From the Top: Pinion's Christoph Lerman

If there is one company that could feasibly break the derailleur's stranglehold on our rear axles, it's Pinion. A small company from just outside the German automotive heartland of Stuttgart, they are the first people to get a gearbox to market that, at least on paper, starts to offer a viable alternative to our current drivetrains. And, regardless of how you feel about the prospect of having a gearbox on your bicycle, no half-serious engineering nerd can deny that what they have created is a thing of beauty. Taking their cues from the automotive industry, then stripping, refining, and perfecting the concept to a 2–3kg box that should be reliable for six-figure distances with almost no maintenance. Christoph Lerman is one-half of the partnership that dreamed up such a component, then coaxed it from imagination and drawings into a solid, dependable block of metal. We sat down with him to try and find out about visualising complex systems, the challenges of bringing it to the market and what he thinks is the future of the gearbox in mountain biking.

Where and when did Pinion start? What was the first idea?

It was in 2006. That was a time when Michael and I—we were still studying. Michael studied in Karlsruhe, I studied in Stuttgart. Michael is an economic engineer with a technical background. It's a mix between financial and engineering. I started with aircraft engineering at Stuttgart. During our studies, we had to do a training program and both of us did this training program at Porsche. We didn't know each other before that. That was where and when the idea was born actually, one of our colleagues came to work and he was complaining about his derailleur because his chain broke that morning and was late to work. We thought, "Wait a second, why is there a transmission where you don't have to make any maintenance in a car or a motorbike, and why do bicycles have the derailleur?" That was the ignition for Pinion, we thought "Okay, maybe we can transfer what we've seen in Porsche or learned in the automotive industry and transfer it to bicycles." That was the beginning.

So was Pinion your first job out of university?

We didn't found the company then in 2006. We founded the company in 2008, so we were two years, like everybody. Everybody has a great idea, but most people, they don't follow the idea. It's just an idea, and they never realise it. We just thought about it, and it was more like a hobby to work a little bit on the gearbox. In 2008, we were at a point to say, "Okay, we should try this. If it works, let's do a prototype."

Your technology is basically derived from cars, but the technology is miniaturized? Is that a fair assessment of your product, or is that oversimplifying it?

It's oversimplifying a little actually because the gearbox in a car is still pretty different to a motorcycle, especially the shifting mechanism. Of course, you also have gears. The calculation of gears and everything is pretty similar to a car gearbox, but how we shift it is different. In a car, you usually use clutches, which you move sideways from one gear to another gear. There's not enough space in a bicycle transmission to use that space for clutches, so we don't have these kinds of clutches. We have ratchet pulleys.

Did you consider a clutch? Is that something you looked at in the beginning?

Oh, there were many different attempts, like planetary gears. We also thought about CVTs but never really followed it because there are many aspects going against a CVT, and it's pretty tough to develop a CVT which is comparable to a regular transmission in terms of efficiency, weight, durability. We didn't follow through on that. Other aspects like planetary gear systems or needle-bearings. It was not like, "Okay, that's how it has to look." It was much more complicated in the beginning. Even the first prototype we built, there were four shafts, and we could reduce it to two shafts. There are only two gears which are engaged under load, so there's a very high efficiency because the rest of the gears are just free-spinning. Actually, that's the challenge for our development, to simplify it to an essential core mechanism. You have an idea, and you make what is brilliant maybe at the first glance, but then you realise… Okay, you have to put another mechanism around it, and another one, another one. The basic idea gets more and more complicated. The challenge is to reduce it again, to simplify it. You have to run round in circles because unfortunately, normally you don't get there at once. It's a process.

Your production gearboxes are, in some ways, a very simple system. But in other ways, this is insanely complicated.

Definitely, it is. We use a rotating camshaft, you just engage or disengage the ratchet pulleys, and it's actually quite easy. The ratchet pulley is preloaded by a spring. Actually, the spring wants to push the rear part of the ratchet pulley inside the shaft which means that the front part would come out of the shaft because it's also rotating around this axle. The spring pushes the rear part of the ratchet pulley down onto the camshaft. As soon as there comes this gap, it can push the rear part of the ratchet pull inside this gap, and the front part will come out.

How do you come up with something like this? Can you visualise this in your head?

Yeah. Actually, it starts on a white piece of paper where you have the boundary conditions. You know that you want 18 gears. It was also a process to realise those 18 gears in two separate stages with a three-speed and six-speed gear stage, which are shifted independently from each other, actually. Of course, the two camshafts are connected, but there's one camshaft for each gear stage. This is for the six-speed gear stage. Then you know that you have to shift the six gears independently from the three gears and that this sequence has to repeat three times. You have to shift gear one, two, three, four, five, six. At that time, the first gear and the second gear stay still engaged. Then you shift from six to seven. Inside the gearbox, you've shifted the first gear stage from gear six back to gear one. At the same time you shift from gear six back to gear one, then it starts again.

