kmxtornado's first e-bike conversion build thread *photos*

I've read through all the "front wheel hub vs rear wheel hub" threads (yes, like all 7 of 'em) and I've gone through the FAQ's = Basic Stuff thread. Now onward. I plan to convert my current bike to electric in the next 9-12 months or so - plenty of time to learn. I'm willing to do whatever research I need to do, but I'm really lost when it comes to amps, volts, compatibility, calculations and all that engineering smart-people jazz. I'm hands-on and work on my bent trike all the time and come from a design background. Okay, now for the bike info....

MY INFO:
- Why an ebike? Purely for commuting and casual entertainment/fun.
- Weight: 155lbs
- Bike: Old school (sorta, like 12 yrs old) Specialized Mountain Bike. No suspension. No model b/c they don't make it anymore. Pretty generic though. It does NOT have disk brakes (nor would I intend to convert it to them).
- Ideal speed: I want to go at least 20mph. I'm fine with less than 30. I don't need to go super fast. It's more of a commuter than entertainment. I know there are legal reasons why I shouldn't go over 20mph, but I'm not that concerned about that.
- Elevation change: Plenty of hills to climb.
- Terrain: All paved roads
- Distance: I only need to travel about 10-12 miles roundtrip (most will be less than that) per charge. This is not to work, so I can't charge before making my return trip. It'll have to be 10-12 per charge, literally (tops). Being that most e-bikes (as I've read from the FAQ's) don't go more than 20 miles per charge, I'm w/in the limit and was hoping I could take advantage of smaller light weight batteries. No SLA batteries please.
- Pedaling? Call me lazy, but I'd rather not pedal. I sweat too easy and I don't want to be sweating when I get to my destination. I ride the trike when I want a work out and want to sweat. The ebike would be for a different purpose.
- Weather: I will never be riding in the rain, nor when it's wet out.

DECISIONS I'VE ALREADY MADE:
I'm trying to do my own research so I don't feel all spoon fed. Here's what I've determined I want (after reading all the pros and cons of this setup, particularly the cons):

- Rear wheel hub motor.
- I've got the 7-speed freewheel already that I'm going to reuse from my recumbent trike. Everything else I'll have to buy including the torque arms that everyone says is so important, which I of course agree.
- Battery mounted in the rear on seat post rack. I realize this will make the bike rear heavy but again, I'm hoping I can take advantage of lighter weight batteries for my short range needs.
- I'm still trying to decide on thumb throttle, 1/2 or full twist throttle.
- I don't mind the "pedal first" starting types if it gives me some sort of advantage (cheaper, etc).

BUDGET?
Well, cheaper is better for me. I won't be riding this regularly but would probably keep it for awhile so I'd rather not spend a ton, but will spend what's needed. If I spend less, I realize I can't have the best. No biggy. Maybe lower to middle range parts. $400-600? Does that work? I got my motor scooter for $1,500 so I definitely don't plan on spending anything near that amount.

DESIGN:
I'm looking for a stealth look. It should look like a regular bike with hidden e-power. That's part of my reasoning for wanting the battery on a rear mounted rack rather than in the middle of the frame (even though that would be way better for weight balance).

WHAT I'M LOOKING FOR:
I'd like some help on specifying components to match the stuff I wrote above. I'm in the middle of reading the review section.

kmxtornado said:

Maybe lower to middle range parts. $400-600? Does that work?

Click to expand...

No, not unless you get some real deals second hand or thieve alot of parts... 400-600 will get you a frock (hub motor) or
a battery pack but not both, well not anything worth
buying that you would likely be happy with for more than 10 minutes, anywayz... I always tell people $au1000-1500
when they ask how much, and that would prolly fall
into what your refering to as a medium range setup.

On your budget if you wish to go with a frock motor, a MAC from Cell_Man would likely be your best option, he can hook you up with premade A123 packs too...might do you a deal if you get the whole lot from him, link in my sig to his website shoot him an email for a quote

KiM

Yeah, sorry to break this to ya, after you have done so much research already. As soon as you said the words, hills and no pedal you just added hundreds to your cost. About $1200 tends to be enough for many, and you might be able to get away with less.

Hills, not needing that much speed, not being in a big hurry, and needing it low cost points you again, to Cellman. http://www.emissions-free.com/catalog/i29.html That motor will climb great, and any of his A123 batteries will be lighter because of no need to buy big capacity to power the motor. With the pings I showed carried in the rear on the other thread, you have to have 15 pounds to have the amps you need for a decent size motor.

The really small and cheap motors won't climb the hills well, but would still do ok if the hills are not steep.

