We recently brought you a first look at Scott's ultralight Spark FS bike, and it showed up at Eurobike too. But we've now had a chance to have a bit more of a poke at it on UK soil - no riding, though, this bike had no fluid in the brakes and no gear cables. Or pedals.

This is the top of the line Spark Limited. The most noticable thing about it is the integrated seatpost. Instead of a normal seat tube with a post clamped in it, the Limited's seat tube extends nearly all the way up to the saddle. There's just a specially-made Ritchey saddle clamp attached to it to hold the seat on. Obviously scope for seat height adjustment is somewhat limited, but it saves some weight on the complete bike.

Not that the Spark has any particular need to save weight. This is, as far as we know, the lightest proper full-suspension frame in the world - 1,550g (3.4lb) for the frame, 240g (8.5oz) for the shock, making 1790g (3.95lb) all together. Yes, that's a 115mm travel full suspension frame and shock at under 4lb, a weight that's not terribly objectionable for a hardtail...

There's an awful lot of cleverness going on to get to that weight. Scott has unleashed a new manufacturing process that it calls IMP (Integrated Molding Process) which is used to make the top tube, head tube and down tube all at once as a single unit, thus using considerably less material. There's also no cosmetic weave on the frame (the outer layer that makes most carbon bikes look like carbon fibre). It's all very clean-looking, particularly details like the smoothly-integrated front shock mount. The back end is carbon too, right down to the dropouts. And yes, you get a replaceable derailleur hanger.

The actual suspension design doesn't particularly break any new ground, being a fairly conventional seatstay-pivot design with a linkage-driven shock. The shock itself is a joint venture with DT Swiss. Despite only weighing 240g, the Nude shock still manages to pack in Scott's trademark on-the-fly travel mode adjustment - a fully-open 115mm travel, a stiffer 70mm "Traction Mode" and a full lockout.

The Limited complete bike features a full Shimano XTR groupset, Mavic CrossMax SLR wheels, RockShox Reba World Cup forks (with, of course, a carbon crown and steerer) and Ritchey finishing kit. Claimed weight is a startling 9.9kg (21.7lb) and the UK price is an equally startling £4,499.

Only the Limited gets the integrated seatpost - the Spark 10, 20 and 30 all have a more conventional setup. The £3,799 Spark 10 has a Fox F100RL fork, DT Swiss wheel package, Avid Juicy Ultimate brakes, X.0 transmission and Truvativ Noir cranks. Then there's the mostly XT Spark 20 (£2,899) and the "entry level" Spark 10, with an LX/XT transmission mix, Avid Juicy 5 brakes and a Reba SL fork.