My 48v 500W Cruiser Chopper Project

chopper_elec

100 W
Joined
Jun 13, 2012
Messages
241
Location
Victoria, Australia
Hey all,

I thought I might share a project of mine.I've always wanted to have a motorbike but since i'm not too confident on the road I thought I would explore the options of converting a bicycle, moreso in particular a Chopper Style one.

I ended up buying a Flight Dragster bike a few days ago and i've started working on some 3d models and some calculations on how to mount the batteries, speed controller and other electronics.

Vehicle Specifications:
Flight Dragster Bike
24" Front Wheel
20x4" Fat Rear Tyre

I have gone for a front hub kit since I am unable to find one to suit the very fat 4" wide tyre at the back.

The idea would be to build a charging system that would be able to charge each battery pack seperately which would keep the packs in good nick as well as allowing me to fully charge the whole pack in about 1 hour or so. I am still working out a plug system in way that each battery when charging would be isolated from the rest without having to disconnect the series bridges (maybe I could use a number of switches to isolate the series).

The bike will have a H3 Fog Light on the front for those days/nights I might need a bit more light. It will be powered from an auxiliary 12v battery which will still need to be designed. The bulb will be replaced using a h3 LED light which has 1/6th of the power usage.

Motor Choice
I will be using a 36v 350w 24" Front Wheel eBay kit as the power source. I was quite specific in wanting the twist throttle which will be great.

Battery Choice
I know they aren't the most popular but I got a decent price for a set of 3 12Vx 12ah SLA Batteries for around $90aus which was good enough to try out. Long term LifePO4 will be good but cash is a bit shorter than expected at the moment.

Creature Comforts
- GPS/Music Supplied by my Wildfire G8 Phone on a handlebar mounting kit
- I am working on a Custom Trailer which will be used to store food, supplies and the possibility of extra batteries depending on the distances travelled. I'm tempted to chuck in 3 small 55ah 12v car batteries in the back and do some long distance rides lmao. Weight would be an issue haha
- eBay Alloy Pedals :)

Wearing the style
I seem to like to look the part when cruising around on an old dragster/chopper so i've made a few small purchases off eBay which include some oldschool leather/metal riding goggles, a brown leather jacket and a white scarf hahaha

As you can see I like to have a joke around, and what better way than to have a fun environmentally friendly bike.

Here are a few of the bike.

I used 3D so I can plan everything out easier than I can draw.

My skills aren't the best in 3d but they are functional hehe

bike9.jpg

bike10.jpg


Here is a 3d render of how the batteries may be positioned in a saddle pack
bike8.jpg


Any comments would be more than welcome :)
 
Willow said:
save your coin, and go for at least 66V Lipo and rear wheel drive. It's where the fun starts.

I think i'm moreso worried about the legalities pushing up that high haha.

I was looking at a 36v 500w kit at the moment which should be good to test out.
Even anything more than 250w is not allowed.

Mind you this is all used for "offroad use" only so it won't matter :p
 
you can limit power with a Cycle Analyst - or similar device should you find yourself needing to. Go for power in the first instance, you will only wish you had, and end up spending twice as much. LIPO is light, small and powerfull.
 
Willow said:
you can limit power with a Cycle Analyst - or similar device should you find yourself needing to. Go for power in the first instance, you will only wish you had, and end up spending twice as much. LIPO is light, small and powerfull.

Thanks for your information, much appreciated.

Lipo is definitely light and very dense for its power output. I tend to be a bit of a chicken and stick with SLA and Nimh as I used to race with RC cars and have been brainwashed with the videos online of Lipo fires. Even though I know they are very good, I seem to stray away.

I will save up for a lifepo4 one day.

I've decided for now to keep with the 36v 500w version. I wonder if the 48v version may be worth pushing for
 
When you say dragster in the title, I hope you're not expecting your current plan to be quick. It also will also handle terrible like all chopper-styled things.


That's all fine if its what you're looking for. I want to make sure you're aware before investing in anything and being disappointed with the results.

If you're shooting for something you can roll around the neighborhood on for a few miles without pedaling, you're on track. If you're looking for something to drag race, you gotta scratch everything you've got going there and start over.
 
liveforphysics said:
When you say dragster in the title, I hope you're not expecting your current plan to be quick. It also will also handle terrible like all chopper-styled things.


