Revonte in Taichung

The Taichung Bike Week and Eurobike form the big duo of events as far as the bicycle industry is concerned. To describe the nature of the events, Eurobike is the place to show what you have and Taichung is where agreements are written and hands shook. After the very successful launch of the Revonte ONE Drive System at Eurobike, we had our eyes on the Taichung Bike Week well in advance.

Same but Different

Eurobike is mostly about industry people, but on the last day of the fair is also open to regular consumers. Taichung is strictly business, meaning that It is aimed only towards professionals who work in the industry. It is also rare that brands launch any new products during Taichung since Eurobike is a better place to that as far as timing and publicity are considered.  

The difference in geographical location between the two events also effects. Eurobike can be considered a truly international event, meaning that people attend literally from all around the world. As one can guess, most of the Taichung attendees have an Asian background, which makes sense location-wise and because the majority of the manufacturing takes place in Asia. 

The Agenda

Our agenda was simple: to have as many productive meetings and customer negotiations as possible.

Our position in the market is very favorable since we do not have any competition with similar qualities. Sure, the array of e-bike motors is vast and plentiful, but no other drive system has as integrated automatic and stepless transmission that runs on a robust and care-free single-speed drivetrain. Couple that with our highly customizable software and we can confidently say that the Revonte ONE Drive System fights in a class of its own.

Industry heard our message during Eurobike, and people know what we are about, it was all about negotiations at this point. The goal was achieved since the number of productive and large-scale meetings was plentiful. Not much can be disclosed at the moment, but things are progressing and moves are being made!

What Is Going to Happen Next? 

We are working hard and long to get our “prototype fleet” in prime condition to kick off the test rides. The whole Revonte ONE Drive System will go through an arduous testing process to expose and smooth out all the possible kinks in the hardware as well as in the software. 

Test ride opportunities are naturally available for all interested (industry) parties. If interested and you have not jumped on board yet, sign up to our newsletter or contact us by email [email protected]

The Early Adopters

This gives us a nice transition to our early adopter phase. If you want to be among the first ones to run the Revonte ONE Drive System and gain the competitive advantage along with it, right now is the last possible moment to hop on board! 

A limited amount of our valued customers are featured in our soon-to-be-released joint public note that describes their design approach and the branch of bicycle industry they are offering their products for. 

Contact us by email and our sales team will get back to you swiftly.

Optimizing the motor and the CVT

Hi there – nice to have you reading this! My name is Dr. Antti Lehikoinen (just Antti will do), and I’m working as a special advisor for Revonte.

This post will take you through what our team has spent the last few weeks on – optimizing the Revonte drivetrain. It’ll cover the benefits and workings of the CVT drivetrain, some challenges we’ve faced, and finally the basics of modern optimization. I’ve tried to keep the amount of raw tech to a minimum, to make the text readable to anybody who understands bicycles.

Please let me know in the comments if I made it or not 😊

Why CVT?

As you might know, the Revonte drivetrain utilizes a continuously variable transmission, otherwise known as a CVT. As its name suggests, a CVT does not have a discrete set of fixed gears. Instead, any transmission ratio (within a certain range) can be reached.

But why use a CVT, you might be wondering. Why not simply have a traditional bicycle gearbox or wheel stack?

Well, there are several reasons for that.

First, a standard fixed-gear transmission has, well, fixed gear ratios. Anybody who’s ever ridden a plain 3-speed bicycle has certainly been climbing a moderate uphill where gear 1 was far too slow, while number 2 was already a tad too heavy. Of course, you could avoid that situation by riding a fancier 21-speed mountain bike, but then you’d be spending far more time going through gears once that uphill suddenly turns into even ground.

Which brings us to the next item: a 21-speed gearset obviously has lots of parts. It’s heavy, there are more parts to service and maintain, and a higher chance of one of them breaking down as they were never designed for e-bikes.

