Also thought I'd post to see if anyone else had some difficulty getting the combined speed/cadence sensor unit to mount well on their TT/tri bikes. On my bike there is not much space between the spokes and chainstay so I was limited to only a small area fairly far back to mount the magnet where it wouldn't strike the chainstay - of course I had to mount the sensor back there as well. This moved the cadence sensor back as well giving me only a small length of crank arm right adjacent to the pedal spindle to mount the cadence magnet but looked like it would work - the problem I had with the cadence sensor was the distance between the crank arm and chainstay is too far for the magnet to work with sensor (that's even with mounting the sensor on the side of the chainstay vs underneath like on my road bike). I ended up fabricating a spacer to mount under the sensor against the chainstay to move the sensor close enough to the crank to pick up cadence. Seems to be working.
