82 GL1100, first project

[GrayGhost]

Hey guys! I'm Brandon from Colorado and I'm looking to do my first EV conversion. Before jumping in the deep end on a car, I am looking to convert my dad's 82 Honda GoldWing to electric. I have done some research, but I can only go so far on my own. Hoping some of the great experience on this forum will help me to hone in my design.

I'm looking to use it to go to work about 40 miles round trip (can charge at work if need be), 80% highway 75mph speed limit. Will probably never take passengers, so probably me (250 fat pounds) + 50-lbs at most. Regen would be a plus, but not required. Don't have a specific budget, but figuring it will be around $5-6k all in. Here's what I have so far:

Bike: 1982 Honda GoldWing GL1100, stock weight 595-lbs, deiced, 357-lbs. Water cooled. Shaft drive with 3.1:1 final gear.

Battery: 2x Chevy Volt 48V batteries in series for 96V, and 45Ah 2.1kW (Gen1) or 52Ah 2.5kW (Gen2). The size and shape of one battery is almost exactly the same size as a single head of the original 1100, so I will be able to 'duplicate' the look and feel of the engine with the batteries sticking out the side. The batteries will be protected by the original crash bars and a custom built enclosure. With a little creative engineering, I might be able to squeeze in another 1-2x 24V 1kW (Gen1) batteries for a 120V 3S or 72V 2S2P configuration. All these batteries are designed to be liquid cooled, but could be modified for air cooling. Each 48V battery weighs 45-lbs (Gen1) or 36.5-lbs (Gen2) and 24V Gen1 batteries are 21-lbs.

Motor: This is where I really need help. I am considering the ME1616 if I decide to utilize the bike's liquid cooling, or the ME1507 if not. I am having a difficult time finding consistent specs and available models (1304 or 1302?) for Motenergy motors. I see some lower tiered motors, but not sure if they will have enough power. I have also just started reading about Zero motors, but don't know much about them or where to get them.

Electronics: One nice feature of the GL1100 is that the visible gas tank is just a cover with the real tank underneath, so I have quite a bit of space to mount my controllers, chargers, etc in the gas tank area without much modification. Obviously, most of this will be decided by the motor and battery, so not too worried about it at the moment.

Appreciate any input you guys have for me, even if it's just to tell me I'm crazy and should take up basket weaving. Looking forward to hearing from everyone!

 

[Balmorhea]

The liquid cooled motor seems like a good match to the bike, as long as you limit the maximum current to something like the original engine’s maximum. Maximum stall torque of the ME1616 is about 50% higher than the transmission was originally working with.

I think it’s cool that you’re reinventing your dad’s bike.

 

[John in CR]

If you really want to cruise at 75mph with that big heavy bike, you should plan on double the battery. Making that big a hole in the wind at that speed chews through battery capacity. You didn't mention terrain, but I sure hope it's almost dead flat pushing all that weight. If there's much in the way of hills, that's a whole separate issue for which water cooling might need to come into play.

Those who love the idea of liquid cooling never consider that ICE's have to dissipate the heat of an explosion at about 2000°C. With an electric motor you don't want those copper windings getting to even 200°C, and the cooling liquid can't really get very close to what needs cooling, so in comparison to ICE liquid cooling is marginally effective with electric motors due to the small temperature differentials in the heat transfer path. Air cooling can (depending upon motor design) put the cooling flow in direct contact with the hottest parts of the motor. You're not trying for Tesla performance, and you don't want to push your batteries hard enough to require liquid cooling, so lose all that weight and pick up the extra space. Those same motors you're looking at didn't come with a liquid cooling option 10 years ago, and their performance stats haven't changed. The reason it's been added is really only because so many have requested it, so why not add the money making option, that might be useful in only the tiniest percentage of use cases.

If you want to cruise at 75, then you need a top speed of at least 85, because riding around at WOT and slowing due to every tiny road grade or puff of headwind is a ridiculous way to ride. That means you need to gear for about 95-100mph without any load (wheel off the ground).

Make sure your motor and controller get good air flow for cooling and get some air flow around the battery too. The Volt modules are great with only live metal surfaces at the top, so they're easy to make sufficiently weatherproof while allowing air flow around them to avoid building up heat.

 

[amberwolf]

I'm looking to use it to go to work about 40 miles round trip (can charge at work if need be), 80% highway 75mph speed limit.

at those speeds (and higher, which you'll need at some point) you're probably going to use well over 100wh/mile, and with the (lack of) aerodynamics of this bike, probably twice that or more.

so assuming it's very high usage, let's say you need at least 8kwh of battery for the full 40 miles (assuming you can't recharge for some reason, you don't want to be "stuck" at your destination) (and not leaving much, if any, spare for detours, headwinds, hills, pack aging, etc). depending on what you end up actually using, that will probably weigh between 100-150lbs+ with enclosure/etc., and be about the size of a middling-large human torso.

