Help me build an e-bike. Yeah!

If you were the smarter, wiser, more experienced version of me and wanted to build an e-bike for your daily commute (details below) what products would you buy and from whom?

1. You broke open the piggy bank and found $2k, but you might remember where your wife hides hers if needed. :wink:
2. The commute is 16 miles each way with a few serious hills (1/2 mile long and steep)
3. The battery can be charged at work and at Home. (unless your thinking of using a fuel cell or portable nuclear reactor)
3. You're a big guy, 250lbs. Sorry.
4. Your not interested in top end speed so much as climbing power. :?
5. the commute is mostly paved.
6. You still want to pedal. :lol:

For climbing power:

Direct drive 9c lookalike ampedbikes/ebikekit/cell_man kit.. can make tons of power but drags on the pedals some. Dead reliable though

Mac/bmc geared motors, no pedal drag but reliability has been questioned lately. Super efficient and can hit very high top speeds on less voltage.

For battery,

Cheap option: Read about LiPO on here and see if it's for you. You can dump tons of amps out of those batteries. 15ah should do the trick for you, and should get you from work & back. These batteries are also very light.

Mid price option: 20ah 48v ping pack. Don't go smaller. The smaller the aH, the less amps it can put out, then you end up abusing the cells and tripping the BMS. The upside is that these are dead simple to charge. The downside is that they are heavy.

Best option: If you have extra cash that you don't mind blowing, build a 44v 16ah headway pack and balance charge that sucker with a hyperion 14s charger. It will last a long time and can put out a good amount of amps.

Townie 8 speed feet forward bike or Used recumbent, with Cyclone chain drive 500 w, 20 amp hour of 24v Lith Iron phoshpate.

The big guy thing makes the hill steeper, that's for sure. But how steep? A place called map my ride may be able to help you find out. Not sure if it works outside the USA, if not there may be similar road biker tools, or google map tools you can find out the grade with. Mapping short sections of just the hill gives more accurate readings of the grades.

If grades are less than 5-6% , and assuming you are willing to do some pedaling on at least the steep bit, then a typical direct drive motor will do it for you, powered by 48v 15 ah of pingbattery lifepo4. (hears certain es members groaning) Lots of other options for the battery, but for sure you need 15-20 ah of something lithium. You need more than you actually use, to keep the battery lifespan from being shortened, as neptronix points out. If your controller is any stronger than 25 amps, then you need bigger sizes in the batteries like pings. You may opt for a stronger controller to get up those hills, so consider the 48v 20 ah if you buy a 35 amp controller.

But with a 250 pound rider and hills 8-10% in grade that are 1/2 mile long, then you may want a strong gearmotor like the puma or BMC, or a non hub motor like the cyclone, or even a home built chain drive using a wheelchair motor or other stuff like RC motors. Generally using higher amp controllers, these types will of course need a bit better batteries than the ping that can run a 20 amp hubmotor.

$2000 is just about right for the budget, allowing the purchase of slightly more expensive bike kits like the BMC, and good batteries to go with it. $1500 is about right for a more minimal kit such as a dd motor and ping.

Depends on the hill. BMC 600w is great for weight on hills, but a 9X7 9c is better for a comuter, and would be fine up most hills for a 200 pound guy.

A 6X10 9C at 60 volts would be ideal, but no one is selling them in the US right now.

Ping 48V20Ah would be best for cost and conveniance.

Best bike would be a large triangled frame mountian bike with fat street tires. the open triangle is so you can fit the battery in the frame for the best ballance. Full suspension is nice, but skip it if you don't find a high end suspension bike in your budget. cheap full suspension bikes are worse than nothing.
Check Craigslist. the best bikes and deals are 10 to 15 years old.

Thanks for the quick feedback you guys rock. I really have no reference point to gauge the grade of hills and so I might have overestimated their size, "seriously steep" to me....after checking mapmyride appears to be about 4% grade or less (how disappointing) , but to a 250 lb rider on a hybrid bike it might as well be a mountain, and by the end of a weeks commuting you might find me doing the walk of shame on the steepest parts.

After reading through the various discussions about lipo vs the Pings I think I'll go with the Ping 48V20Ah for a commuter build for convenience. I like the idea of creating my own lipo pack with the higher c ratings but i would probably want to use that more for a weekend, off-road bike where I have the time to properly monitor the charging and balancing.

Well there you go. The 9 continent hubmotor in 2807 will work fine for you. no problems with 4%, though pedaling up it for half a mile sure can be! For street commuting, I personally like front hub. The motor up front balances better if you already have a 15 pound battery on the back rack. But for novices this means you must have steel forks on the bike. A 48v 15 ah ping will be big enough for the distance, and easier to carry on the bike than a 20 ah one. If you don't have rear suspension and there is room there, then carry the battery in the frame triangle.

You definitely need suspension, even if it's just front suspension forks and a suspension seat like the ThudBuster. As a large guy the tendency will be to sit down on the seat, so bumps will hammer directly up the spine. You mentioned "mostly paved", ie bumps assured. The suspension also helps reduce the hammering on the spokes and the rest of the wheel assembly, and these lightweight guys complain about broken spokes, so imagine a large guy.

Thanks again for the help. I've been going back and forth between front or rear motors and it sure seems like it would be a much better distribution of weight to have the motor in the front and the batteries in the center... or back. I am undecided on the frame. I was looking through a lot of the threads and there seems to be quite a few people using the Tidal force s-750, and if they are still available that might be a good way to go. but some of the builds with the Electra Townie 21 also look nice. I can also get my hands on a specialized hardrock frame for free. decisions decisions.

So far its looking like
1. nc26 9c 2807 motor with an upgraded 35 amp controller from http://www.ebikes.ca/store/store_nc.php
2. either a 48v 15ah or 48v 20ah battery from http://www.pingbattery.com/ (I think I'd rather have the bigger one. Whats an extra 5 lbs on a 325lb+ bike and rider rig? or is it more of an issue of finding a place to store the 20 ah battery? in which case would it be better to get the 48v30ah battery and sling it over a couple side satchels?) grrr.
3. ThudBuster!
4. So now i need to choose one of the frames above... or another... and a steel front suspension fork to go on it. any suggestions?

With the 35 amp controller, you will need 20 ah of the ping. So you have a battery able to produce the 35 amps when you need it. A 48v 15 is only good for 30 amps. Carrying it is difficult, since you get a 20 pound block too big for most rear bags and such. Some have opted to use two 10 ah batteries so they can carry in panniers, but that adds a lot of expense and complexity.

Front steel suspension forks are pretty limited in choices. Most are 40 mm travel, and pretty much junk, but still better than nothing in my opinion. Sometimes you can find them in 60 mm, and though still a pogo stick, the extra 20 mm makes them much better.

You might opt for no suspension to begin with, and later on, with some real world experience make the switch to aluminum front suspension. I have done that, but I don't recomend starting out with alloy forks and front hub for newbies at all.

Since you are heading towards a more high power type bike, you might want to look at some of the threads in the lipo noob thread links in battery section. Much better for packing power on a bike, but less long lasting and more complicated to charge in general compared to a "plug and play" cheap lifepo4.