Inside Pinion
The gearbox. The white whale of mountain bike drivetrains. On paper they make a lot of sense, centralising weight, eliminating the chain influence from the suspension and removing the fragile derailleur from its exposed position. The problem has always been the execution. There have been multiple attempts to get one right over the years, but out in the real world they have always been too heavy, create too much drag or are simply too complicated. The fact is that the modern derailleur is a finely-tuned precision implement and to convince the masses to step away from them needs a gearbox that is better than they are.
Back in 2011 a German journalist showed up on my doorstep with a bike equipped with a gearbox crafted by ex-automotive engineers. That was the Pinion P1.18. It looked wild and in the car park it felt like it might just work. A year later I flew to Northern Germany to try riding one. It was pretty good, but still had some quirks and a lot of weight. In the intervening years they may not have set the mountain bike world alight, but for serious bike-trekking enthusiasts, Pinion are the market leaders - if what you need is ultimate reliability, they are the name to turn to.
Last year they launched their re-worked C1.12 gearbox to the world, which is lighter, a little less bulky, but still as bombproof. Pinion themselves would admit that they are not quite at the point where their drivetrains are going to takeover the mountain bike market, but while their progress is slow and steady, they certainly show all the promise of being the people who will finally crack the gearbox problem...
We visited their headquarters, just down the road from Mercedes Benz and Porsche, near Stuttgart, Germany to take a look behind their doors.
Christoph Lerman and Michael Schmitz, the founders of Pinion.
The heart of Pinion's gearbox. Fearsome is the only word for the engineering that goes into one of these, and a it is instantly clear where the extra weight in the system comes from - these things are built to deal with a huge amount of torque - up to 250Nm, which is equivalent to a small car. They are also built to withstand these forces for a long, long time. Pinion expect a lifetime of over 100,000km for one of these gearboxes, with no maintenance aside from the occasional cable change and a little lubrication.
The upper array of sprockets in the gearbox is the critical part of the system and once you start digging into how it all works, it is clear how impressive a feat of engineering it is. This group is made up of two separate groups - the three sprockets to the left are the equivalent of triple chainrings, so there is a small, medium and large. The second group of six is equivalent of a 6-speed cassette - so between these two groups they combine to offer the18 gears in this gearbox.
The axle has two separate parts to allow the two groups of sprockets to move independently.
This two piece axle allows the groups of sprockets to move independently.
Beneath those sprockets lies this adjustable cam - this is the part the shifter actuates to change your gear and it took a solid half hour of squinting and stupid questions to even start to understand how it works. The shifter moves the cam through 18 unique positions, sequentially, each of which locks one sprocket from each of the two groups to create a gearing combination. This takes you through from the smallest gear up to the largest, engaging different sequences of sprockets to create a very smooth progression through the 18 gears.
This should be a test for engineering aptitude. If you can look at this and quickly understand how you would create something like this to drive the cam through those 18 precise combinations, sign up for your engineering degree now. For the rest of us, it is looks deceivingly simple, but to get your head round how you can create all those combinations is mind-bending stuff. Talking to owner, Christoph Lerman, he could see this in his head and it makes instant sense to him.
Each position of the cam pushes forward a different combination of these pawls to lock the desired sprockets in place.
One of the challenges of a gearbox is the amount of torque that goes through it - with a standard chainring that torque is dispersed over a relatively large area that can be relatively inexpensively replaced. In a gearbox the sprockets are far smaller and replacing them is no small job. With a five year warranty and an expected lifespan of well over 100,000km, you end up with this kind of burly sprocket.
You can use a simple torx key to cycle the cam through its movements to get a better idea of how it moves.
The inside of the shifter assembly - this is the part of the gearbox that needs the most maintenance, the cables need changing ever so often.
Once you have your internal mechanism, you need a box to keep it in. This is the original, 3D-printed casing.
They did run through a few iterations before they were happy that the design was both as strong and minimal as it possibly could be.
The evolution of the new C1.12 casing.
A look inside at the casting shows how much attention has been paid to every detail.
That said, they have to - the moulds for casting the magnesium casing cost around the half million Euros mark. It is an eye-watering investment for a company the size of Pinion to make, but it also makes a very clear statement about they want to do things - they come from the engineering tradition that spawned Porsche and Mercedes and the idea of doing something by half does not exist in that world.
Once you have a gearbox you need to find a way to fit it onto a bicycle. This too took many iterations to perfect - trying to reduce the weight, maintain stiffness and strength in the frame and make life as easy as possible for frame builders.
All the design for the Pinion gearbox is done here in house and their plans for the future are more than interesting. In the near future they are looking closely at the cranks, hinting that switching to other material could save a lot of weight. Ask them about the future and they are confident that it is entirely possible to get the weight on a par with a standard drivetrain...
