My 48v 500W Cruiser Chopper Project

[Architectonic]

I was originally going for nimh from rc cars but the temptation of lifepo4 was just too much. Has anyone ever had any safety issues with them like we do with lipo batteries? Lifepo4 seem so much more forgiving.
from

Here is some serious battery abuse from Liveforphysics:

The hacksaw test:
http://www.youtube.com/watch?v=8IBapfB0Imo

Puncture test:
http://www.youtube.com/watch?v=8IBapfB0Imo

More tests with various Lithium chemistries:
http://www.youtube.com/watch?v=dree0rTr1HM

[chopper_elec]

Haha thanks for the vids.

I noticed in my pics just then that I put the torque arm on the wire side. I also noticed there was no thread on the end where the wires come out lol.

Is it normal for the droputs to have some rounding in them at the very top? Just looks like part of the design. Not all the for out has this but I could rotate the axle a few degrees inside the dropouts.

Would it be more appropriate to put the torque arm on the non wire side?? I was thinking of running 2 but space is a bit limited on the wire end.

[chopper_elec]

Here is my rendition in 3D of how I was going to use the P clamps to mount the controller to the bike

[chopper_elec]

Big news everyone, i've decided to go with a rear hub motor kit that i've finally sourced from hong kong

Its going to be quite expensive but then again the wheel is quite uncommon

I'm looking at around $340 for the kit plus $140 shipping to Australia.

The benefits
- I will feel much more confident that the dropouts will be a bit safer.
- I have more space to mount a very decent torque arm on the rear
- The hub setup will be a lot less noticable on the rear
- It will look better

[Pedalex]

good to hear you´ve found one. i hope you ordered a fast woud motor for that small 20" wheel

[chopper_elec]

good to hear you´ve found one. i hope you ordered a fast woud motor for that small 20" wheel

I wasn't sure if it was a high wound motor unfortunately, I will see if I can get this information from the manufacturer. If I could get to 25-35km an hour i'd be happy in the long run.

Thanks for all your help through pm mate

[Idontwanttopedal]

I be keep eye out see how your kit works

[chopper_elec]

I be keep eye out see how your kit works

Yeah for sure, me too. I think the rear wheel kit would just sit much neater and i'll be less worried about those front forks/dropouts holding up.

The rear axle has an awesome layout perfect for a torque arm. I'll 3d it tonight lol.

I'm going to be taking the unpowered vessel for a nice ride this week for a 30-50km ride (depending on weather) which is no mean feat on a chopper bicycle haha.

I will be testing out my new android app "Strava Cycle" to see how well it maps out the run. I will also have my eBay special speedometer tracking my other runs.

[chopper_elec]

Hey all, My next developments have been working with the rear arms in place of my new48v 500w rear hub motor in the next few months. I have noticed that the rear arms are completely flat, which means that I can run a torque plate on both sides and bolt them upto those 2 bolt holes on the left hand side. So I got to work planning out a template for my torque arms.




The first step was to do it with a piece of cardboard which worked quite well for a rough template, then I had an idea. I took a photo of the rear arm and put it into Adobe Illustrator to convert into a vinyl sticker. This could then be applied to the 2-3mm thick piece of alloy to get a better outline before cutting it out.



Here is an example of the vinyl sticker outline. I was pretty impressed with how it turned out, it was a bit of a draft to see if it would work. I will take a better quality image and retrace it (you'll notice in my example the lines aren't straight where the axle goes).Great example to test out some prototyping though, converting an image to a vinyl template.

[Idontwanttopedal]

Did you found out any info on the motor

[chopper_elec]

Did you found out any info on the motor

Unfortunately not yet, the details of the motor seem to be from Conhis based on the look/design. Should have a decent amount of power for just cruising. I do believe it is available in a number of specs. Will ask more about it tonight,

[chopper_elec]

A little update for everyone. Funds are getting better each day and that 500w 48v motor may be ordered any day now. I am going for another pedal powered only ride tomorrow which should be great. The weather is getting better.

I am in the process of truing my front wheel, i've nearly got it perfect (few mm off) but my actual tyre doesn't look like its seated right so i'm going to take that off tomorrow and recheck.

I got my bicycle kids trailer, it looks so great I feel like keeping it as is haha. I was able to remove the actual fabric frame without having to cut any of the stitches. I'll chuck the polyester fabric from the trailer in the washing machine. I did notice that I could actually flip the trailer upside down which would actually lower it around 2 inches which not only looks better but functions equally as good. I was even able to shorten the width of the trailer down by pushing in the little spring clip in the middle of the trailer in, and slide the 2 pieces of piping closer together. I just need to drill in a hole or two so that spring button will clip inplace and hold the tubing together.

[chopper_elec]

Seems like I may end up having to run my 24" front wheel, i'm having a lot of trouble trying to source out a 20"x4.25" hub motor setup.

I'm wondering if I would have any issues with my dropouts on the front failing with a 48v 500w hub motor.

I'll have a decent torque arm setup, but i'm more worried about the actual welds on the front fork dropouts pulling away haha

[Sacman]

Hi,

I don't know why I didn't catch this thread of yours earlier. I could have shared some important info early on for you. But better late than never I guess so here it is...