Thank you KiM for bringing me back to reality.

Dogman, you replied!...and so quickly. I've been reading up on a lot of your posts and you seem to know what you're doing. So thanks for your comment. I definitely don't want to be spending upwards of $1,000 for sure. I'm looking to purchase a dream machine (not e-bike related) for $1,200-1,700 so I'd like to save my funds for that. It just feels weird to be selling a Yamaha Vino 125 for $1,500-1,700 only to spend the same amount or similar on an e-bike. I can appreciate the costs for people who are high performance riders and ride e-bikes as their primary mode of transportation, but maybe it's just not for me to have something so hardcore.

Maybe to lower my costs, I can get something that's more of a pedal assist rather than a full on sit-there-and-just-pull-the-throttle sorta bike. Anything else I can do to lower the cost? I suppose I can get SLA batteries, but that's an area where I'm willing to spend more money to NOT have to do. I suppose a front wheel motor could be significantly cheaper?...yet, I'm paranoid from all the talk about magnets falling out and locking up the motor and people flying off. Ugh.

San Fransisco Bay Area?
You'll need a gear motor like the BMC or the MAC. There just aren't alternitives in your price range. Go with Cell_man's MAC for best price.

The only way to shave the price is by getting a 9C and expecting to pedel a lot on S.F. type hills.


As much as I love Ebikes, you're going to be hard pressed to replace a 125 scooter with an ebike. An ebike would easily replace a 50cc scooter, but for the money, a 125 is still more practicle in places like S.F.

One of cellmans smaller, low wattage gearmotors is quite adequate for many commuters. Small gearmotors work great for going max speeds of 20 mph, and a 350w assist up a hill really is quite an assist. They are quite capable of climbing hills to about 7% grade, but you must pedal briskly on the hills or motors overheat. These smaller watt motors reallllly bog down on steep hills, but do OK on 4%. Like in the midwest rolling plains.

A kit like this, using poor, overly heavy lead acid batteries could get you going, but would have only about 6 mile usable range. Riding it farther would risk battery damage. http://www.e-bikekit.com/shop/index.php?p=product&id=133&parent=0

But in the bay area, hills are notoriously steep. You need the more powerfull motor. That's not the real problem, the real problem is good batteries can cost $500 to a thou more. The longer range you want, the more you spend and the harder to carry it gets. That cellman deal, with the Mac torque model motor is about as good as it gets, without going to much more unreliable vendors in china.

I'll definitely look into the BMC and MAC to educate myself a bit more on those. I currently don't know anything about those motors. Thanks for being sensitive to my price range. As long as the e-bike has assist, I don't mind pedaling if it can keep my costs down.

It'll definitely be tough to replace the 125cc engine with an e-bike for sure. I'm not expecting to get to the places I'm hoping to reach in the same amount of time or with the same relaxation as sitting there on my butt with my feet stationary. Hahah. I know the e-bike will be slower and I'll just have to schedule more time to reach my destinations which is fine. Another reason for a light weight battery is so that I can remove it and carry it with me in case I'm in a not-so-great part of the City (which unfortunately can be everywhere).

SUMMING UP MY SACRIFICES: since I clearly need to in order to get anywhere near my budget
- I have to pedal. Pedal assist is fine. I don't have to turn this thing into a motor scooter.
- Low range. I suppose I can cut my expected range to cap at 12 miles before a charge. No more 20 mi for me.
- I'd still like a rear hub motor, but I suppose if I can save a ton, I'll take a front mounted one and just ride slower to be on the safe side.
- Perhaps my budget needs to increase to the neighborhood of $700? Ouch....but still definitely not $1,000. For the money, I just feel like I could buy an already made e-bike that probably looks better and can fold for $1,200. So to spend anything near that on a conversion wouldn't make sense to me. I don't need super custom. I don't plan to race this thing or win any shows. I most likely will be only taking trips in the 5-7mi range more regularly than anything that will top 10-12mi. A generic kit or setup would be perfectly fine.

Hopefully these new/additional sacrifices can help me get on something. What do you guys recommend now? Meanwhile, I'll be researching that BMC/MAC motor...

One little fact that seems often missed is if you purchase all of your components from the same supplier, you can get stuff that is plug and play. Not only can you make a critical "let the smoke out" mistake when trying to connect components from different sources, It can be a giant, time consuming, pain in the ass to find suitable plugs to connect everything.
To make the battery cost burden a little easier, factor in the fuel savings.
For maximum enjoyment on a first build, consider the entire kit, including charger from the same source.

