It’s tempting for a manufacturer to drop the entry point on a range as low as possible. Has GT cut too many corners to cut the price of its Helion Comp or has budget suspension performance got a new benchmark?
Frame and equipment: impressive, bar a few teething troubles
GT launched its Independent Drivetrain suspension design nearly 20 years ago and it’s sticking to its guns with the latest evolution of the system. The downside on a discount bike is that it’s arguably the most complex suspension structure in widespread production.
The shock drives through the base of the seat tube so there’s no getting round a multi-part selection of curved hydroformed tube sections as well as intricate forgings for the seat tube straddle section, a big horseshoe section to mount the main pivot and the large two piece clamshell welded together to form the dangling bottom bracket section. Even the front derailleur is bolted onto a separate arm that’s in turn bolted to the underside of the seatstay bridge and has to be fed through a curved cable tube of the type you used to see on V brakes.
A neat gauge helps simplify suspension sag setup
As impressive as it is to see how it all dovetails together, this type of assembly is expensive to produce. This leaves less money for the rest of the bike, and the lower that price point the closer you get to compromising performance.
Initial impressions are good. The 740mm bars are wide for a 110mm travel bike and hint at more control and chaos taming potential than you’d expect in this category. An 80mm stem keeps it easy to hold online on climbs or under power. It syncs well with the 69.5-degree head angle, not too fussy when you’re just cruising, but well weighted on turn-in if you need to whip it round something tight.
Despite the cross-country intentions, the cockpit setup is modern
But where a lot of cheaper full sussers suffer is the quality of the damper and fork, and at first we thought that GT had fallen into the trap. The X-Fusion rear shock was stubborn to move and if it did it then cannoned back to a savage metal on metal top out.
Hoping it was an irregular issue with our shock rather than a cost-cutting compromise too far we contacted X-Fusion in the US who came back with a simple ‘try this’ fix. Just unscrewing the air sleeve then popping it back on recharged the negative spring chamber that helps get the shock movement started and prevents it bouncing all the way back to the stops. With that back to correct pressure and an extra bit of Slick Honey grease around the seal head we were back in supple, consistently controlled business.
Ride and handling: stiff, smooth and grounded
Despite the complex looking suspension architecture and QR skewers rather than thru-axles, this is an impressively stiff frame in terms of twist and lateral flex. The relatively short 110mm travel enables GT to sit the Helion low to the ground, and together with the well-balanced suspension weight it’s a naturally grounded feeling bike.
The lack of thru-axle doesn't stop the Raidon fork working well
This secure feeling is enhanced by its unique suspension action. The key feature in terms of suspension reaction is that the joint between the front and rear frame halves is higher than a normal suspension setup. It can swing backwards and upwards away from a frontal impact (boulder/step/root) much more easily than a low pivot.
Normally this increased backward and upward swing would cause massive pedal pull back, directly opposing suspension function and power transmission and causing pedal bob or choke problems. However, the cranks are mounted on a separate section, sitting between the central mainframe pivot and the junction with the rear frame at the bottom. The shock is squeezed between the top of this independent section and the mainframe. Because the crank moves backwards roughly half the distance of the axle as the shock compresses the effect on pedalling and suspension is also roughly halved.
The Independent suspension reaction amplifies smoothness over small bumps and rough patches, creating a remarkably floated ride for a bike at this price. Wallop something big flat out and the back end copes much better than you’d expect for a 110mm bike. With the transmission only semi connected from the whole shock absorbing process you can keep cranking to top the speed up without getting a beating through your feet or interrupting impact composure.
The X-Fusion rear shock is supple and controlled
The Raidon fork coped well with a range of rubble and trouble too, which is a good job as the rear suspension tends to keep the whole bike glued down rather than waving its front wheel in the air. Add the sorted handling and rear end stiffness and the GT swerves and flows through everything from rolling singletrack to techy trails with enthusiasm and more control than you’d get from a hardtail or most suspension bikes at this price.
The constant midsection movement does create a slight ‘rubber chain’ softness underfoot when you really put the power down but the consistent trail connection gives the Helion outstanding traction. This gives it fine technical climbing ability on challenging sections and bagged it significant summits during testing despite its speed rather than grip focused WTB rubber. On smoother trails or fire roads you can engage the remote control fork and shock mounted rear lockout for a solid pedalling platform.
Climbing ability is impressive, both on smoother trails and technical ascents
Considering the frame complexity and low cost it’s not as heavy as you’d expect. Though it’s not exactly light either, those fast rolling WTBs stoke its speed and your ego nicely so you’re not longing for a hardtail as soon as the trail heads upwards.
There are detail issues, such as Alivio shifters restricting it to a nine-speed block despite SLX derailleurs, and stuck on rather than lock-on grips (as in the online specs). But given the ride we’d be happy to overlook easily upgraded details if it was our wallet we were opening.
This article was originally published in What Mountain Bike magazine, available on Apple Newsstand and Zinio.
via BikeRadar.com http://www.bikeradar.com/mtb/gear/category/bikes/mountain-bikes/full-suspension/product/review-gt-helion-comp-15-49121/?CPN=RSS&SOURCE=BRGENHOME
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