Please help me put an ebike together that meets my specific needs
 

So I have been planning to build an ebike and using it as a commuter for a couple of years now. It seems that everytime I get ready to do it, something happens to prevent it.

Anyway, I am ready now and planning to start as soon as this weekend or next weekend.

What I am trying to do is put something together that meets the following:

1: Will reliably carry me (and I weigh around 245 pounds).
2: Will hit 20 MPH with no pedaling (or faster).
3: Will make it up a decent hill with no pedaling.
4: Will be as light as possible.
5: Will easily fit on a folding bike with 20" wheels.
6: Will not have any drag if I pedal without motor power.
7: Will be as quiet as possible.
8: Will have a range of at least 10-15 miles with no pedaling (the more the better but I need at least 10-15 miles).
9: Can be kind of hidden so it looks like a normal bike.
10: Can withstand a ride in the rain.

Basically, the idea is to have a small folding bike I can ride to the train station, fold it up and carry it on the train, and after getting off the train riding the bike the rest of the way to work. I would then fold the bike up and keep it in the office. And of course, do it all again to get home.

Now I am pretty sure I will have to compromise on some of those. But I'm hoping you guys can help me find the best combination that meets the most of those requirements. It looks like there are new technologies/vendors/etc than there was when I researched this a couple years ago, so I am somewhat out of the loop.

Any ideas or suggestions would be very much appreciated.

A BioniX kit plus your choice of folding bike.

http://nycewheels.com/bionx-electric-motor.html

Looks like the Bionx kit will do the trick, but it costs over $1700 for a decent one (350w). Any cheaper options out there?

bafang geared motor (20") very light - $300
infineon 48 v controller $70
hall throttle $15
freewheel if rear hub $20
lifepo4 48V 10ah from ping, ecity power,headway around $400 or so
wires and miscellaneous connectors

I'm having a hard time finding anything on the bafang geared motor. Can you link me up? I found this:
http://www.szbaf.com/en/Product.asp?CategoryID=275
but that doesn't really give me any info. Are one of those the motor you were talking about?

You need to give us the following information in order for us to give you a better answer:

1. What is you budget?
2. Do you have good mechanical skill on bikes?
3. Do you have good electrical knowledge and skill?
4. How much weight can you carry along with you on the bus & train?
5. What else would you typical carry to commute/work along with your future electric folding bike?
6. Are you good on riding smaller wheels bike and still be able to balance well especially on turning & braking?
7. Would you ride your electric bike in rain?
8. Do you have an existing folding bike in mind? If so, which one?
9. What is the maximum weight limit for your folder?
10. How long would you keep your electric bike? Yes, it does matter because of different quality products.

I have multiple folding electric bikes from 8", 16", 20", 26", and 700c size wheels and I have tried all of them to commute. I have unfortunately spent a fortune but have learned a lot from it as a hobby and possibly businesses in the future. The key here is optimization. :)

1: My budget is around a grand.
2: I have decent mechanical skills on a bike. I have some bike shops around for the complex stuff too (but they don't sell anything ebike related around here).
3: I have decent electrical knowledge and skill, but I am by no means an electrician or electrical engineer.
4: Not sure what you mean here. I am hoping to keep the bike as light as possible (say around 45 pounds tops), I weigh about 245. I don't think the train has a carry on weight limit- whatever you can carry and fit into your personal space.
5: I would have a backpack with my lunch, water jug, work stuff, etc- weighing around 5-10 pounds.
6: Yeah, I can ride a bike and turn and brake. 20" wheels should be no problem for me.
7: Yes, I will probably ride in the rain. Especially if it's sunny when I ride to work, and starts raining while I'm already at work. I will be stuck there with the bike, and will definitely ride in that scenario.
8: No, I don't have a bike in mind yet. I am currently looking for the cheapest and lightest one. So far the lightest ones I can find are around 25 pounds.
9: I haven't found one yet. I'm guessing it will be around 250-300 pounds though. Hopefully after riding for a while i will lose weight and meet the requirement.
10: I guess I will keep it until it breaks. Until I need to replace the battery, at least.

I want this bike to be able to get me there and back with no pedaling whatsoever. It is only a few miles to the train station (total- from my house and my work combined is only a few miles). And I will obviously pedal some, but if I decide not to I want the bike to be able to handle it. And hopefully at some point as I start getting the hang of it I can eliminate the train and ride the 20 miles to work. I would probably build a new bike for that though.

Get this one from Wally to save you troubles. The bike weights around 42 pounds without the battery. Therefore, by adding 4 x 11.1v RC Lithium Polymer batteries + new controller + throttle will get you the speed + the weight limit you want within you budget. :)

http://www.walmart.com/catalog/produ...uct_id=8467100

Do you think that one from Wally would be strong enough to pull me up a hill though? And light enough to carry around?

I'd rather just build my own if I have to replace the battery, controller, throttle, etc anyway. There are tons of folding bikes out there that only weight 25-30 pounds for less than $300. If I could put a $700 kit on one of those it would probably be better than that Wally unit- don't you think?

The Wally ebike is barely enough to support your weight but should be doable. Your arms & muscles will get strong if you carry it everyday.

You can build your own with a Dahon or Downtube folding bike for < $300. However, putting everything yourself will likely to go over your budget one way or the other. You may have to purchase certain components more than once to compensate mistakes when you assemble it. Believe me, it will happen. :crash:

I really am pretty set on building my own. I want that satisfaction of knowing I put it together. I should be fine as long as I have a halfway decent set of instructions.

I don't want it to be too heavy though. If it's much heavier than around 45-50 pounds I will probaly ride it for a week and then go right back to driving. I just can't see myself struggling to lift a heavy bike on and off the train.

I am hoping around $700 (give or take a little) for the kit, and around $300 (give or take a little) for the bike should be able to get it done. I just need to hopefully get pointed in the right direction.

Try http://www.ebike.ca They have a Nine Continent Conversion Kit in a 20" wheel for $435.00 USD, plus battery ($300 to $550). I bought an eZee kit and highly recommend it (it is more than you want to spend). I am of a similar weight and I am able to get around the hills here in Atlanta just fine.

I have no connection to ebikes, just had a good customer service from them. I suggest you contact them and ask them for recommendations.

Here you go. They also have fronts too.

http://holmeshobbies.com/product.php...&cat=20&page=1

None of our Public transportation around here will let you bring a battery onboard.

Just a thought.

Here's what happened inside the BaFang hub motor with the gears stripped:

http://www.endless-sphere.com/forums...e.php?id=14801

http://endless-sphere.com/forums/dow...e.php?id=14802

http://98.131.176.65/endless-sphere/GEDC0799.JPG

http://98.131.176.65/endless-sphere/GEDC0800.JPG

http://98.131.176.65/endless-sphere/GEDC0801.JPG

What's the story on that messed up Bafang motor? How did that happen? Was it from normal use or was it modded in some way?

I was leaning towards the Bafang but if it's going to burn out on me then I should stay away from it.

Ampedbikes is supposed to be selling a freewheeling motor that rivals the Bafang but without the noise or gear stripping.

I do like the motor because of its lightweight & high torque design. However, it is lightweight because the nylon gears is being used instead of the steel gears. The gears were messed up due excessive load @ around 300 lbs I believe. Since most American are typically overweight so it may only be suitable the Asian market.

I agree with Americans being overweight; probably not so much on this forum, but I think that notion has no impact on that Chinese' over scrupulous design.

The fact that heavy riders break them is just a side effect of choosing inappropriate materials to save a buck.

I believe I read they were trying to reduce the noise -steel gears are loud, I've read.