fit. I haven’t tried it myself, though.
In the “worst” case, as you wrote, you can get a Rotor BB.
Quality products for sure. I have one of their cassettes which is a few grams lighter than the SRAM equivalent.
Cost estimate:
$475-$675 Rotor Kapic R34 Carbon Crank, 30mm spindle, BB spacers
$78-$91 Rotor 26T ring
$56-68 Rotor BSA30 BB
Total: $611-$844 + shipping + possibly an import tariff, or not.
I think the Kapic MTB option will have too many cons.
Q factor: Red/145 vs Kapic/152
Chainline: Red/45mm vs Kapic/52mm
No weights on Rotor’s site but R2-bikes lists Kapic arms at 358g plus 30mm spindle at 133g.
Red E1 with spindle is <309 for 165mm crankset.
180g+ is too much to ignore especially for a hill climb build.
I’m looking for simple and quick to switch out and as light as possible.
I’m getting a local quote for a custom CNC ring from someone who does custom motorcycle and auto parts. He was very interested and confident it would work.
I was surprised I couldn’t locate a ready-made solution considering how popular hill climbs are in the UK alone. Maybe it’s too small a market overall.