Inside the gearbox, one, two, three, four, five six, and in the second gear stage, the second gear is engaged. These are the gears seven to 12 in the overall gearbox, and again from 13 to 18. By knowing that, you know that you have 360 degrees of rotation to switch six gears. Which means, okay, one gear step is 60 degrees of camshaft rotation. You see, it's a process. Then you know, okay, I have 60 degrees to engage and disengage a ratchet pulley. Then within these 60 degrees, there's a certain tolerance you have to consider. Then you have inside movement, engaging and disengaging, and then you can put that on these 60 degrees. That's how you proceed to define the result of such a camshaft.

Your new C12 seems to be a big step from the P18. It seems to be much closer to something that could be accepted by the mass market. Is that your goal with that?

Yeah, it is. With the C-line, for us, it was the first step to bring the gearbox or the Pinion system out of the niche where we are at the moment and where we started. For a young company, it's pretty tricky to bring such a product to the market if you don't have the resources to build millions of gearboxes at one time, which means a lot of tooling cost and everything. That was one reason to start in the premium segment. Actually, it's normal to bring new technologies out in the premium segment of the market, it doesn't make sense otherwise. If you go from the Formula One to the road car, it's no problem, but from road car to the Formula One, it's not so easy. That's why we started in the premium segment, and now we feel so comfortable with our technology because we have been on the market for almost five years, since 2012, with very good experience in the field in terms of service rates and customer feedback.

For us, it was time to make the next step to bring this technology from 3,000 € bikes instead of, let's say 7,000 € bikes… That's another aspect actually, our suppliers are usually automotive suppliers. They are used too much higher quantities than what we are manufacturing at the moment. This leads to longer lead times because we are on a lower priority at our supplier, like, for example, BMW. We need those kinds of suppliers because we need the quality. A small gearbox company, probably they wouldn't be able to produce these kinds of gears at that quality and those costs.

Was there a point where you considered doing your own?

Not at the moment. Maybe. We are still considering producing some parts on our own in the future, but the quantities… You need some special machines, which are so expensive that you have to keep them running 24/7 so it's worth buying the machine. They are very efficient, those machines, so they can produce a lot of parts. To keep it running 24/7 you have to produce a lot of parts, but we are not at those quantities at the moment. Maybe in the future when the quantities are rising.

We are still considering producing some selected parts them here in-house because you're so much more independent of what's going on outside with your suppliers. When you produce your own parts, it's a kind of dream that you go into the facility and you see the gears plopping out of the machine.

One of your guys told me that the casing for the C12 gearbox is a half-million Euro cast.

Almost, yeah.

That's a huge investment for a company of your size.

It is. That's, for example, a part we never could do on our own because there are so many processes besides the actual casting process connected to that manufacturing process. That's a special facility, actually.

It's always interesting to talk to German companies about ownership as they tend to be privately owned, which means they can maybe take a longer view of things and make decisions that wouldn't necessarily get past shareholders.

At the beginning, the whole Pinion thing was an idea we all believed in, but it was not clear how to make a profit with it. Even the first years of when we still were in production, it was still an investment. Now, it's slowly turning to a profitable company. It wouldn't have been possible without shareholders or investors that don't believe in the company. It's essential to have those people on board.

How hard is it for a small company like Pinion to break into the market?

Well, pretty difficult actually. Our main market at the moment is Europe. In Europe, you have many trekking, touring, and urban bikes. The mountain bike market to Pinion is quite a small market at the moment. I think the reason for that is different actually. One is that the market is dominated by two companies, Shimano and SRAM, and it's very strongly marketing driven, more than with the trekking market which is very conservative. People buy what magazines tell them to buy, and magazines often write what big OEMs place with them by advertising or whatever. It's not so easy for a small company to enter this market. You need an opinion leader who introduces such a new technology to the market, and others will follow. That's the strategy. Of course, if you want to have an opinion leader, it's usually a very large company. These companies have certain conditions for how they decide to make a bike. For example, they won't start to make a bike for 500 units or something like that. They only would start if they can go for large quantities. To go for large quantities, they need a certain price level, which we didn't have so far. With the C-line maybe we do.

The chicken and the egg then?

It's a similar situation, but now we are one step closer to that situation. We have the C-line as a cheaper base, which is more interesting for larger OEMs who have maybe a minimum quantity of one or two thousand bicycles to start even the project. Otherwise, they wouldn't even start. It's not a technical reason why they are not doing it. That's what I believe. It's more like a formal or bureaucratic reason actually, "Okay, we have to make at least this quantity to that price." We don't fit in that metric.

