As we all know, beauty is in the eye of the beholder. So it's no wonder that classic fat bikes have always divided the mountain bike community. "Poser bikes for the ice cream parlour", say some. "Practical machines for big adventures", say others. The pioneers of the Iditarod race, the legendary bike marathon through Alaska, were certainly not show-offs on their original fatbikes. To avoid sinking on the gruelling course on snow and ice, they widened the forks and rear triangles and built two or even three wheels next to each other. Today, the descendants of these specialised machines have become a permanent fixture on the mountain bike market. The die-hard fat bike scene swears by the advantages of the thick tyres - and in any terrain, not just on snow and sand. Despite all the enthusiasm for fat tyres, fat bikes have some serious disadvantages on normal trails: they accelerate less quickly because they are simply heavier and don't steer very precisely. But what if you tricked the inertia of the bikes with powerful motors?
To find out, we pitted two e-fat bikes against each other. The Haibike Xduro FatSix 8.0 comes with Yamaha's PW drive for 3499 euros. The significantly more expensive Mondraker E-Panzer R is powered by the Bosch Performance CX motor. First of all, we went into the real element of fat bikes: snow and ice. On the Stelvio glacier, they were able to show what they can do. In the late summer slush, the narrow tyres of classic bikes would sink mercilessly. But the 4.0 tyres of our test candidates, filled with only 0.5 bar air pressure, have such large contact surfaces that the frozen snow cover does not collapse. Even on the more softened, slushy areas, the specialists still have excellent control. Steep ski slopes - both uphill and downhill - are really fun.
In these wintry conditions, the bikes don't have much in common. The better equipment of the Mondraker with larger brakes and the more powerful Bosch motor can hardly show its advantages here. Only the Maxxis tyres with their coarse knobs grip the snow better than the weaker-profiled Schwalbe tyres on the Haibike.
But how do the fatbikes perform on normal trails? The fatbikes clearly show their character on the gravel track on our test ride just outside Munich. On both bikes you sit quite sportily and all the controls are in the right place. The huge balloon tyres literally soak up small to medium-sized obstacles, providing comfort and enormous safety. Nevertheless, the suspension travel provided at the rear by the tyres alone is no substitute for proper suspension. If you sit lazily in the saddle, every pothole will hit your back unpleasantly and the rear suspension will lose contact with the ground all too quickly due to a lack of damping. Like all hardtails, fatbikes also require an active, forward-looking riding style. The large distance between the cranks (Q-factor) also takes some getting used to. Of course, the fat tyres require a lot of space, which manufacturers can only achieve by widening the chainstays. The cranks on the Mondraker are a full three centimetres further apart than on normal bikes, and on the Haibike it's even four centimetres. This is clearly noticeable when pedalling.
Fatbikes also require familiarisation on the trail. You lurch somewhat awkwardly through the bends. You can't expect the kind of precise steering behaviour you're used to from standard tyres. The narrower and more blocked the trail, the more likely you are to touch down with the cranks and get stuck - another consequence of the wide crank spacing. Steep climbs are all the more fun. With their long wheelbases and steep seat angles, the fatbikes climb in exemplary fashion. The balloon tyres interlock perfectly with the ground on steep climbs and provide plenty of traction. At least as long as it's dry. They don't like wet roots at all. Even the rather heavily profiled Maxxis tyre on the Mondraker slips away abruptly here.
In direct comparison, the Mondraker is slightly more agile and direct on the trail than the Haibike. You feel comfortable and secure, sitting in the bike rather than on it. On steep ramps, you benefit from the powerful thrust of the Bosch motor and the high-traction tyres. Downhill, the Mondraker has sufficient reserves for the range of use with 125 millimetres, and the brakes decelerate well thanks to the large discs.
