I've had one of those on a single speed I bought at a garage sale that was just a little too small for me. Been using it for about 1 1/2 years and no problems. When I orignally put it on I just tightened the bolts to the same (estimated) torque as the bar stem was originally tightened. Recheck it occasionally in the first few weeks of use to make sure its still secure. I wouldn't use it on an MTB that'll be jumping curbs or used on dirt tracks, but it works great for road riding/commuting. If you don't like it you might be able to put some BMX-style riser bars on that Marin.