We've used MyCHrons in all our karts for years. We've only had 1 problem with a unit, all the others have been bulletproof.

 

I have the UltraLap timer works extremely well under all conditions including snow. I have yet to put the transponder out and it always picks up someones... Bang for the buck goes to UltraLap. The more money the more bells and information.

 

Geoffrey was right. This thing is tiny. Maybe I can mount it on the wheel.