Comparing Benefits/Disadvantages to 36v 350w & 36v 500w

[chopper_elec]

Hey all,
I'm building up an electric chopper bicycle and i'm upto the stage where I am just finalising my order

I was hoping to get around 30-35km an hour speed wise

I do like to make sure I have enough range. I'm using 3x 12v 12ah SLA Batteries

The 2 choices were the following:

36v 350w ebay hub kit
I liked this particular kit for the longetitivty in battery life, but since its going on a 24" wheel i'm worried top speed maybe less than expected.
Visually this motor is smaller than the 500w hub I believe too (less obvious). I can freewheel with this kit which I like, most of the time I want to pedal but just have the system there to back me up if required.

36v 500w ebay hub kit
I believe this kit should have no worries getting to 30-35km an hour on a flat ground. I'm a bit worried about longetivity of the battery. I can't freewheel with this kit as its a direct drive kit. This will make pedalling more difficult and may wreck the moment.


Would I be likely to notice the difference much between 350w to 500w?

Any comments would be fantastic and much appreciated.

[Drunkskunk]

You will notice a difference.

First off, to go 35km/h you're going to want a 500watt motor. A 350w motor can do it, but it's topping out. the 500w motor can do it without stress.


At a constant speed, the motors will use nearly the same amount of power.

But those are very different motors. Comparing them is sort of pointless. they work in different ways. A geared motor will accelerate efficiently, while the direct drive will cruse more efficiently. A direct drive motor is near silent, while a geared motor can be quiet, but isn't as quiet as a direct drive. A direct drive motor can take more abuse and climb long hills without over heating. a Geared motor can climb short steep hills better but may overheat on long hills.

Basically, you're very likely going to want a 500 watt motor. But you'll have to decide if you want that Direct drive, or to get a 500watt geared (BMP, MXUS, ect.)

[chopper_elec]

You will notice a difference.

First off, to go 35km/h you're going to want a 500watt motor. A 350w motor can do it, but it's topping out. the 500w motor can do it without stress.


At a constant speed, the motors will use nearly the same amount of power.

But those are very different motors. Comparing them is sort of pointless. they work in different ways. A geared motor will accelerate efficiently, while the direct drive will cruse more efficiently. A direct drive motor is near silent, while a geared motor can be quiet, but isn't as quiet as a direct drive. A direct drive motor can take more abuse and climb long hills without over heating. a Geared motor can climb short steep hills better but may overheat on long hills.

Basically, you're very likely going to want a 500 watt motor. But you'll have to decide if you want that Direct drive, or to get a 500watt geared (BMP, MXUS, ect.)

Thanks so much for the information. Is there any particular issues with pedalling even with a Direct Drive?

Would I likely get around the same mile range if I was to keep the motor to flat grounds moreso?

Its a hard choice now haha. I'm wondering if i'd need at torque arm for the ebay 500w 36v setup?

[dogman]

Pretty soon, you'll be looking at the 48v ebay kit, and then you probobally should have a torque arm. That for sure gets you the 35 kph, maybe even 40.

Wattage ratings from one motor to another can be misleading. They may, in reality be closer than you think, or further apart. For me, 35 kph can definitely take 400w, or 500w if slightly uphill or into wind. Quite likely, the 500w motor and the 350w motor have max amps that are higher.

Lots of the 350w motors do tend to have max speeds closer to 30 kph than 35, so the 500w motor would be a good choice. And it's very likely the same kit can tolerate running on 48v, if it's too slow after all.

[chopper_elec]

Thanks again

I still have the option to change from 36v 500w to 48v 500w. I wonder if a 48v 500w kit running on 36v would be as good as a 36v 500w running on 36v.
I could install a torque arm quite easily if required as the bottom of the fork has a cutout/keyway that I could easily make a torque plate out of

[motomech]

Since range was the first thing you listed, forget the boat anchor SAL batteries and get a modern chemistry battery like a Ping.
And since it's a chopper, go with the motor you like the looks of. Frankly, I think a big DD motor out frt. would look silly.
Either motor will handle the speeds you are looking for.

[chopper_elec]

Since range was the first thing you listed, forget the boat anchor SAL batteries and get a modern chemistry battery like a Ping.
And since it's a chopper, go with the motor you like the looks of. Frankly, I think a big DD motor out frt. would look silly.
Either motor will handle the speeds you are looking for.

Thanks for that. SLA's are definitely on the plans in the very near future. Just trying to get it functional sooner than later haha.
Its lost money in the end, as they are just lead bricks but it would be good to run some tests with.

I've seen some pics with a DD motor installed and its quite a futuristic look, it looks better than I thought. Its very Blade Runner/Fifth Element especially with the shiny black/silver effect.

I ended up upgrading to a 48v 500w system which should have a bit of extra poke. I'm still working on a suitable torque arm to suit. I will try contact the bike manufacturer to find out what materials were used for the dropouts.

I just bought a 36v charger doh. I'll need to get another one now lol

Thank you all

[motomech]

Ok, you know the scoop the batteries. You'll never get very far on lead.

"I've seen some pics with a DD motor installed and its quite a futuristic look, it looks better than I thought. Its very Blade Runner/Fifth Element especially with the shiny black/silver effect."

Futuristic? Blade Runner was made 30 years ago, hard to believe it.
Actually, it's my all time fav. movie and holds up well.
Can Ridley do it again?

[chopper_elec]

Ok, you know the scoop the batteries. You'll never get very far on lead.

"I've seen some pics with a DD motor installed and its quite a futuristic look, it looks better than I thought. Its very Blade Runner/Fifth Element especially with the shiny black/silver effect."

Futuristic? Blade Runner was made 30 years ago, hard to believe it.
Actually, it's my all time fav. movie and holds up well.
Can Ridley do it again?

True mate haha. Its scary to think it was made 30 years ago. One of my all time favourites too, stunning story.

Lets hope they don't stuff it up on the remake doh

I did actually find a supplier that can provide a 20"x4.25" 500w 48v hub motor which is awesome. If I hadn't made my order I would have got that too.

Maybe eventually i'll get a twin hub system lol.

I am sure long term i'd try and get the hub motor in the rear as it will be much more hidden away.