The Diamondback Quantum NEX is a style-driven, urban mountain bike designed for young professionals who wants to cruise to work, the coffee shop or the gym on a cool bike. Sounds like a good idea.
If you like the looks of the new BMW 5 series you’ll like the looks of this bike. Convex and concave surfaces make this bike frame look futuristic and undoubtedly stylish. The curved crease lines accentuate the angles, and surfaces catch the light beautifully. It looks cool and like it would deliver a fast and smooth ride.
Nearer the truth is that it is a heavy, sluggish and uncomfortable machine.
The principle of hub gears, especially for a commuter bike is a sound one. They are maintenance free and generally work well but on this bike, the 8-speed Shimano Nexus hub is well over-geared for anything but flat riding. Changing the rear sprocket should easily rectify this problem.
The drum brakes are an appropriate choice and provide ample stopping power, although they are a bit spongy, as all drum brakes tend to be. The handlebars and stem come as a one-piece combo, with a triangular stem construction giving a totally uncompromising, extra stiff setup. The problem with this is that they send every bit of road vibration straight into the arms and can cause wrists to ache.
The same stiffness seems to be consistent throughout the frame and makes the suspension seat post a real necessity. The 36-spoke wheels add to the stiffness, to an extent that even the high volume fat tyres specced on this bike can’t dampen. But, everything else being equal, while the tyres look cool I would prefer durable and puncture-resistant slicks on a commuter.
The geometry of the frame seems a bit odd too. The reach to the bars is about right for a rider my size, but I couldn’t get the saddle anywhere near high enough, partly due to the travel in the suspension seat post.
My other big gripe with this bike, and indeed with this whole class of bike, is the lack of mudguards and rack. Okay, a rack and ‘guards might not look cool, and not many other urban Mtbs have them either (exceptions being the £299 Kona Smoke and Ridgeback’s Rapide Equipt range which tops out with the £349 Momentum). Others do though have mudguard and rack mounts and they could have been provided here. Given the vagaries of the British weather the option to fit guards would be particularly useful.
The Quantam’s frame and the component selection mean that the bike has a very minimalist look, with clean lines – definitely a head turner. Sadly it’s performance doesn’t match its looks.