Enviolo sells one of the most advanced bicycle transmissions in the world. And its best trick is that it simply makes riding your electric bike better. That doesn’t mean learning about how a continuously variable transmission works isn’t interesting and engaging, because it is. In fact, that is why we invited David Hancock from Enviolo to join us for The Electric Bike Podcast from EVELO. You can listen to the podcast here and follow along with the transcript below. Armando: Continuously variable or stepless transmissions are among the most popular features you can find on an electric bike or a conventional bicycle. They're popular because they have a significant impact on how the bike handles and performs, whether you're going up a hill or riding down a long incline. Now, my name is Armando Roggio and in this episode of The Electric Bike Podcast from EVELO, we're going to speak with David Hancock, who is the managing director of Enviolo, the company that makes many of the continuously variable transmissions that you'll find on our bikes and other electric bicycles. David, hello, and welcome to the podcast. David: Thank you. Thanks for the invitation.‹ Go back to the blog
From Fallbrook Technologies to EnvioloArmando: So, I'd like to start off real quick by helping the listeners know who you are, in a sense. Could you tell us a little bit about how you got into the bicycle industry and what your background is? David: Okay. That's not the most straightforward answer, but I'll be happy to share that. So Fallbrook is a company that was founded on a transmission architecture that was not specified or designed specifically for any one application, or any one use case, or one any one industry. The transmission architecture was meant to be industry agnostic, and I came to Fallbrook during the phase when it was not focusing on the bicycle industry. So that's why it's maybe a little bit more coincidental that I do work in the bike industry now. So I'm an outsider from the bike industry. I have 20 years experience running small divisions or small businesses between 30 and 50 people, that make stuff. They make a product, fix it when it breaks, design it to be better than the competition, sell it, market it, put it in a box, ship it. I don't have experience with big companies, I don't have experience with service companies. I'm a small company, small product company guy. And I came to be in the bike industry because I was working in a company that made a generator for large freight trucks, and Fallbrook happened to acquire that company. I was a partner in that company, and Fallbrook brought me in and spent about a year, figuring out what do we do with this guy? And about that time, Fallbrook wanted to make a decision about their bike business, so they decided that since David is outside of the bike business, he might have a fresh perspective. But since David is an insider to product businesses and small businesses, he might have a little bit of an advantage there, in that evaluation process. So, in 2013, I led an evaluation team to decide what to do with Fallbrook's bike business, which is now called Enviolo. And during that evaluation process, we decided that the product was perfect for e-bikes and perfect for high use bikes, like bike sharing bikes, and we went and built a business plan to go and be a European based e-bike company that we executed in 2014.
Living in the NetherlandsArmando: And that's how you ended up in the Netherlands, right? David: Yes. Originally, I was going to stay in the States and we thought we'd have about one half of our staff in the States and one half in Europe. And I was going to stay in the States and then my wife and I became with child — her a little more than me — and our one and only child was born in 2015. So here I was, flying back and forth from Austin, Texas to Europe once every six weeks, once every eight weeks, and decided that I just didn't want to keep doing that. If they wanted me to be in a leadership position, that I should move over there or we should phase me out, and I guess you can tell what decision Fallbrook made now, because we've been living here four years. Four years and three months, and are happily integrated into Dutch life.
