Yamaha MT-10SP tech | Putting the semi in semi-active

 

“Öhlins kit is usually recognisable by an ability to combine supple ride quality with stunning control, but this set-up on either of the pre-programmed settings doesn’t have the ride quality on bumpy roads.”

Steve Rose, BikeSocial's publisher after riding the Yamaha MT-10 SP for the first time.

 

There’s a good reason Steve can’t feel a definitive benefit from the MT-10SP’s semi-active Öhlins suspension – and that’s because it turns out it’s very hard to detect one, whether you’re measuring it with a sensitive 3-axis gyro or an arguably even more sensitive backside.

As it happens both are in play as BikeSocial compares a standard Yamaha MT-10 with its conventional usd KYB forks and KYB rear shock on stock settings, and an MT-10SP with its Öhlins semi-active system on its ‘road’ setting. And, riding along the same stretch of standard-issue back road, at an identical combination of speeds and the same gear, rider, and conditions, BikeSocial’s datalogger (a tank-mounted smartphone running an accelerometer analyser, but data produced is analogous to our perception of ride quality) can find no appreciable difference in the ride quality between either bike. And our back-up datalogger – my bottom – can’t either.

The test is approximately two miles in each direction. Road speed on the outward leg is 40mph; on the return it’s 60mph. The logger is attached to the bikes’ tanks in the same place, recording acceleration in three planes. The bikes are into top gear as soon as possible and recordings are logged from that point, then overlaid.

 

MT10SP suspension graph


The graph is a snapshot of typical data from the 40mph test run (the 60mph run is the same shape, with higher values) and shows very little difference in either frequency or intensity of chassis vibration between the semi-active Öhlins MT-10SP and the non-active KYB MT-10. The reason the graph lines aren’t more closely correlated is because although every effort is made to ride an identical path, even a slight deviation will produce a different input. But that’s okay – what we’re looking for is an overall impression of the ‘noise’ of the rides, and the data agrees with our riding impressions; there’s not a lot in it.

But that doesn’t mean the Öhlins kit is a waste of money. There is a plausible explanation for the similarity of the semi-active and non-active suspension results: altering ride quality may not be high on the design criteria of the Öhlins system for the MT-10SP.

 

Ohlins active suspension box

 

Suspension is, obviously, fundamental to chassis dynamic; but, broadly, it dictates ride quality and chassis control. Ride quality is – generalising again – how effectively suspension manages the feedback of irregularities in the road surface to the rider. It’s not the only factor; tyres play a huge part, and seat, handlebar and footpeg mountings and positions are also important. Conventional wisdom suggests these irregularities usually generate short, high frequency deflections that require responsive and sensitive damping reaction at relatively high damping speeds.

Meanwhile controlling the bike’s chassis dynamic – dictating and maintaining the desired front-to-rear balance under braking, cornering and acceleration to maintain optimum performance – is often regarded as an opposite damping function; damping speed is longer, lower frequency and with larger deflections.

The opposite nature of the damping leads to the idea that the twin requirements are exclusive, and suspension is a compromise between them. That’s not the case in theory but, when suspension is designed down to a low, fixed price that’s often the way it feels: you can have stiff suspension for a choppy ride and composed chassis dynamics, or softer suspension for a smoother ride but wallowy chassis dymamics. Ride quality or handling? But you can’t have both.

Either way, it’s possible the MT-10SP’s semi-active Öhlins are damped to provide a wider range of chassis control under different riding environments – so, for example, if you’re leaping over the Mountain at Cadwell one minute, then gently bend-swinging on the A153 to Louth the next, the SP will automatically adjust to control the Yamaha’s suspension to give you the same chassis balance. Meanwhile the stock MT-10 will be optimised at one location, but not the other (unless you break out the screwdrivers and twiddle in the paddock).

At least that’s a theory.

 

Damping system

 

Conventional suspension – your front forks and rear shock – is a fairly simple system; like a pogo stick, they separate the top bit of the bike (the engine, frame, and you, or the sprung mass) from the bits in down by the ground (tyres, wheels and brakes; the unsprung mass). If impacts from the road surface aren’t absorbed by springs, ride quality and grip pretty much disappear. It’s a bit like jumping off a wall and not bending your knees when you land.

But springs don’t just manage forces fed into the bike from the road; their other job is to control the dynamic attitude of the sprung mass – which is a complicated way of saying when a bike accelerates, brakes or changes direction, the suspension controls the rate at which the sprung mass reacts.

The important word there is ‘rate’. Springs, on their own, tend to bounce: they compress under a force, then extend, the compress, extend, compress etc. If they’re allowed to do this freely on a motorbike, the springs will be constantly deforming as multiple forces stack up and feed into them before they have a chance to recover. Riding a bike on springs only is a good way to become seasick.

That’s where damping comes in. Damping is – broadly – a way of tempering the spring’s tendency to bounce; it slows the spring down and absorbs some of the force. It does this by being pushed and pulled through orifices inside the forks and shock. If you want to adjust the characteristics of the damping – have more or less of it – you need to adjust the screws that, generally, restrict the oil flow. And that needs a screwdriver, and for the bike not to be moving (unless it’s BMW’s older ESA system – and Ducati, Yamaha and a few others used a similar system – which adjusts it electronically when you push a button).

