Updated: Mar 6
When Tiller Rides began, we didn’t set out to build a new ebike around a revolutionary frame. In fact we didn’t set out to build an electric bike at all. What we set out to do was build a bike that had all the features urban riders said they needed to make using it for everyday transport as easy as using a car. What they wanted was a bike that could be used in everyday clothes without getting dirty or sweaty. They also wanted it to be easy to use and not require lots of accessories to be carried around. And finally they wanted it to be stylish so they could use it for all types of trips - including getting to and from work in work clothes, going out for dinner, or attending a work function.
To meet all these demands the Tiller Rides design team needed to create a bike that was stylish, had electric assist and had a wide range of needed features integrated in a seamless way. It was this last requirement, integrating all the features, that required us to rethink the standard tubular bike frame.
It is surprising to discover that the standard tubular bicycle frame has changed little since the invention of the modern bicycle by John Kemp Stanley back in 1885.
Since 1885, the tubular bicycle frame has been made in a seemingly infinite range of shapes sizes and arrangements but using essentially the same tubular construction method. This ongoing use of tubes is largely driven by the fact that tubes are relatively simple to make, shape (usually in a 2D form) and weld together.
Examples of common modern tubular framed bikes
The problem with using tubes for a bicycle frame is that because the tubes are usually of a small diameter, and hence have limited space inside, it makes it very difficult to add features such as lights and locks without bolting them on the outside. This is especially a problem with the invention of the electric bicycle which requires several large items such as a motor electronics, displays and batteries to be added somewhere.
It was this challenge of integrating all the needed features, especially the electrics, that lead the Tiller Rides design team to consider using a different frame - one that was hollow and so could house most the features internally without affecting the aesthetics.
After careful consideration the Tiller Rides designers decided to use a monocoque (french for single skin) type frame where loads are supported through the frame’s external skin (like and eggshell). This type of frame is hollow because it doesn’t require a load-carrying internal frame.
Interestingly, the shift from tubular or chassis frames to monocoque-like frames, where pressed sheets of metal make up the load carrying part of the vehicle, occurred in the car industry back in the 1920’s and 30’s. While a pure monocoque proved not to be the optimum solution, most modern cars are semi-monocoques made of pressed sheet metal.
In the bicycle industry however, while there has been a few experiments with monocoque type frames over the last 50 years, the Roadster's frame is the first monocoque frame (that we know of) that is used on a commercially produced bicycle. It is this innovative piece of engineering that gives the Tiller Rides frame a significant edge over other ebikes because of its ability to provide superior functionality and style.
Being able to do function and style at the same time is what makes a Tiller Rides ebike the ultimate urban transporter.
By Julian Ilich - Co-Founder of Tiller Rides