Forget high pivot idlers, Geometron goes back to the gearbox with a Pinion drivetrain on its latest G2 bike.

Need to know

• Geometron G2 comes with a Pinion gearbox option, with choice of anything from 9-18 speed
• G2 will be available from summer 2024, once final testing on shock positioning is complete
• The G2 aims to compete with the best enduro mountain bikes, from Trek, Specialized and Nukeproof
• G2 should cost around the same as a G1, with a small premium for the Pinion gearbox… £8,000 perhaps
• Travel ranges from 160-180mm, G2 comes with mullet, 29er or 27.5in wheels as required
• Full custom geometry, and Geometron’s mutators on seat stay and chainstay fine tune BB height, rear triangle length and head angle

Geometron G2 keeps the same geometry as the original bike, and now brings the Pinion gearbox to the design

Geometron is one of the most influential brands in mountain biking. Alongside Mondraker, much of the credit for today’s modern sizing and geometry must surely go to the Forest of Dean brand, which for a decade or more told all of us we were riding bikes too darned small. Of course they were right, the industry and riders slowly crept closer to the geometry charts of Geometron’s now-retired G13, a bike built by Nicolai but radically slackened and lengthened by Geometron.

Job done then. Except, the longer, lower and faster philosophy was only half the theme dreamed up by Chris Porter and Geometron. That left the complimentary other half, the eventual elimination of the rear derailleur, hanging in the breeze. 

The original Nicolai Ion GPI in action in 2016, the bike used a belt drive and was optimised for a 10-speed drivetrain

Part two begins right here, with the brand’s latest and as-yet unnamed new bike, which for convenience’s sake we’ll call the G2. Currently just a test rig, hence the multiple shock position points, the idea is to bring the bike up to date and add a Pinion gearbox option. History buffs amongst us will know Geometron already went down this road with a modified Geometron/Nicolai Ion GPI (look it up on mbr.co.uk) some seven years ago. So why now? After all, Pinion has made no major changes to its gearbox short of reinforcing the chain tensioner and Smart.Shift electronic shifter as an alternative to grip shift.

“It does feel a little bit like going back to our roots where we started seven years ago,” says designer Marcel Lauxterman. “The main drive is that we want to do what excites us to ride for the next five or six years.”

Pinion chain tensioner is a more robust affair on the new bike

Back to the ‘box

The original Geometron bike with its Pinion gearbox and belt drive was designed around a 10 or 11 speed drivetrain and therefore just wasn’t optimised for the straight chainline a gearbox with its single rear sprocket demands. “The G1 and the new bike are designed for 12 speed and a 52 cassette, and that changes all the anti anti squat values.”

The gearbox’s time has come at last then, Geometron says, the new G2 is built to take advantage of the new parts available to bike designers (shocks, drivetrains and hardwear) and integrating the better climbing efficiency developed for the G1 and adjusted via the multiple shock positions on the test rig.

Multiple shock mounts on the G2 allow Geometron to fine tune the suspension and placement of the EXT Storia shock

“We are really happy with the kinematics of the G1 and all the adjustability of it and being able to alter the chainstay length,” explains Sam Robson from Geometron. “Integrating the Pinion gearbox was another step forward because we’ve now got a consistent chainline to make the suspension platform more consistent, without the chain flapping about.”

The goal then is to make the G2 Pinion bike feel exactly the same as the current G1, so a current Geometron rider need only get used to the gearbox, with no need to adapt to a new bike’s suspension feel or geometry. “That said, we’ve got different suspension layouts that we can test to further optimise the bike,” Sam explains. 

Geometron’s mutators, here on the chainstay, let riders tweak the geometry to resize the back end and change the BB height

Why the drive towards a gearbox in the first place though? Simple, it leads to better suspension performance, which Geometron has always pushed for, and the effect could be as pronounced as ditching the front mech some 10 years ago, according to Marcel.

“With the standard 10-51 tooth cassette now gone from the bike there’s no need to compromise the suspension performance and try and optimise it for 12 different gears,” he says. “It’s nice from a frame designer’s perspective then and it’s similar to when we ditched the front derailleur, it opened up so many different variations on frame layout.”

Latest Pinion gearbox can deliver its power through 18 gears if required, but Geometron suggests 12 is about right for power delivery

Geometron’s original gearbox bike was ahead of its time and arguably too early for riders to get behind, while the cost was prohibitive. “The market has definitely changed now though,” Sam says. “The bike design is still the largest cost but the second largest cost is now the drivetrain. With SRAM T-type the second most expensive thing on your bike is now a wearable part. If you’re spending £2,000 on a drivetrain per year then the market is ready for a more robust drivetrain package you get more value for money from. A lot of people would rather spend £1,500 on a gearbox that’s got a 10,000 mile service life on it.”

Geometron has always been an unorthodox brand, doing things differently not to make a splash but in search of a better way. So while plenty of brands are adding complexity to their enduro bikes with high pivot idler designs Geometron is moving the other way. Is a gearbox a better way to control the chainline and thus improve suspension performance? Probably. Are riders ready to throw out the only consistent part they’ve ever known, the derailleur? Perhaps.

Geometron wants performance and reliability, hence the Pinion gearbox, external cable routing and high-end 7072 alloy frame