Will probably never take passengers, so probably me (250 fat pounds) + 50-lbs at most. Regen would be a plus, but not required.

the easiest way to get regen (without worrying about stressing drivetrain components) is to use a hubmotor. you won't get much power back out of it (unless you have really long downhills *after* youv'e discharged the battery enough to accept that much more recharge); mostly it's good for saving on brake wear.

if you're not concerned with brake wear, it's mechanically simpler to not worry about regen, as it complicates torque transmission, in that the drivetrain and/or axle mountings have to withstand sudden high torque spikes *in reverse* of the normal direction; braking torque can be much higher and much more sudden than acceleration torque.

but a hubmotor in the rear wheel (instead of a motor and transmission/drivetrain in the frame) would still leave you much more space in the frame for your battery, which you may well need, if most of your riding will be above 75mph (because a 75mph limit means traffic you must maintain pace with may well be above that speed a majority of the time--you should verify what speeds are actually common there at the times you will need to be on it). qsmotor and other companies make motorcycle hubmotors that can either be laced into the existing rim (or a new rim) or that have their own integrated rim built in (the latter makes a "simple" wheel-swapout relatively easy).


the disadvantage of a hubmotor is that it will require some modification of the swingarm's dropouts (making "torque plates" to bolt to them to secure the axle flats against any possible movement), and it will lessen the response of the existing suspension. (that could be retuned to fix that, but may require replacing active components).


but the swingarm modification/torque plates will probably be significantly less work than making motor mounts and shaft-drive-to-motor-shaft interconnection.

Battery: 2x Chevy Volt 48V batteries in series for 96V, and 45Ah 2.1kW (Gen1) or 52Ah 2.5kW (Gen2).

do you mean kw, or kwh? the former is a unit of power, and the latter is a unit of capacity--the difference is extremely important.

if it's the latter, you may need four, rather than two, of those modules, depending on the actual power usage you experience at speed, and whether or not you can actually recharge at your destination, as well as whether you end up with headwinds that make you use more power, or detours, or loss of capacity as the pack ages (and how much capacity each pack *actually* has when you get it, vs what it's advertised to have).

if you like, there are simulators out there that will give basic wh/mile information if you have the cd/cda numbers for the bike. others like the http://ebikes.ca/simulator can give more detailed information, but you'd need more info about your system to use it's "custom" options in the dropdown menus to set it up accurately. (it was designed for simulating ebicycles, so while it's physics and such are useful regardless, it doesn't have any built-in options for motorcycle-class controllers, batteries, motors, aerodynamics, etc., so you have to use the custom options to set each of those up).

without knowing the specifics of your parts to fill those fields, i guesstimated and setup a few systems that would provide the approximate speed you're after, and i get around 200wh/mile or more. your power usage may be better (or worse!) than that.

in these guesstimation simulations, power usage from the battery itself is around 16kw+ (up to 20kw+), and power usage at the motor is around 14kw+ (up to 18kw+) (so there could be as much as 2kw+ of heat to dissipate from the whole system).

 

[GrayGhost]

Wow, thanks for the info guys, definitely gives me a lot more to chew on!

I think it’s cool that you’re reinventing your dad’s bike.

It's definitely one of the perks of this project. Unfortunately, he passed away about 6 year ago, will be a great experience in so many ways.

If you want to cruise at 75, then you need a top speed of at least 85, because riding around at WOT and slowing due to every tiny road grade or puff of headwind is a ridiculous way to ride. That means you need to gear for about 95-100mph without any load (wheel off the ground).

By my calculations, the 3.1:1 stock final gear ratio tops the 5000rpm max motor out at 105mph, a 6000rpm motor at 125mph. 75mph has it running at about 3500rpm. I don't need to cruise at 75mph, 55-65mph would get me by just fine. Living in Colorado, highway "traffic" speed is anywhere between 45mph and 95mph. You also brought up grade, one way is relatively flat up hill with about 1000ft of elevation gain, only about 1 mile of any kind of real hills.

You're not trying for Tesla performance, and you don't want to push your batteries hard enough to require liquid cooling, so lose all that weight and pick up the extra space.

This is definitely something to consider. I was keeping it in the picture since the bike was built for it and it could be a simple integration if need be. I can also split the system to only cool the batteries or the motor. However, I won't be sitting in traffic trying to keep my ICE cool, so this may be a non issue. The only time I will be creating heat I will be moving, so as you suggest, it may be better to just ditch the weight and complexity.

The Volt modules are great with only live metal surfaces at the top, so they're easy to make sufficiently weatherproof while allowing air flow around them to avoid building up heat.