That's all fine if its what you're looking for. I want to make sure you're aware before investing in anything and being disappointed with the results.

If you're shooting for something you can roll around the neighborhood on for a few miles without pedaling, you're on track. If you're looking for something to drag race, you gotta scratch everything you've got going there and start over.

Thanks for the info mate. Your 100% right they handle quite badly. Before I got started I took the bike for a decent long ride (about 20 miles) on all sorts of terrain, up and down hills, smooth roads, gravel etc. What is great is I loved the bike as is, I just wanted to cover more ground and get upto speed a bit more easily. Battling the hills was also something that was quite difficult.

The main reasoning behind the powered system was that certain hills were quite difficult as there is only 1 gear available which is great for cruising, it allows you to cruise at a decent pace on straight ground but is more than inappropriate for any inclines. I'm hoping to get a system that will allow me to enjoy the best of both worlds.

I think my comments of a "dragster" were moreso associated with the name that the bike was marketed as. I would best define it as a cruiser, enjoying it for the sheer fact that the seat is low, handlebars are high up and there is heaps of room for gadgets on the handlebars.

I really appreciate the comments, last thing i'd want is to build it and be disapointed.

Any comments on my awesomely stunning 3d work? (far from it lol) haha.
 
Ok, perfect, you're right on target for reaching those objectives. The only thing to do differently is the lead. Starting with a lead battery setup just means you will quickly be buying Lithium, and could have saved the money spent on lead towards buying lithium in the first place.

Lead is where about 90% of ebike builds start, and it's the cause of about 90% of those builds not being a satisfying experience.

If you plan on using it regularly and putting some miles on it, just wait and save up until you can buy lithium from the start, and you won't have to buy your battery and charger setup twice.
 
I saw some poor guy today trying to pedal something like this up the bridge approach. Seriously, he was weaving all over trying to apply any significant pedal power. Very good candidate for electric assist!

Cruiser or "Dragster looking" is more appropriate description. Luke's right on about the batteries, save the lead my friend. Make sure you got good brakes, everything tight and enjoy the ride!
 
Listen to the guys advising to ditch the lead, lifp04 ping pack would suit your requirements.

I like cruiser style bikes, very relaxed riding style, started fabrication of my third custom framed cruise recently
As am matter of fact :)

Final_RC_Cruiser_Series_Pics_1024ReZ.jpg

^^^ Hope this might provide a Lil inspiration for you, this is one
Of my custom cruisers...

Best of luck with the build

KiM

P.s where in Australia are you?
 
liveforphysics said:
Ok, perfect, you're right on target for reaching those objectives. The only thing to do differently is the lead. Starting with a lead battery setup just means you will quickly be buying Lithium, and could have saved the money spent on lead towards buying lithium in the first place.

Lead is where about 90% of ebike builds start, and it's the cause of about 90% of those builds not being a satisfying experience.

If you plan on using it regularly and putting some miles on it, just wait and save up until you can buy lithium from the start, and you won't have to buy your battery and charger setup twice.

Yeah your not wrong, I got the 3x 12v sla batteries for around $85us for all 3 so it was a very cheap option at first. Since working with lead in the past, I wasn't so keen on the weight and bulkiness. I will start saving up for some lithium batteries in the next few months. I couldn't resist not having any power for my new motor haha.

Ykick said:
I saw some poor guy today trying to pedal something like this up the bridge approach. Seriously, he was weaving all over trying to apply any significant pedal power. Very good candidate for electric assist!

Cruiser or "Dragster looking" is more appropriate description. Luke's right on about the batteries, save the lead my friend. Make sure you got good brakes, everything tight and enjoy the ride!


Yeah its very difficult going up any hills. I had to make left and right turns to try and cut into the hill, otherwise its too much stress

The bike still uses an old style cantilever setup, i'm hoping for now I may be able to find some better brake pads to hold up a bit better? Some new alloy brake levers will be in order too.

Cruise/Dragster looking is definitely more of a description. Its quite comfy to ride except for the fact that there are hills lol.

I would have held off on the sla if I could afford the $350-$400 extra. I really wanted to get started with a battery source of some sort.
 
AussieJester said:
Listen to the guys advising to ditch the lead, lifp04 ping pack would suit your requirements.

I like cruiser style bikes, very relaxed riding style, started fabrication of my third custom framed cruise recently
As am matter of fact :)

^^ Hope this might provide a Lil inspiration for you, this is one
Of my custom cruisers...

