You can tell that long travel is big news these days because GT's sole 100mm (4in) travel bike is this range-topping 1.0 mode l with all the trimmings. Although it loses over an inch of travel to its i-Drive 5 counterparts, the lighter construction and top-notch spec should make it a good bet for all-day trail riding.
The Frame
GT's i-Drive design flummoxed many riders in its first incarnation. With much of the mechanism hidden away in a complex, oversized bottom bracket shell, it was hard to understand and even harder to service. The newer version achieves the same end result - shifting the bottom bracket slightly rearward as the suspension compresses to counteract pedal feedback - via a simpler mechanism. In its 100mm (4in) travel form, some of the extra strength and rigidity is sacrificed in exchange for a lighter set-up with a more conservative appearance. The trademark GT pierced top tube is still there though, complete with GT logo.
Here's how the i-Drive system works: the swingarm rotates around a large pivot at the bottom of the down tube and drives the Fox Float RP2 shock directly. The bottom bracket, meanwhile, sits in its own housing, which in turn is connected to a large pivot on the swingarm via a short linkage and anchored to the underside of the down tube with a leaf spring.
The linkage and spring tether combine to move the bottom bracket housing very slightly rearwards as the suspension moves through its travel; hard to explain but easier to see working. Despite the hint of Heath Robinson, the set-up is well put together and tidily finished. Years of tweaking and honing have obviously paid off.
Breaking the trend for Fox front ends, GT's designers have equipped the i-Drive 4 1.0 with a RockShox Revelation fork offering 115mm (4.5in) travel. Boasting all the bells and whistles - including a negative air chamber for more supple small bump response, and adjustable compression and rebound damping and lockout - it's a good match for the rear end.
The Equipment
Spec watchers and showroom browsers will soon spot the GT's speccing coup de grâce: an XTR rear mech. Despite its glitzy appeal, it doesn't add noticeably to the bike's function and, in fact, we'd prefer to see a cheaper mech and lighter rear cassette instead.
Still, there's little to complain about elsewhere. The wide handlebar gives stacks of control, the Kenda tyres are generously profiled and grippy, although there's little mud clearance around the chainstays at the rear, and the Avid Juicy Five hydraulic discs serve up monstrous degrees of stopping power.
blasting singletrack or negotiating a tricky, slow-speed descent, the GT flatters your skills
The ride
Some bikes just feel right as soon as you climb aboard, and the i-Drive 4 1.0 is one of them. Proof, if ever it were needed, that a bike is more than the sum of its parts, the GT's easygoing trail manners are the result of a combination of well chosen components and a suspension design that does its job with little fuss. The roomy but not overstretched top tube works well with the wide, confidence-inspiring bar and shortish stem to produce a ride position that's simultaneously comfortable, efficient and responsive. Whether you're climbing, blasting singletrack or negotiating a tricky, slow-speed descent, the GT flatters your skills.
Matching a longer travel fork to a shorter travel rear end may seem like a daft idea, but this bike proves that it can be done. The Revelation fork takes time to set up properly, but it's time well spent. Big ring mashers will appreciate the lockout for climbs, and the extra half inch or so of travel over the rear end never gave us any cause for concern.
At the rear, things aren't quite so clear cut - opinion is divided on whether the i-Drive system's much vaunted floating drivetrain really delivers what it promises. Some riders claim to feel a little hesitation in pedal response on bumpy granny ring climbs, despite GT's claims of pedal neutrality. We reckon it's down to where in the pedal stroke the rearward bottom bracket movement happens to occur, but in any case, it's less noticeable than with Mongoose's conceptually similar Freedrive set-up.
Does the i-Drive 4 1.0 cut it as an all-day trail bike? Yes, if you value slightly lower weight over slightly longer travel. But there are cheaper bikes out there, and the competition is tough.