I was wondering about this. I imagine it would be relatively simple to seal the electronics. I also wondered if it would be worth the time and effort to break apart the battery and build custom cooling plates to go between the battery cells (replacing the ones designed for liquid) that attach to external cooling fins. Probably way more work than is necessary, but hey.

at those speeds (and higher, which you'll need at some point) you're probably going to use well over 100wh/mile, and with the (lack of) aerodynamics of this bike, probably twice that or more.

so assuming it's very high usage, let's say you need at least 8kwh of battery for the full 40 miles (assuming you can't recharge for some reason, you don't want to be "stuck" at your destination) (and not leaving much, if any, spare for detours, headwinds, hills, pack aging, etc). depending on what you end up actually using, that will probably weigh between 100-150lbs+ with enclosure/etc., and be about the size of a middling-large human torso.

I was considering taking the bike in one of two directions, making into more of a cafe racer style (which is something my dad would have liked) and trim it down to the bare minimum, or, putting a faring on it to make it more like a traditional GoldWing. Not sure if this will help my aero, but it's a thought.

I could potentially get 10kWh (you got me kWh, not kW lol), but will definitely lose the traditional look of the bike unless I modified it to run under the seat, will have to look into that. Keeping it looking the same, I am looking at max 7.5kWh @ 48V 1s3p or 72V 2s2p (72V would require splitting a 48V module into two.); 5kWh @ 96V 2s1p; if I could stuff an additional battery in, 10kWh @ 96V 2s2p.

it's mechanically simpler to not worry about regen, as it complicates torque transmission, in that the drivetrain and/or axle mountings have to withstand sudden high torque spikes *in reverse* of the normal direction; braking torque can be much higher and much more sudden than acceleration torque.

Not married to Regen, but if the motor supports it, figured it would be a 'why not' scenario. Didn't take the deceleration torque into consideration. Would this be that much different than downshifting an ICE? I would also think a shaft drive would be well suited for this kind of torque, but I don't know for sure.

As far as hub motors go, I have considered them, but haven't really been sold on them. Seems like a lot of work to do and they don't appear to have the same amount of power as the frame mount motors do. The stock tire size for the GL1100 is 130/90-17 and it doesn't like anything larger. Looks like the 8kW motor full wheel motor would work, but not sure how the shaft drive affects the mounting.

So far, the frame mount motor has not limited my battery, but I need to make better measurement to know for sure.

Thanks for the info everyone!

 

[amberwolf]

I was considering taking the bike in one of two directions, making into more of a cafe racer style (which is something my dad would have liked) and trim it down to the bare minimum, or, putting a faring on it to make it more like a traditional GoldWing. Not sure if this will help my aero, but it's a thought.

probably not enough for high speeds to make a big difference, though it would likely make some.

i would bet that you'd have to do something like a craig vetter streamliner body to really make a big difference.
https://www.google.com/search?q=craig+vetter+streamliner&tbm=isch


Not married to Regen, but if the motor supports it, figured it would be a 'why not' scenario. Didn't take the deceleration torque into consideration. Would this be that much different than downshifting an ICE? I would also think a shaft drive would be well suited for this kind of torque, but I don't know for sure.
i don't know. if downshifting an ice gives a huge sudden slam of torque backwards from the wheel into the engine, suddenly and drastically reversing the direction of torque it had just been producing to acclerate you so it can begin braking you, then i guess it would be fine.

otherwise, in a "panic stop" situation, with regen setup to be able to nearly lock up the wheel (or to actually do that), the amount of torque, and the sudden reversal of it, could damage things. it happens on hubmotor systems all the time, and those are "designed" for this purpose (albeit badly in almost all cases)--axles are sheared off, or spun in the dropouts from inadequate clamping, etc.

As far as hub motors go, I have considered them, but haven't really been sold on them. Seems like a lot of work to do and they don't appear to have the same amount of power as the frame mount motors do. The stock tire size for the GL1100 is 130/90-17 and it doesn't like anything larger.

a hubmotor in a wheel can have as much power as any other motor.

the differences are primarily that:

--"middrives" (non-hubmotors) can be smaller for the same power, *if* they spin proportionally faster, because power is torque x rpm.

--middrives can have a transmission with multiple gear ratios between them and the wheel to allow for multiple optimal gearing vs speed ranges, so you can still *use* the entire power band of the system both at low speeds and high speeds.

without the multigear transmission, the hub and middrive can be the same, depending on the actual dyno curve of the specific motor in question vs the gearing of the system / wheel diameter.

so that only leaves the "potentially-smaller-for-the-same-power" difference, if there's no multigear transmission.

hubmotors have the advantage that they are simpler, and there is really nothing mechanical to fail between motor and ground besides the tire, rim, and spokes (which are also in the path for the middrive), as long as the axle mounts are correctly made.

a middrive has several possible failure points in addition to the tire/rim/spokes, which are the sprocket (or shaft adapter) mounting on the motor output shaft, the chain (or belt or shaft), and the receiving sprocket (or shaft adapter), and any gearing that is between any of those points.

