Anyone reverse engineered Harley's throttle-by-wire?

[trevc2]

Has anyone taken a look at these to see if they can be adapted for use as a more reliable ebike throttle system?
http://www.ebay.com/itm/Harley-Davidson-Throttle-By-Wire-Sensor-and-Harness-Touring-/251418987659?pt=Motorcycles_Parts_Accessories&hash=item3a89bd4c8b&vxp=mtr

They're based on a dual set of hall sensors, and it seems there's a handlebar insert with sensors + the housing parts which slide over the exterior of the bar. The hall signal cables are then routed to an external controller/actuator.

It feels like we're still stuck with only two options for throttles: Chinese garbage or Magura(with no redundancy and not much in the way of weather-proofing). It would be great if we could incorporate something more reliable like the Harley system, or whatever manufacturers of electric motorcycles are using. I assume the Harley bars are also 1" instead of 7/8", which doesn't help our cause.

I hope that we start to see some new ideas for better and safer ebike throttle control.

 

[NeilP]

Are yo going to want to pay what harley sell their throttle for though?..I am scared every time I go to the store to buy Harley parts...so scared in fact that my Sportster has been in dry dock for three years...

 

[trevc2]

The second-hand market for the Harley throttle components seemed fairly reasonable. I think anything under $100 is ok for a throttle, if it means you're getting something reliable. It would be great if new controllers like the Max-E/etc could accept dual sets of throttle sensors inputs to help in managing fault conditions and improving accuracy.

Does anyone know what companies like Zero and Mission Motors are using for throttles on their production bikes?

I think putting $1 Chinese throttles on >5kw bikes is insane. Magura is a bit better, but still not great. It's still a single point of failure and not even weatherproof.

Are yo going to want to pay what harley sell their throttle for though?..I am scared every time I go to the store to buy Harley parts...so scared in fact that my Sportster has been in dry dock for three years...

 

[gwhy!1]

I have my own very nice throttle interface... 8)

 

[trevc2]

I have my own very nice throttle interface... 8)

You're just going to tease us like that? Looks like a great setup. What did you use, and how does it work? Looks like you've wired up sensors to the cable of a gas Trials throttle.

The grip looks very similar to an ODI Ruffian, which are awesome narrow grips.

 

[gwhy!1]

The throttle itself is a regular motorcycle ( trials bike ) cable pull type. Any type of cable pull throttle will do the job. The interface is home made, and I have the molds to reproduce the parts. The cable pulls a hall sensor from one end to the other where the magnets are. Different spring strengths can be used to get the desired feel of the throttle, That's about it really, I am in the process of testing durability and if all goes well the interface will be for sale.

 

[trevc2]

Very nice. How does it feel compared to a Magura?

I drilled a new hole for the tension spring on my Magura (increased tension), then sealed it back up and applied a touch of teflon lube to any moving surfaces. Definitely feels better now.

The throttle itself is a regular motorcycle ( trials bike ) cable pull type. Any type of cable pull throttle will do the job. The interface is home made, and I have the molds to reproduce the parts. The cable pulls a hall sensor from one end to the other where the magnets are. Different spring strengths can be used to get the desired feel of the throttle, That's about it really, I am in the process of testing durability and if all goes well the interface will be for sale.

 

[gwhy!1]

it feels just like a real motorcycle throttle, it snaps back very well, has no slack and the fact that is a non- contact device means that it will be more reliable than a magura .... I used a magura for a while but didnt like it and after about 3-4 hours use the pot started to get worn and non-consistant,
so quick answer... in my opinion my interface is 100% better than anything else on the market for the price .

edit:
Only criticism of it is, wish it was a lot smaller.

 

[trevc2]

If you build any extras, or do a short run, please put me on your list of early buyers. I'd get a high quality throttle to go with it, screw the cost. I'm sick of the toy stuff.

The nice thing about your design is that it wouldn't be terribly difficult to add dual-halls for when controllers start to support redundancy, etc.

it feels just like a real motorcycle throttle, it snaps back very well, has no slack and the fact that is a non- contact device means that it will be more reliable than a magura .... I used a magura for a while but didnt like it and after about 3-4 hours use the pot started to get worn and non-consistant,
so quick answer... in my opinion my interface is 100% better than anything else on the market for the price .

edit:
Only criticism of it is, wish it was a lot smaller.

 

[Matt Gruber]

What is going bad? I've got 7 ev's and no throttle failures. I dont ride in the rain. Is that it? water?

 

[t3sla]

ORO ( Taiwan) make an awesome quality plug and play hall throttle. They could gain from increasing the rubber grip thickness, apart from that they are gravy.

 

[trevc2]

What is going bad? I've got 7 ev's and no throttle failures. I dont ride in the rain. Is that it? water?

Nothing's gone wrong so far, I'm just not impressed with the Magura (all plastic, feels cheap, not weather proof). The Chinese ones aren't even an option, those are for kids toys. The Magura isn't much better. We're building what are essentially very light motorcycles and then using crap throttles. Seems strange

Only criticism of it is, wish it was a lot smaller.

It's probably still smaller than other potbox models:

Curtis PB-8 5k
http://www.thunderstruck-ev.com/curtis-pb-8-pot-box-replacement-for-the-pb-6.html

 

[trevc2]

Happen to have a link? The only Oro models I could find didn't look very promising. They had that cheap electric scooter-y appearance to them.

ORO ( Taiwan) make an awesome quality plug and play hall throttle. They could gain from increasing the rubber grip thickness, apart from that they are gravy.

