8 Week Electric Bike Design Project

Joined
Jul 8, 2010
Messages
27
Hey Guys,

I posted a thread earlier about developing a low cost e-bike solution. We showed off some concepts but now we're done and have some photographs for you. We were designing for the low end market, so we utilized the Currie drive system and lead acid batteries, but our goal was to integrate the batteries and all the wires and controller into the frame with grace and style. The panels were vacuum formed styrene backed with fiberglass for rigidity. The project was about 8 weeks long, but the first two were spent doing research. Before this class I had never even heard of e-bikes, and in the past few months we developed a fully working prototype. With the weight properly placed in the center of the frame the bike corners like it's on rails, and feels good to ride. It's hell of a lot of fun. If you have any questions feel free to ask. I look forward to your feedback.

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Looks good, lots of room for custom battery packs as well. You can make that as one of the upgrade options. Heck, you can easily replace the currie motor with an RC one and really have a high performance version. Lots of possibilites with the way you have your design and still keep cost down.

Well done.
 
kfong said:
Looks good, lots of room for custom battery packs as well. You can make that as one of the upgrade options. Heck, you can easily replace the currie motor with an RC one and really have a high performance version. Lots of possibilites with the way you have your design and still keep cost down.

Well done.

Thanks for the kind words. That was the idea, to have the option for SLA or lithium etc. The next iteration is going to have a bit more sexiness, but I'm really proud of what we managed to accomplish in such a short amount of time.
 
That is seriously outstanding job and not just because you have had 8 weeks 'experience' with e-bikes
to learn the ins and outs!

The vacuum formed housing is outstanding and something others here should be looking at rather than reaching for duct tape and cable ties
as battery fixing solutions... Well done to you and others who worked on the bike to get it to this stage.

I am also very curious the method used to fasten the housing to the frame, i can see the chrome dome nuts on the housing around its perimeter, its the inside and how you have made the brackets? with bolts mounted on them i presume? i would be very very keen to see as i will be making a similar enclosure for my latest custom build and am a lil up in the air how i will fasten the fiberglass 'halves' to the frame while still allowing reasonably speedy and uncomplicated entry to the enclosure for battery maintenance etc...

KiM
 
The two halves are actually fastened to each other. The batteries are in a spot-welded cage that were U-bolted to the frame. All the wiring was routed through the housing. So far it's been fairly maintenance free, but in the next iteration we are planning to have everything more accessible. We are also working on creating a "wiring loom" to try to clean up the mess under the fairings. We have been in constant contact with the president of Currie Tech, and are anxiously awaiting his response to our project.
 
That's a nice-looking solution, and would lend itself to just about any ebike system. The only drawback is that nearly every frame would need a different vacuform casing (that's a lot of molds). Depending on design, it could be made to fit some mild variations for each different mold, though. Some frames would need a different battery cage, too.
 
nice work! looks very professional
 
Yup very nice good job!
 
Very nice! No suprise that it resembles the EV Global bikes. Good design just tends to end up in a similar place.

In the looks dept, it definitely beats a lot of stuff I've seen. One of the issues has always been the desire of some to remove the battery pack for security. This has led to lots of uglier battery packs on rear racks that compromise handling, or a pod in the frame that looks funny compared to a sleek fairing.

Hopefully you have the funding in the future to put some lifepo4 in that box, and maybe one of the better hubmotors.

Where are you located? There is a race in Tucson every spring for motorized bikes.
 
Glad it helped you get the grin. Way to go!
 
That is one nice piece of work, jonpanichella! Do you have photos of how you made the vacuum forming? It looks tempting for me to make one for my trike.
otherDoc
 
Yep everybody has the grin :mrgreen: More pics! Any build pics? Some under the covers.. Very professional..
 
Hahaha thanks everybody for the kind words. I'm in the process of uploading additional pictures right now which may help take a lot of the mystery away.
 