By contrast, the Revonte CVT through inside the pedal hub. All that comes out are the pedals, and then the chainwheel and the chain. It’ll be easy to keep it clean, and you’ll only have to oil the chain a few times a year or you can even choose to use a belt drive.

Furthermore, we only use robust components that have stood the test of time, like spur gears and electric motor. This makes the system extremely durable (especially compared to some other CVTs on the market), while also bringing the total number of moving parts down to the level of a standard 3-speed hub gearbox.

And obviously, it’s a CVT. You’ll be able to maintain a comfy cadence of 60, no matter how fast you’re going, or how steeply you’re climbing.

Challenges we’ve faced

Of course, it’s not all honey and no sting with CVTs.

CVT systems – all CVT systems – are by nature a little less efficient than regular gearboxes. For that reason, they usually adopt a configuration illustrated below (artwork by yours truly).

On the left side there are the pedals. (Obviously!) The power coming in from the pedals is split between two parallel paths. The majority is led along the lower path – a highly-efficient conventional shaft plus standard gears. The remainder is led above, through the actual variable part. Here, speed can be traded for torque, or vice versa. Finally, the powers are combined in a kind of differential, and led into the rear wheel.

As a result, biking happens. And, by changing the transmission ratio of the variable part, we can change the total pedals-to-wheel ratio. Handy, isn’t it?

Also, by using this kind of a power-split approach, the losses in the variable part can be minimized. After all, a big part of the total power goes through a conventional transmission, which is very efficient.

However, the optimal split ratio depends heavily on many factors, such as bike speed, pedalling torque, preferred cadence, the configuration of the conventional-gear path, loss characteristics of the variable path…you get the point. For instance, a drivetrain optimized for steep uphill riding at 8 km/h loses some of its efficiency when cruising around the countryside at 25 km/h.

To complicate things further, all of the above was assuming no assist coming from the battery. Once we consider that, we have even more choices to make. For instance, should we put the assist right after the pedals? Immediately before the wheel? The lower path? The upper path? Or some combination of these? You get the point. And then there are all the dimensions of the individual gears and motor parts to consider.

So, how to wrap all these together?

Optimization

We begin by defining a representative drive cycle – an imaginary cycling trip with both mountainous terrain and urban crosswalks included. Everything, from the gradients to the speeds to the time spent in different environments, was adjusted to best represent a typical cycling behavior of the Revonte end-user. This drive cycle is then coupled to models representing the various components – gears and electric motors – to evaluate the system as a whole.

Of course, this alone doesn’t exactly help in choosing all the dozen parameters discussed above.

Luckily, we don’t have to make all the choices ourselves. Thanks to the advances in computers and in the science of optimization, we can now (and did!) automatically analyse tens of thousands of configurations to find the best fit for our application.

Since a CVT is a rather complex system (you are probably starting to see this by now), something called multi-objective optimization is used. True to its name, the ultimate goal of multi-objective optimization is to find the solution that is best in the all possible senses: the lightest, the most affordable, the most efficient.

But, as you’ll undoubtedly guess, such a solution almost never exists. For that reason, the realistic goal is finding the best possible trade-offs between different targets.

These can be nicely visualized as something called the Pareto front. Despite the weird name, the Pareto front is nothing more than a curve (or surface) visualizing the best trade-offs attainable.

An illustrative example between price and weight can be found below (NOT representative of final Revonte results – just an example). What you can read out of the curve is that a 3-kg design would cost a bit over 200 Euros, while the price of a 1-kg solution would be close to 600.

Like mentioned, that is just dummy data, but you certainly get the idea. Indeed, the main benefit of Pareto optimization is to let the designer make the final choice between different trade-offs. Like if the price would suddenly explode below 2 kg of weight, you probably wouldn’t want to go there.

But how does the optimization work?

Alright, this part is not directly related to the Revonte drivetrain itself. But, it’s still such interesting information that I decided to include it nevertheless.

Namely, how does the optimization work? Like, really work?

Well, we used a specific genetic algorithm (SPEA2 for those really detail-oriented). Genetic algorithms work by maintaining a large set of different designs – called a population of individuals. See where the name ‘genetic’ comes from already?

