too roughly on lap 7's portagewunlap togo said:I've used a 3rd eye or Deda dogfang chain keeper with my 39/46 double for the last 7 years. I've only ever had my chain go under the chain watcher and get jammed in a crash 1 time, and I was able to yank it out from there and continue the race. I've not dropped my chain or had any other chain/front rings problems at any other time in those 7 years.
I use these things on all my road and cross bikes, they're cheap insurance against a dropped chain and they work brilliantly for cyclocross. Even on a drivetrain with a perfectly adjusted front derailleur, the chain can get bounced off under cyclocross racing conditions. The chain watcher almost completely eliminates this common problem.