eGoldwing

[Jmforeman02]

I’m considering building an electric goldwing using a 1st or 2nd gen frame (‘75-‘83). My thinking is that I shouldn’t have too much trouble fitting a powerful motor and plenty of battery once I take out the big engine, transmission, gas tank, etc. I could even do water cooling for the motor (and possibly the battery) if required because the goldwing has a radiator. And since the goldwing frame is built to handle a lot of weight, I shouldn’t have too much trouble holding all the battery. Also, it’s drive shaft driven instead of a chain so it should be really quiet.

Doing some math and if I’m getting it right, I would only need a max of 3500 rpm on the electric motor combined with the stock final drive gear of an ‘83 goldwing and stock tire size to get a top speed of 87 mph. I need enough control to operate it safely at low speed, and enough power to maintain highway speeds of 75+ mph continuously including up bridges and hills.

My budget for electrification is $4K not including the cost of the bike itself. I’ll DIY everything including building battery packs. What electric motor would y’all suggest?

 

[Eastwood]

I’m considering building an electric goldwing using a 1st or 2nd gen frame (‘75-‘83). My thinking is that I shouldn’t have too much trouble fitting a powerful motor and plenty of battery once I take out the big engine, transmission, gas tank, etc. I could even do water cooling for the motor (and possibly the battery) if required because the goldwing has a radiator. And since the goldwing frame is built to handle a lot of weight, I shouldn’t have too much trouble holding all the battery. Also, it’s drive shaft driven instead of a chain so it should be really quiet.

Doing some math and if I’m getting it right, I would only need a max of 3500 rpm on the electric motor combined with the stock final drive gear of an ‘83 goldwing and stock tire size to get a top speed of 87 mph. I need enough control to operate it safely at low speed, and enough power to maintain highway speeds of 75 mph plus continuously including up bridges and hills.

My budget for electrification is $4K not including the cost of the bike itself. I’ll DIY everything including building battery packs. What electric motor would y’all suggest?

To be able to continuously hold 75mph you need a big battery. How far is your commute or how much range are you looking for?

 

[Jmforeman02]

To be able to continuously hold 75mph you need a big battery. How far is your commute or how much range are you looking for?

I don’t need too much range. 100 miles would be nice, but I’d probably settle for 75. For my commute I really only need like 15 - 20 total including running a few errands if necessary. I’m only about 5 miles from work. But there are some friends I’d like to be able to ride over and see about 30 miles away.

 

[harrisonpatm]

I don’t need too much range. 100 miles would be nice, but I’d probably settle for 75. For my commute I really only need like 15 - 20 total including running a few errands if necessary. I’m only about 5 miles from work. But there are some friends I’d like to be able to ride over and see about 30 miles away.

You may need to reel in your expectations a bit. Clearly you have some mechanical experience and seem to know your way around these machines, so it's not that you DIYing everything is an issue. Issue is going to be range at high speeds.

I get 100wh/mile on my 365-pound motorcycle. You're looking for 75 mile range at minimum. This will be about 7.5kwh battery, let's call that 8kwh. For lithium ion, that will weigh in the range of 75 pounds, just for the cells, not including a sturdy enclosure. And this is on paper; real world experience suggests that you're not going to get your on-paper range when you're actually cruising on the freeway. Your bike is also going to weight quite a bit more than mine as well, and I never break 55mph, so the faster you go, the less range you'll get. Meaning my 100wh/mile is probably not going to happen on a Goldwing, closer to 150wh/mile.

I will say this, though. If there was a common enough motorcycle frame that's big enough to hold a big honking battery for max range, it's a Goldwing. I look forward to seeing your progress. On the shaft drive as well: I hear it can be tricky to custom mate an electric motor to a shaft, rather than a belt or chain.

 

[Chalo]

If you use less bike, you'll need less motor, less battery, less money to convert.

There are plenty of old bikes out there with lower gross weight and more favorable market price. But you could do a lot worse than Goldwing's accomodations for motor and batteries.

Fully faired Goldwings have worse aerodynamics than naked ones, because their windshields are designed to make a "bubble" bigger than the bike and rider. Great for long miles in the saddle, but not great for efficiency or speed.

 

[Chalo]

You may need to reel in your expectations a bit.

I think that's correct.

I get 100wh/mile on my 365-pound motorcycle.

