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[Frank]

Go back to first principles:

F = MA  For a given weight (mass), in order to accelerate at a certain rate, it takes a certain Force (torque at the rear wheel, divided by wheel radius).  With limited torque the force available for acceleration is necessarily limited.  Using a gearbox can increase the torque/force but can be limited by two things.  (1) speed limit of motor, (2) force you're trying to overcome.

If it takes 50 pounds of force to overcome friction at 30 mph and your system can only provide 40 pounds you won't reach 30 mph.

Upgrading the cam chain is a good move.

[Csecrist12]

Go back to first principles:

F = MA  For a given weight (mass), in order to accelerate at a certain rate, it takes a certain Force (torque at the rear wheel, divided by wheel radius).  With limited torque the force available for acceleration is necessarily limited.  Using a gearbox can increase the torque/force but can be limited by two things.  (1) speed limit of motor, (2) force you're trying to overcome.

If it takes 50 pounds of force to overcome friction at 30 mph and your system can only provide 40 pounds you won't reach 30 mph.

Upgrading the cam chain is a good move.

Good idea with taking it back to the principles. It goes along with the ICE as the range of RPM's has a limit of torque as you were discussing. Same goes with the electric motor, but the key to this concept is the gear box/transmission with it as you mentioned, it can increase the torque needed. I'm not saying this small electric motor of mine that I have will do the job, I'm more curious to see if the concept is there before I drop a few G's on a larger motor, controller an dbattery pack. If the concept is there with solid evidence, then I will upgrade accordingly

[gregj]

I like this experimental approach. Heaps can be learned from it and an interesting take on existing bike modding for electric.
One point I might make is the use of 520chain. Wouldn't something like 420 or even 415 be lighter smaller and almost certainly capable of taking the load ( I stand to be corrected, but 415 was used on GP125 motorcycles and is capable of handling that ). Reduce your driveline inertia a fair bit.
A reinforced belt would also do the same .
I assume you are dumping the clutch altogether, because it is unneeded. This would allow the drive side to be sealed from the transmission and keep the oil for the gearbox only.
I will follow with interest.
One point. Not limited to your project alone.
Motorcycle handling is coupled to the rotating mass in the engine. If you remove that mass it will change the handling . That is a solid lump of fast spinning gyro.
 Hub motors add much rotating mass to the rear wheel AND eliminate the rotating mass in the centre of the bike. I have noticed that most emotorcycles seem to be ridden more upright and this amy be a function of this. Worth considering as a side issue as you build. Most people seem to ignore it.

[Csecrist12]

I like this experimental approach. Heaps can be learned from it and an interesting take on existing bike modding for electric.
One point I might make is the use of 520chain. Wouldn't something like 420 or even 415 be lighter smaller and almost certainly capable of taking the load ( I stand to be corrected, but 415 was used on GP125 motorcycles and is capable of handling that ). Reduce your driveline inertia a fair bit.
A reinforced belt would also do the same .
I assume you are dumping the clutch altogether, because it is unneeded. This would allow the drive side to be sealed from the transmission and keep the oil for the gearbox only.
I will follow with interest.
One point. Not limited to your project alone.
Motorcycle handling is coupled to the rotating mass in the engine. If you remove that mass it will change the handling . That is a solid lump of fast spinning gyro.
 Hub motors add much rotating mass to the rear wheel AND eliminate the rotating mass in the centre of the bike. I have noticed that most emotorcycles seem to be ridden more upright and this amy be a function of this. Worth considering as a side issue as you build. Most people seem to ignore it.

I really appreciate your comments and points you have mentioned to say the least. My grandfather and I did consider a smaller chain, but what I had on hand is what I'm more leaning on at the moment. Plus, since I'm wanting to do a split sprocket on the crank shaft, this would allow me to easily change the gearing ratio along with the chain size as well.

I'm most likely going to leave the clutch for now until I have done further testing, but that is a really good point to add.

I'll keep an update on this project and see what is needed.

Any idea on the battery pack to keep the costs down? I saw some harbor freight solar batteries with 12V 35AH rating which wouldn't be bad for a cheap build, but would love to get my hands on a Chevy volt battery pack or some valance batteries as I have another EV trike build I just picked up.

[gregj]

I am just starting to learn about the electric motive side, so I am not the person to ask about batteries. I come from a street and  racing ICE motorcycle space. Lots to learn. Surprised about how little is talked about the handling as almost everything about an emotorcycle will change the chassis dynamics.
I started by noticing people recommending hub motors on a motorcycle. For an ICE bike, the rotating mass of a hub motor would be a serious consideration, yet only a few notice the point. NOTE. I didn't say it was a bad thing, only that it is a consideration that needs proper investigating.

[Crissa]

The centrifugal weight of electrical motors is just much less than that from ICE bikes, I guess it just doesn't get people talking much.

Also, the people who race electrics tend not to post around here, and they're pretty rare still.

-Crissa

[Demoni]

Have really enjoyed the progress updates with this project, would love to see more photos! Plus that video you teased in your original post.
Wanted to throw my 2 cents in, I beg your forgiveness for my ramblings...

Appreciate that if the bike works its performance will leave a lot to be desired. Stock that motor put out 40hp,
I have concerns if the 2.8hp of that motor will be able to turn the drive line over.
Hopefully it works well enough to inspire you to move into phase 2 taking what you learned and building on it.
Halving the torque output of the motor (due to the 2:1 ratio from the motor to the cam gear) will not help matters. You might want to try a 1:1 ratio to start with.