Thanks! One complaint we received was the amount of wires these things had either bothered or intimidated new customers, so we did our best to hide them. The next iteration should have a gracefully through out cable management system or wiring loom.
 
I like the design and how the electrical components are hidden inside the plastic. Good work! I just have 2 questions.

1. How do you replace the batteries when the go dead? Can you remove them even after being welded?

2. What was the total cost to build the bike?
 
I completely agree with your decision to have a base package with SLA batteries. It keeps the purchase price down, and when they wear out, the customer has the option to upgrade the battery pack if they want.

I HIGHLY recommend that you spec a front wheel with the 6-hole boss that allows a customer to bolt-on a front disc, and also spec a front fork with the 2-hole flange allowing a front disc caliper to be bolted on. It would be a very minor cost increase, but if a customer wanted to upgrade to a front disc it would not require the customer purchasing an entirely new wheel and fork (plus swapping the fork out).

Nothing wrong with the base model having front rim brakes, but any potential customer would immediately see that a brake upgrade (even if they never went through with it) would be easy and affordable to do themselves,...just a thought.

Looks great, best of luck!

second edit: The more I look at the bike, the more I like it! The hard case not only hides and secures the batteries and wiring, it really looks good. I would also add a Thudbuster seat, BMX handlebars to give the handgrips an 8" rise (try it!), front disc brakes, and I would move the kick-stand farther back so the left pedal couldn't hit it when rolling the bike backwards in the garage. Plus a cheap speedometer and a cargo rack and baskets of my choice...I have two bikes with that same frame shape...I would buy something like this, and I can see others buying it.

All of these things I'm suggesting are mods the customer could do to personalize the bike for themselves, but the only part I would have you do is make the front brakes "disc-ready". That part would be difficult and expensive for the customer to do.

EDIT: here is the original thread with many proposed bike frame graphics:

http://endless-sphere.com/forums/viewtopic.php?f=3&t=20166&start=0
 
lester12483 said:
I like the design and how the electrical components are hidden inside the plastic. Good work! I just have 2 questions.

1. How do you replace the batteries when the go dead? Can you remove them even after being welded?

2. What was the total cost to build the bike?

The battery "cage" is actually open at the sides, and the batteries themselves are held into the cage with the u-bolts used to mount them to the frame. We were planning on doing a fully removable battery but simply ran out of time. We were the only group to actually have a working final prototype, most of them were just foam and fiberglass mockups.

The total cost was around 500 or so dollars, some of which we were reimbursed. We found the donor bike at a salvage store for a whopping 70 bucks, so we bought 3 curries as parts bikes. We also had parts donated by both Fuji and Sram. Over my internship I plan on doing a bit more "designing" to get everything sorted, including a cable management system and some modifications to the form. Nothing major though.
 
spinningmagnets said:
I completely agree with your decision to have a base package with SLA batteries. It keeps the purchase price down, and when they wear out, the customer has the option to upgrade the battery pack if they want.

I HIGHLY recommend that you spec a front wheel with the 6-hole boss that allows a customer to bolt-on a front disc, and also spec a front fork with the 2-hole flange allowing a front disc caliper to be bolted on. It would be a very minor cost increase, but if a customer wanted to upgrade to a front discm it would not require the customer purchasing an entirely new wheel and fork (plus swapping the fork out).

Nothing wrong with the base model having front rim brakes, but any potential customer would immediately see that a brake upgrade (even if they never went through with it) would be easy and affordable to do themselves,...just a thought.

Looks great, best of luck!

Hey thanks,

We based a lot off the incredible feedback you gave us a few months back. Thanks for the suggestions!
 
Good job keeping the cost down. I good looking bike like that can compete with and possibly beat out the overpriced A2B and Sayno Eneloop.

You should also add a speedmeter or Cycle Analyst.
 
Nicely done! If you guys ever branch out to vacuum forming lipo battery pack enclosures I bet there would be quite a bit of interest? I would love to have a clean, well fitted, hardshell package for my cells.

all best
 
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