The principle of semi-active suspension is to remove the screwdrivers and buttons, and instead allow the bike’s ECU to decide – based on the general style of riding you’re undertaking ­– to adjust the damping for you, while you ride. The key is it can respond very, very quickly to its environment. Stepper motors in the forks and on the rear shock almost instantaneously and continuously alter damping settings every few milliseconds to match prevailing road and riding conditions. You make a basic selection at the bars of the range of damping you want (based on the kind of riding you’re planning on – sporty, urban, touring etc) and then, using data from the bike’s gyro and accelerometers, the ECU can try to maintain the ‘ideal’ ride quality and handling character. 

 

 

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Second Opinion | Steve Rose 

OK Computer?

Yamaha’s MT-10SP has bleeps and bytes, not bells and whistles. Steve Rose wants to know if this is the beginning of the end or the end of the beginning.

‘What do you think of it?’ It’s a simple question that, as a professional rider I ought to be able to answer. Thing is, Yamaha’s MT-10SP has left me temporarily speechless and the noises going on in my head don’t really equate to any known language.

What do I think of it? Hmm. The simple answer is fast, furious, hard to ride well and, er, a very digital motorcycle. By that I mean it exists in the world of noughts and ones. Either-or, black and white.

There’s nothing subtle about an MT-10SP. No point making minor throttle adjustments or shifting body weight in a corner. It feels like one of those bikes in Tron. Simple inputs bring serious output. The throttle action is direct and effective. Changing gear is a necessary mechanical process not the subtle art-form of 35 years’ experience and cornering is somehow ‘taken care of’ by a load of plastic, metal and fluids contained somewhere down below.

I feel like a passenger on this bike, not the rider. A bit like being on a horse. My role is to make the initial input that gets it going and then, some others to change direction, but other than that I really have very little control at all. That’s an exaggeration, of course, but not a huge one. Compared to something like Aprilia’s V4 Tuono, which is the closest comparison I can think of, the MT feels sharp abrupt, almost clumsy while my memories of the Aprilia are of a flowing, controlled lunacy, where I felt like the one in charge.

Ridden more gently, the MT-SP is fine. Consistent, predictable, easy to control. The biggest difference between this and the standard MT-10 is the electronic, semi-active Ohlins suspension (and a higher price tag). Ohlins kit is usually recognisable by an ability to combine supple ride quality with stunning control, but this set-up on either of the pre-programmed settings doesn’t have the ride quality on bumpy roads. There’s plenty of options for change via the menu button on the right hand handlebar and I suspect that Yamaha’s engineers have chosen standard settings based on what they think most customers are expecting from a 160bhp super-dooper-naked bike. Which is fine unless you’re late home, commuting aggressively and taking to the back roads to avoid the traffic.

The engine is the same and it has the quick shifter (common to all MT0-10s for 2017), but no auto-blipper meaning you do the ‘Chump-and-grind?’ quick shifter wince with every down change. The other significant change is a beautiful TFT screen, brimming with clear, accessible information on pretty much everything you might need including which of the four riding modes you are in and the associated settings, all of which can be changed.

More miles brings more familiarity and understanding of how the MT responds to rider input. After a couple of days and a few hundred miles I’m starting to get the hang of it. I try and make a comparison with my distinctly-analogue 2002-model Fazer 1000. Riding the old bike is a bit like what I imagine flying a Spitfire would be like. Constant, subtle movements of hands, legs and bodyweight guiding a simple bike to where I want to be. In comparison, the MT-SP is like flying a Eurofighter. One action, effectively flicks a switch that operates a computer that fulfils a pre-programmed algorithmic instruction that I could never do as quickly. Except, right now it feels like it’s doing this via a 1981 Sinclair Spectrum interface and tape deck. Ok, that’s an exaggeration, but the MT-10 rides like a halfway house between the subtlety of analogue and what will be the sophisticated minutiae control of advanced digital motorcycling.  We have to go through this to get to that and at the same time there’s a whole load of Euro-4 restrictions fouling up the experience.

From here to there I don’t believe the MT is any faster than my Fazer, but it feels like it. Much more aggressive, much more exciting and involving, much more of an experience. Surprisingly though, given all the sophisticated electronic control, the MT uses a lot more fuel to go no faster, averaging 36mpg (my Fazer’s worst ever tankful was 41mpg, usually it’s at least 45mpg) and a flashing fuel light at just over 100 miles.

At the end of my time with it I’m still not sure what to think. There’s no denying the efficiency and brutality of the MT’s performance, but the flipside of that is that it feels soul-less to me – like the difference between dancing sexily to Smokey Robinson or simulating breakdown to Gabba Techno (ask your kids). Everyone else I know who has ridden one loves it, but I haven’t connected with the MT-10SP. We don’t want the same things from motorcycling and, funnily enough, I enjoyed a recent ride on an MT-07 far more than this bike.

Sorry.