Tenor: The wear is adequate to the field of use. A very positive result we had not expected like that. It is not that we consider e-mountain bikes as excessively prone to wear, but we thought that psyche would play a trick to many e-bikers. “Subjectively all components wear down extremely fast,” says e-MTB designer Lutz Scheffer in this connection. “But this is primarily due to the fact that bikers with e-motors ride a lot more, in particular more altitude metres and material-consuming trail kilometres.”
Scheffer himself rides about 100,000 e-MTB altitude metres per year, he therefore knows what he is talking about. For retailers and manufacturers the difference is yet more noticeable, as completely new buyer groups come into extreme terrain thanks to the motor assistance. “In former days the mountain bike was pure sports equipment, there were hardly any heavy-weight persons riding in the mountains. The load weighing on the bikes and the components not only increases due to the heavier inherent weight of the bicycles, but mainly due to heavier riders,” says bicycle expert Dirk Zedler in this respect. To put it plainly: E-mountain bikes have to bring down 100 kg riders safely more often then usual mountain bikes. And also commuters doing many altitude metres in any wind and weather every day want to be made happy for good.
Do e-MTBs withstand continuous use? Or is electronics too sensitive? And are the high propulsing forces too brute? The weak points of e-MTBs
Problem area gears
Sprockets and chains are classic wearing parts on bicycles and of course on e-mountain bikes too. A motor clearly increases the load. The motor power provides every amateur biker with an acceleration like cross-country hero Nino Schurter. This affects chains, sprockets and chainwheels a lot. “Chain suffering and sprocket wear is a major issue on e-mountain bikes,” confirms graduate engineer Dirk Zedler. Apart from the extra power there are further crucial points: The motor propels forward less sensitively than experienced bikers can accelerate. Gears are therefore often shifted under full load. The motor still propels, i.e. provides further propulsion, when the cranks already stand still. Therefore chain sucks or sticks in the drive train of e-MTBs more generally result in sudden failures, such as torn rear derailleurs or chains. “For this reason I always take a piece of chain and a chain lock with me”, says frequent rider Lutz Scheffer. He also recommends cassettes with steel sprockets. “The service life of aluminium sprockets on e-MTBs is only short. This time we mean cheaper is better.” The only explicit e-MTB-gear system, Sram’s EX1, therefore relies upon cassettes with eight steel sprockets. Unfortunately, this has never become fully established in the market,” says Zedler and calls on e-bikers to take a close look at their needs when choosing their bikes and components. Frequent riders should invest in durability. Bosch drives are a special case, by the way. “The super small drive chainring strains puts extreme strain on the chain, a real chain eater”, says Zedler. After about 1000 kilometres at the latest it will be over.
Dipl.-Ing. Dirk Zedler, bicycle and e-bike expert
„Chain suffering and sprocket wear is a major issue for e-mountain bikes. After all, any ordinary person can suddenly climb a mountain like a world-cup pro.”
Author: Florentin Vesenbeckh