Drunkskunk said:

...As much as I love Ebikes, you're going to be hard pressed to replace a 125 scooter with an ebike. An ebike would easily replace a 50cc scooter, but for the money, a 125 is still more practicle in places like S.F.

Click to expand...

It all depends how you ride the scooter vs. the bike. I just sold my 50cc Honda Scooter. It was hopped up to do mid 40's, so it was a little more like a 125cc than the average 50cc. I used it primarily for commuting and assembled the ebike for a similar commute. I put off immediately selling my scooter when I put together the ebike because I wanted to compare the differences. I just sold the Honda scooter, though I'm keeping my big 500cc Aprilia scooter, because its been months since I really rode the thing for any stretch. The ebike certainly rides different and the commute is changed in response, but it was a great replacement. In fact, my geared motor 48V lithium batteried bike is probably the kind of bike the guy who started this thread is looking at. My 6 miles each way commute is about 10 to 15 minutes longer by ebike vs. scooter. But I simply enjoy the trip more and appreciate pedaling along a few stretches for a bit of exercise (without the all-out sweating I do when taking my pedal bike the same route). My route includes a set of very San Francisco-like hills, 800 feet elevation gain over 1 1/2 miles on one hill, and I generally pedal along to keep the riding at 15 to 18 mph.

The ebike is smaller, lighter, simpler, and easier to park and lug around. All those things were true about the 50cc Honda in comparison to bigger scooters and motorcycles I previously owned and its not like the lil' scooter was a whale. But the ebike was just more bicycle-like, duh, which is what I always wanted from my motorbikes and scooters and never truly got. There are people with different commutes or routes which would favor a 150cc or 250cc or even 500cc motorbike (I've owned all and see the advantages). But bigger is not always better.

kmxtornado said:

...SUMMING UP MY SACRIFICES:[/b] since I clearly need to in order to get anywhere near my budget
- I have to pedal. Pedal assist is fine. I don't have to turn this thing into a motor scooter.
- Low range. I suppose I can cut my expected range to cap at 12 miles before a charge. No more 20 mi for me.
- I'd still like a rear hub motor, but I suppose if I can save a ton, I'll take a front mounted one and just ride slower to be on the safe side.
- Perhaps my budget needs to increase to the neighborhood of $700? Ouch....but still definitely not $1,000. For the money, I just feel like I could buy an already made e-bike that probably looks better and can fold for $1,200. So to spend anything near that on a conversion wouldn't make sense to me. I don't need super custom. I don't plan to race this thing or win any shows. I most likely will be only taking trips in the 5-7mi range more regularly than anything that will top 10-12mi. A generic kit or setup would be perfectly fine.

Hopefully these new/additional sacrifices can help me get on something. What do you guys recommend now? Meanwhile, I'll be researching that BMC/MAC motor...

Click to expand...

I have a geared motor kit from Amped bike running a 48V battery from Chicago Electric Bikes. I spent around $1100 or 1200 for the kit, battery and a decent used Schwinn. There was no real difference in price between front and rear hub motors. I also recently bought my Dad a $1400 factory electric bike (iZip Zuma). Its a nice package and its truly turn-key. I have no qualms suggesting one for anybody looking for a complete bike. But my slightly cheaper ride is a bit faster and pulls the hills better.

My humble advice...get a complete bike if that's what you want as there are decent one's available. But they'll cost more and won't be all that much better. However, either way, I suggest you up your price a couple hundred bucks (that's what you'll save in not plating and insuring a gas scooter in comparison) to the $1000 to 1200 range and don't look back.

It is definitely going to cost more than you'd expect to easily do big hills, especially long ones, and have any kind of range, unless you're willing to do lots of pedalling. I don't have much in the way of hills here in Phoenix, but there are a few, and my bikes are really heavy (especially since I tend to be carrying cargo or pulling a trailer). Even just with the bike's weight on the flats, startups are like short hills, and with the trailer loaded up with dogs or dog food on DayGlo Avenger, with the Fusin front geared hub, it takes a lot of pedalling to keep from melting the motor, so that I can keep the speed up. Going slow makes the problem worse.


For hubs, geared motors will be better for the hills, because they can go slower and not be as power-hungry as a DD, but on really long hills or a lot of them, you may want to watch the temperature *inside* the motor, as it might be hot enough to cause damage in there (softening gears, aging insulation, overheating halls), without even making the outside much more than warm, until the heat has had time to soak thru the layers of air and metal. A DD hub you can tell much quicker when it's too hot, by checking outside rather than inside, but it can still heat up pretty quick inside and not feel it outside. They just don't do as well going slow up long hills as a geared motor would.



