Tubing profiles on the XSL are seriously sculpted. Both the top and down tubes are hydroformed and the uninterrupted seat tube gives you a full range of saddle height adjustment. Squaring the front triangle is an hour-glass shaped head tube that houses a hidden headset, where the cups sit flush with the frame. Moving rearward the swingarm is made from rectangular profile tubing and rotates on oversized cartridge bearings. Cable routing is neat but the final cable guide for the disc brake hose is too close to the brake caliper.
Our test bike was delivered with no air in the Manitou Radium RL shock — no big deal. But when we tried to inflate it we couldn’t attach the shock pump, as there wasn’t enough clearance between the swingarm and the shock valve. To solve this we simply flipped the shock round, and we suggest you do the same — it has no effect on suspension performance as the shock is a closed unit. Up front the Slate fork is Manitou’s replacement for the Splice. The Comp model specced on the Diamondback is coil sprung and has external rebound adjustment at the foot of the right leg, and a lockout/compression adjuster up top. The lockout has no bypass circuit so you need to be extra careful not to leave it locked out on the descents. The stock spring rate on the Slate was very firm and we struggled to get 100mm of travel out of the fork.
Spoke tension on both wheels was good and this was one of the first things we checked when we were trying to ascertain why the bike felt flexy. The WTB Moto Raptors are pretty good all-round tyres and the decent side knobs definitely feel good on loose, loamy corners. The tyres are narrow enough for riding in the mud, and on hard-pack fire roads they roll pretty fast.
The 70mm FSA stem is one of the shortest on test and definitely gave the Diamondback a fighting chance in the handling and confidence department. Shimano LX disc brakes on a £1,000 bike are unheard of: lever shape is excellent, and they are super reliable and easy to bleed. Diamondback has specced the brakes with organic pads, but if you are mostly riding in wet conditions swap to sintered metal pads when the originals wear out, as they last longer and dry out quicker. Two-piece cranks are amazing on a bike at this price; in fact all of the finishing kit on the Diamondback is simply first rate.
The over-sprung Manitou Slate fork on the Diamondback did nothing to help the handling, but fortunately this problem is easily cured by fitting a softer spring. The dead feel of the rear suspension, which only really works on big hits, is harder to fix. You can’t preload the rear suspension on the Diamondback then spring out of a turn, making it feel lacklustre to ride. Even with the high pivot placement there isn’t much noticeable pedal feedback when seated but this is because the suspension doesn’t move very much. Which is also the reason why the Diamondback can get away with the incredibly low 12.5in bottom bracket height. Additionally the back end has a considerable amount of flex in the dropouts, and when railing corners it feels as if the rear tyre is too soft, even if it is not. Hit a small jump to flat and the entire bike squirms when you land. Not what you’d expect from a 32lb, 5in-travel bike. Flat corners are the Diamondback’s forte as the long wheelbase and low bottom bracket allow you to find grip where others simply wash out.
The Diamondback XSL Comp highlights the fact that you can’t tar all single-pivot bikes with the same brush, as it feels completely different to the ’Dale even though it shares the same shock. It’s got a great spec for the money and if Diamondback could make the chassis stiffer without adding weight, and get a shock that works better with its suspension configuration, it would be on to a surefire winner.
MBR RATING: 5/10