Everything used to be simpler. 26-inch wheels ran through all mountain bike classes. What's more, a mountain bike was only a mountain bike with this tyre size. Then Gary Fisher, of all people, one of the forefathers of the mountain bike, came along and triggered a heated debate with his 29-inch wheels. At some point, everyone realised that the big wheels had some advantages. They provide more stability and roll better over obstacles. Later, a third size, 27.5 inches, came onto the market and the old 26-inch wheels disappeared from the scene. 27.5 and 29 inches - both wheel sizes have now become established in all E-MTB categories established. Some of them are even offered as mixed models. So 27.5 inches at the rear and 29 inches at the front. This is an indispensable trend for e-MTBs with great market significance.
But who needs which size now?
As I said, 29-inch wheels generally roll better over obstacles and stabilise the bike when riding fast. However, 29-inch tyres are said to be not quite as manoeuvrable as their smaller counterparts. The disadvantages also include the higher weight due to the design, which is particularly noticeable in the lower price categories. In addition, the 29-inchers take up more space. It is easy to build 29-inch bikes with large frames, but all the more difficult with smaller frame sizes. The bottom line is that smaller body sizes and/or smaller wallets have more advantages with 27.5-inch wheels on an E-MTB - and vice versa.
Mullet bikes: E-MTBs with both wheel sizes
The MX wheel mix, also known as the mullet, is here to stay. Here, manufacturers combine a 29er front wheel with a smaller 27.5er at the rear. The idea behind this is as simple as it is logical: the front wheel scores points for its good rollover behaviour, which provides more riding safety and smoothness. The rear remains more manoeuvrable. This is particularly interesting on E-MTBs, as the combination of a voluminous motor and large rear wheels makes it difficult to realise short rear triangles. With the smaller rear wheel, the designers have more room to manoeuvre, which makes short chainstays possible. This favours the manoeuvrability of the bike. It is not without reason that many manufacturers rely on this combination. Our practical tests regularly show that the concept works. However, the basic rule is that all three wheel sizes can be used to build harmonious E-MTBs - depending on the type of rider and area of use.