 

[Matt Gruber]

Dont underestimate kids toys sold by major retailers! I find the quality to be very good, due to lawsuit worries. Kids beat the crap out of toys, so they have to be very strong. Walmart doesnt want to sell something that gets them sued. My first Razor E300, from2004 was recalled for a new fork. Kids were breaking them doing stunts. I didn't send mine back, i dont stress mine, and it is fine. As for throttles feeling sloppy, they have to have lots of slack so they dont jam. Get over it.

 

[gwhy!1]

What is going bad? I've got 7 ev's and no throttle failures. I dont ride in the rain. Is that it? water?

noisy pots and very twitchy bikes that need very percise control just dont mix . A pot thottle on something that do not require this fine control will be fine . My application requires constant adjustments of the throttle and on a road bike ( or MX ) these adjustments are normally slow, non-critical changes that are needed.

Edit: The magura throttles ( I have tested 2 ) are still functionable for normal use and the worn pots are not a issue on a less twitchy bike.

 

[gwhy!1]

some e-bike hall throttle are better than others, but the general design of them will always make them prone to damage from being drop on ( more so than a real motorcycle throttle )

 

[Matt Gruber]

gwhy
i sure agree with that! I've often had to modify mine for smoother adult control. Last week I added a 2.5" palm lever and my new ebike went from nervous and twitchy, to easy to work. Took a half hour. Nothing internally changed.
But i'm an adult. if you trash your bike, i suggest a half throttle like razor uses, with mods to meet your needs.
Even 10 years ago Razor knew a full throttle would be smashed. so they used a half, that won't smash. But imo the spring is too stiff, so i agree there is room for improvement. One i took out the spring, the other i added a thumb lever with a light spring. either could be dropped without damage.
One i put a pot in series with the hall. that was for lower max speed. There are endless mods possible with a throttle.
One i have yet to try is a push button control panel from a vcr. 4 switches, off, low, med, high. Why twist at all? brake lever cuts power. endless mods possible

 

[100volts+]

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[trevc2]

some e-bike hall throttle are better than others, but the general design of them will always make them prone to damage from being drop on ( more so than a real motorcycle throttle )

It sounds like there's several motorcycle manufacturers using high-end hall setups or similar, I'm surprised we haven't seen more of them torn apart and adapted to ebike usage. Why people would be satisfied with the plastic junk on bikes with any power, I have no idea. Your mini potbox device is the best solution I've seen so far. The Curtis PB-6 (and similar) would also work well, but they're a bit bulky.

My ride is only just over 6kw and I still think it deserves a real throttle. My next build is based around a Cromotor, pushing much higher power, so there's no question investing in a decent throttle setup is worthwhile.

How much power is your build with the custom potbox + domino?

 

[gwhy!1]

it can programmed upto 15kw ( its programmed for 8kw at the mo ) and currently geared for 28mph so this combination of power and gearing makes it a very twichy bike indeed.. even though the bike weights in at around 55kg.

 

[Lebowski]

I use a what's apparently called a potbox on my bike. Disadvantage is the very small throw, I get only about 300mV between throttle closed and full throttle.


That's why I changed to a linear potmeter for my recumbent, much better and almost the full voltage range:


I use a half-grip shifter for my cable operated setups, with the ratcheting mechanism removed.

 

[gwhy!1]

This is a pic of my first attempt at a home made pot throttle/cable pull. it uses a 10k pot designed for this application ( the 10k track was only somehthing like over a 100degree span ) it work ok but again it became noisy after a couple of hours use. After this attempt is when I realised that the only way Im going to get the reliability that I want its going to have to be hall sensors.

 

[trevc2]

There's definitely some good quality pots out there, like ones intended for the audio industry that can be abused for years and still track accurately. Unfortunately they get quite expensive

My Magura is still working ok in terms of feel, but just today I noticed the throttle now "walks" around slightly when I maintain the exact same position on it. You can hear the controller alternating between 2 or 3 close power values.

This is a pic of my first attempt at a home made pot throttle/cable pull. it uses a 10k pot designed for this application ( the 10k track was only somehthing like over a 100degree span ) it work ok but again it became noisy after a couple of hours use. After this attempt is when I realised that the only way Im going to get the reliability that I want its going to have to be hall sensors.

 

[Matt Gruber]

don't overlook the millions of throttle pots used on EFI cars ~1984 to 2000?
called a TPS- throttle position sensor, about $25 new, they usually work 100,000+ miles without problems. car will jerk when they go bad. They prove that a pot can last and LAST! I've got an early model, maybe someday i'll make a thumb control from it. BUT, nothing will be easier than adding a lever to a full twist grip and using the palm/wrist for speed control. This way the large upper body weight controls speed, instead of tiny finger muscles. Took me 10 minutes to bend some tubing, clamp it on and test it. 20 min of fine tuning, and a foam pad, and it is done.

 

[gwhy!1]

TPS on cars will be heavily filtered for noise and may also have a addition pot that may be used for error monitoring..ICE motors are also very slow in responding to throttle input ( compared to electric ) more upto date TPS use non-contact devices as it has proven to be a lot more reliable. A lever type of throttle on a very twitchy bike is not a option you need to be holding on to the bars without compromise this is also the reason why a half grip is not suitable. With a half grip it is quite difficult to modulate the throttle precisely using your thumb and pointing finger an still have a good grip on the bars, it not be so much of a problem for lower/less twitchy, powerful e-bikes tho.