Batteries will still be your biggest cost (other than shipping, which can sometimes outstrip the parts themselves!). Definitely don't go SLA. I've used different types and sizes for quite a while in various ways, and after those experiences, I would not want to use them for anything except stationary purposes if I could help it, unless I just really needed ballast weight on a vehicle for some reason. On hills you're just decreasing your power-to-weight ratio for no good reason.

Some form of Lithium is your best bet. Don't forget to factor in C-rate of the battery into your figures, either. You'll need a battery that can continously easily put out the current you'll need for climbing the hills, without sagging the voltage much, otherwise towards the end you may well have significant charge left but be unable to use it because the battery's (or controller's) LVC will cut the pack out as soon as you try to go up another hill.

If you can afford it, plan for more Ah than you need, by at least 20% and preferably 30-40% or more. If you only have exactly enough Ah, you are not going to make it on that day that it suddenly gets colder than expected, when the pack ca't quite put out as much power. Or when there is an unexpected headwind that you can't completely overcome by pedalling more. Or there's a sudden detour for accident or construction that you have to go 2-3 miles around. It really sucks to then be pedalling a heavier-than-usual bike up big long hills, when the pack runs dry too early. I usually end up walking the bike at that point.

Thanks for the 20-30% increase in Ah load recommendation.

Gordo said:

One little fact that seems often missed is if you purchase all of your components from the same supplier, you can get stuff that is plug and play. Not only can you make a critical "let the smoke out" mistake when trying to connect components from different sources, It can be a giant, time consuming, pain in the ass to find suitable plugs to connect everything.
To make the battery cost burden a little easier, factor in the fuel savings.
For maximum enjoyment on a first build, consider the entire kit, including charger from the same source.

Click to expand...

That would be super duper ideal. That would be soooo much easier as I totally agree with you. Do you know of one such product? I'm currently still reading up on the review site about ebay kits at the moment but am curious about your thoughts on any specific kit you personally recommend.

nuevomexicano said:

Drunkskunk said:

...As much as I love Ebikes, you're going to be hard pressed to replace a 125 scooter with an ebike. An ebike would easily replace a 50cc scooter, but for the money, a 125 is still more practicle in places like S.F.

Click to expand...

It all depends how you ride the scooter vs. the bike. I just sold my 50cc Honda Scooter. It was hopped up to do mid 40's, so it was a little more like a 125cc than the average 50cc. I used it primarily for commuting and assembled the ebike for a similar commute. I put off immediately selling my scooter when I put together the ebike because I wanted to compare the differences. I just sold the Honda scooter, though I'm keeping my big 500cc Aprilia scooter, because its been months since I really rode the thing for any stretch. The ebike certainly rides different and the commute is changed in response, but it was a great replacement. In fact, my geared motor 48V lithium batteried bike is probably the kind of bike the guy who started this thread is looking at. My 6 miles each way commute is about 10 to 15 minutes longer by ebike vs. scooter. But I simply enjoy the trip more and appreciate pedaling along a few stretches for a bit of exercise (without the all-out sweating I do when taking my pedal bike the same route). My route includes a set of very San Francisco-like hills, 800 feet elevation gain over 1 1/2 miles on one hill, and I generally pedal along to keep the riding at 15 to 18 mph.

The ebike is smaller, lighter, simpler, and easier to park and lug around. All those things were true about the 50cc Honda in comparison to bigger scooters and motorcycles I previously owned and its not like the lil' scooter was a whale. But the ebike was just more bicycle-like, duh, which is what I always wanted from my motorbikes and scooters and never truly got. There are people with different commutes or routes which would favor a 150cc or 250cc or even 500cc motorbike (I've owned all and see the advantages). But bigger is not always better.

Click to expand...

I can easily see both your points of view. In DRUNKSKUNK's defense, I don't think he'd disagree with anything you said (I probably shouldn't be speaking for him). Do you have a particular kit you recommend or did you build your setup from scratch? You're correct BTW about my intentions. Short commute knowing it'll take a bit longer to get to my destination which I'm totally fine with. Enjoy the weather a bit more and getting somewhat of an exercise would be okay.

nuevomexicano said:

kmxtornado said:

...SUMMING UP MY SACRIFICES:[/b] since I clearly need to in order to get anywhere near my budget
- I have to pedal. Pedal assist is fine. I don't have to turn this thing into a motor scooter.
- Low range. I suppose I can cut my expected range to cap at 12 miles before a charge. No more 20 mi for me.
- I'd still like a rear hub motor, but I suppose if I can save a ton, I'll take a front mounted one and just ride slower to be on the safe side.
- Perhaps my budget needs to increase to the neighborhood of $700? Ouch....but still definitely not $1,000. For the money, I just feel like I could buy an already made e-bike that probably looks better and can fold for $1,200. So to spend anything near that on a conversion wouldn't make sense to me. I don't need super custom. I don't plan to race this thing or win any shows. I most likely will be only taking trips in the 5-7mi range more regularly than anything that will top 10-12mi. A generic kit or setup would be perfectly fine.

