I have a pair of these - fantastic sound quality, originally bought them for on the plane, total blocks out the background noise etc.
Tried them on my bike- I have a Tour-X helmet, fine putting them on but I couldn't get my helmet off! I think it must be something to do with the shape and angle of the coil housings. I had to flick them out with my finger whilst my helmet was still on - not easy.
I have since replaced them with Sennheiser PX100 (removed the frame and the earpiieces fit exactly in the ear space of my helmet) sound not as good but I had them lying around so they'll do for now.
best regards,
Dave