Knolly Bikes is a relatively new Canadian brand. Its first bike offerings have been of the DH/freeride persuasion, but this is the new Endorphin - a 5.5in travel trail/all-mountain bike.

And when we say "new", we mean it. This is one of only two Endorphin prototypes in existence, and the other one was missing a fork so that wasn't rideable. This bike was only assembled the day before Interbike's Dirt Demo kicked off, and apparently we were the first people to have ridden it. Which is always a little unnerving, but after a little while we decided that nothing was going to fall off and our confidence increased.

The most distinctive feature of Knolly's bikes is the "4x4" double-linkage suspension design. The chainstay, seatstay and first linkage are essentially the familiar four-bar layout, but rather than the shock being driven directly off the top linkage, a second linkage piggybacks off the first. The two linkages straddle the seat tube, so you can drop the seat all the way. Obviously that can be achieved with a single linkage, but then you're more limited on shock placement and leverage ratio manipulations.

Geometry is 69° head and an effective 73° seat. Or thereabouts - with the actual tube being at a relaxed angle, the effective seat angle varies with the seat height. The chainstays are a notably short 16.6in. One useful feature of all Knolly bikes is that they're available in a big range of sizes, right down to an XS (about 15in) - potentially particularly useful for women riders.

There are plenty of neat details on the frame. We particularly like the interchangeable rear dropout/caliper mount. The prototype also had an adjustable lower shock mount offering BB height and angle changes, but that won't feature on the production models.

It's a huge amount of fun to ride, with a very plush suspension action. You get a fair bit of movement under power, but that's the trade-off for the suspension chewing through pretty much anything with essentially no pedal feedback. If you find it bothersome - on a long, smooth climb, say - the RP23 shock's ProPedal lever can be brought into play.

The cockpit layout helps you to keep weight over the front when seated, but makes it easy to get it back if conditions demand. It's certainly a bike that rewards being ridden with a degree of commitment. We like it.

Find out more at www.knollybikes.com - UK distribution is handled by Riding High UK (www.ridinghighuk.com).