Kettenspalt-Einstelllehre

Setting up a rear derailleur used to be pure trial and error for me, but this little gauge gave me an exact chain gap measurement on the first try. It clips on simply and the markings are easy to read even in dim garage light. Shifting has been crisp ever since.

Setting the chain gap used to be pure guesswork until I picked this up, and now the derailleur shifts clean through every gear. The gauge itself feels sturdy enough to toss in the toolbox and forget about until the next drivetrain swap.

The gauge takes the guesswork out of chain gap measurement, and the markings are easy to read even in dim garage light. Only gripe is that it's sized for one drivetrain family, so it's useless on my other bike.