Just bought an Epic which takes a 34.9mm seat clamp. My old Salsa quick release doesn't fit and I want a new one to match my skewers as well as possibly a clamp but they are only made in 35mm. Will this 0.1mm difference mean my seatpost will keep slipping, its a Thomson by the way in case that matters?

chances are the machining tolerances allow for maybe +/- .1mm anyway, give it a try but if it doesnt work you could always try filing the inside of where the skewer passes through to open it out so it`ll compress more. just a thought.

You'll be fine, the size is actually 34.9, Salsa just call it 35.

Few years ago there were only 3 sizes, 28.6, 31.8, 34.9. It's only recently there's frames like On-One and Cotics which have 30s and stuff!

Went and bought the Salsa clamp not QR and it doesn't work, seatpost spins with not a huge amount of force but the Specialized quick release holds both the stock seatpost and my shimmed Thomson tight.

Back to the shop with it, guess I will just have to get a Hope one instead.