No version of a Goldwing, not even a mock-up, weighs anywhere close to 365 pounds. Without bodywork, I'd expect roughly double your consumption. With stock Goldwing fairings, I'd expect closer to three times your estimate.

 

[gromike]

What would be a good candidate for a road ebike conversion. I have a 1988 Honda Hawk that's just sitting there, A single swing arm basket frame, all aluminium. Not that I need to go there, but just asking.

 

[Jmforeman02]

You may need to reel in your expectations a bit. Clearly you have some mechanical experience and seem to know your way around these machines, so it's not that you DIYing everything is an issue. Issue is going to be range at high speeds.

I get 100wh/mile on my 365-pound motorcycle. You're looking for 75 mile range at minimum. This will be about 7.5kwh battery, let's call that 8kwh. For lithium ion, that will weigh in the range of 75 pounds, just for the cells, not including a sturdy enclosure. And this is on paper; real world experience suggests that you're not going to get your on-paper range when you're actually cruising on the freeway. Your bike is also going to weight quite a bit more than mine as well, and I never break 55mph, so the faster you go, the less range you'll get. Meaning my 100wh/mile is probably not going to happen on a Goldwing, closer to 150wh/mile.

I will say this, though. If there was a common enough motorcycle frame that's big enough to hold a big honking battery for max range, it's a Goldwing. I look forward to seeing your progress. On the shaft drive as well: I hear it can be tricky to custom mate an electric motor to a shaft, rather than a belt or chain.

So at 150wh/mile * 100 miles= 15kwh. I know more about motorcycles than electrification. How much weight / volume / cost should I expect for 15 kWh?

 

[Jmforeman02]

N

I think that's correct.



No version of a Goldwing, not even a mock-up, weighs anywhere close to 365 pounds. Without bodywork, I'd expect roughly double your consumption. With stock Goldwing fairings, I'd expect closer to three times your estimate.

A naked 1st gen goldwing weighed in at close to 600lbs wet. Minus engine w/trans, gas tank, quad carbs, etc is probably closer to 300lbs (educated guess). A lot more when you add back in battery and an electric motor.


Isn’t weight more of a consideration for acceleration than highway speed though? I would think aerodynamics would be much more important for highway speed, and I feel like if it has the power to maintain 75mph continuously that it should have more than enough peak torque for the acceleration that I expect at the low end. I’m not building a racing bike. Am I wrong about that?

Also yeah I was thinking that the big frame of a goldwing should make fitting whatever motor I need no problem and give me plenty of room for battery. Especially since the gas tank on a goldwing is in the frame. The thing on top where gas tanks usually are on bikes is just a storage box which I could replace with even more battery or fill with electronics if necessary.

 

[harrisonpatm]

So at 150wh/mile * 100 miles= 15kwh. I know more about motorcycles than electrification. How much weight / volume / cost should I expect for 15 kWh?

Ok, keep in mind that these are estimates could go up or down.

For raw cells, with no connections or housing, no structure, a good place to guess for budget reasons would be about $100-150/kwh. We'll use the $150/kwh figure, because at that estimation, youd be looking at somewhat higher end cells that can handle better range and power. So $150/kwh x 15kwh = $2,250, just for the cells. You'd still have to make a full battery from said imaginary cells.

Weight: decent quality lithium ion cells will have an energy density of around 300wh/kg. 15,000kwh/300wh.kg = 50kg on paper, or 110 pounds. Again, just for the cells, just on paper.

A related thing about speed to keep in mind for electrification, is that an increase in speed requires a squared increase in power. Meaning, higher speeds require exponentially more power to achieve, not linearly more power. I say this because if you decrease your top speed goal of 70-80mph, you'll get more range out of it. I get 100kwh/mile because I don't go on the highway.

 

[harrisonpatm]

Isn’t weight more of a consideration for acceleration than highway speed though? I would think aerodynamics would be much more important for highway speed, and I’m confident that if it has the power to maintain 75mph continuously that it will have more than enough power for the acceleration that I expect at the low end. I’m not building a racing bike.

It is a major consideration, for sure, and I'm not the expert who can cite explanations in this particular area, but you'll need to keep in mind how quickly the power curve rises with speed.

But as chalo mentioned

But you could do a lot worse than Goldwing's accomodations for motor and batteries.

The frame size means that if you don't mind a bigass battery, you may be able to utilize the massive frame to that effect.

I personally would love to see an electrified goldwing.

 

[Jmforeman02]

Ok, keep in mind that these are estimates could go up or down.

