http://www.bikebling.com/Spinergy-X-...xaero-lite.htm
Call this place, ask for Leo. tell him David with the Tarmac sent you. They have a Spinergy regional rep that works at thier store. His name is Randy. He has no issues getting you a set with higher tension. I started on these wheels when I was 300 lbs, They have never come out of true or had any issues. I crank out stupid amounts of power when I sprint and I have not had an issue. Testing my power I peaked at 1600 watts in a sprint. To give you an example of how hard I thrash, I have had a headset come loose 3 times, crank once, shifter once, and I broke 2 novatec hubs. These wheels are nice and light and are priced right. I highly reccommend them for bigger guys. I hope this helps out
