Safe Speed Forums

A European project funded by the EU Commission, called SAFERIDER is developing a force feedback throttle to restrict speed on motorcycles. Basically the control principle is based on gradually increasing the stiffness of the return spring adding a simulated stiffness when a speed warning has to be transmitted. The system consists of an electric motor that is connected through a pulley on the return cable of the throttle.

Some people think that these devices are useful or not in cars, trucks and vans - many including myself do not! But on a motorcycle there is a fundamental problem which is related to stability. The throttle is fundamental to the stability of the bike and the gadget that this project consortium is developing is dangerous. My experience with the EU Commission is that they will support the outcomes of the projects that they fund, even if the results are complete rubbish and useless.

I don't want to abuse this first post by linking it to a campaign against throttle control, but I'd like your opinions first.

Admin : Thread moved from Here

I have often thought that some sort of device which stiffened the throttle spring when you reached the speed limit would be quite useful. Not stiff enough to stop you going through it but enough to warn you. And I would want to be able to turn it off

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

I assume you're referring to ISA (Intelligent Speed Adaptation) ?



Whilst the throttle on cars has no effect on stability of the car ? hmmmmmm.

My line of thinking on these types of things is that:
a) if properly (i.e. safely) implemented they shouldn't compromise the stability of the vehicle (perfectly possible).
b) in almost all circumstances on public road whatever the vehicle you shouldn't be so close to the limit that a throttle intervention would be irrecoverable.

The more vunerable the mode of transport, the more control I would want over the speed and acceleration to get my self out of danger, how often do people walking speed up or even jump to avoid danger? slowing people down in events which have danger thrust upon them, to the point of them not being able to take avoiding action, is ridiculous and can only be thought up by someone who has never experienced danger.

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

Yes, but to nowhere near the same extent.

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

I was once on a road where a speed trap created a dangerous situation, which forced me to go at 93mph on a 60mph to resolve it, at the speed trap site. So, nobody was hurt because my 1000cc motorcycle (BMW R100GS) could go 33mph over the speed limit. Furthermore, I was able to prove this in court, and Special Reasons were accepted.

I would be against any artificial limit.

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http://kalvis.com/

An interesting idea!

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http://kalvis.com/

Not on a motorbike for reasons of stability - and yes this is another version of the ISA which is now being re-invented by this project consortium as part of a series of "warning" Advanced Rider Assistance Systems with EU funding.

For further details see http://www.righttoride.co.uk/?page_id=1955

Thanks for your comments, much appreciated

I understand the stability of motorcycles very well, both as an advanced driver, and in terms of the Newtonian dynamics of motorcycles. I think you are overstating the stability aspects of this, and there are better reasons for objecting to it.

Can you explain your stability concerns? Under what conditions do you see the stability to be a problem?

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http://kalvis.com/

Elaine

Lets take it back a step - why do this at all ?

Why assume that people cannot 'cope' with all the throttle.
If I am overtaking using ALL the throttle is best - that old addage of only using 3/4 and 'keeping a reserve' is nonsense - why ? What has to happen to consider it then necessary ? You need it 'now' and make the overtaking action totally safe.

To restrict any vehicle (and I do ride but not ridden a seriously powered bike), makes me question the fundamental purpose. I see no gain from it at all that simple training and education cannot resolve.

The whole concept that 'slower must be safer' is non-sense, appropriate speed to conditions is safe, that can be well under any posted limit to times when above it too can be safe (still illegal obviously).

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Safe Speed for Intelligent Road Safety through proper research, experience & guidance.

There have been many discussions about ISA in these forums - one link here... there are many dangers with ISA and throttle / braking controls.
Not least - what happens when it goes wrong, because it surely will ?

I also foresee a return to simple mechanical vehicles and bike to overcome this - or more people turning back to older vehicles to side step the issues.
Most average riders seem to be more interested in skilled riding than the average car driver, which is interesting in itself. To kerb a throttle and loose this depth of control can and would IMHO effect many aspects of bike handling, stability as you suggest being just one.
To have any system take over your choice of ability to be in control questions the responsibility of the ability of any motorists.

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Safe Speed for Intelligent Road Safety through proper research, experience & guidance.

