Milwaukee’s innovative idea would target old and new riders alike.
A M A Z I N G S T U F F A M U S T R E A D!
By Ben Purvis
Harley-Davidson’s problems have had plenty of publicity in recent months but they largely boil down to two factors: an ageing fan base and difficulty attracting new buyers—very much the same for all of motorcycling.
Some criticism of Harley has been ill-deserved—after all, despite the company’s staid reputation it’s a leading light in some areas of technology, including electric bikes—but it’s also clear that the type of heavyweight cruisers and tourers making up a big slice of the firm’s profit margins have problems appealing to novices, and aren’t easy practice for the oldest of motorcyclists. Their sheer size and weight, which is part of their attraction for some, mean they can be hard to handle, particularly at low, maneuvering speeds. But what if Harley created a form of rider-assistance system that eliminated the possibility of an embarrassing low-speed tip-over? That’s precisely what this new patent is intended to address. The firm’s idea, as revealed in this new patent application, is to add a gyroscope to help maintain balance when stationary and at walking speeds. Bolted into a standard-looking Tour-Pak top case, this isn’t the sort of micro electro mechanical gyro that forms the basis of modern inertial measurement units in many new sport bikes. Instead it’s a traditional, spinning-mass gyro—the sort that was used for guidance on the Apollo moon missions and effectively a scaled-up version of the seemingly gravity-defying children’s toy gyroscopes.
The gyroscope itself is made up of a heavy flywheel, spun to between 10,000 and 20,000 rpm by an electric motor mounted in a gimbal that, during normal riding, allows it to freely move in both the roll and pitch axis. That means, apart from some additional weight, it doesn’t influence the bike’s behavior.
At low speeds (below around 3 mph) the gyroscope comes into action as a balance aid. A clutch engages locking the gimbal’s roll axis to a lever connected to a computer-controlled linear actuator. That gives the computer the ability to tilt the spinning mass from side to side, creating a force that influences the entire bike. Tip sensors, also mounted in the top case, register when the bike starts to lean to one side and the computer and actuator work to compensate for that lean.
It takes relatively little force to do this, provided it’s applied before the bike has started to lean too far, so the small movements applied to the gyroscope are enough to allow the bike to self-balance. For a novice rider who wants a Harley cruiser but doesn’t have years of experience to draw on, that’s a potentially huge benefit. It’s also a potentially big attraction for older riders, or simply smaller ones who are worried they’re lacking the leg strength to hold up a big Harley that’s started to topple over. As soon as the bike reaches speeds over 3 mph, the gyro’s actuator is disengaged, allowing it to lean and balance normally.
Perhaps the slickest element of Harley’s patent design is the fact it’s self-contained. Rather than being built into a bike, the whole gyroscope unit and the computer controlling it is mounted in the Tour-Pak top case. That means it only needs an electrical feed to operate and could be retrofitted to virtually any number of the firm’s bikes. The patent suggests that a second wire could take speed-readings from the ABS or that a built-in GPS system could be used to measure speed instead.
For new riders it means the gyro could be removed once they’ve gained the confidence to ride without it, and for ageing motorcyclists the design means they could retrofit their existing bikes to add the balancing system so they’re not forced off two wheels purely due to weakening legs.
While a patent application is far from a guarantee that an idea will make production, if this design is proven to work the way Harley hopes, then it could be a revolutionary addition to the company’s offerings.