Nasty Truvativ Omniums issue

Bit of a bummer for you as this is a known issue with those cranks. In their quest for stiffness they have beefed up the spider by a few mm thicker and on frames with thicker stays they strike.

Cheers Zouo, I didn't realise it had been encountered previously. At least it's not the frame ;) So, thick chainstays and Omnium cranks are a bad idea. Noted!

Luckily I have a fallback plan for the cranks.