Hopefully these new/additional sacrifices can help me get on something. What do you guys recommend now? Meanwhile, I'll be researching that BMC/MAC motor...

Click to expand...

I have a geared motor kit from Amped bike running a 48V battery from Chicago Electric Bikes. I spent around $1100 or 1200 for the kit, battery and a decent used Schwinn. There was no real difference in price between front and rear hub motors. I also recently bought my Dad a $1400 factory electric bike (iZip Zuma). Its a nice package and its truly turn-key. I have no qualms suggesting one for anybody looking for a complete bike. But my slightly cheaper ride is a bit faster and pulls the hills better.

My humble advice...get a complete bike if that's what you want as there are decent one's available. But they'll cost more and won't be all that much better. However, either way, I suggest you up your price a couple hundred bucks (that's what you'll save in not plating and insuring a gas scooter in comparison) to the $1000 to 1200 range and don't look back.

Click to expand...

If it's really in the $1,000-1,200, maybe I'm in the wrong place and e-bikes aren't for me. I just can't help but to think with some sacrifices, something along the lines of an ebay kit might be decent especially since I'm new to this and it's only my first real e-bike. Not even sure if it's really for me.

Maybe I should rename the thread, "Please recommend me a kit."

I know I'm getting at the most, 5x less the performance with a cheapo sub $300 ebay kit compared to that of a custom setup . But being that I don't know squat about Ah, voltage, and how they all come together (I don't want to burn or explode anything), I figure a cheap kit might be the perfect for me - at least until I get used to it and learn more about the systems. Very tempting.... I've been reading the yescomusa review on this forum and there looks to be positive feedback on the kit.

FOLLOW-UP QUESTIONS: To narrow down what kit, what concerns or what should I be asking myself to determine the following?
1. How do I determine how many watts I want? What does this factor impact? hillability? acceleration? Err, I dunno.

2. How do I determine how many volts I want? From what I know about this, the higher the volt, the larger capacity battery which probably just means extending the range that I can ride the e-bike. If I'm not intending to ride it for long, I won't need a 48v kit right? So 24v or or 36v kit would do just fine for me?

3. If I increase the wattage but keep the voltage the same, what happens? I have a higher performing bike that doesn't last as long? I'm I understanding the definitions and logic correctly? Instead of going to Architecture school, maybe I should have gone to Engineering.

Thanks again for everyone's responses so far and putting up with a newb. I hope to be joining your crew as a rider soon. I'm not trying to be lazy, so if there's any additional info you need from me so you guys can help, please let me know what I haven't yet talked about or what info I haven't yet provided. Thanks!

kmxtornado said:

I know I'm getting at the most, 5x less the performance with a cheapo sub $300 ebay kit compared to that of a custom setup . But being that I don't know squat about Ah, voltage, and how they all come together (I don't want to burn or explode anything), I figure a cheap kit might be the perfect for me - at least until I get used to it and learn more about the systems. Very tempting.... I've been reading the yescomusa review on this forum and there looks to be positive feedback on the kit.

Click to expand...

The problem you're going to hit is SF hills. Many Ebikes simply won't handle it. They're burn up trying. The MAC is the cheapest motor I can recomend that is known to work IN SF.

But if it wasn't for those hils, you could get away with a much cheaper Ebike. I've built one for $203 including the batteries, that were otherwise headed for the trash bin. Others have built even cheaper than me, but none of them could handle what I remember of the Bay Area's hills.

You were right, I don't disagree with nuevomexicano in principle or in general. My recomindation was specific to your needs alone. In your situation, I don't think you can build a bike you will be happy with for the budget you have. If you lived in Flatsville Kansas, it would be a diffrent story.

Thanks SKUNK. Gotcha, so MAC it is. I did a quick search though and that's not a hub motor is it? If it's not, then it's going to be way too tough for me to learn how to mount that stuff with additional chains, etc.

I know there are sacrifices I need to make to fit in my budget. I'm not asking for everything and the world, so I might have to avoid hills which might actually be okay. I'm not looking to climb Lombard Street or anything like that. I consider 15% grade pretty darn steep even though there are tons of hills here steeper but even those I don't intend on climbing. I know from my experience on a recumbent trike that it's a total PITA.