Michael and Christoph are very involved in the product development, keeping their hands-on with the gearboxes they produce.
The pins for the cam are punched in, one at a time.
You can't really tell here, but the silver crown at the top of the assembly is spring-loaded to help keep the cam in place.
Ready.
It is then placed into the main body of the cam.
The sprockets are mounted, one at a time onto the axles.
The shifting mechanism runs on a bearing situated within the gearbox.
The bearings that the axles run on are pressed into the body.
Many gearboxes, ready to ship.
Every single gearbox is run through a control procedure. This tests the basics of the gearbox, will it pedal? Will it shift? What is very intriguing about this process is that the shifting is tested by a belt while the gearbox is under load. Out on the trail you cannot shift under load. When asked about this Pinion explained that it is a question of torque, the gearbox itself will shift under load, but using a cable shifter you cannot generate enough torque to do it. However, if you were to have an electronic shifter with a servo motor of some kind, then it might be possible...
Finally the gearboxes are treated in a pressure oven to make sure they are completely sealed.
Once the checks are complete, each gearbox is marked with a warranty sticker.
Nico is the Pinion service department. If you are selling as many gearboxes as Pinion are and have one man doing your warranty and repair, it's fair to say that your products are pretty reliable.
The repaired gearboxes are mounted to this test mules for checking before being sent back to customers.
There's no denying that bikes built around Pinion's gearbox are nice and clean.
And one local builder, Quantor, has even mounted one to an XC race hardtail.
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maybe he should be looking at eBikes..
1. Going to a trigger style or electronic shifter.
2. Aftermarket or carbon crank arms (160-180mm)
3. The C1.6 or equivalent needs to debut on a DH bike.
4. An Idler Pulley or someway to take up chain slack other than the current down low guide
I can tell you your problem. Less engineering, WAY more marketing.
Sincerely,
Every other bike component manufacturer on earth
(Wait, whaaa?)
I was always taught to ease off on the pedals when you shift, especially on a downshift, on traditional cassette/derailleur gears to avoid that horrific crunch of the chain being twisted up and over the next sprocket under load. In which case, I don't see how the gearbox not being able to shift under load to be a negative?
Even on a motorsport spec dog-box you have to ease the throttle (done either manually or electronically) when smashing through the gears.
What about a sprint to a finish line?
Pinion is suitable to recreational and tourist bikes.
No way it can be successfully used on race or aggressive rides.
But they start brain washing us now, so in 2-3 years (I bet less) when they push this stuff live, the general public will be "ready". Innovation, the American way.
As for the pinion gearbox, I dont see it as much an issue, except maybe at a higher level than me. On the other hand, I can see many cases where shifting without turning crank would help A LOT, and that is something current shifters cannot deal with.
Hyperglide shifting was designed for MTB because being able to quick shift is the difference between making it over or falling down.
How can you sprint while having to stop pedaling?
Moreover did anybody here actually rode Pinion?
I can tell you the power transfer is lousy, more items between your foot and the real wheel, more energy lost and mushiness feel.
If you or anybody here did, this is the exact same thing, but moved to the front.
You need to stop pedaling while chasing gears.
If that is not a problem for anybody, then you may just want to get an electric bike as you don't ride hard enough.
With a pinion (and I assume other boxes), you just ease of the cranks for a split second, shift and keep on your way. You can be coming into a techy climb that you forgot was there in literally the highest gear, and crank it into the lowest AFTER you've started up a climb. There are problems with eh gearbox. Claiming that shifting is one of them is decidedly luddite and ignorant.
@TheRaven the shifting is entirely different, so it negates the problem. It shifts instantaneously, so it only takes maybe a quarter or half second of letting up. I thought it would be a problem, too, but you get used to it and it's actually better. You can drop like 4 gears right out of a corner. Really nice for riding unfamiliar trails and not making those mistakes that totally kill your speed.
Imagine having to change gear while sprinting—yeah, right, Ritchie rude is going to stop spinning 120rpm for a fraction of a second so he can get a better gear. Please.
Gearbox have been around since the 1920's and they were abandoned back then because 1 weight 2 drag/inefficiency 3 cost. Then they come out with the greared hub-which is the exact same functionality.
At least try to ride a three speed or commenter bike before having an "opinion".
Bicycle evolution had always been following basic key elements:
- weight reduction
- less drag
So no, if you have to let up on the cranks AT ALL, it's not going to work for my AM bike. Now my trail bike, I could likely make that work. Not that it would never be a problem, just that it would be rare enough for me to let it slide.
