A prototype is a preliminary model of something. Projects that offer physical products need to show backers documentation of a working prototype. This gallery features photos, videos, and other visual documentation that will give backers a sense of what’s been accomplished so far and what’s left to do. Though the development process can vary for each project, these are the stages we typically see:
Proof of Concept
Explorations that test ideas and functionality.
Demonstrates the functionality of the final product, but looks different.
Looks like the final product, but is not functional.
Appearance and function match the final product, but is made with different manufacturing methods.
Appearance, function, and manufacturing methods match the final product.
This project started when I wanted to try out electronic shifting, but didn't want to replace my trusty 9 speed drivetrain with an 11 speed shifter/derailleur/cassette/chain.
So I decided to make my own.
I wanted a system that would work with existing components and be applicable to any bike from 5 speeds up to 11. I also never liked having to buy all one manufacturers components for things to work.
The resulting system is a digital system that replaces the shifter and it's cable, but keeps your derailleur, cassette, chain, and crank. After 8 generations of prototypes the complete system weighs less than the mechanical trigger style shifter I had to begin with. Cyclists always love less weight!
Each system is composed of 3 parts:
1. Actuator assembly. Total length of the actuator assembly to the cable exit is 8.5". This is typically attached to a seat stay above the rear derailleur with velcro or zip ties.
2. Ring Shifter. This is sized to fit standard 7/8" handlebars (most straight and MTB bars). Currently, the ring will not fit 1" diameter bars (most commonly drop bars as used on road bikes). Should this Kickstarter succeed and the demand exists for it, a version to fit road bars may be created.
3. Independently sourced battery:
By using hobby industry standard batteries, the cost of this component is significantly reduced. A typical proprietary battery for a big manufacturer shifting system is $100 with a proprietary $70 charger. I've been using batteries that are around $5, and have an excellent hobby battery charger that cost $40. If you are into radio controlled cars, drones, planes, etc. you probably already have the charger.
Specification of the battery you will need to provide:
- JST connector
- 2S (or 7.4V)
- Recommend capacities from 180mAh to 1200mAh. (I use a 300mAh cell weighing 19g that I recharge about once every 3 months of riding). Capacity and how many times you shift are related.
- Discharge rate capability. Any battery with greater than 15C rated discharge capability should be fine.
- Chemistry can be Li-poly, LiFe, or equivalent. Most likely you will find Li-poly batteries an inexpensive and good choice.
One of the happy consequences of using this shifter system is that it allows you to intermix different manufacturers components. For example, I am using a Shimano cluster with a SRAM derailleur (which I prefer for their smooth action). My cluster is a 9 speed and the derailleur is intended for 11 speeds. Finally - no more having to choose which "house of components" you belong to!
Even crazier, I built a system for my wife that started as an 8 speed cassette with the lower 2 cogs replaced with much larger ones that are 11 speed spacing. So her cluster is not evenly spaced across it's gears. I did have to switch to a narrow chain, but the system works beautifully. Try that with a mechanical shift system.
If you are into tinkering with bike components, this system frees up what you can do.
Long shift cables
So what does this system have to do with long shift cables? Well, if you ride a tandem and have 100" shift cables, you know that "shift feel quality" doesn't really exist. When new, the cables mask the nice crispness of the system, and as the cables wear, you're lucky to be able to shift at all. This system doesn't care how far away the derailleur is, and the longer a cable it's replacing, the more the weight savings. The electrical connection is a standard hobby radio control servo cable, so extensions of any length can be easily purchased from a hobby store.
Pushing a button is easier
One advantage of an electronic system is that some people find the actuation of a mechanical shifting system difficult or awkward. Pushing a button is pretty easy and promotes keeping your hands firmly on the bars.
What about the front derailleur?
You can install a separate system for the front derailleur. And like the rear system, it might weigh less than your existing shifter. You would, of course, only program 2 or 3 positions for it. Since most front derailleurs do not have cable housing going directly to them, mounting of the actuator will be either on the top tube, or the down tube with a cable housing running to the last frame cable stop.
However, the system really shines when your drivetrain is a 1X? configuration. With today's wide range rear clusters and add on gears, and the ability to mix and match these components, this really makes a 1X conversion attractive. It'll also save a good amount of weight compared to a 2 derailleur system.
How weather proof is it?
The system is water resistant, but not immersion proof as shipped.
The most exposed part of the system is the actuator as it is down on your rear triangle. It is IP54 splash resistant. You can improve its water resistance by spraying the entire assembly with Plasti-Dip. This also allows you to make a statement with your choice of color! Note that if you have to disassemble the actuator for any reason (rare, at best), you will have to cut through the Plasti Dip, or peel it off. Both are not hard.
The shift ring and battery both stay pretty protected as they are up on the handlebars. Shift ring electronics are conformal coated. The battery can be sprayed with Plasti Dip, wrapped, or mounted inside the handlebars if you chose the right size.
A funny thing happens with an electronic shift system. It can actually shift faster than a mechanical system, but it will feel like there is a delay. This is due to the perception of the mechanical system. You technically start the shift when your finger or thumb touches the shifter. You then push the control a good distance until you reach the actual shift point. Your brain doesn't count the time from when you touch the shifter to when you push up to the click. It seems instantaneous, but it is not. With an electronic system, all there is is the button press. The shifter acts, but you are already waiting for it because your actions are done. So it takes a little getting use to. I find that it falls to hand pretty quickly.
Once the system is mounted, a simple procedure to setup each gear position is used as shown in the video:
The system has 11 gear capability. Each gear holds the position that the derailleur should be in. The adjustment procedure changes this position value.
The system comes with the default programming of 9 gears evenly spaced in positions 1 - 9 with the remaining 2 gear positions (10, 11) containing the same value as position 9. This is an attempt at providing the most likely starting positions for the most likely systems. The system is capable of pulling 2" of cable, which in my experience will cover most derailleurs.
If this Kickstarter is successful:
We will move quickly to produce the system. Preliminary quoting of the electronics, sub-assemblies, and plastics of the system has already been completed. Once funded, we will secure final quotes and order parts/assemblies. Then we will follow through with each vendor until their output is received at our facility where final assembly and test of each system will be performed. As final systems are produced, backer systems will be shipped out until all backer rewards are fulfilled.
This process is estimated to take 5 months until the first systems are shipped. Given that we are a small operation, the remaining systems will ship out at a fixed rate until the final volume is reached.
Risks and challenges
This is a product designed by me and draws on my experience as an engineer. While it has been prototyped and ridden over a period of a year, it does not benefit from the kind of manpower, testing, and wringing out that a large manufacturer of bicycle components can devote to the process. Fit, finish, and performance benefit from only the work of 1 engineer.
Small volume manufacturing will rely on leading edge technologies, like 3D printing and can be risky.
This system is likely to require some fiddling with to work well on your bike. You should be capable of working on your bike and able to devote time over several riding sessions to fine tune the system. It is possible that the system will not work in all situations due to an unforeseen design issue.