What is a CVT?Armando: That's awesome. So let's turn our attention a little bit to Enviolo. Obviously, the product that we use on the bikes we make that a EVELO, is your continuously variable planetary, which we frankly call a continuously variable transmission. Is there a difference between those terms? David: Yes. A CVP, continuously variable planetary is a specific type of a CVT, a continuously variable transmission. So there are other architecture styles that can achieve a CVT, other than a planetary style. So it just depends on how specific you want to be. All CVPs are CVTs, but not all CVTs are planetary. Armando: Understood. It's kind of the square and the rectangle thing. David: A little bit, yeah. Yeah. So there are belt CVTs and there are conical CVTs, and there are other architectural concepts out there. Armando: So with that in mind, why don't you describe for us a little bit about how the CVPs that your company builds, work? David: Sure. Our CVT uses balls that have a hole drilled through the middle, and, therefore, an axle can go through the ball. Then there are these arms out to the side that can tilt the ball one way or another. And when it tilts all the way in one direction, we call that underdrive, and that would be a ratio below 1:1. Then they can also tilt into overdrive, which is a ratio above one-to-one. Our transmission has about 400% in theory, 400% theoretical ratio range. We sell it at about 380% to kind of get it out of the extremes. So, that means that no matter where we want to set underdrive and overdrive, it needs to stay in about a four-to-one ratio. So if we set underdrive at 0.5, then overdrive is going to be 2.0, considering one-to-one would be, the wheels are spinning at the same speed of transmission spits. Armando: If I'm thinking of underdrive for example, am I saying that the plate — if plate is the right term — on the side where the force is coming from, if you will, is going faster than the side where the output is. Is that a fair way of looking at it? David: Yeah. Well, let's just say it really, really layman. Underdrive helps you climb a hill. Armando: Perfect. David: So underdrive is going to let your feet and legs go at a faster ratio than the wheel. And then overdrive is the opposite. It's going downhill, where you don't want your legs to be flailing at the same ratio as your wheel speed. Shifting Under Load Armando: What is the advantage of this kind of transmission, versus the old gears that I had on my bike, when I was growing up? David: Yeah. So there are a lot of, let's say, detailed advantages, but macroscopically, there's one giant advantage that is our master unique selling proposition. And that advantage is that we can shift under load. So while power is going through our transmission, we can shift ratios or gears. We don't really have gears, but in that sense. So, you don't need a clutch, to think of an analogy, on a car. You can move between different ratios, without interrupting the power. While that is nice on a non-electric bike, because your legs are the motor, that becomes incredibly important on an electric bike, because the human can't easily interrupt the power from the engine. So, that unique selling proposition really creates all kinds of opportunities for it. It makes the product more robust, it makes the product more enjoyable, it makes it have smooth shifting. It makes it have a lot of different things. But, all of those different details that we sell on, that we use as attributes to talk about a product, they really all go back to that one central theme, we can shift under load, under power. Armando: That makes sense. And that's again one of the reasons that your CVT is often paired with an electric bike.
Manual or AutomaticArmando: Now when it does come to shifting under power, or I guess anytime, you have a couple of options, a manual and an automatic. Talk a little bit about the differences between those two. David: Sure. So our manual shifter is what you would expect. It has no electronics in it. It has cables that run from the handlebar through the frame of the bike, to the rear wheel, where the transmission is, and when you twist the cable one way or another, it changes the ratios. That is fundamentally the same as all of the competitive products, whether it's a derailleur or an internal gear hub that does have gears and does not have CVT. You turn something on the handle a wire and a cable pushes or pulls a device attached to the transmission, and therefore changes the ratio.
David Hancock with the Enviolo CVT.So our manual shifter does what is sort of expected of bike transmission systems, and has been over the last several decades. We also have an automatic system and that relies on electronics. The difference there is that our electronic system puts a small servo at the rear wheel, which is a little bit like a window lift motor, as far as configuration and power. That servo waits for a signal from the user, and that signal can be a bunch of different ways. It can be from something on the handlebars, it can be from an app, it can be from a third party device. It waits for a signal, and that signal tells our transmission what ratio to go to. And what does that mean? That means that we can do really cool things. Like, if you want the person's legs to always be at the same RPM, we can monitor wheel speed, we can monitor pedal speed, and then we can always adjust the ratio of the transmission to keep the person at the same cadence, or keep the person's legs at the same RPM. It's almost like a reverse cruise control. In your car, you set the speed on your cruise control, but the engine varies the RPMs to keep that speed. This is just flipped around. This one, we keep the engine, which is your legs at the same RPM, but we can vary the speed. So if you want to speed up, you just try to peddle a little bit harder and therefore the transmission tries to slow you down, because it's trying to keep your cadence the same and therefore the bike goes faster. And then vice versa, if you slow down your legs, transmission makes it easier to pedal, which keeps your RPM the same, but then the bike where to slow down.