button head allen bolt. it's one of three bolts that goes on the sprocket adaptor Manic Mechanic makes. i don't think daledoo has one of those, but it's the same principal.
sounds like the bolts on the kit sprocket are hitting the C/B arm, right?
find a friend with a vice and make a "Z" out of the arm, or you can do it with a couple crescent (adjustable) wrenches.
if you've got sprocket (metal) to spoke (metal) contact, you'll mess up your spokes over time, and possibly having your wheel fall apart.
OR, you can find a hardware store that carries countersunk bolts, and put those in your sprocket. you'll have to countersink the holes in the sprocket. you can do that with an over size drill bit.
i know, this is probably way over your head. sorry.