Best of luck with the build

KiM

P.s where in Australia are you?

Wow Aussie those pics look unreal. I wish I could make my own bike. Do you know roughly how much they set you back each?

Thanks for the inspiration. I am just in Eastern Suburbs of Melbourne. And yourself?
 
chopper_elec said:
AussieJester said:
Listen to the guys advising to ditch the lead, lifp04 ping pack would suit your requirements.

I like cruiser style bikes, very relaxed riding style, started fabrication of my third custom framed cruise recently
As am matter of fact :)

^^ Hope this might provide a Lil inspiration for you, this is one
Of my custom cruisers...

Best of luck with the build

KiM

P.s where in Australia are you?

Wow Aussie those pics look unreal. I wish I could make my own bike. Do you know roughly how much they set you back each?

Thanks for the inspiration. I am just in Eastern Suburbs of Melbourne. And yourself?

I didnt keep track of the expense side of things, at a guess around 1500
all done with freight etc included...Frame was only about 60 bucks worth of metal and 100 for
powdercoating...Im in Perth W.A myself, heap of Eastern stat e-bikers on the forum ;)

KiM
 
Wow that worked out cheap for all the metal. I'm in the works of building a trailer at the moment for the bike.

I was going to use tubular alluminum, build up a jig out of wood and G clamp it all up. I will eventually have an exhaust place weld it all up for me as I have little idea how to weld anything haha.

I will probably use a single wheel and mount the trailer to either the back axle or from the seat mount. Any recommendations on this side of things?

I'm still debating whether i'll go the dual wheels or stick with 1 in the back middle section.

Long term i'd use the trailer to store food and a small fridge which will work off an auxillary 12v battery.

Style wise i'm hoping the trailer will look as good as the bike does, so I may end up going for one of those childrens bicycles and cut into the actual frame build off the frame from there.
 
If your wanting to carry a fridge I would consider using the frame from a childs bike trailer if you lack the means to fab
ricate from scratch, something like this perhaps-->

bumper-adventure-solo-childs-cycle-bike-trailer-free-delivery-11-p.jpg

With minimal tools it wouldn't be too difficult to strip the canvas off cut out a wooden base and bolt it along with some sides on to make a neat little trailer, I actually found one of these trailers kerbside during council rubbish collection and intended to do exactly this but never got around to it...

KiM
 
That would work perfectly, my only worries was in relation to fitting through a set of barrier poles that I have close by to the bike track.

There is a large pole inbetween the actual entrance to the park that I like riding down and I can barely fit on my bike. I could always cut and narrow down the trailer to suit. I may even use some wire mesh sheeting on the bottom of the plate which I could then use to keep things from falling through. I am going to go hard rubbish collecting.

Thanks for the awesome suggestion
 
I'm still on the hunt at the moment for a bicycle trailer to work off but I have just missed all the hard rubbish collections in my area.

I do have quite a few goodies coming in the mail this/next week:

- 48V 500W Front 24" Hub Motor, Battery Bag, Twist and Thumb throttle, 48v motor controller
- Bluetooth 2.1 Wireless Stereo Headphones/Headset
- 4x Brand NEW 12V 12AH Sealed Lead-Acid Battery AGM
- Spoke Bike Bicycle Wheel Spanner Wrench Adjuster Tool
- 48V SLA Battery Charger
- Old Style Motorcycle bicycle Goggles Chopper Scooter Sunglass
- New Mountain Bike Riding Bicycle Winter Damping Antiskid Full Finger Glove M
- 2 Pcs Alumnium Alloy Nonslip Pedals Silver Tone for Mountain Bike
- New LCD Bicycle Bike Computer Odometer Speedometer
- White Super Bright H3 7.5W Car Auto LED Day Driving Fog Light Bulb Lamp DC13.6V
- Bicycle Motor Mount Holder For HTC G13 Wildfire S A510e

I ended up getting a torque arm kit from Glow Worm Bicycles,

My dropouts on the chopper bike are quite thick from what i've noticed, I was wondering what my chances are like to have issues with the 48v 500w motor?
My bicycle has a triangle shape eyelot in the middle of the fork plate that the drop out is on.

Torque%20Arm.JPG
 
The 20x4.25 rims and tires are available from ChoppersUS i run one on my cruiser also. They are of pretty poor quality
though, dunno if i would trust hem with a heavy frock motor laced into them...