I was working on a chopper project of my own earlier this year. It's a Giant Stiletto for my brother. He likes riding the bike but it's difficult to ride in the steep hills where whe lives. Some of those steep hills have up to 15% grades. You practically have to pedal standing up and that's not cool nor comfortable on a chopper bike. So I "electrified" the bike so he could enjoy riding it around all those steep hills.

For the electrics... I chose to give him a BMC V2-T (torque) motor, a 18-FET BMC controller, and 12s LiPo batts (44.4v nominal, 50.2v hot off the charger). I mounted the controller and the batts on the bottom tube.

For the wheels... he had a 24-inch wheel in back and 20-inch wheel up front. I know a hubmotor up front on a chopper would feel sluggish and terrible for steering so I decided for a rear hubmotor. I bought a 3" wide black anodized rear rim (as an upgrad from his original 1.25" rims; fortunaltely I was able to find one with 36 spokes). I bought the black spokes and had them cut to the proper length, then laced up the BMC V2-T motor to that 3" rim.

For his brakes... he originally had 6" disc brakes. Fortunately the BMC motor had disc brake mounting holes allowing me to keep those rear disc brakes. But I also upgraded those brakes to a larger 8" disc and better Avid BB7 brake calipers.

Anyways, I've yet to finish the bike but here is the results on the day of the initial test ride...

[Sacman]

The BMC V2-T motor is a geared hub motor that has plenty of torque @ 44.4v to climb up the hills as seen on this video.

There is an equivalent MAC 10T geared hubmotor that's availabe now for half the cost. In fact, if you look online at http://www.emissions-free.com/catalog/c5_p1.html you'll see the MAC 1000W Rear Kit (high power) for $385 that comes with both motor & 12-FET controller which is just slightly more than the $340 motor kit you were looking at getting. You can even ask Cellman to see if he can have that motor laced up into a 20-inch rim for you.

The benefits of having a geared hubmotor is that:
-it freewheels (and doesn't have the cogging/drag that direct drive hubmotors have)
-is much lighter

Since you have a smaller 20-inch rear wheel you also might even consider getting the faster wind MAC 8T or 6T motor.

You might also look into upgrading to disc brakes since rim brakes are a PITA to use on wide rims. I know you might not have the mounting holes on your frame for the disc brake calipers but Cycles US now sells this aluminum billet disc brake adapter bracket that allows you to put those disc brakes on. FYI the MAC motors all have the mounting holes for disc brakes just like the BMC motors do.

[chopper_elec]

Wow thank you for both of your replies. I have found out that the kit I was after in ebay spec is going to set me back $500us including postage which is pretty expensive. Thats just for a hub motor with rim and tyre, 48v controller and a hand twist throttle.

I have sent off an email enquiring about a motor package. I have no problems spending a bit more for a better setup. In the end i'd love a setup that allows me to ride the bicycle like a bicycle, and any other time with power on it helps me out.

I'd love to upgrade the rear brake at some stage, the idea of a freewheeling rear wheel will be fantastic. Not to mention the less weight.

My only issue is having to find a suitable rear hub motor that would fit neatly in my wide forks, considering there is a 4.25" tyre in the back its quite a bit of space.

I'd love to convert the bicycle to use a 6-7 speed system on the rear. It would make those hills a lot easier.

You know you have a good e-bike when you are happy to ride it without the motor haha. This would be one of the longest projects ever (without actually getting any progress) haha.

I am having some trouble with finding a pannier/bicycle rack that would suit my rather large rear tyre space.

I'm wondering if the increase to 1000w would make much difference from the 500w? I'm thinking it will be a bit less noticable that way if I got a 500w instead.

Optimally i'll be looking at a top speed of around 35km an hour.

[AussieJester]

Seems there's alot of faffing about, asking and re-asking same questions, just fit the motor you have use the torque arm a and ride the bike, it will work fine....if you want a rear hub, talk to Es member cell_man he sells Mac motors for a better price than you're finding on Ebay, he's a trusted seller ..has quality motors and batteries...

KiM

[chopper_elec]

Seems there's alot of faffing about, asking and re-asking same questions, just fit the motor you have use the torque arm a and ride the bike, it will work fine....if you want a rear hub, talk to Es member cell_man he sells Mac motors for a better price than you're finding on Ebay, he's a trusted seller ..has quality motors and batteries...

KiM

yeah there has been a fair bit of re-asking from my part, I think i'm just moreso concerned about those dropouts failing under the torque with that 48v 500w motor of mine.

My only real issue at the moment is mounting the battery, I wanted to mount it on the back above the back wheel with a rear bicycle rack but I was not able to find one that would suit as yet.

That means I can actually go out next week and test it out yay. Like anything, projects are things that can be worked on in time. There is no reason to not try out my hub motor.

I think its all the reading up that i've done that has scared me to any dangers involved in the torque arm. I will machine a little diamond piece this week for the drop outs and actually enjoy the thing

Thanks Aussie

[chopper_elec]

I have so far been in contact with about 5-6 suppliers so far discussing options to source out a 20"x4.25" rear wheel but so far there had been no prevail.

