How do you know if you’ve seen a glimpse of the future? Sci-fi films of the 1960s showed us a world where we’d all have robot butlers and flying cars, but we’re now living in that future and things haven’t changed so much. Sure skirts are a bit longer, cars uglier and we have iPads, yet if someone had skipped those fifty years in between, they’d still be able to recognise the world around them. If the past is any guide, the world of tomorrow will look a lot like today. So if we wonder about the future of mountain bikes, most things will stay constant: two wheels, cranks in the middle and a handlebar at the front. How and where we ride bikes won’t be that different either. Change the fundamentals and you no longer have a mountain bike. Present technology, however, ensures that there is still much room for future improvements - and the fact that we still rely on derailleur shifting is glaring evidence.
Pinion's Gearbox - Ready for the Future
For those who spend time thinking about this future, gearing has been a constant theme. Derailleur mechs have a number of obvious flaws, like how easily they can be destroyed by a stray rock, the fact they put weight on an awkward part of the bike and that are they open to the elements. Yet nobody has managed to find a suitable alternative yet, well until now - maybe. We have been monitoring the development of a German-made 18-speed sequential-shift gearbox designed specifically for mountain bikes. The Pinion P1.18 gearbox is now nearing production and its future looks very bright.
| Drive side with the Pinion-equipped Alutech Fanes. The chain tensioner sits behind the gearbox and doubles as a roller guide. The front sprocket diameter was chosen to work with the most popular suspension designs. To adjust the gear ratios to suit track or terrain conditions, simply change either sprocket of the chain drive. |
Since we first saw the Pinion gearbox at Eurobike last year, we’ve made no bones about the fact that we like it. We got to try it briefly last year and were impressed. Since then we’ve been itching for a chance to take it out on the trail and on a trip up to see Alutech bikes in Northern Germany, we finally got that chance. Alutech let us spend a day doing skids and wheelies around their home trails on the shores of the Baltic Sea. They had mounted it to a modified version of one of their popular Fanes enduro bikes and we took it for a ride along the coast and another around the woods above their headquarters.
| And now the non-drive-side. Notice the dual-cable drive where it enters the gearbox housing to actuate the rotary shifting mech. he eight-speed transmission is very compact, which concentrates its weight low in the frame. One thing worth noting is that the gear casing is larger than a standard bottom bracket shell at the crank axle. Alutech redesigned its swingarm pivot location and linkage to adapt the Pinion transmission to the frame while retaining the correct chainstay length.|
First time on the bike and heading out, you notice that you can just jump on it and ride. That is important. If you’ve used a gripshift system before then the Pinion's shifting system will be very familiar. Those who haven't, don’t be afraid. Twist-shift systems work quite well - SRAM wouldn’t have bought them back if they didn’t. People who worry about twisting the shifter when they pull on the bars either haven’t used gripshift, or set their bike up badly when they did. The single twist shifter moves through all 18 well spaced gear selections in sequence, with a reported, 600-percent spread from lowest to highest - a greater range than you would get with a 3 x 10 derailleur drivetrain and without any of its overlapping or duplicate ratios. Being able to move through every gear with a single shifter is one of the big advantages of the system: easy access to such a wide range.
What the twist-shifter does mean is that you have to think about brake lever positioning, especially if you have small hands. Most current brake-lever systems are based around triggers which mean they can be run close-in to the grip. With the barrel of the twist shifter in the way, smaller-handed riders may struggle to properly reach the blades on some brakes, like the relatively short-bladed Formula set that were mounted on the test bike.
| That shifter. Unlike any current mountain bike system, the Pinion gearbox needs two cables to operate its rotary shifting mechanism - this is one of the reasons why a conventional thumb shifter wouldn't work with the P1.18 gearbox.|
| A look into the Pinion P1.18 gearbox reveals a lot of trickery. There is a mirror-image, matching stack of gears on each shaft that mesh together and turn freely on the shafts. When you call for a shift, pawls inside the hollow shafts pop up underneath selected gears to lock them in place. The disproportionate size of the teeth of the gears is necessary to match the diameters of opposing pairs of gears inside the transmission, while ensuring that each of the 18 speeds are evenly spaced. Much engineering went into the P1.18 gearbox before a single piece of metal was cut. Photo by Jens Staudt. www.mtb-news.de|
| A look at some of the meshing gears on the second shaft (left) and a number of gear-shafts showing the cutaways where the shift pawls reach through to lock in the gears (right). Understandably, Pinion did not want to show us the actual shifting mech. Photo by Jens Staudt. www.mtb-news.de|
Riding the Pinion P1.18 Gearbox
When you properly get going you start to realise that you will need to learn a few things about how to ride with a Pinion gearbox. First off there is how quiet it is – there’s no reassuring clunk when you shift gear and because the box has such a wide spread of gears, each gear is very close together. This means grabbing one might not be enough to feel it through the pedals, but then you have to work out how many you need and it’s easy to grab too many and find yourself in too tough a gear. This is a matter of getting used to the system though. One thing we particularly like is how it affects the weight placement on the bike – all the central, low-down weight is a recipe for a well-balanced ride.