Thanks again everyone for helping me so far. You guys are so quick to respond! I'm already narrowing down my choices and your advice and feedback is very much appreciated. If any of you guys decide to get into the recumbent world, I'll treat you equally as well at bentrideronline. That's a promise!

UPDATE:
I read up more on the MAC motors and at least on the website I looked through, it was about $800 for the kit and another whopping $600 for the battery. Did I get something wrong? Maybe I really do need to look at skipping hills and getting an ebay or yescomusa kit and reserve myself for the flats.

The MAC is a hub motor! It just has planetary gears in it.
otherDoc

This is only a suggestion, as we all know by now.

YOU ONLY GET WHAT YOU PAY FOR!

This guy is chaep. Others have his stuff, Some like it and some don't!
http://www.ebay.com/itm/1000W-48V-E...Cycling_Parts_Accessories&hash=item1e5b4c3c4c

As you haveraed we all suggest a geared motor for big hills.
gear motors are great climbing big hills but are also have gears inside that can melt if not watched for overheating.

If I was able to get started again with all advice I have read hear and other posts it's, CELL_MAN.
He has the right stuff for your application. AT a fair price.

As for the throttle, with twist grip shifters you wil need the thumb throttle. Or scrap the shifter and got half twist. but since you will need to pedal you will need the gear shifter, so back to the thumb throttle.

Bottom line is, you will pay more than you have planned, either at the start. Or later, to correct the short commings you run into by cutting corners in the original build.

Dan

Here's what I'd recommend to stay within your budget.
http://endless-sphere.com/forums/viewtopic.php?f=4&t=29426
Buy 6 of the 4s 5000mah turnigy batteries for ~$130 and run them as 12s2p. Controller lvc will shut off before they get too low. I think HK also has a 200W charger for about $40. get that to parallel charge them in about 2-3 hours.
I think that's under $500 and should work great even on the hills.

kmxtornado said:

...If it's really in the $1,000-1,200, maybe I'm in the wrong place and e-bikes aren't for me. I just can't help but to think with some sacrifices, something along the lines of an ebay kit might be decent especially since I'm new to this and it's only my first real e-bike. Not even sure if it's really for me.

Click to expand...

You get what you pay for. But you're in the relatively ebike friendly city of San Francisco, so why not hit the local shops and ask (beg) around among the local riders/builders for test ride?

I will second (third, fourth?) the recommendation to get a MAC from cell_man given your needs. (Check his profile or look in the for-sale forum)
BMC/Puma/eZee motors are good but too expensive, they'd blow out your budget.

You could get a 10-turn or 12-turn high torque motor that would be able to get you up medium hills and offer a top speed of 15-20mph at 36V. The kit with controller and throttle is $350 (plus a bunch of shipping from China). Or you could get only the motor for $250 (also cheaper shipping), and lace it into the rim yourself if you know how to do that, or have the LBS do it for you. Then you'd add a 6 FET controller and throttle from Lyen (in San Francisco) which will cost you less than $100.

Then the rest of your budget is for a 36V battery capable of putting out 20 amps, plus charger. cell_man's A123 packs with BMS can do that no problem even in the smaller/lighter 9.2Ah size. A ping 15Ah battery will be bigger and heavier and not able to run at higher amperages (should you decide to upgrade your contoller), but would also give you more range for around the same price.

You could also go with two or four 6s LiPo packs from HobbyKing. This can actually be the cheapest solution, although not quite as simple to use and charge compared to a pre-made pack with a BMS -- little bit more you have to learn for safety etc. If you go Lipo you will need (a) charger+power supply - for a cheap option, Imax B6-AC is slow at 50 Watts but it's an all-in-one charger/balancer/power supply (b) ideally, at least one if not two cell monitors such as celllog 8m, (c) series/parallel adapter set from forum member icecube57 or build your own.

So for the total budget you're looking at around $600-$700, plus shipping from China (and hopefully no import duties but maybe a little of those too).

http://www.emissions-free.com/catalog/i22.html Mac from Cellman, is $350. Including the controller and throttle.

It's called a 500w motor, but the wattage can be increased by using a 48v battery. The battery you want,
http://www.emissions-free.com/catalog/i29.html is the freaking problem, at $600. You could get a 36v cheaper, but it would have a hard time getting you up SF hill grades. The last resort would be to get some sla batteries now, and get lithium later.