For raw cells, with no connections or housing, no structure, a good place to guess for budget reasons would be about $100-150/kwh. We'll use the $150/kwh figure, because at that estimation, youd be looking at somewhat higher end cells that can handle better range and power. So $150/kwh x 15kwh = $2,250, just for the cells. You'd still have to make a full battery from said imaginary cells.

Weight: decent quality lithium ion cells will have an energy density of around 300wh/kg. 15,000kwh/300wh.kg = 50kg on paper, or 110 pounds. Again, just for the cells, just on paper.

A related thing about speed to keep in mind for electrification, is that an increase in speed requires a squared increase in power. Meaning, higher speeds require exponentially more power to achieve, not linearly more power. I say this because if you decrease your top speed goal of 70-80mph, you'll get more range out of it. I get 100kwh/mile because I don't go on the highway.

Appreciate the info. Unfortunately, where I live, not going on the highway is a non-starter. You can’t get anywhere worth going without getting on a highway with at least a 60 mph speed limit with the speed of traffic being at least 5 mph more than that.

 

[harrisonpatm]

For reference, modern electric cars are in the range of 200-250wh/mile, but they can only do it because they can have a fully enclosed shell designed for max aerodynamic efficiency.

 

[harrisonpatm]

Appreciate the info. Unfortunately, where I live, not going on the highway is a non-starter. You can’t get anywhere worth going without getting on a highway with at least a 60 mph speed limit with the speed of traffic being at least 5 mph more than that.

For sure, and your project isn't impossible by any means, and not impossible on a goldwing. But probably not for $4k.

 

[Jmforeman02]

For sure, and your project isn't impossible by any means, and not impossible on a goldwing. But probably not for $4k.

Damn. I really appreciate all the info. Well I will probably have to postpone it then, but what kind of motor should I be looking at since that determines everything else.

Also is it possible to build it with maybe 5kwh of batteries and very limited range initially and add 2 more modular battery packs later to expand the range when I have more money?

 

[floydr]

Search for Trevor Williams in DIY Electric Vehicles facebook page. His 1980 Goldwing conversion is Nice. But as harrisonpatm much more than $4000. His Motor $2-5 K with controller.
Later floyd

 

[Jmforeman02]

Search for Trevor Williams in DIY Electric Vehicles facebook page. His 1980 Goldwing conversion is Nice. But as harrisonpatm much more than $4000. His Motor $2-5 K with controller.
Later floyd

Will do. Thanks.

 

[Chalo]

So at 150wh/mile * 100 miles= 15kwh. I know more about motorcycles than electrification. How much weight / volume / cost should I expect for 15 kWh?

This isn't a pack I'd recommend for your project, but it's close to the size you mention. 195 lbs for 13 kWh in a package. Note that the more power dense the cells, the heavier the battery tends to be.

51.8v 252ah 13.05kWh 14s ESS Battery Module with BMS

You can pick up from our Bensalem, PA location for free or we have excellent freight rates which include residential and lift gate service. We also have a shipping calculator at the bottom of this page to quickly estimate your shipping costs. These batteries were likely used as backup only. The...

batteryhookup.com

 

[Jmforeman02]

This isn't a pack I'd recommend for your project, but it's close to the size you mention. 195 lbs for 13 kWh in a package. Note that the more power dense the cells, the heavier the battery tends to be.

51.8v 252ah 13.05kWh 14s ESS Battery Module with BMS

You can pick up from our Bensalem, PA location for free or we have excellent freight rates which include residential and lift gate service. We also have a shipping calculator at the bottom of this page to quickly estimate your shipping costs. These batteries were likely used as backup only. The...

batteryhookup.com

Cool thank you. 200 lbs should be workable on a naked goldwing once you subtract the heavy engine and gas tank, assuming the motor and other new additions aren't more than another 200 lbs. The stock goldwing was about 600 lbs and could carry a rider, a passenger, fairing, and saddlebags. If I drop the engine w/ transmission, exhaust, and gas tank, that has to be at least a 200 lb savings. If I give up fairings, saddle bags, and the ability to carry a passenger (none of which I have any interest in) that should be at least another 250 lbs in capacity.

Would it be possible to build a battery pack of say 5kwh for very limited range, then add 2 more later as I get more money to expand the range? Kind of a modular battery system? Might help with distributing weight correctly in the bike as well.

