We rode a prototype of Knolly's Endorphin trail bike at Interbike 2006 - a year later, here's the production bike. There aren't any fundamental changes from the proto - the top tube's a whisker longer but that's about it. This is very clearly a finished bike, though, complete with laser-engraved bearing caps and linkages.

The Endorphin has 140mm of rear travel and is designed to work with 130-140mm forks. What's interesting about the Endorphin is where it's come from - Knolly is best known for big-hitting freeride bikes, so what the Endorphin very definitely isn't is an XC bike on stilts. Out on the trail it exudes go-for-it attitude, with a really stout feel. While it's not the lightest 140mm frame out there at around 7lb, it's still an entirely agreeable weight and we'll take an extra half pound and have a bike that all goes in the same direction any day of the week.

One of the major contributors to the Knolly's exemplary behaviour is the attention that it pays to the pivots (and with the trademark Four by 4 linkage, there are quite a few of them). With bearing seats machined to a tolerance of 0.006mm, double-row German-made INA bearings and precision stainless steel spacers, there isn't a hint of wobble in the back end and the bike tracks laser-straight. Knolly reckons that it could knock over $200 off the frame price by switching to Chinese-made bearings, but it doesn't want to - you've got to respect that kind of commitment to stuff that you can't see.

While it looks slack in pictures, the effective seat angle is up around 73°, giving great weight distribution for the climbs. And if things get a bit hairy on the way down, the seatpost will go all the way down and out of the way. It's a great ride, and we're looking forward to giving it a go on some UK trails - we reckon that the Endorphin is going to be a killer bike for the rockier end of the British trail spectrum...