At the moment, there's a lot of planned turnover with mountain bikes. The expectation is you keep a bike two, three year's time, whereas if you're making a gearbox that you guys are saying it'll last 100,000k. Is that a tension for you?

I don't think so because the system itself offers so many advantages, especially to mountain bike kinematics. You only have one sprocket in the front. You have the mass in the middle of the bike. All of our gearboxes we have on the market so far, they all fit into the same standard. Also, future gearboxes will fit into the Pinion standard. It is not our intention to make a lifestyle product which lasts only two years. Our philosophy is to make a durable product, a reliable product you can say, okay, in five years, I can still use it. If you want to use it still or if you want to buy an updated, lighter version which may be available in five years, you still can put it in the frame, but the philosophy is still to make a durable product which works for a long time.

I have a 10-year-old VW Golf, and maybe it's not got Bluetooth, but it's fine. Where if you look at a 10-year-old mountain bike, you wouldn't really want to ride that anymore. Is that rate of progress a problem for you?

I don't really think it's a problem because a good Pinion mountain bike in market production would be so different and so way ahead from that what we have at the moment, I think that's more than two years in the future where you would say, "Oh, I don't want to ride that anymore." I think the Pinion's technology puts something to that bike which makes it more durable for more than two years.

Realistically, will we see mass market bikes with Pinions in the coming future? Is that something you're working on?

We are attracting some larger manufacturers since we have had the C-line. I think so, there will be something in the future, some larger companies coming up with a Pinion bike.

Obviously, the weight is always an issue with the gearbox. At the moment, you guys say it's a 600-gram offset between that and a standard derailleur drivetrain?

Around that, it depends on the frame design. It depends on which gearbox you use. For example, with a C12, it would be like six to 800 grams plus, but with the mass in the middle of the bike so out of the rear wheel, especially on a full suspension bike, the rear wheel is lighter than ever before, which is very positive for how the suspension works. I also think if you look at the development of bicycles, there were always some steps with new technologies, like disc brakes.

Disc brakes are heavier than rim brakes, but they made it to the mountain bike. Suspension bikes are heavier than non-suspension bikes, but this technology brought benefits, so people accepted some extra weight. From that point on, of course, the manufacturers try to reduce the weight again and then new technology came. I think with Pinion, we are also at such a point where we are just ahead of a situation where people are putting gearboxes on their mountain bikes. Of course, the weight will increase a little bit, but at the same time, it will have benefits on the other end. We are working on a lot of gearboxes in the future.

One of your team said that, for instance, with a change of material in the cranks you could save 150g. You could, in theory, have lighter sprockets. Is this something you've already done? He reckons you can get to the same weight as a standard mountain bike.

On the same weight, it's not completely impossible, but it's always a question of how much energy do you put into development and how much money are people willing to invest or to spend for a high-end gearbox. We're using common automotive materials for the gears, which are very high quality, but of course, there's still some aerospace stuff which you could use. At the same time, with the material we are using at the moment, the design is very conservative because of our intention, in the beginning, was to make a gearbox which was reliable and durable instead of having a very light one which breaks after 5,000 kilometers. We started with a conservative design to get some experience with it on the market. You cannot do this just with testing, you still always need some experience over years with the product. That's where we are now after a couple of years, and from that base on, we're really confident that there's still a huge potential for wide optimisation.

To what extent has your automotive background influenced the way your product is and how is it different to other mountain bike products because of that?

The positive influence was I think we were very analytical. The situations and the steps we made with the product, it's very automotive style to make it analytical. Maybe in the bicycle business, it's often more like following the belly feeling, with how to make things. I think that was one of the main reasons why we came so far because our products are actually on the edge.

If you look at the car transmission, you have to transmit 200 or maybe 400-newton meters in a VW Golf. You usually have around six gears. The weight of a car transmission is between 80 and 120 kilograms. In the bicycle, in our gearbox, we also have to transmit around 250-newton meters, so the torque is pretty much the same as in a car. It's very high, only the rotation speed is much higher on the car. Actually, that's what damages your parts, the torque. That's pretty much the same as the standard car.

As I said, six gears in a car transmission at 120 kilograms, we have 18 gears at the same input torque and make it less than three kilograms, 2.1, 2.2 kilograms. The product design actually is pretty much on the edge. You need some analytical process of thinking to do that. I get the impression that other components in the bicycle industry, especially the components, also decide the same way. You cannot just do something.

What would you like the next evolution of your gearbox to be? How would you like it to change for your next step? What would your next goal be?

I think with the C-line, we have a pretty good base for future developments. Our goal after P and C-line is not to make a third product line of gearboxes. The focus is more on shifting devices. Not everybody likes the rotary shifter. Many people prefer to have a trigger shifter, electrical shifting systems, so these are projects we are investigating at the moment, how we could approach these things for the Pinion system.

Posted In:
Interviews From The Top