Cannondale's 4.5in travel Rush was introduced to plug the gap between the all-mountain Prophet and the race-specific Scalpel. And, while it's certainly stiff and pedal efficient, it's no lightweight singletracker.
Oversize Issue
The oversized One Point Five head tube for the Lefty fork is externally butted and the down tube swells towards the bottom bracket. The top tube follows a large radius curve to pick up the forged rear shock mount and the front end of the swing-arm is a single piece forging with a front plate for stiffness.
The back is disc specific, with hose tucking neatly under the arm and rear gear cable threading through the inside. There are up and under bottle cage mounts on the down tube, but even on the large size you can't get your shoulder into the top corner for carrying.
Even by large frame standards, this is a monster. At 113cm, the wheelbase is far longer than most downhill bikes we've tested - let alone XC bikes - and the top tube is an inch longer than an average large, too. The same proportions carry right through the range, and even the small has the same wheelbase as the large Santa Cruz, so bear this in mind when you're sizing. However, our orang-utan limbed writer Matt found it to fit spot on - so well worth checking out if you're a gangly sort that usually has difficulty finding bikes that fit.
The long wheelbase makes it super stable at speed, but forces you to swing extra wide round stumps or tight corners. Combined with a slack 69-degree steering angle, there's no chance of making snap reaction line changes without a week's written warning, either.
Unlike most long bikes it's remarkably stiff along its axis though, and the same is true of the single-legged fork. This adds extremely accurate feedback and line holding to its already enhanced stability, and it carves big, fast turns with incredible precision. The stiffness is obvious when pedalling too, and while it's a heavy bike, it still gallops along the fl at briskly once you've got it moving.
The suspension is also massively stiff which leaves the Rush behaving like a hardtail most of the time, however soft you run the shock. Again, this is great for ripping up fire-road climbs, but it spins rather than grips on techy, rooty climbs and it chatters and rattles across small bumps and hard ground. The lack of suspension 'stick' means it tends to snap out suddenly and dramatically, rather than sliding if you push the back end too hard through corners. The good news is that the Lefty fork upfront is one of the best of its kind we've ridden in a while. The air oil guts 'pfi sh' and 'hiss' vocally on rough ground, but size specific compression and rebound damping is as accurate and controlled as any other fork here, and tracking stiffness is fantastic. Tyre/tube removal is easy and mud clearance massive too, although the loose rebound top cap kept falling off even when tightly screwed on.
The cost of the American hand-built frame and unique fork weighs heavily on the rest of the spec, though. The cheap FSA chainset is a particular low point, and while the rest of the SRAM/Avid kit is good and the wheels are okay, the whole bike is heavy. This makes a serious upgrade program to release the potential of the lightweight frame a real priority.
A Brush With The Rush
We can see where Cannondale is going with the Rush, and that's up and down very long fire-road climbs during European marathon races. Here the long wheelbase, stiff frame, low bottom bracket and all but locked compression damping on the rear shock would work really well. Unfortunately, the ponderous handling and lack of small bump compliance don't translate well to most UK trails and the heavy overall weight is rather a chore, too.