| When we said we took the bike for some skids and wheelies, we meant skids and wheelies.|
Shifting is the big deal with the Pinion system. With this prototype you cannot shift down gears if you are putting too much load through the pedals – in other words if you’re really putting some abuse uphill it won’t change gear until you release pressure for a split second. If you are bowling along easily you can shift down, but when more power becomes involved, you can’t. When you are pinning it downhill, you can shift up into a harder gear, no matter what you’re doing on the pedals. Like a car, however, you need to let off momentarily to shift back down through the gears.
Pinion says the tolerance for shifting will be improved in the production version, so you will be able to shift when more power is going through the pedals than you can on this prototype. However, we suspect this will always be a feature of how the Pinion behaves and it’s something you will need to learn to live with. Look at the world outside of mountain bikes: at your car, your motorbike, in fact pretty much every geared thing you can think of. They all have clutches. In case you’re not familiar, a clutch disconnects the gearbox from the power and allows you to change gear smoothly. If you drive an automatic transmission it doesn’t mean there isn’t a clutch, just that the car does that part of the gear change for you. When you are riding the Pinion gearbox, you become the clutch and in a short time, downshifts become a reflex action.
| Forcing the bike onto the line - the low-centre of gravity is noticable out on the trail and it feels good.|
Mountain bikes don’t have clutches – to get into the mechanics and possibilities of that gets too involved for this short article. Without a mechanism to separate the gears from the power you need to find another way and fortunately you find that opportunity naturally in the vertical moment of the pedal stroke. When both cranks are vertical there is no power going through the gearbox, so you can shift. This means you can grab a gear no matter how hard you push, you just need to plan ahead a little bit and time your shift. And that’s the nut – you will need to learn how to use the Pinion gearbox to really get the best out of it. Is that a bad thing? We’d say no – you had to learn to use a derailleur in the first place, you had to learn to shift gears on a car or a moto, so learning to use a different gear system on a mountain bike shouldn’t be a big deal.
One thing we would like to see is an agreement on standards for fitting gearboxes to bikes. At the moment Pinion are still a relatively unknown company outside Germany and we can appreciate that as a frame-builder it could be a big ask to commit to a system from a company like that. Especially because frames will need tweaking, as in the case of this Alutech, to accommodate the size difference between a bottom bracket and a gearbox, and there is a cost in doing that. Yet if SRAM, Shimano or some third player could agree to work to one standard then surely framebuilders could feel confident enough to make the investment to build frames that can take gearboxes and we would be one step closer to geared transmissions being common to mountain bikes.
| Once more for luck between those two big trees.|Pinkbike's Take
|After all of this we are left with more questions. How well will it survive out in the wild? What happens if it does need maintenance? How do you change a shifter cable? But it's a continuing theme with this Pinion system - the more we find out, the more we want to know. It genuinely does work and we like what we have seen so far. We can't wait to get a P1.18 on long-term test to see how it does and if the rumours of a hydraulic trigger shifter ever come to life, well that could be something truly special. Have we seen a glimpse of the future of mountain bikes? Maybe... - Matt Wragg|
What Pinion says:
|Having the premiere test of the P1.18 on Pinkbike was something we had been planning for a long time, but it was the final 2012 production version that was supposed to be tested, not the pre-production version from 2011 Matt was riding. We were supposed to get the P1.18 into regular production at the beginning of May - as we were timing it on the delivery dates our suppliers assured us of. The internal P1.18 parts are produced by different German automotive suppliers and one of them admitted a delay in production of three months on short notice, which came as a surprise to us. The part was that important and challenging that we couldn't change the supplier. The bad news reached us when the date for the test-ride with Pinkbike was already set and we seriously considered cancelling it. The shifting performance under load is an important issue when riding a Pinion-equipped bike, and it is the major improvement we made from the pre-production version of the Alutech Fanes test-bike to the final version. We have completely redesigned the ratchet braces inside the freewheel that are responsible for a smooth and well-defined shifting process. As Matt has pointed out correctly, you can't shift the P1.18 from a long gear to a short gear under full load. That's not the problem. You can't do it with a hub gear either nor from a bigger to a smaller front sprocket with a derailleur system. You need to diminish the load for a split second. On this pre-production version of the P1.18 you can shift under full load from a shorter to a longer gear and with the final version of the P1.18 the shifting from long to short will significantly be improved under part load. The first P1.18 serial gear boxes will now be shipped to the bike manufacturers at the beginning of August. - Falco Mille, Brand Communication|
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