How much suspension travel do you need to create that signature ‘riding on air’ feel?
HEAD-TO-HEAD
Plenty of downhill bikes now use mid- or high-pivot suspension designs. These allow the rear wheel to move backwards as well as up when you hit a bump, in theory giving a smoother-feeling ride and more grip and speed. But those benefits shouldn’t be reserved for DH racers. Surely, enduro, trail and even, to an extent, XC riders would all benefit from better suspension? Surprisingly, then, high-pivot bikes designed for pedalling are few and far between. In a bid to find out why, we’ve taken two examples with differing amounts of travel and tested them head-to-head.
But first, how does a high-pivot design work? On a low-pivot bike, the main pivot (or, on linkage designs, the ‘instant centre’) sits right behind the top of the chainring, on the upper chainline and close to horizontal to the rear-wheel axle. As the suspension compresses, the wheel arcs up and forwards. Raise the main pivot above the rear axle, though, and as the suspension compresses, the wheel moves up and backwards to begin with, before again arcing forwards. This makes it less likely to get ‘hung up’ on square-edged bumps, so it should roll over the terrain better, increasing speed, traction and control. It also means the bike’s effective chainstay length grows, rather than shortens, through much of its travel, improving stability at speed.
These performance benefits do come with some compromises. As the wheel arcs back, the cassette and chainring move away from one other, ‘pulling’ the cranks back – a sensation known as ‘pedal kickback’. To mitigate this, an idler wheel is required to route the chain close or next to the main pivot. This can also help combat suspension bob. However, designing a frame around an idler can be tricky, plus many believe they create extra drivetrain friction. Other issues include higher frame weight and the need for a longer chain.
If you’re convinced of the benefits of high-pivot bikes, you’ll need to work out how much travel you need, which is something this test should help you decide. Can the design really make a bike feel like it has more suspension than it does? Or are you better off opting for more travel, in which case is the extra potential weight and drag akin to putting down an anchor? By lining up a 145mm-travel bike against a 170mm one, we hope to find out.
There’s no ‘silver bullet’ bike design that can cure a rider’s technical, confidence or set-up issues, but there are bikes that can do a significant amount of the heavy lifting