 

[floydr]

Smart #1 Battery Module | 16.5 kWh | Greentec Auto 102lbs(46.35kg) 25s. I don't know if the module can be reconfigured to fit the bike but at 6.36lbs (2.89 kg)/kWh I doubt you will find a lighter battery. according to the specs listed on the website, 178Ah x 90V the battery could hold as much as 16.02 kWh not the 16.5kWh listed in ad a call to them for clarification Might be in order.
later floyd

 

[harrisonpatm]

Would it be possible to build a battery pack of say 5kwh for very limited range, then add 2 more later as I get more money to expand the range? Kind of a modular battery system? Might help with distributing weight correctly in the bike as well.

Thee short answer is yes,.but complicated. It would be essentially 3 different batteries in parallel.

First problem you run into is that when you want to add the second and third battery to the first, they would need to be at the same voltage, to avoid damaging the batteries. That's easy enough to do once or twice, but not something you'll be able to easily "hot swap" in a out often.

Seconds problem is that riding around with one small 5kwh battery by itself means that the solo battery needs to be capable of supplying all the power needed to drive the motor, on it's own. At the very least, itll stress the cells more and wear them out faster. And to build a proper 5 kwh pack capable of the power delivery you want is going to need some of the highest quality cells, meaning, more expensive.

Consider this option: build it with a small pack, sure, and run it for a year or two. But instead of adding 2 more packs in parallel when your budget allows, you should consider replacing the entire 5kwh pack with a 15kwh (again, when budget allows).

My motorcycle uses a 5kwh pack. It's a reasonable/smallish size, but it does work. And consider that the advantage of building it first with just the small pack, and running it for a year or two, means that you have time to evaluate how well you did on your first EV build, and you didn't blow the budget on a 15kwh battery. You'd be able to evaluate all your mistakes, and return to or remix the project with more knowledge, and a much bigger battery

 

[Jmforeman02]

Thee short answer is yes,.but complicated. It would be essentially 3 different batteries in parallel.

First problem you run into is that when you want to add the second and third battery to the first, they would need to be at the same voltage, to avoid damaging the batteries. That's easy enough to do once or twice, but not something you'll be able to easily "hot swap" in a out often.

Seconds problem is that riding around with one small 5kwh battery by itself means that the solo battery needs to be capable of supplying all the power needed to drive the motor, on it's own. At the very least, itll stress the cells more and wear them out faster. And to build a proper 5 kwh pack capable of the power delivery you want is going to need some of the highest quality cells, meaning, more expensive.

Consider this option: build it with a small pack, sure, and run it for a year or two. But instead of adding 2 more packs in parallel when your budget allows, you should consider replacing the entire 5kwh pack with a 15kwh (again, when budget allows).

My motorcycle uses a 5kwh pack. It's a reasonable/smallish size, but it does work. And consider that the advantage of building it first with just the small pack, and running it for a year or two, means that you have time to evaluate how well you did on your first EV build, and you didn't blow the budget on a 15kwh battery. You'd be able to evaluate all your mistakes, and return to or remix the project with more knowledge, and a much bigger battery

Okay. Thank you! Any advice on the motor?

 

[harrisonpatm]

Okay. Thank you! Any advice on the motor?

I'll let someone else jump in on that advice. I like hub motors for my use, but they wouldn't work well for your application, Plus you're planning a shaft drive, also something I have no experience in.

 

[spinningmagnets]

Performance goals are fine if you have a very large budget, and deep resources.

I'd convert he GW and see how it goes. For around town, you might be able to get by with 72V, but amps will be high, and acceleration might not be too exciting.

If you want to use an affordable and reasonably available system, a wrecked Zero motorcycle can provide a 28S / 100V controller and motor. If there was any way to use the stock GW transmission, this might be a viable option.

If you want more volts than 28S, then you have to choose a controller that will work at that voltage, with high Amps too.

 

[Jmforeman02]

Performance goals are fine if you have a very large budget, and deep resources.

I'd convert he GW and see how it goes. For around town, you might be able to get by with 72V, but amps will be high, and acceleration might not be too exciting.

If you want to use an affordable and reasonably available system, a wrecked Zero motorcycle can provide a 28S / 100V controller and motor. If there was any way to use the stock GW transmission, this might be a viable option.

If you want more volts than 28S, then you have to choose a controller that will work at that voltage, with high Amps too.

The goldwing transmission is built into the engine case so it’s not really possible to use the transmission.