KiM
 
AussieJester said:
The 20x4.25 rims and tires are available from ChoppersUS i run one on my cruiser also. They are of pretty poor quality
though, dunno if i would trust hem with a heavy frock motor laced into them...

KiM

Yeah they aren't the best of quality, my rim isn't even perfectly round (the brake touches the rim everytime it gets to a join in the rim).

I was hoping to source out a complete rim/hub setup for the rear, it would make the motor more hidden. I'm wondering if the quality of the dropouts would be pretty decent on a chopper? From what I could see they are about 5mm thick steel. I am just working around how this torque arm will sit neatly or whether I may end up needing one after all. (I hear torque arms are recommended for 500w+
 
I am still trying to understand the limits of the bike, I ended up buying it for around $200aus new (rrp $400) but in the back of my mind i'm always worried about its safety abilities.

The bike was sold by Goldcross cycles so i'm sure it has its ADR approvals or else they couldn't technically sell/stock it.

For some reason i'm worried about the idea of adding a 500w 48v motor is going to bring the bike to a miserable end (frame cracking etc) but the bike is neatly welded throughout and has a nice sturdy feeling like any other bicycle i've had in the past.

The front dropouts seem decently strong enough either out of steel or alluminium but i'll still be running a torque arm kit just in case.

I get worried the bike will fall apart haha

I did however measure out the V brake pads, the rear is 70mm and the front is 60mm which is very strange. I would have thought it would be better to have 70%/30% F/R ratio on the brakes similar to a car.

I did end up finding some decent 70mm front and 70mm race V brakes off ebay that seem decent enough:
http://www.ebay.com/itm/4-Pairs-8Pads-Red-72mm-V-Brake-Pads-Shimano-XTR-/190690692439?pt=Cycling_Parts_Accessories&hash=item2c660d0d57#ht_861wt_1270

It should be a decent brake upgrade, my front spokes need an adjustment too as its rubbing against the rim at the moment.
OBE-M12R.gif
 
After some fantastic advice from everyone on here I ended up putting an order for the Kool Stop Salmon Pads for front and back.

They should hold out quite well for my riding.

I've started getting quite interested in Road Bicycles (the ones with the thin 700c tires) so its likely I will start another project in the next few months haha. That bike will be used for riding to work (only 8 or so km away) which will have a pretty brisk hub setup on it (I won't be late that way lol)

I received my 4x SLA 12v 12ah batteries and they are a tad bit heavier than I thought lol.

12kg feels quite heavy haha. Thats ok though for now as I can seperate them throughout the frame (2 near the pedals, 2 on the battery tray on the rear wheel).
 
Seems like I may be returning the SLA batteries after all. I didn't quite realise how heavy they are. 4x 12v 12ah batteries feel as heavy as a car battery. And thats for only 12ah.

I am looking at sourcing out some Lifepo4 batteries now, I am still particularly worried about the dangers of charging the battery etc after working with some lipo batteries in the past.

I was quite interested in this particular example:
http://www.aliexpress.com/product-fm/502612684-Electric-motocycle-battery-pack-lifepo4-battery-pack-48V10Ah-wholesalers.html

Is there any bad experiences in the past from lifepo4 batteries amongst the community :)
 
What can I say... I'm soooooooo happy that I received some parcels today.

The kit comprises of a Conhis 48v 500w Hub Motor on a 24" Rim, a Thumb and Twist Throttle, Battery Bag and a Battery Tray

I'm super impressed with the service I got from the store I bought it from on Aliexpress.com

It was sent on Friday last week and it Arrived this morning. I am placing an order with them this week for a 48v 10ah LIfepo4 battery first thing tomorrow.

img20120621190536.jpg


img20120621190521.jpg


The good old SLA batteries in the battery box (not good but very heavy lol)
img20120621190547.jpg
 
chopper_elec said:
I didn't quite realise how heavy they are. 4x 12v 12ah batteries feel as heavy as a car battery. And thats for only 12ah.
Although it's really for only about 5-6Ah, as that is all you would likely get out of them. ;) That's just how SLA is. :(

I started with SLA, 2x 12Ah, then 3x 12Ah, then 2x 31Ah, then 3x 18Ah, then 4x 18Ah, and I was wondering when I would collapse a frame with it. :lol:
 
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