Cambridge Consultants Develops Smartphone-Powered Automatic Shifting w/ Di2
There’s no doubt in our mind that wireless electronic shifting will happen sooner rather than later, and it’s projects like this that push us closer to the future.
Engineers from UK-based Cambridge Consultants have developed a system that communicates between Shimano’s Di2 electronic group and a smartphone (iPhone or iPad in this case) using Bluetooth Smart. You may recall from our recent conversation with Wahoo Fitness about their tech using BT Smart that it’s a very low power communication protocol, making it ideal for things where big, heavy batteries are bad, bad, bad.
The system is designed to run in either manual or automatic mode, and no, it doesn’t require you to shift from your phone’s screen. In manual, wireless shifter buttons on the handlebar let you control front and rear derailleurs like normal, albeit the signal may pass through the iPhone first. In automatic, you’d set your selected cadence and the bike would shift on its own.
How? Check the details and video below…
By measuring cadence and speed from sensors on the bike (which, coincidentally, Wahoo currently offers), the program or app would tell the bike to shift to maintain the preset cadence. The rider could adjust the desired cadence at any time manually, too. Where the system gets really interesting is when the environment changes. Using the phone’s accelerometer, it could sense braking forces and automatically downshift the appropriate number of gears depending on the severity of the slowing or stop. That way, you’d start pedaling in the right gear rather than mash through a big one until you could shift on your own…assuming you had the where with all to maintain a light pedaling action as you were slowing.
Hit a climb and the accelerometer would sense the incline and downshift according to the angle and drop in speed. That, and by accessing the iPhone’s GPS chip, it could even predict climbs and descents and pre-shift at just the right moment!
Because it controls both the front and rear derailleur, it can also prevent severe cross chaining or bad gear combos that strain the chain.
Even more interesting is the potential for training. Couple this with a Bluetooth Smart enabled heart rate monitor power meter (like Stages) and the app could very easily help keep you in a certain power range. Well, at least the right gear and cadence to give you the opportunity to stay in the right power band…making the resistance is up to you, which could be easy enough if you’re indoors on a trainer.
Two concerns remain: Interference causing unintended shifting, and dead batteries. The former shouldn’t be an issue because of Bluetooth’s frequency hopping tendencies, and the latter shouldn’t be too big of an issue because a) they say small coin cell batteries would power accessories for almost a year and b) you could always shift with your phone to get back home.
We’re also thinking it could be a boon to e-bikes to help manage power usage by adjusting the cadence and gearing.
The system isn’t for sale yet. They’ve hacked it together with a Di2 group for now, intercepting the wires and implanting a wireless receiver that takes the BT signal and electronifies it. They’re looking for interested partners to bring something to production and will display it for real at CES 2013.