What you need to do is go measure the grades you will be riding. You can go to various websites, such as Map my ride, and measure the steepness of the hills you plan to be riding on regularly. If they are above 6-7% grade, then you will have the problems Drunksunk talks about. If your route is only about 5%, then you could go with this, http://www.emissions-free.com/catalog/i16.html And this. http://www.emissions-free.com/catalog/i25.html

As Nuevomexicano says, the small gearmotors can climb. The problem with them is that they get hot fast when climbing too steep hills, because they don't have the wattage to go fast enough up steep hills. So Albuquerque hills are ok with the small motor, but really, the burque hills are not that bad. They are exactly like the ones I have. SF hills are that bad. But if you keep your ride short, then you can still get away with the smaller motor.

If you had the budget to spend, and some experience with RC car and helicopter batteries, I'd be recomending completely different stuff. My dirtbike CLIMBS! But it wasn't cheap and it is complicated to run high power lipo batteries.

The minimum wattages you really need to climb steeper hills, such as 10% for longer durations than a mile, is 1000-1500w. This is exactly what you get with the mac torque model motor, run at 48v with the cellman 30 amp controller. 30 amps x 48v = 1440 watts. So you see that the 250w kit, the muxus falls a bit short. 17 amp controller x 36v battery = 612 watts. So that one will climb slower, which causes more heat, shortening the lenghth of the hill that the motor can do. If your big hill on the route is short, like a mile or less, you are good enough with the muxus. But if you have 6 miles of pretty constant hill on your route, you definietly want the 1440 watts of the Mac. With the Mac, pedaling may still be optional on 7% grades. With the Muxus pedaling all the way up hills is nearly mandatory.

Dogman kicks butt. You're awesome. Thanks so much for all that. So I did what you recommended and went to Mapmyride to see the elevation changes. Unfortunately, it's way off. One of the hills I cross (or would like to cross) is one of the steepest in SF and the website says it's only 5%. I've read a few things online that says Mapmyride is fairly inaccurate and can be off by up to 7%! So I guess I'll have to figure some other way to get the elevation changes. Either way, I can avoid that hill. No biggy. Again, I don't mind taking the long way home if I can save a few bucks on the machine.

A BIT ABOUT HILLS:
There isn't a hill I can't climb in SF on a regular human powered bike other than one next to Lombard Street which is just ridiculous. If it has stairs (which that one does, then it's "ridiculous" in my mind). So I figure with some electric power, it's just a bonus. Except for that little thing called (battery weight, especially if I go with SLA bats) which would more likely than not, slow me down even if I was pedaling w/o assisted e-power. Even if I were to conquer some hills though on my regular or ideal route, they would definitely not be even a single mile long. We don't really have hills that long. They're probably extreme to some people in elevation change, but short - for the most part.

SO WHAT NOW?
You said, MUXUS but you mean MXUS from http://www.emissions-free.com/catalog/i16.htmlright? It says the kit comes with everything but the battery. From what I've read though, it's recommended I get a torque arm kit even for rear steel dropouts right? So you're telling me I can get away with the MXUS kit which is even cheaper than the ebay YESCOMUSA ones?...and it's better?

FOLLOW UP QUESTIONS:
- Do all kits take any sort of battery? SLA or Lithium? But of course the strength motor determines the strength of battery needed, I assume.
- I love your explanation Dogman about needing 1000-1500w for hills over 10% that are at least 1 mi long. What are the wattage requirements for hills 7% and below that are definitely shorter than 1 mi long?
- Sorry for the spoon feeding request, but if I were to go with this MXUS kit, what battery do I need from that website? b/c yeah, that $600 would rip me a new one.

kmxtornado said:

From what I've read though, it's recommended I get a torque arm kit even for rear steel dropouts right?

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A geared hub can put even more torque on the dropouts than a DD, under the right load. Ask my poor DayGlo Avenger's dropouts about that. :lol: (including the 10mm wrench I used as a single torque-arm first, that got pried open enough to start to spin the axle--mind you that was a 36V motor run at 48V, pulling a trailer full of St.Bernard/GermanSheperd mix. )

So...a torque arm is a really good idea.

- Do all kits take any sort of battery? SLA or Lithium?

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Yes. Power is power, no matter what it comes from, but...

But of course the strength motor determines the strength of battery needed, I assume.

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...this. ^^^^

For instance, while SLA is heavy, and you wont' even likely get half the Ah out of them that they're "rated" for, in our usage, they can certainly crank out the amps when you need them if you use ones large enough for the purpose (17-20Ah size). At smaller sizes, 12Ah or so, they will sag a lot more when you suck large currents from them, and 7Ah units will not work really well for this kind of thing (they don't even run my 12V incandescent lighting very well).

NiCD and NiMH are sort of middle-of-the-road, with the one good thing they do well of being run into the ground, down to nothing if you ahve to, and still working after you recharge them (though they may take several shallower cycles to recover to full capacity sometimes).

