Before I even threw a leg over the GT Sensor 9r, I was sceptical. My experience of 29ers was limited to a couple of rides on a rigid singlespeed, and while it was impressive, it was still a rigid singlespeed. It didn’t make me want to go out and buy one, or go back to a hardtail, but I could see the benefits of big wheels for such a bike. I just didn’t think I needed one to replace my trail bike.
Months went by with no other big wheel experiences, but the amount of hype, good press and word of mouth was getting harder and harder to ignore. After Caleb, another 29er sceptic, came back raving about riding the Sensor Pro at the GT launch in Italy (see issue 38), I was curious to have a crack at something with some cush at either end. Enter the 2010 Sensor 9r.
I always thought that 29ers looked a little bit weird, and were gangly and slow—a bit like myself, really. I also assumed that, like me, they would take a little bit of getting used to. But while riding on tarmac to get to the trails, this bike instantly felt like it was ready to roll and roll and roll. Kind of like a fat tyred, squishy road bike. The fit was good; although I felt at first like I was climbing onto a horse, once saddled up it was more a sensation of sitting in rather than on the bike. The low bottom bracket coupled with the big wheels no doubt contributed to this. Once on board everything felt natural and in the right place.
When we hit the dirt though, things really started to pick up. The trails were mostly uphill with frequent rolling sections, and while the weight of the bike was a little more that my regular ride, it still climbed with aplomb, especially if I kept on the gas and used the trail contours for momentum. Cornering was the most unusual sensation, and the first few switchbacks revealed I’d need to rethink my lines, but once again it was a pretty quick transitional period. I was soon thinking that this could indeed be the future of mountain biking, and I hadn’t even pointed it downhill or had it up to full speed.
Once those things came into the equation, the Sensor really came into its own. The first section of fast, flowing trail was tackled with caution, as the ride characteristics were clearly different to those of a 26 inch bike. The subtle shifts in bodyweight necessary to clear rough, rocky sections on a 26 inch were soon put aside as I learnt to point and shoot a bit more. Roll-overs seemed to be shortened by the big wheels, and sections of sharp, baby-head sized rocks were miraculously smoother than before. Was it all in my mind? A placebo perhaps?
GT’s i-Drive suspension platform has been around for a long time now, and it’s still doing its job as advertised. It may not be the plushest of suspension systems, but it’s still one of the better pedalling ones. It’s firm in both open and ProPedal settings and stays active under braking, and the bigger wheels stay planted when you’re on the anchors through rough corners. I ran the shock in the open position for most trail conditions, and when I increased the sag to about 30 per cent it certainly brought the rear end to life. However, with the complexity of the system, and the location of the lower link and dogbone in the firing line of mud and muck, there tended to be a pretty big buildup down there. The front derailleur cable routing also places it in a position prone to contamination over time.
The parts pick is solid, if not flashy. The Shimano SLX shifters and derailleurs didn’t miss a beat, and the Avid Elixir brakes were strong and had good modulation and lever feel, although there was too much fluid in the rear line. This was quickly remedied, and the brakes kept doing their job after that.
The tyres are Kenda Karmas, and I thought they might not have sufficient knobs for good traction in the slop. But they hooked up admirably, maybe due to the bigger contact patch provided by the wheels. Confidence in slippery corners was amplified to 11. Fox suspension has always been a personal favourite, and the F29 15QR fork tracked straight and felt plush right out of the box. Having only rebound and lockout adjustment doesn’t bother me a bit; in fact, the fewer dials to worry about the better, as this makes setup simple. Ditto for the Float RP2 out back, with rebound, open and ProPedal settings. Just set the sag and go. Nice.
With my initial big wheel phobia placated, every ride on the Sensor was a fun experience. The more I rode it, the more I liked it. Sure, it requires a slightly different riding style in some situations, but wasn’t that the case the first time we rode with front suspension, or full suspension, or disc brakes? True, 29ers may not be for everyone, but if you get the chance, check ’em out—like me, you may just find yourself considering a switch to big hoops. The GT Sensor is definitely one bike that is worthy of a good hard look. I didn’t want to stop riding it.