Everything’s better with lasers, right? From the company that brought you the laser stem alignment tool, we present – the Linientreu laser derailleur tool. Most mechanics are probably asking why you would need such a tool, but Tune says that the device makes it easier to set up your shifting, whether you’re a complete novice or a seasoned pro…
Fitted with a 5mm Allen or T25 Torx bit, the Linientreu is designed to plug into the fixing bolt of your rear derailleur. Then the adjustable laser can be moved so that the beam is cast directly on the upper pulley wheel of the rear derailleur.
Theoretically that should allow you to perfectly align the derailleur with each gear for perfect indexing, and Tune even claims it allows for precise limit adjustments as well. It seems like the device would also indicate whether the hanger is straight (at least in certain directions) since the laser would have a diagonal slant – though without using it, it’s hard to tell how accurate it would be.
Tune says the tool is compatible with 7, 8, 9, 10, 11, and 12 speed drivetrains and is patent pending. No price is given, but since it’s Tune – the tool weighs 200g.