GT has done some frame tweaking for 2007. Most obviously the top tube has been lowered to improve standover clearance. Last year’s oversized head tube with semi-integrated headset has been replaced by a conventional head tube to increase the choice of aftermarket headsets. GT has also slackened the head angle on the ID5 by 0.5deg to 69deg to improve stability, but it’s still steeper than all of the other bikes on test, bar the Trek. At the heart of the i-Drive design, the Flex-Bone has been replaced by an i-Link; it still performs the same function by keeping the floating bottom bracket anchored to the front triangle — it’s just more robust now.
Rear dropouts are fully replaceable leaving the door open for GT to provide a 10mm bolt-through or Maxle version. But the bolts worked loose after a couple of rides.

Instead of opting for a lockout, the Marzocchi MX Pro gets an ETA adjuster. So when you flick the red lever atop the left leg the fork gets held down in its travel, becoming firmer and noticeably less active. This improves the geometry for climbing, by shifting the rider’s weight forward to stop the front end lifting, while maintaining some front suspension. In the showroom the Marzocchi won’t feel as good as other brands as they have a definite bedding-in period, but once up to speed the damping is good, they are very plush and ultra-reliable.
The Fox Float R shock on the rear is pretty much industry standard and our pre-production test bike came with middle ProPedal valving. More about that later.
Groupset We were surprised to find the Hayes Sole brakes on the ID5, not only because the GT is the most expensive bike on test but also because it has a reputation for incredible value for money. To be fair, they are the only sub-standard components on the bike.

Contact points are excellent. Soft, comfortable lock-on grips that won’t rotate when wet, and while saddles come down to personal choice, most riders find the SDG Bel Air a comfortable perch. The 27in-wide Truvativ handlebar has a good profile and the extra width means that you can chop it down. It’s nice to see a matching Truvativ stem and seatpost, but we would have preferred a slightly shorter stem than 90mm to help combat the GT’s steep head angle.

Even though the GT and Cannondale offer the same amount of rear travel, the ID5 3.0 didn’t do as good a job of isolating the rider from the trail. It’s fine on bigger hits when the shock is pushed deep into its stroke, but the back end chatters across roots and stutter bumps. We initially thought it was due to stiction in the pivots, but we dropped the shock out of the frame and the swingarm moved very freely. Possibly the ProPedal valving in the Float shock is too high for the bike, because even in the workshop with no air in the shock the i-Drive system wasn’t the easiest to get moving. A call to GT confirmed that production bikes will have a Fox Float shock with minimum ProPedal. The Marzocchi fork got better with time and completely outclassed the rear suspension. With steep geometry and its efficient pedalling action the GT rockets up climbs and we never once reached for the ETA adjuster. But we weren’t doing soul-destroying fireroad climbs.

Based on the performance of the bike we actually tested, the GT should have scored seven because we weren’t overly impressed with the rear suspension. But having ridden other ID5s we know that the design has more potential and GT has assured us that bikes in shops will have the correct shock — hence the eight rating. The GT’s chassis is a solid foundation on which to upgrade but it is still very much a long travel XC bike and the geometry is slightly steeper than the shorter travel, lighter Specialized FSR XC.