Looks like the 8kW motor full wheel motor would work, but not sure how the shaft drive affects the mounting.

don't know on that part; i haven't worked on that part of a goldwing (just wiring up on the dash/steerer, and oil changes, on a friend's). most likely you could remove the shaft drive components, at least the output gearing, to get them out of the way, if they are obstructing something. if not, they could be left alone.

the dropouts are probably horizontal slots already, so you just need a plate that firmly bolts to or clamps onto the swingarms there, that has holes exactly the right shape and size for the axle ends (a double-d normally), so the axle can't spin or move relative to the swingarms.

if it has disc brakes, then you may need to use spacers on the rotor itself on the motor side to ensure it lines up perfectly with the caliper. that, and all the other stuff above, is something you should work out before buying a hubmotor, to ensure that it is all easy to do (and/or possible--there are some motors and some frames that just arent a good match)


either way, the hubmotor is just an option for if you *have* to have that space in the frame for battery. if you don't, then you should build the system the way you prefer to, that does the stuff you want it to and looks the way you want it to.

 

[GrayGhost]

otherwise, in a "panic stop" situation, with regen setup to be able to nearly lock up the wheel (or to actually do that), the amount of torque, and the sudden reversal of it, could damage things. it happens on hubmotor systems all the time, and those are "designed" for this purpose (albeit badly in almost all cases)--axles are sheared off, or spun in the dropouts from inadequate clamping, etc.

I think this hit the nail on the head. With the minuscule return, it's probably not worth the risk of regen.

so that only leaves the "potentially-smaller-for-the-same-power" difference, if there's no multigear transmission.

This is pretty much what I am looking at as I am not planning on a transmission. I will be looking into the hub motors much more seriously and what it will take to integrate. With the extra space, I might be able to utilize 3 of the 64V 3.3kWh modules from a Gen2 Volt for 96V and 9kWh.

 

[amberwolf]

if you want to "see" the difference between running a small motor in the frame at high rpm thru a reduction, vs a larger hubmotor at low rpm in the wheel, use the http://ebikes.ca/simulator .

it doesn't matter that it's bike parts, not mc ones. first try out a motor in system a, using even the default setup if you like, except reduce human watts to zero. then use the same motor with the setup otherwise identical except use the option for a middrive/gear reduction on the motor section, and a proportionally higher voltage, for system b. play with different speeds, throttle levels, slopes, winds, etc.

next, try a smaller motor (you might have to look up the names of the motors on the grin tech website or here on the forums to find their basic power levels) in the system b middrive setup, and a larger one in the system a hubmotor setup. play with that the same way.

whle it's not quite the same as directly comparing the options you would use on the mc, it will show you the principles behind this, and give you a feel for how the differences affect system needs and usages. under some conditions you'll find the middrive/geared system may operate better or longer before overheating than the hubmotor; under others they'll be similar.

depending on your specific usage scenario, it may not make any significant difference.

but under some conditions, the difference might be worth the middrive. depends on whether those conditions apply to you, and for how long at a time, etc.

 

[Balmorhea]

The GL1100 is a shaft drive bike, which to me suggests that the path of least resistance is to couple a shafted motor to the transmission and leave everything else stock. That is also the method that will preserve the most of the bike's aesthetic qualities (while still giving it the quiet dignity and decency of an EV).

Using the stock tranny will allow you to have 5 different efficiency sweet spots/equilibrium speeds.

 

[GrayGhost]

if you want to "see" the difference between running a small motor in the frame at high rpm thru a reduction, vs a larger hubmotor at low rpm in the wheel, use the http://ebikes.ca/simulator .

Great info, but a lot to unpack. Will have to spend quite a bit of time playing with that one.

The GL1100 is a shaft drive bike, which to me suggests that the path of least resistance is to couple a shafted motor to the transmission and leave everything else stock. That is also the method that will preserve the most of the bike's aesthetic qualities (while still giving it the quiet dignity and decency of an EV).

Using the stock tranny will allow you to have 5 different efficiency sweet spots/equilibrium speeds.

I agree, it sure would be nice to have gears! Unfortunately, I am not very experienced with transmissions and I cannot tell with diagrams how difficult it would be to divorce the tranny from the engine case.

 

[Balmorhea]

I agree, it sure would be nice to have gears! Unfortunately, I am not very experienced with transmissions and I cannot tell with diagrams how difficult it would be to divorce the tranny from the engine case.

Ah, that’s right. Unit transmission, engine oil gear lubrication, wet clutch. Not a straightforward retrofit like a car or a Harley big twin.