The actual optimization then happens by creating new generations of individuals from the previous one, based on simple rules utilizing random numbers. Like in Darwinian evolution, the best individuals are favored in the process. This way, each successive generation tends to get closer and closer to the right optimal design.

This process can be seen in the animation below, illustrating a very early-stage optimization run of a then-scrapped design. Each dot you see is an individual drivetrain design. To tell the different generations apart, the first ones are illustrated in blue while deep red is used for the final one.

As you can see, each generation represents slightly better designs – lower losses and lower maximum internal temperatures.


Conclusion

Phew, that was a long one. As a reward for making it this far, you can read the highlights in a convenient list:

  • A continuously variable transmission (CVT) always lets you ride with the best possible gear.
  • The Revonte drivetrain combines CVT with simplicity, robustness and low maintenance.
  • Actually designing the system was a daunting task in the beginning…
  • …but we made it, with some state-of-the-art optimization techniques. And lots of sweat.

Thank you for reading! Please comment, share, and get in touch!

Dr. Antti Lehikoinen

We are now Revonte

Revonte is creating a revolution in the e-bike technology

Freedom to innovate remains the heritage along our journey to make better e-bikes. Our new name underlines the evident new digital era movement in the e-bike industry. We are not happy to make small steps and call them innovations. We are one of the drivers of this industry to push things entirely onto a new level – make the digital revolution in e-bike electronics and services.

The story behind the name comes from Aurora Borealis, the Northern Lights, called Revontuli in the Finnish language. Electrically charged particles created by the solar wind forms an extraordinary light phenomenon in earth’s magnetosphere here at the northern latitudes nature. Name itself is a combination and word puzzle of those words, revolution and revontuli.

Similar to that, our personal “charge” comes from the dedication and passion for developing one of the greatest devices of mankind, e-bike, to its extreme. Making citizens life under the Revontuli better is our goal. We integrate the gearbox in the central motor, services to our system heart and diagnostics in our system soul. That makes lighting experience for every user.

from the CEO’s corner

Antero

Future of e-mobility

Eurobike 2018

Eurobike is now behind us, and slowly all the aftermath is done. It’s great to notice the ever-increasing interest on e-bikes and the effort manufacturers put into them. The whole industry seems to be moving forward and is slowly transforming from traditional bike manufacturing towards e-bikes with all the new possibilities.

Innovations keep gaining traction, and it’s great to see e-bike manufacturers embrace and test new models with new motor manufacturers – of which there seems to be more than ever. Competition is always good news for consumers and manufacturers alike since from hard competition innovations arise faster. E-bike market appears to be dividing into two segments of more heavy duty high-performance e-bikes and lighter e-bikes that are more focused on the riding experience.

Where is the future of e-bikes and e-mobility going?

It doesn’t take a genius to see that sharing economy is coming fast. Especially in the bicycle industry with companies growing at an enormous rate – unreachable for many traditional manufacturers. For example, Chinese bike sharing company MoBike (founded in January 2015) was sold for $2.7B to Meituan Dianping making it likely the most significant purchase ever in the bicycle industry.

It is no wonder that these bike sharing start-ups are gaining value so fast. Cities all over the world are growing, making the traffic ever increasingly more congested. For cities, these type of operators who provide their bikes to the town, free of charge, can feel like a blessing – which allows the technology providers to grow at tremendous speed.

However, to make the sharing solutions popular, it requires complex yet seamless integration between hardware and software. When e-bikes with recharging stations are added to this equation, the whole solution becomes even more complicated. At the moment electronic solutions in the market don’t allow manufacturers to provide shareable e-bikes easily.

While public bike sharing solutions keep growing and getting more and more popular, new solutions for transportation are on their way in the start-up garages and product development labs all over the world. New concepts of light electric vehicles keep popping up almost daily, some more sophisticated than others.

