TASTE CAN HELP DECIDE
It's amazing what a rear derailleur can withstand. Even tens of thousands of kilometres don't seem to affect the gear changers, apart from tortured derailleur pulleys. Rebuilding to a new version is often not really necessary. In most cases, a new Bowden cable is all that is needed for the derailleur to pull the chain over the sprockets for another five years.
For the "XT" part of our Scott, a quick massage with a cleaning cloth would have been enough - spring, joints and pulleys ran perfectly. If you still decide in favour of a new derailleur because of the look or the smoother operation, there is no getting around a larger investment. Shimano and SRAM have developed their systems into self-contained units in recent years. Mixing parts is not recommended. First of all, however, you have to decide between the individual modes of operation. And this is best done during a test ride at the dealer. On paper, neither Shimano nor SRAM have anything in common. Both systems work with low manual forces, are light and also work well under load. The decision between SRAM and Shimano can therefore be left entirely to taste. Sounds simple, but it's not. Both companies also offer their own in-house alternatives: Shimano retrofit levers from the old and popular "Rapid Fire" series, with SRAM you have the choice between twist grip and "Trigger" toggle shifters.
Tip: the Rohloff "Speedhub" - install and forget.
POTENTIAL OPTICS ★★★✩✩✩✩
POTENTIAL WEIGHT ★★★✩✩✩✩
POTENTIAL FUNCTION ★★★★✩✩✩
