In South Wales, the bow tie loops used to work very well. I’m not sure how they would fare with carbon fibre frames (and ally for that matter). As you say, there is still steel even on carbon fibre bikes, but I wouldn’t know if that is enough for a loop to detect on highest sensitivity
Leaving to one side the discussion around the best type of detection for bicycles (best left for another discussion) and focusing only on loops
If specifying a detection loop for bicycles at a stop line, what shape and what orientation would you use and why. Particularly interested in views on Bow-Tie shape loops.
Also can anyone confirm success with detecting high end bicycles (carbon fibre frame and wheels) with loops. I’d imagine the only bit with a hope of being detected is the cranks/chain/pedals/gears and that a conventional loop doesn’t stand a chance, and there seems to be more and more of that type of bicycle on the roads.