Even if there are hardly any noticeable differences in snow and ice, the favourite disciplines of fat bikes: On the trail, the cheaper Haibike struggles to keep up with the Mondraker. Even though Yamaha's affordable PW motor in the Haibike feels very refined, it simply provides less thrust on snappy uphills in comparison. The cranks also sit far apart on an outdated square axle. The brake discs are slightly undersized at 180 millimetres at the front and the tyres have a low profile. Overall, the Haibike is more suited to leisurely cruising, while the Mondraker can also be used for more technical trails. It is a fact that the balloon tyres are not the last word in wisdom on technical trails. But that won't diminish the enthusiasm of the die-hard fans of this type of bike.
CONCLUSION by Markus Greber, EMTB test manager:
Fatbikes feel at home wherever classic tyres would sink in mercilessly: snow, sand, gravel, mud. In winter through deep snow to the ski hut, or endless tours on the beach in soft sand - that's where the e-driven monster bikes definitely make sense. On classic mountain bike trails, fat bikes are sluggish, imprecise and, due to their wide design, the cranks tend to bottom out early. This makes them more of a second bike for the winter than a universal bike for trails and tours. In a direct comparison, the Mondraker is more versatile, but the Haibike is significantly cheaper - not exactly insignificant for a second bike.
The details of the fat bikes from Mondraker and Haibike
MONDRAKER E-ARMOUR R 26"
Reach height 1358 hm
Time / 500 hm³ 22:36 min.
Price 4199 Euro
DRIVE
Engine Bosch Performance CX
Maximum torque
¹ 75 Nm
Battery¹ / weight² / price Replacement battery Bosch Powerpack, 500 Wh / 2690 g / 699 Euro
Circuit Sram NX (11-speed)
Translation (v. / h.) 14 / 11-46
Display / Size Bosch Purion / 31.5 x 3.5 mm
EQUIPMENT
Fork / damper Rockshox Bluto RL Solo Air / -
Spring travel (f. / h.) 120 mm / - mm
Telescopic support Onoff Pija Dropper / 150 mm
Brake / Disc Ø (front / rear) Shimano MT 520 / 203 mm / 203 mm
Impellers DT Swiss BR 2250
Wheel size 26" (f.) / 26" (h.)
Tyres v. / h. Maxxis Minion FBF EXO TR DC 26 x 4.8 / 26 x 2.8
MEASURED VALUES
²
Sizes / frame material S / M / L / XL / Aluminium
Weight 22.8 kg
Centre of gravity height 492 mm
Handlebar width 760 mm
Crank length / Q-factor 170 mm / 214 mm
Reach / Stack 470 mm / 634 mm
HAIBIKE XDURO FATSIX 8.0 26"
Reach height 1408 hm
Time / 500 hm³ 25:32 min.
Price 3499 Euro
DRIVE
Engine Yamaha PW
Maximum torque
¹ 70 Nm
Battery¹ / weight² / price Replacement battery Yamaha Lithium Ion, 500 Wh / 3000 g / 849 Euro
Circuit Sram NX 11 (1x)
Translation (v. / h.) 38 / 11-42
Display / Size Yamaha LCD / 45 x 68 mm
EQUIPMENT
Fork / damper Rockshox Bluto RC Solo Air/ -
Spring travel (f. / h.) 100 mm / - mm
Telescopic support XLX All Mtn / 100 mm
Brake / Disc Ø (front / rear) Magura MT 32/ 180 mm / 180 mm
Impellers Haibike The Hup hubs; Alexrims Blizzer k80 rims
Wheel size 26" (f.) / 26" (h.)
Tyres v. / h. Schwalbe Jumbo Jim EVO TLE Pace Star 26 x 4.0
MEASURED VALUES
²
Sizes / frame material S / M / L / XL / Aluminium
Weight 23.3 kg
Centre of gravity height 507 mm
Handlebar width 780 mm
Crank length / Q-factor 170 mm / 224 mm
Reach / Stack 445 mm / 650 mm
¹Manufacturer's specification
²Determined on the test stands in the EMTB test laboratory, weight without pedals.
Average value from the reach height test over the entire distance.
