They are great... Guys I train with use them, I will get one for next season. The only downside is that you need to go within 70cm or so of the sensor... so when timing a flying 200 on our 333m track, we put one sensor about 3/4 up the bank on the start line (200m to go), then one at 100m to go, and one at the finish line.
Just have to make sure that other riders (especially the moto) know the sensor is there and to avoid it.
We have a pretty good group at our sprint sessions so it isn't really an issue.
JMR
Thanks much for the information.
I saw that Free Lap has a "Velodrome" kit that you can tape down a wire which attaches to the sensor. Also, I was thinking of using two of the TX Junior sensors. It may be easier to set them up on a 333m facility with the TX Junior on the wall stationed at the 200m line and the second TX Junior sensor at the finish line. The price is pretty reasonable as well. Thanks again.