- GT i-Drive XC 2.0
- Hot Wheels 01202 732288
After a couple of years of uncertainty, GT has settled down. Forget about them going bust, getting bought, losing distributors and all the rest of it. GT is well and truly back. The i-Drive XC is an all-new bike, sharing only a name and a general concept with the original i-Drive. The XC i-Drive promises to be lighter than the original (which lives on in longer-travel applications elsewhere in the range). There’s a lot of sophisticated competition out there, though, so how does the new GT stack up?
GT has always made distinctive-looking frames. And that’s not a euphemism for ‘ugly’ – we’ve always found GTs to have a very fair line to them. The IDXC continues a long and honourable tradition, managing to use a completely new frame design but somehow still being obviously a GT. There’s actually a strong hint of GT’s original RTS full susser to the profile of the IDXC – pierced top tube, the angle of the seat stays – but this is of course an entirely different bike.
At a glance, especially from the drive side, the IDXC looks like a single-pivot bike. And as far as the rear axle’s concerned, it is. There aren’t any extra pivots between the main one at the front and the axle, so the back wheel moves in a simple arc about the obvious pivot just above the big ring. That gives the first part of the axle path a distinctly rearward slant, which does two things. First it makes the back end more sensitive to bumps (which come from the front). Second it makes it less sensitive to vertical forces like the rider’s legs going up and down.
So why not just have a single high pivot? Well, ordinarily that rearward axle path would lead to chain growth as the rear axle moves further from the bottom bracket (actually it’s not quite as simple as that as the chain doesn’t pass through either point, but for the purposes of this discussion it’ll do), which means that as you go over bumps the pedals try to spin backwards. Not ideal. The old URT designs were a way around this – by putting the BB on the swingarm the length of the transmission never varies. But they had their own problems (suspension not working so well when you stood up and the like). The i-Drive takes a different approach. The bottom bracket floats, being carried on an extra linkage hanging off the front of the swingarm. It’s connected to the main triangle by a strut. The upshot of all this is that as the suspension compresses the BB is shifted backwards a little bit, just enough to take the pedal feedback out but not so much that you can feel it.
The first incarnation of this system had (and indeed still has) a dustbin-sized BB shell with a big eccentric cam running on huge bearings and a hole in the front where the link strut comes out. It works, but it’s heavy, early versions were a bit troublesome and servicing was a bit involved. The XC version is a whole lot simpler and more accessible. You can take the whole thing to bits with a 5mm Allen key and a BB tool and there’s just four bearings, all the same size.
Sitting between the two halves of the frame is a DT Swiss air shock. We haven’t encountered one of these before, but it’s a tidy-looking unit. The mounting hardware is particularly noteworthy, using spherical bearings at each end. That stops any twisting or flex in the swingarm getting passed to the shock, which should extend the life of both the shock mounts and the shock itself. The side-mounted air valve and big, easy to turn rebound adjuster are also nice touches.
The frame itself is built from good old 6061-T6 aluminium tubing. It’s a pretty slimline device, particularly the back end. There’s a GT trademark gusset under the front of the downtube, a GT logo stamped into the closed end of the top tube and an integrated headset up front. Mud room isn’t massive, but adequate with the 1.9in tyres fitted. We like the front-facing seat clamp slot and there’s plenty of scope for dropping the seat. We’re not such a fan of the single bottle mount underneat the down tube. Yes, said tube is somewhat higher than most but it’s still a pretty inaccessible (and mucky) location for a bottle. Fine for light batteries, but if you’re a bottle fan you might want to shop elsewhere…
At £1,299 there’s some pretty stiff competition out there, but as far as spec goes GT’s offering is very strong. We had to read the price list twice to make sure we’d got it right – we’d been riding around on this for weeks assuming it was fifteen hundred quid.
It’s a very mix-and-match bike, with bits from a number of manufacturers. Even the Shimano transmission parts are drawn from three different groupsets – Deore shifters, LX chainset and XT rear mech. The mech’s a Low Normal (aka Rapid Rise) unit which will doubtless cause howls of protest in some quarters but once we’d reprogrammed our brain we got on fine with it.