Thank you for thinking of using clamping arms over the ISIS spindle. That should have been done years ago by FSA or RF.
Sincerely,
Guy who got headache from RF ISIS cranks.
Personal Observation - The clamping arm is a great concept, added to 48 spline spindle gives more clamping area which allows more torque to move through the splines to the spindle, which decreases the ability of the aluminum arms interface to migrate/deform under heavy impact loads. Which was an issue with 6000 series Alu arm, retainer bolt ISIS interface cranks. Unless the idea is to allow the arms to fail before critical forces deform the gearing axle, hindering operation?
Not sure I understand this... Via the Pinion site the P and C series 1.6, 1.9, 1.12 & 1.18 all share the same frame mounting solution, and same ISIS 'style', crank arm to axle interface.
Am I missing some thing ?
Do people put out this much torque ?
If someone can post a link to a picture or a video of a human being strapped to a machine with cranks and pedals, with a screen next to it showing torque in Nm - thank you...
Yes @atrokz, good weed indeed.
But Richie Rude with e-bike engine support could easily hit 750Nm powering out of the turn..
or send us a message with your email
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Me? I require 36.
That said, given the money & opportunity, I'd ride a belt driven pinion 1.12 today. The weight difference is already low enough for my personal taste.
I usually generate a 1300W sprint (1.75mech HP @tire) on my rides and excepting one single severe incident on a "launch start"with my dirt jumper I have never had an issue with chains and drivetrains in terms of power transfer and reliability.
For my age that is a decent figure and know that Mr. Atherton regularly does 2000W on a perfectly set up bike as a race run. No doubting the bulletproof-ness of that.
It is really cost and availability. Is there was a decked out Santa Cruz V10 or Nomad CC adaptation that came out tommmorow that was within 2 lbs of the lowest end C models you would find me walking over to the LBS to place a pre-order.
Cut the service life and the torque rating of this box, then we’d get closer to the weight, with the trade-off being a 2-3 year re-build interval. Given the complexity of these things, I wanted if LBS could refresh / overhall?
The pinion looks easier then the damper rod to do, but would also require some specialty tools and someone with mechanical aptitude to have it done right. That being said, how much would it cost to overhaul it? I would think it would be an 6 hour job at $50 an hour?
add up the cost of a replacing an eagle, couple of chains, you might be ball park.
Regardless of feasibility, if you could have a gearbox like Pinion, or a true continuously variable transmission (CVT), which would you choose? In other words, would you want pre-defined gear ratios where each "click" of an indexed shifter goes to a defined gear, or an infinite number of ratios between high and low gears where you'd push/rotate a lever to any position between two points?
CVT sounds good, eliminates the need to find the sweet spot.
Basically:
Constant pedalling effort CVT would be brilliant
Occasional / broken pedalling efforts: Better to have indexed gears
But do not see why that has to be such a big difference after all this time with development
Surely the heavy part could be reduced more without causing them to wear out too quick?
Would like to help, but what would it take to be allowed to do that?
For instance if your racing and know you need to grab two or three gears after the next turn you can do it before the turn while continuing to pedal and stay in your current gear, then let off power (stop pedaling) through the turn, and come out of the turn in just the right gear with out a turn of the cranks. Or you can change gears over a jump in the air and be in what ever gear you want with out a turn of the cranks...
That said there is noticeable drive train loss.
I forgot that the pinion doesnt have a 1:1 like rohloff has. Thats true, it is a difference. That said, 3 gears meshed isnt a 14% loss.
In theory I'm like "yeahhhh maybe"
In practice I'm like "but nahhhh"
Anyway. I can't wait till the C1.12 hits the market properly, I don't suppose there's some info on which companies (if any) apart from Ghost are looking to make a bike with it?
Could it be that in the future we will see Pinion integrating e-motors on bikes?
As anyone in the UK knows, bearings are sealed but UK winter riding kills them. I had a Hammerschmidt, which was also well made, but they couldn't seal it against water / dirt and I had to take it apart every few weeks in the winter to remove the grinding paste that had got in.
How will this be different ?
www.youtube.com/watch?v=xHWqlfDZnmQ
Just two variable gears instead of lots of moving parts
The new C12 is 2100g, C9 is 2000g and the C6 is 1800g.
So the new casing effectively saves roughly 200g which is pretty good.
I might consider the C9 as an upgrade to my P12 - the range is only slightly less (and i very rarely get up to 12th gear) and add carbon cranks into the mix then I'd be looking at a weight saving of potentially 500g (assuming saving of 150g on cranks) bringing the weight under 2kg. Which would be ace.
I can't wait to tell everyone i'm passing that "v-tech just kicked in yo".