With a bit of luck I was contacting conhis motors regarding the specs and motor that I was after, to which they were able to make up a custom one with those sizes and even include a tyre and the rest of the kit goodies.

The price should be around $430 including express shipping which is a pretty good price compared to the others i've been looking at which were over $500.

I'm hoping to get cruise control and i'll be set.

I do have an opportunity to up the power from 500w to 750 or 1000w but at the moment i'm hoping to try still get longetivity.

Am I likely to feel the difference that much with a direct drive in comparision to a hub? In the articles i've read the resistance is similar to running a mountain bike style tyre.

I'm nearly there, to be honest i'm much happier to know that i'm getting the correct size rear hub, it will look a bit less obvious on an already obvious bike haha.

I went for a good 20km ride over the weekend through a park close by. I really only struggled up the hills. I have one of those cheap speedos and i'm not sure where the instructions are for calibrating it. On the screen it comes up with a range of numbers from 100-250 but in my measurements of the wheel I couldn't figure out what this number was to put in for the radius of the wheel?

[Architectonic]

Seems there's alot of faffing about, asking and re-asking same questions, just fit the motor you have use the torque arm a and ride the bike, it will work fine....if you want a rear hub, talk to Es member cell_man he sells Mac motors for a better price than you're finding on Ebay, he's a trusted seller ..has quality motors and batteries...

Agreed. Ride what you have, worry about changes later.

The Conhis motors are probably going to be geared too slow for a 20" rim. I would go for a Cell Man 6T MAC and lace the rim yourself, or take it to a bike shop. I'm not a fan of low power direct drive motors at all, the advantage of the geared motors is they ride like a normal bike when the motor is off.

(assuming the dropout width of your bike is standard - otherwise rear hub motors are not such a great idea)

[chopper_elec]

Yeah my only issue has been finding a hub motor that will fit in the very wide 175mm dropouts.

[Scruffoid]

Dont limit the power to 500W when they can give it 1000W.

You limit the power yourself by how far you turn the throttle, the extra power will surely come in handy.

Why have a Ferrari and then speed limit it to only 100Km/Hr.

Just my opinion.

Wayne

[chopper_elec]

Dont limit the power to 500W when they can give it 1000W.

You limit the power yourself by how far you turn the throttle, the extra power will surely come in handy.

Why have a Ferrari and then speed limit it to only 100Km/Hr.

Just my opinion.

Wayne

My only issue is having the tempation to go faster on a cheap bike lol. I was thinking that the 750w or 1000w might be too much amp draw for my lifepo4 48v 16ah battery

[Scruffoid]

I have no idea how you battery is wired up etc but i would suggest that in a 16AH configuration that it is running multiple cells in Parallel and based upon that alone the amperage to supply 1000 W at 48 Volts is 1000/48 = 20 Amps. I think youll find that 20Amps wouldnt even make the batteries stress at all.

You worry way to much about stuff. Just build it get it running and start enjoying it.

1000W of power is nothing, you can pedal it with that much power with your feet. A human can produce some serious power its just for small bursts. Isnt it something like So it will all be good on your bike.

Elite track sprinters are able to attain an instantaneous maximum output of around 2,000 watts, or in excess of 25 W/kg; elite road cyclists may produce 1,600 to 1,700 watts as an instantaneous maximum in their burst to the finish line at the end of a five-hour long road race.

So get off you bum plug it all together on the bike adn show us a picture of the thing put together and your grin of riding it.

[chopper_elec]

I have no idea how you battery is wired up etc but i would suggest that in a 16AH configuration that it is running multiple cells in Parallel and based upon that alone the amperage to supply 1000 W at 48 Volts is 1000/48 = 20 Amps. I think youll find that 20Amps wouldnt even make the batteries stress at all.

You worry way to much about stuff. Just build it get it running and start enjoying it.

1000W of power is nothing, you can pedal it with that much power with your feet. A human can produce some serious power its just for small bursts. Isnt it something like So it will all be good on your bike.

Elite track sprinters are able to attain an instantaneous maximum output of around 2,000 watts, or in excess of 25 W/kg; elite road cyclists may produce 1,600 to 1,700 watts as an instantaneous maximum in their burst to the finish line at the end of a five-hour long road race.

So get off you bum plug it all together on the bike adn show us a picture of the thing put together and your grin of riding it.

Haha yeah I sure do worry a lot. I have made my order from Conhis, I would have loved to try through Cell-Man but its been a while and hadn't heard from them.

I have my order below. The 25amp controller will more likely put the motor into the 800w realm if I have calculated correctly, but the speed controller will cut out at no more than 25amp which is good.

I'll actually record a video on that first acceleration lol.

Assembled Hub Wheel:
48v 500W 20" x4.25" Wide Rim, Spoked and Assembled with Tyre and Tube

Motor Controller Specs:
New Style 48v Max 25amp Controller and Controller Bag

Throttle:
Twist Throttle with Key and matching Handlebar Grip for Non throttle side