They’re the nastiest of bike racing crashes, breaking bones and smashing bikes from Bemsee to MotoGP. But bike tech firm Bosch reckons it could soon make them a thing of the past.
High-sides – they’re the proof that there is no god. One minute you’re having a ball, hard on the brakes, slashing through a bend, knee on the deck. The next, you’re looking down on proceedings, like one of those people who has ‘died’ in the operating theatre, watching your bike fly through the air, in a moment of calm. Not for long though, as you smash down into the tarmac, crunching your collar bone, and seeing your bike cartwheel across the gravel, possibly now in flames.
The mechanics of a high-side are generally pretty straightforward. Usually, the rear wheel loses grip on the way out of a corner, under power. The back end steps out, and as you shut the throttle, the tyre suddenly grips again. The compression and extension of the suspension violently jerks the bike sideways, throwing you up in the air, and tossing the bike up and over the high side – hence the name. Compared with the lowside – a graceful slipping away of the bike from under you usually mid-corner, it’s far more violent and spectacular.
The high-side has come in and out of vogue as bike tech has changed over the years. The 500cc two-stroke era of Grands Prix saw some truly orbital high-sides, which declined as the four-stroke era kicked off. But German bike tech firm Bosch reckons its next generation of IMU (inertial measurement unit)-based traction control ECUs will be able to completely control rear wheel slides, with a very high degree of precision.
You might have heard of Bosch’s IMU unit – it’s standard equipment on all the current top-level superbikes as well as high-end naked and adventure bikes. The theory is simple enough – a smart black box of tricks can measure how the bike is oriented in space – how far it’s leant over, whether it’s wheelying or stoppying, and if it’s sideways or in line relative to the direction of travel. That info, plus the rate of change of position, added to the two wheel speed sensors, lets the ECU work out if you’re crashing or not, how high you’re wheelying, whether the back end is spinning – and a heap of other stuff. From that info, you can use the throttle-by-wire and ABS controls to give you wheelie control, engine braking control, launch control, pitlane speed limiter and smart traction control.
The current generation of IMU system is very smart – but it’s not quite clever enough to control rear wheel slides completely. The ‘yaw’ measurement is currently ‘worked out’ by the system rather than measured directly, so it’s not quite fast enough for the control needed to balance a bike with a smoking rear tyre, 15 degrees sideways out of a corner. But the next generation system, that Bosch is testing right now, and which will be on the street in 2019, will measure ‘yaw’ directly, and will let almost any old muppet come out of a bend sideways.
Fair enough. But what’s this got to do with racing? Obviously most race series have controls on electronic aids, with control ECUs and limits on aftermarket parts. But the head of Bosch’s Two Wheel division, Geoff Liersch reckons the firm might be able to make a safety case to Dorna and other race organisers. “We’re very interested in racing but at the moment, the regulations don’t allow for the tech,” he told BSN in Milan.
“But when we get to the next step with the technology maybe we can look at that from the safety point of view in racing. Obviously in racing, one of the biggest thing is a massive high-side. At that point in time the rider is clearly not in control anymore. So imagine a system where you can let it happen, you get to a point where clearly the rider can’t control anymore, and we can bring the bike into a safe situation.”
It wouldn’t be a total get-out-of-jail card though. Liersch suggests a system of time penalties if a rider has a ‘high-side’, so there’s still a downside, just not a physical one. “Maybe they get a 10 second penalty if it happens, we can tell when the intervention occurs. Okay, you have to go to pitlane for a penalty, but at least you’re not going to hospital.”
He doesn’t see it happening straight away. “For me it’s a much longer term topic – there are a bunch of regulations and everything else when you come at it.” And the Bosch man reckons riders would happily take the next-generation tech on board.
“Riders today complain because we intervene before the edge of their capability. But if we can get to a stage where the rider still has to fight for themselves, but when we get to the stage that it’s dangerous we can pick it up – that, for me, is very interesting. Maybe not for the very highest levels, but certainly in other race classes that exist round the world, we can avoid a lot of broken bones.”