I would expect if compulsory speed limiters were brought in that sales of new motorcycles apart from small commuter models would completely cease.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

I don't see where it says it's a speed limiter; just more effort needed to twist the throttle wide open?
More to make it a little harder to accelerate excessively quickly, but not impossible as in trakgalvis' example.

I am a extremely experienced motorcyclist, and still think the stability issue is being overstated, though I agree with many of the other points in this thread. I drive a lot, and I only use a motorcycle. Most motorcycles have rev limiters, to stop the motorcycle exceeding max revs in each gear, but this is not considered to make them unstable.

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http://kalvis.com/

On a power motorcycle with say a 0 to 60 of 3 seconds, there are a lot of times when you would not use full acceleration. If you want to me to describe them in detail, I will.

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http://kalvis.com/

It's very simple.
the right hand has many function to perform on a m/cycle.
Engine revs.
Braking.
Indication (at least on mine).
Head/side lights.
The last thing I need is a stiff twist grip to contend with, and one which varies it's stiffness with either engine speed or road speed.
The idea behind all these on m/cycles is not to limit the speed but to limit m/cycles.

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

I agree there are a lot of good reasons not to want this system, but do you think aguments about stability are valid? I would be more concerned about repetitive strain injury, say.

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http://kalvis.com/

Agreed I can think of two more too, holding onto the bike and steering (even the push steering).
One balances partly through your body and partly from hand grip / arms and head movement.
The body ends up working 'at one' with the bike.
There seems to be different systems that are 'on offer' from this Company and throttle limiting devices that are for other vehicles inc cars too is firmly on their menu.

I agree that on very powerful bike that perhaps not 'all the throttle' would always be needed for every overtake. To complete the overtake in the best timeous manner is best practice.

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Safe Speed for Intelligent Road Safety through proper research, experience & guidance.

Thanks for moving this thread - I had thought that it should be in the motorcycling thread, but I guess this is the best place for it.

Re stability, I think that the comments from Duncan MacKillop, advanced motorcycle trainer, are my best response to that question.

"I too was involved in the initial consultation for the Saferider project and like the other trainers, I could immediately see that there was a serious problem with trying to achieve safety through interfering with the throttle. At my riding school, the very first thing we do is to get the students to understand what the throttle actually does and not what they think it does.

The primary function of the throttle is to turn our bikes from something that is statically unstable to something that is statically and dynamically stable. Few of us can keep our feet on the pegs and balance a stationary bike simply by using shifts in bodyweight, but this all changes once we open the throttle when the task of balancing on the bike becomes immensly easier. This change in stability state comes from the forward motion of the bike and nowhere else. Unless we ride in a land that is on a permanent downhill slope, then the throttle is the only thing that can give us the stability we need.

The secondary function of the throttle is to control our suspension. Most riders know that the forks extend when we open the throttle, but around 90% of my students think that the rear suspension compresses at the same time. Few riders appreciate that the rear suspension also extends when we open the throttle. This extension of the suspension when we open the throttle gives us lots more ground clearance which is essential in any corner as well as putting the suspension in its sweet spot.

Finally, the throttle does the relatively simple job of changing the speed of the bike.

With an open throttle, a bike is more stable, has better ground clearance and has improved suspension function. With a closed throttle a bike is less stable, has less ground clearance and reduced suspension function. Of these two states, which is the safest?
Most government agencies like to believe that the throttle only makes bikes go faster and therefore safety can be improved simply by closing the throttle and slowing things down.

Helping these agencies to understand the somewhat counterintuitive relationship between throttle, stability and ground clearance will go a very long way to improving motorcycle safety rather than the somewhat dubious functions envisaged in Saferider".

Hope this helps

Nobody had been talking about closing the throttle, until now. Are you really claiming (now) the plan was to completely kill the power? If not, what you are saying does not apply, does it?

I think the best way to fight a bad suggestion is for the comments to be well targetted on exactly what that suggestion would mean, rather than general statements, which do not exactly apply to what is being talked about.

I really do have a very good understand of the dynamics of a motorcycle, but wanted a very clear statement of what instability would be caused by the suggested proposal.

On a technical point, a motorbike is never statically stable, but as you point out under power is dynamically stable.

So, what exactly is the proposal again?

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http://kalvis.com/