Engine Safety Interlock for Motorcycles

[posplayr]

Hi just looking for input before I commit to building anything like this.

I know most of you want to strip this stuff out, but there may be a few people that might want to actually incorporate a design that actually works. I think it would basically replace this with a few added features. Especially nice if you plan on an alarm system and especially if you do a remote start

There have been various threads discussing various kinds of safety interlocks for clutch, kickstand and neutral.

For example, the GS Suzukis only have the aggravating clutch safety switch, most modern bikes have some combination of logic to protect you from your own harm. The usually thing that I see is that the safety logic is designed to be easy to implement even if it prevents you from doing something that you really want to.

For example on a GS forcing you to pull the clutch to start the bike even if you are in neutral.

On other bikes, not allowing the engine to run with the side stand down, even if you are in neutral.

There are probably other bike safety designs that are equally as frustrating but the truth be told no matter how silly you might think a safety interlock is there are absolutely certain conditions under which you don't want your bike to start or run. The problem is most designs don't just exclude these safety conditions , but because of overly simplified safety designs they also stop you from doing things that you really want to do. Like start a bike with the kick stand down and clutch engaged because you are in fact in neutral and there is no safety issue and you do this all the time while putting your helmet and gloves on.

So while you might only begrudgingly agree that maybe there are some benefits to an interlock, and even if it is only making you just a little bit safer I know that many will still want to opt out because they figure it is just something else to fail and leave you stranded. OK so the risk (of failed interlock) v.s. benefit (of safety) may be tilted more toward the risk of being stranded (because you are a really a good and experienced rider and you just never screw up ).

Well, you have to ask yourself a question; What is likely to happen first? Will the interlock fail and strand you before if keeps you from hurting yourself? Are you that good that you never make a mistake before a piece of gear fails. So this is really a personal decision and given and option of being stranded or of being safer it is kind of a toss up, and many will go for the added risk than to bother with an interlock.

But what if there is no way the interlock will strand you, and it will only "protect you " in the specific situations that you really want it to be there, excluding all the conditions when it would just be in the way. In addition if you are screwing up it will not just cut your engine or stop you from cranking, but it will also tell you why with a buzzer. Is that really that bad?

What if you were trying to install a motorcycle alarm, and there is this new option for remote start. Do you want to really install that without an effective way to prevent starts that will end up with the bike laying on the ground?

In addition, motorcycle alarms usually have a wire provided to immobilize your ignition when activated. When the wire goes to +12V the bike can't run. How do you disable your old UJM bike that doesn't have an ECU without running a relay that is going to draw a bunch of power. Well this is also something that the Engine Safety Interlock can easily provide.

So this thread is really a small market survey for determining interest for such a device. Read the description below and leave any feedback pro or con. I really don't think there are going to be too many people interested but I can't really see doing an alarm integration without having some of these features. I'll use the information to decide if I build any of these beyond a few prototypes.

TIA

 

[650Skull]

82 and 83 are the years the side-stand safety relay was included. Most of the problems associated with this is that owners do no know it is on the bike so when it can't start they come on here asking for help. Haven't heard of them failing but that's not to say they can't.

Having broken clutch cables before i wouldn't like to have a safety relay stopping the bike from starting in gear without the clutch engaged

Had to use the electric start with the bike in gear to get it rolling before riding without a clutch.

I assume the Safety rely would not allow that to be done.
How would the safety relay affect rolling starts?

Most bobber chopper guys are pulling the electric starter and having kick only and the bike wont start by kicking if the clutch is engaged

 

[posplayr]

82 and 83 are the years the side-stand safety relay was included. Most of the problems associated with this is that owners do no know it is on the bike so when it can't start they come on here asking for help. Haven't heard of them failing but that's not to say they can't.

Having broken clutch cables before i wouldn't like to have a safety relay stopping the bike from starting in gear without the clutch engaged

Had to use the electric start with the bike in gear to get it rolling before riding without a clutch.

I assume the Safety rely would not allow that to be done.
How would the safety relay affect rolling starts?

Most bobber chopper guys are pulling the electric starter and having kick only and the bike wont start by kicking if the clutch is engaged

Within reason any logic could be designed, the question I'm trying to get at is how would you want an interlock to work and what options to incorporate.

You do bring up some different situations, but some of them fall by the way side. For instance, with kick start bikes the conditioning of START on anything is irrelevant as there is no starter. There certainly is no need to disable the ignition if there is a rider kicking the engine over. If there is some risk he can take that risk on without needing a brain box (all be it simple) to try and protect him.

As far as the clutch engagement example, I'm assuming the clutch switch is at the clutch perch and not at the transmission. I guess that may not necessarily always be the case but that was my assumption. So pulling a clutch handle with broken cable should be no issue if that is what it takes to run crank the engine in gear.

If you really need to roll your bike by cranking the starter motor (i.e. in gear with clutch engaged), you would have to disable the ESI as that is exactly what it is trying to prevent.

 

[650Skull]

There is no clutch switch The bike has to be in neutral. XS650 wont start in gear with the clutch engaged

 

[TwoManyXS1Bs]

Not an expert on this, but I believe some earlier models used a 4th (yellow) wire off the stator to sense if the engine is running, to disengage the starter before it can be hurt, faster than the typical rider's reaction time...

 

[posplayr]

There is no clutch switch The bike has to be in neutral. XS650 wont start in gear with the clutch engaged

EDITED:
On second thought I think the combination of the logic for both START and RUN requires a clutch switch in order to not be intrusive.
For example there are times on my GS1100ED that I cant get the bike into neutral unless the engine is running. I would like to be able to pull the stand next to the bike with the clutch pulled and start it. Then slip it into neutral and let it idle with the clutch engaged. In order to allow that WITHOUT hazard, I need a clutch perch switch

Maybe a jumper for no clutch switch to modify the internal logic or just pull the clutch signal to +12V. I'll look into it.

The START logic is looking for either CLUTCH or NEUTRAL to allow the solenoid to be energized. So if there is no clutch switch and you don't want to install one you can just leave that input "OPEN" and the START will only be controlled by the NEUTRAL switch.

 

[posplayr]

Not an expert on this, but I believe some earlier models used a 4th (yellow) wire off the stator to sense if the engine is running, to disengage the starter before it can be hurt, faster than the typical rider's reaction time...

Yes I forgot about the "running detect" off of the stator. It would be pretty easy to detect the stator voltage but the timing of how fast to do this might be a little tricky.

On the other hand a typical stator (for any PMA bike) has to be able to put out 15V at idle so that with a couple volts of R/R drops it can still charge at 12.8V. So the stator output will pretty much rise linearly from 0 volts when the engine is not rotating to 15V at what ever the idle is.

Just thinking this through it is probably sufficient to detect about 7.5V as that is going to correspond to 1/2 of idle speed which is likely well above the starter speed. I might be possible to just set the voltage to some fixed level and it would essentially work for any bike with a +12V system. Once detected (engine at 1/2 idle speed), it would be straightforward to cutout the START signal.

Thanks I'll add that "feature". It would certainly be of value if you were doing a remote start (assuming it is not already there)