Spotted, tucked into a corner at Eurobike, was this slick aluminum Intense M1 Pinion DH prototype sporting a gearbox and their latest Smart.Shift electronic shifting. Now, Intense already has a recently updated M1 DH bike with a new high-pivot, 6-bar adjustable travel suspension design that’s been proven by their Factory Racing team on the DH World Cup circuit. So, what is there to gain by recreating that bike with an electric shift gearbox and a belt drive?
Besides a 100,000€ reward from Gates… a lot of performance benefits, too!
Would you ever think of automatic shifting on a DH race bike?
Intense M1 DH electric shift gearbox mountain bike prototype
We often hear about the low maintenance benefits of gearboxes and belt drives. But there are fewer real deep dives into the true racing benefits of such a setup, as well. Gates has certainly sparked some good discussion with their offer of a 100k€ bonus purpse to the first Elite DH World Cup win on a Gates belt-drive mountain bike. And Gamux Factory Racing with their production Sego have gotten a good head start.
But count this high-pivot Intense M1 Pinion prototype gearbox DH bike as further proof that a gearbox may be able to help you go faster in the type of races where a fraction of a second makes all the difference in the world.
Better weight distribution. Reduced unsprung mass. Lower center of gravity. No vulnerable derailleur to bash against the rocks.
What’s new, turning a World Cup DH bike into a gearbox bike?
It’s no simple or cheap project to design, develop, and build a World Cup DH racing prototype. But Intese is all-in.
It certainly helps that their latest World Cup DH race bike – the M1 – is already made of more-prototyping-friendly 6061-T6 aluminum. And it doesn’t hurt that it recently got a complete high-pivot, idler pulley, 6-bar suspension update that lends itself well to strapping a gearbox underneath.
To make that work, Intense really only needed to reshape its chainstays and rebuild an all-new bottom bracket cluster to house the Pinion. Effectively, it looks like all of the suspension linkages and much of the shock tunnel carry over. And Intense keeps the seatstays, toptube, headtube, and most of the downtube from the regular M1, too.
Still, creating the new bottom end for Intense’s M1 Pinion DH gearbox prototype was no easy feat. So, Intense turned to the German rapid prototyping experts of Trumpf to 3D-print a number of elements in weldable alloy to complete this project bike, and hang a Pinion gearbox off it.
Then, of course, they had to create a new Gates centerline-compatible idler pulley for it, and rig the Gates tensioner pulley off the motor to keep belt tension through 202-212mm of rear wheel travel.
Pinion C1.6i 6-speed electronic Smart.Shift gearbox
Interestingly, most performance-focused gearbox bikers are usually trying to get the most gears and the biggest gearing range possible. But in DH racing where special 7-speed derailleur systems already abound, Intense opted for the simpler and lighter C1.6i 6-speed gearbox.
The magnesium casing C1.6i still gives the Intense M1 Pinion prototype gearbox DH bike a wide-enough 295% gearing range. Plus, it’s almost 15% lighter than the 12-speed version, and a claimed 1800g for the regular gearbox. But that little i also means that this is an electronic shift Smart.Shift version.
This adds back some weight – with an internal battery and electronic actuator – but replaces the sometimes sluggish feel of the Pinion twist-shifter with a push-button electric trigger shifter. It also means that Pinion times your shift to the dead spot in your pedal rotation if you are pedaling. So, you can shift under load better than ever (as much as a gearbox can ever really be shifted under load).
The entire gearbox setup gives this Intense M1 Pinion DH prototype an incredibly clean and simple rear end, with no derailleur to worry about. And also you still get to choose your desired hub, like this fast-engaging Onyx.
One more thing…
Pinion actually debuted their electronic Smart.Shift shifting system a couple of summers ago on bikes, where it could plug into their big onboard batteries. And they could be configured for some automatic shifting functions too – along the same lines as the Shimano eMTB-specifc AutoShift & FreeShift modes we’ve tested, but here since the gearbox can shift even when you are not pedaling it could apply to regular bikes, as well.
Pre.Select would automatically shift you into an ideal gear based on speed as you coast, and Smart.Select would automatically shift to a preset gear for starting from a stop. Neither of those really made it to any pedal-powered bike because you needed a speed sensor to make it work.
But do you see that wire running on the inside of the non-driveside chainstay (above)? We don’t know why that would be there, unless it was a speed sensor.
So it looks to us like Intense created their M1 DH race prototype, not with only electronic gearbox shifting, but automatic Pinion Smart.Shift gearbox shifting.
We can really see that Pre.Select function coming in handy for certain racetracks, where a racer could program it to automatically have the perfect gear set to attack out of a super technical section, letting them concentrate on controlling the movement of the bike.
Intense says only, “We’re true to our core values, constantly evolving, pushing boundaries, and developing our bikes.” Bringing automatic gearbox shifting to the DH World Cup sounds like pushing boundaries to us too…
