I purchased the 31.8 clamp size for a loaded touring conversion. Mounted on an aluminum flat top drop handlebar there was just enough room to avoid the cable adjusters from hitting the handlebar stem face. Brake clamps have some ability to rotate so I could securely mount them on the beginning edge of the wing. New brake cable pieces added extra needed mils. Got help for mounting instructions online as they operate opposite of STI brifters, pushing cable housing instead of pulling brake wire. Just be sure to take your time. Completed and re wrapped they look and perform great. Can't wait for summer touring.
I have installed these brake levers on 2 of my bikes, a Trek 520 and Trek 970 (converted to a touring setup with drop bars). They're easy to install, solidly built and they function very well. I use the bikes for daily commuting and longer rides in the weekend.
Got the old lady into road cycling...to make it safer for her I wanted to install crossbar brakes. These were very easy to install and give her access to brakes in two places. Great, quality product!