With that said it's amazing what low power motors can be capable of. My first bike was a 1980 Puch Maxi, single speed pumping out all of 2hp. Was still able to manage 30mph.
My first bike with gears was a 2004 Aprilia RS50, cranking out a massive 12hp through a 6 speed gearbox. On flat ground 80 was doable, put a hill in front and 60 was it.

The transmission is going to be your best friend.

I am curious to see how much vibration is introduced by the now unbalanced crank lobes, hopefully minimal but excessive vibrations could cause premature bearing wear/failure.
If you have any plans to open the motor cases I would strongly suggest cutting off as much counterweight material as possible.

+1 on swapping the cam chain for something more robust, a quality 415 chain is more than up to the task. Ideally the motor controller has some sort of "soft start" function to reduce further.


Regarding batteries
I would use lead acid as a last resort, especially buying them new. The weight of a 48v pack would be 100lbs, you would also need to do a lot of work to safely secure them to the bike.
LiFePO4 has around 3x the capacity or 1/3 the weight for the same capacity. There are sources for used cells.

I would suggest leaving the clutch on the bike as an extra layer of safety, if a bracket gear or sprocket breaks you have the ability to disconnect the rear wheel preventing a lock-up situation.


Also where are you located? There might be some local resources that you could utilize.


Happy Building!

[Csecrist12]

Have really enjoyed the progress updates with this project, would love to see more photos! Plus that video you teased in your original post.
Wanted to throw my 2 cents in, I beg your forgiveness for my ramblings...

Appreciate that if the bike works its performance will leave a lot to be desired. Stock that motor put out 40hp,
I have concerns if the 2.8hp of that motor will be able to turn the drive line over.
Hopefully it works well enough to inspire you to move into phase 2 taking what you learned and building on it.
Halving the torque output of the motor (due to the 2:1 ratio from the motor to the cam gear) will not help matters. You might want to try a 1:1 ratio to start with.

With that said it's amazing what low power motors can be capable of. My first bike was a 1980 Puch Maxi, single speed pumping out all of 2hp. Was still able to manage 30mph.
My first bike with gears was a 2004 Aprilia RS50, cranking out a massive 12hp through a 6 speed gearbox. On flat ground 80 was doable, put a hill in front and 60 was it.

The transmission is going to be your best friend.

I am curious to see how much vibration is introduced by the now unbalanced crank lobes, hopefully minimal but excessive vibrations could cause premature bearing wear/failure.
If you have any plans to open the motor cases I would strongly suggest cutting off as much counterweight material as possible.

+1 on swapping the cam chain for something more robust, a quality 415 chain is more than up to the task. Ideally the motor controller has some sort of "soft start" function to reduce further.


Regarding batteries
I would use lead acid as a last resort, especially buying them new. The weight of a 48v pack would be 100lbs, you would also need to do a lot of work to safely secure them to the bike.
LiFePO4 has around 3x the capacity or 1/3 the weight for the same capacity. There are sources for used cells.

I would suggest leaving the clutch on the bike as an extra layer of safety, if a bracket gear or sprocket breaks you have the ability to disconnect the rear wheel preventing a lock-up situation.


Also where are you located? There might be some local resources that you could utilize.


Happy Building!

I greatly appreciate your input and support for this project. Photos will be coming, but not much has changed until I can get that crankcase back from my grandfather.

My grandfather and I did consider taking down some weight in the lobes for the crankshaft, but we're willing to revisit this if it becomes much of an issue for sure.

I'm also not too confident on the motor I currently am using for this application as it is small for what I'm wanting to do with it. I found it cheap online and took a gamble to see if it would worked on a rough idea I had and the video shows it seems like it will, but not sure once the weight is on. My theory behind the 2:1 E motor to the crank shaft serves the purpose of the rpm's from the small e motor. I know the e motor only has a peak of 4300 rpm's and the peak rpm's for the stock motor is 8500 rpm's and sticking with the stock numbers as much as possible, the gearing would have to be close to 2:1 for efficiencies and normal rpm's of the e motor.

If this does work, I do intended to put a bigger e motor on it, which I currently picked up a few weeks ago, that could work, but the battery pack is my biggest enemy as the cashflow isn't there for this project. I would love to do the LiFePO4 batteries, but the wallet says otherwise. We'll see what comes abount on the market places. I'm in the northeastern part of Indiana so there's a few junk yards, but not many that have the EV's like I would hope along with the companies realizing the value of the batteries in a wrecked out body, so shit out of luck at the moment.

[gregj]

I have had a bit more of a think about your approach.
I suspect that with the rods and pistons removed, the harmonics of the cranks and the, now nonbalancing balance shaft, will cause a big unpleasant vibration once rotating. I think that making a simple shaft to replace the crank and remove the balance shaft completely. Yes I know that splitting the cases on an early Honda is a pain ( and putting them back together even more so). The crank replacement can be a simple piece and even can be hollow and/or made of aluminium.  Less rotating mass. You don't need extra rotating mass for an electric as it doesn't have non power strokes to spin over. The extra mass will create a overrun when you close the "throttle" however.
Still it will be interesting to see how your idea pans out. I will continue to follow.