One of the more interesting ones is the German company Schaefflers Bio-Hybrid. What is so exciting about this type of vehicles is that in future they can solve the bottleneck of bike sharing – logistics. No matter if the bike sharing systems are stationless or fitted with stations the bikes need to be moved around via truck.

Four-wheeler vehicles like Bio-Hybrid can work around this problem with autonomous driving during peak hours to even the distribution. Sure autonomous capabilities still need a lot of work but as the AI evolves and car industry keeps working hard with self-driving cars, who knows how quickly this tech will be available for lighter use. In fact, hacker George Hotz’s company Comma AI has already made pretty good progress with their self-driving hardware that costs less than 1000 $. In case of Comma AI it hooks up with the car regular drivetrain, but light electric vehicles need a drivetrain that is flexible enough for innovations like this to evolve.

What could we learn from innovators in other industries?

Especially in the software industry, there has long been a mentality to fail fast – fail often. It is something that is slowly making its way to new fields. New innovations don’t evolve without failures and in the bicycle industry, especially with e-bikes, we should embrace ideology to test fast – fail fast in order to bring new features to the market quicker.

Most of the new technologies rely less and less on the actual hardware – meaning new features and enhancements can still be made even after the product is sold. One of the key examples here is Tesla with their Autopilot software, which is still work in progress. However, every Tesla that leaves the factory is equipped with the required hardware, so when the software is improved, it can be uploaded to the cars remotely. Another interesting example is Audis new project E-Tron that goes even further with over-the-air upgrades with features like new light patterns for headlights that can be bought later on.

In the e-bike industry, this is something that is not entirely taken advantage as of yet. Current systems can be upgraded via a Bluetooth or USB connection, but the full potential of software is yet to be harnessed. Especially as everyone is still so territorial about their products and ideas that it can take years for new features to hit the market.

Nonetheless, these are exciting times, and for sure the e-bike market will go through significant changes. We here at Revonte believe that new technology should be harnessed to its full power. It doesn’t just make our lives more convenient, but it also improves the user experience and whole progress of electric bikes.

 

Iiro Peltola,

Head of R&D

Who are we

Revonte in its current form was founded at the beginning of the year 2018. Revonte was originally a result of two e-bike enthusiasts coming together being fed up with the domination and restriction current electronic systems could provide. We strive on our passion and believe it should show in our corporate culture and in our products.

We both, me and Antero have worked inside the e-bike industry for years mainly on the reseller side gaining firsthand experience of customer needs. In his previous careers, Antero has been running successful industrial projects from start to finish giving him a great deal of expertise to work as our CEO. I come from a very different background as a millennial tech enthusiast and current mechanical engineer having experienced the rise of social media and service economy.

We both experienced the same limitation of current electronics in our previous product development projects – for me in public bike share project and for Antero in his innovation winning light electric vehicle project which led us to an idea to develop our own. Since then, we have iterated the idea with end users, bike manufacturers and service design experts to come up with what we believe to be a winning concept.

From the start, we have had a great pleasure to work with multiple start-up accelerator programs and great start-up culture here in our hometown Tampere. And it has truly shown – through these couple of months we have managed to iterate our product idea, raise private pre-seed funding, raise public funding, run through a feasibility study of the electronics and software, create initial product designs, design a prototype and strengthen our team. The latest addition to our team is Otto in the role of CTO – a successful serial entrepreneur with tens of years of experience in software development.

But a lot of our success is merit to our subcontractors. We have had the utmost success as well as a good luck with selecting the great partners to work with. For us, the fall of Nokia has been a great deal as it has left a huge amount of capable, brilliant and experienced engineering knowledge for us to make use of.

Our vision is to create a new revolutionary e-bike electronics that raise the bar in every segment from mechanical performance to embedded and cloud software. With the ideology we have learned from the software industry, we can provide new service models, earning methods and quicker product development which ultimately leads to better user experience and brand loyalty.

We believe that from here on we will only accelerate our pace – and we can guarantee You that we are working day and night to make that happen!

Iiro Peltola,

Head of R&D