Bulls uses a 2.35 inch wide 29er Nobby Nic tyre on the front wheel, while a Rocket Ron in Plus format (27.5x2.6) is fitted to the rear. It is clear where developer Gerrit Gaastra copied the trick from: motocross bikes have been riding on a similar tyre mix for years. The theoretical advantages are obvious: the narrower but larger front tyre rolls over obstacles well and can be manoeuvred precisely through the terrain, while the wider rear tyre with significantly more volume ensures increased comfort and traction.
That Bulls the hardtail class 1700 euros is taken seriously is shown by the good equipment of the test bike. With the Shimano XT 2x11 drivetrain, the Rock Shox Reba fork and high-quality asymmetric rims, the latest addition to the Copperhead family rolls proudly into our test. The hermaphrodite then promptly surprises us on the climbs. The slightly profiled rear tyre has little rolling resistance, and the wheel acceleration measured in the laboratory is also better than that of most Plus wheelsets. The sporty riding position encourages you to accelerate. In addition, the concept gives the all-clear for all those who fear for their intervertebral discs, as the promised comfort of the plus tyres is actually noticeable in practice.
Downhill, you will wait in vain for the often criticised, spongy handling of plus bikes. The theoretical concept works. The wheel mix actually combines precise steering behaviour, good rollover characteristics and a little comfort. Although the Copperhead Max RS is no substitute for a fully, it has a wide range of uses.
Ludwig Döhl, BIKE editor:
The concept of different tyre formats in one frame leaves an extremely positive impression and has potential for the future. The Bulls Copperhead Max RS is a successful all-rounder, occasional racers will continue to stick with the conventional 29er.
