Flow's First Bite: GT Helion Carbon Pro

The not-so-minor details


GT Helion Carbon Pro


Monza Bicycle Imports






Killer carbon frame shapes.
Proven suspension design.
Marathon race inspired geometry.
Tricky single ring and low range cassette hack.


Do we really need remote suspension lockout levers?
Non tubeless tyres.

GT fans out there with a penchant for cross country trails now can have access to a short travel bike with the trick new suspension design that has been receiving praise all over our singletrack riddled planet.

**UPDATED – read our final review here.
We have reviewed the 150mm travel GT Force X and the ‘in the middle’ 130mm GT Sensor, now the stout 110mm travel GT Helion will be put through the Flow wringer.
GT Force X review: https://flowmountainbike.com/tests/tested-gt-force-x-expert-carbon/
GT Sensor Review: https://flowmountainbike.com/tests/tested-gt-sensor-carbon-team/
Using GT’s fairly new AOS suspension design (Angle Optimised Suspension) with its super high main pivot and independent bottom bracket linkage, the Helion aims to hold momentum as the rear wheel encounters impacts on the trail. Watch the video below for a clearer understanding of the theory.
GT Helion 1

When unwrapping the Helion from its packaging we were quite surprised how beefy the carbon tubing is, it’s a fatter than a goanna hanging around a public BBQ area. Especially out the back, the large chunks of carbon give us real confidence that although the Helion is a short travel dually, it’s not going to be afraid of going hard on the trails. Front to back, this thing is about as carbon as it gets.
The dead straight top tube and chain stay give the Helion a sharp and precise look, where some bike are curvy and twisted, this bike is sharp and square.
We also love the way the shock sits so low and centred in the frame. In fact, if you take a look at the designs of rear suspension bikes over the last 10 years, you’ll see a real trend of rear shocks getting lower and lower in the bike’s architecture. The benefits of keeping any weighty sections of the frame like suspension linkages and shocks down low does wonders for your centre of gravity when riding, the GT’s must be one of the lowest and centred out there.
At 11.6kg the Helion is pretty spot on, and the dollar figure is also quite fair for what you get in the way of parts. A set of the powerful and reliable Shimano XT brakes plus an XT shifter and derailleur combo means you’ll be shifting gears for a very long time.
GT Helion 21

In true GT fashion, there are some interesting parts from the lesser-known brands on this Helion. RaceFace take care of the cockpit with a flat and wide bar, and a sleek CNCd stem and seat post. The RaceFace cranks aren’t something we see too often, but most interestingly it’s fitted with their ‘narrow wide’ chainring that aims to achieve what SRAM’s X-Sync rings do – ultimate chain retention with just one ring. An e*thirteeen chain guide is fitted for absolute security, but we’re sure that it can run without for that super trendy, clean and quite look.
Single ring drivetrains and Shimano don’t normally mix as a Shimano cassette with an 11-36t range doesn’t give you much when the trails turn steep. So GT have hacked it for you, with a big 42 tooth e*thirteen sprocket fitted to the cassette out back, to give you one more gear in the lower range. It’s cool to see a major brand like GT speccing bikes this way, with real foresight into how many people upgrade their rides over time, just like they’ve done here as per original catalogue spec.
A 32 tooth ring up front keeps the gear range low-ish and we like that. Gearing low is always there smarter option, as you will remember the climbs where you run out of gears more that that rare moment when you’re spinning out down a fire trail or on the road.

GT Helion 33
The black e*thirteen sprocket gives a Shimano 10 speed cassette a super low gear. The 17 tooth sprocket in the middle of the stack is removed, and the e*thirteen one takes up the space at the low end.

GT Helion 13
Hacked for you. How many clever Shimano riders out there have an aftermarket single chain ring fitted like this one?

No dropper posts on this GT, but for a 110mm bike, that’s not such an unusual sight. Its low weight, and minimal travel suggests it’s aimed for the marathon races, or buff singletracks out there. Both the fork and shock have remote lockout controls, with one lever locking both ends out with one thumb actuation. Love them or hate them, remote lockouts when used to their potential can seriously add some pace to your ride. With the ability to quickly stiffen your suspension for sprint efforts, climbs or tarmac sections with one swift motion of your left thumb. Perhaps the fact that it’s a long way down to the rear shock, a shock-mounted lockout lever would be a bit of a stretch to reach on the fly.
Numbers wise, a 69.5 degree head angle means business at the shaper end of the scale, an our medium size frame has a 606mm top tube and a 438mm chain stay, so we’re expecting this long trucker to set singletrack climbs on fire and munch down the miles on long rides.
No front derialleur neatens thing, but does the remote lockout undo that?
No front derailleur neatens things, but does the remote lockout undo that?

GT Helion 17
It’s a great looking bike, but won’t be clean for very long.

It’s off to the trails for us with the ‘marathon meets macho’ Helion. Lets see how it fares with its unique mixture of marathon race inspired geometry and its slightly aggressive component choices. It’s bigger brothers, the GT Sensor and GT Force X were firm and efficient rides that were never afraid of taking a hard hit, so let’s see how this 110mm fella handles the trails.
Read full review here: https://flowmountainbike.com/tests/trail-testing-a-rocket-the-gt-helion-carbon-pro/

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