The prelude ends abruptly. Above Verbier, shortly after the start of a multi-day tour around the Matterhorn, the rough climb calls for the small chainring for the first time. Andrea Beil, a doctor from Miesbach, shifts from the medium to the small chainring, but the chain immediately jumps over with a hearty crash. Another attempt, same result: the small chainring cannot be used.
What happened? A new chain and two new chainrings had been fitted during the service before the tour. Not enough, as it now turns out. The small chainring should also have been replaced by the workshop. Fortunately, there is a bike shop next to the cable car station, and after a forced rest, the tour can begin properly after replacing the small chainring.
Cassettes in the test: the small sprockets in particular wear out quickly
Many bikers have experienced similar situations. When a new chain is fitted, the moment of truth arrives. The old sprockets and new chain only harmonise with each other if the replacement is carried out in good time. If you wait too long, all components of the gearbox usually have to be replaced, because the worn and elongated chain works on the profile of the sprockets in such a way that only the retracted chain fits the sprockets.
The crux of the matter is that it is far more difficult to determine the wear of the cogs than the wear of the chain. The only measuring device for this is the HG-Checker from Rohloff. The small sprockets in the cassette are particularly susceptible to wear because there are only a few teeth available to carry the chain load. However, as the example of the Matterhorn tour shows, chainrings with 22 or 24 teeth can also cause problems.
The entire wear test with the results for the individual Shimano and SRAM drivetrains you will find below as PDF-Download.
We tested these drivetrains from Shimano and Sram:
- Shimano Deore 3 x 9
- Shimano XT 3 x 10
- Shimano XTR 3 x 10
- SRAM X9 3 x 10
- SRAM XX 2 x 10
