This is tried and tested the technology, EBBs have been used on tandems for decades, without problems. You’ll end up using the same dents whether you want to or not, if you try and tighten a bolt on the edge of a dent it will pull itself into it, ever tried drilling on the edge of a hole? The only disadvantage over other types of eccentrics is that you can’t make micro adjustments, once you realise you don’t need to, it’s hardly a disadvantage. If you’d ever tried to remove a seized wedge type EBB, you’d appreciate that simple is best. I’d expect it to last the lifetime of the bike, the only way I could see of damaging it would be if you bolted into the thin section against Thorn’s advice.
I don’t know what’s making your bolts come loose. I check mine weekly, along with every other bolt, fixing and cable, sounds excessive but it’s a routine that take less than 3 minutes. Occasionally (maybe 3 times in 100) one of the bolts has needed a quarter turn. After making an adjustment I'd check it after about an hours use, I'd do this after changing any part on a bike.
If you’re still concerned, why not give Thorn a ring? Don’t restrict yourself to the advice of us amateurs [
]