Slowing down is handled by wavy-rotored Magura Julie brakes. We’ve had bad experiences with Maguras passim but that was some time ago – the current generation seems to be largely trouble-free. The IDXC comes with 180mm front/160mm rear rotors delivering ample power and agreeable modulation. The lever bodies are a bit plasticky, but the levers themselves are metal and pleasingly shaped.
The front end includes a 100mm RockShox Duke XC fork (complementing the 100mm of travel at the back) in an integrated Cane Creek headset. The Duke’s kind of a forgotten fork in the RockShox line-up, but you’re getting 30mm stanchions, easily tunable air spring and respectable damping.
Bars, seatpost and rims are all from Syncros, another name that’s had its fair share of ups and downs. The post is the classic Syncros two-bolt in-line design, complete with a hole in the bottom of the shaft to put a lock through. It’s a beefy 31.6mm diameter. The Lil’ Snapper rims have machined sidewalls for improved braking, if you’re using rim brakes. Which on this bike, you’re not…
The wheel package is completed by DT Swiss Onyx hubs. They’re respectable units although we’ve found the sealing on the freehub to be a bit inadequate in the past. All in all it’s an impressive, well-balanced spec for the money, with no obvious weaknesses.
We never really got on with the original i-Drive, finding it too heavy and too mushy. It was super-plush and soaked up landings a treat, though, so it makes sense for GT to migrate it to heavier-duty bikes. The XC variant feels tauter, faster and more efficient. We can’t quite figure out where the difference comes from. It’s undoubtedly lighter, but we suspect that the BB moves in a slightly different way too. Whatever the reason, it has the desired effect.
We’re used to suspension bikes that are happy when you’re spinning along but get wallowy out of the saddle, but the IDXC does almost the reverse. It’s impressively stable under low-cadence standing efforts but on a few occasions we got carried away with our spinning and managed to set up some sort of resonant oscillation. You do have to spin quite ridiculously fast, though, and we could dial it out with a bit more rebound damping.
Ah, rebound damping. The DT shock is a quality item, but the range of damping adjustment is somewhat different from the norm. We’re used to shocks with, say, 12 or 15 clicks of adjustment and usually start at full fast and add more damping until it stops being too bouncy. That point’s often reached after three or four clicks – we like a fast shock. The DT unit, though, breaks all records for fastness. We adopted our usual setup tactic and nearly went into orbit. Whacking on three clicks made no apparent difference so we decided to start at the other end. A massive 39 clicks later we found full slow, and ended up about eight clicks back the other way. We’d be surprised if anyone used the first couple of dozen clicks. Once set up, though, it’s a competent and lightweight unit and the suspension feels well balanced between front and rear.
It’s a rangy bike, with a 24.5in effective top tube on the Large test bike combined with a 120mm stem. It doesn’t feel unwieldy, though, with the in-line post pushing your weight forward and lending the front end a reassuring handiness. It’s more of a sweeper than a flicker but it’s agile enough for our tastes. The relatively slimline rear end gives a bit when you crank it over in corners but it doesn’t seem to upset the bike’s composure. The shallow tread Tioga Red Phoenix tyres are fast-rolling, good on hardpack but a bit skaty in the wet. We’d probably stick with ’em until they wore out, though.
Positives: Great spec, competitive suspension performance, feels taut and fast
Negatives: Looks not to everyone’s taste, bottle mount location, damping adjustmentVerdict
It wasn’t ever so long ago that it looked like suspension bikes were going to settle down into two designs – single pivots and four bar linkages. And then everyone suddenly came up with something new – Marin’s Quad, Intense and Santa Cruz’s VPP, Rocky Mountain’s ETS and many others. It’s to GT’s credit that they’ve come back from a corporate near-death experience, reworked something that they already had and the result can hold its head up amongst the front runners. It’s not perfect – the back’s slightly twangy and we’d like a more useful range of adjustment on the shock – but it’s very good, and excellent value.