Lithium, depending on type, is a lot lighter for more power than either of the above, but it's more expensive in most cases, and the cheaper you go with it (for the same capacity pack) the more likely you are to run into quality problems, vs doing the same thing with the other kinds of batteries. Mostly because there are more people out there taking advantage of other poeple with Li batteries than the other kinds, nowadays.

With most LiFePO4 you'll want something that is sized for 1C (or less) operation as much fo the time as possible.

With most LiPo, you can probably use them at 2-5C, minimum, sometiems 10-20C or more. But with the caveat that the harder you use them, the shorter their overall lifetime, especially if you use them really hard a lot, and also discharge them pretty far down.

kmxtornado said:

FOLLOW UP QUESTIONS:
- Do all kits take any sort of battery? SLA or Lithium? But of course the strength motor determines the strength of battery needed, I assume.
- I love your explanation Dogman about needing 1000-1500w for hills over 10% that are at least 1 mi long. What are the wattage requirements for hills 7% and below that are definitely shorter than 1 mi long?
- Sorry for the spoon feeding request, but if I were to go with this MXUS kit, what battery do I need from that website? b/c yeah, that $600 would rip me a new one.

Click to expand...

All kits need electricity. They don't care where it comes from. SLA sucks and shouldn't even be considered in your situation. Lipo is the only thing that fits your budget and has the power to push the amp draw you will need. I ride some 20% short hills, and my 1000W motor doesn't break a sweat. I can fly up them at 30mph and I weigh 270lbs. But I'm running 24s (100V) lipo and pulling close to 30amps for short periods. If you don't have money to burn, I've told you what to get. That little 250W MXUS kit is going to cost you more than a 1000W kit by the time you pay shipping and then do all the upgrading you'll need to do. good luck whatever choice you make.

Well, no offense Kmx but I was hesitating to suggest lipo to somebody as completely noob as you seem to be. Sombody with some tech background, or even better, experience with RC toys get's the 12s lipo pack recomendation sooner.

Re the torque arms, perhaps we should have brought that up sooner, but on rear motors there is no universal fits all torque arms we can garantee fits your bike. A few, like the amped bikes model have been used on rear motors. But no one torque arm fits all bikes since they are designed for front forks. There are some good torque arm threads here, and one on the non gear side should be enough for the muxus or the Mac. Mostly, people get a chunk of steel and make their own to fit thier bike. It can be done with really simple tools, file, hacksaw and a drill. Or, a universal torque arm may have an extra part added to make it work, like a peice of steel 1" x 6" x 3/16" . Whatever it takes to bolt the arm to the frame.

I should have mentioned on map my ride, they average the grade. The longer your ride, the longer the distances over which the grades are averaged. So go back, and put in a ride that is just that shortish steep hill you are interested in. Then you'll get the better peak grade readings. My big motor test hill shows about 6%, but look at just the top and you see it's as steep as 8% for the last quarter mile.

One beauty of an ebike is that the long way around gets not only possible, but desireable. You can avoid a hill, busy street, or just stretch it for the joy of the ride. So finding a route that's 6% or less may be possible. At 6% you'll get up the hills with the muxus, but have to pedal briskly. You must keep the motor turning at 12-15 mph to avoid overheating it. You can go slow all you want on the flat, but on a steep hill the motor windings turn into a toaster oven if they don't turn the wheel fast enough.

Since your budget is soooo tight, I'd say go with the the little gearmotor, and the cheapest battery you can manage.
http://www.emissions-free.com/catalog/i16.html Perhaps this battery. http://www.emissions-free.com/catalog/i25.html

Another battery option would be a pingbattery. Slightly less expensive, so you could get 48v, which would really help you get up the hills. http://www.pingbattery.com/servlet/the-13/48V-10AH-V2.5-LiFePO4/Detail This battery would not be able to power a stronger motor later though, while the cellman battery would allow a motor upgrade later. Ping comes with a charger btw, so that helps some. 48v 10 ah ping and the muxus would be my choice in your situation. But much better, would be to spend the thou even if it means waiting till next summer. You'll be pedaling hard up the hills with this, but if you wait till you can afford a battery and the mac, you'll be pedaling up hills, but not popping any sweat. Might be worth the wait for that.

Lastly, a very inexpensive option is the lipo from hobby king. 4 6s 5 ah lipo packs can be bought for around $200-250. Charging and monitoring stuff another $100-150. There you are again near $400, and the lipo lasts about half as long as lifepo4. But they put out great amp rates, and are very small physically. Perfect for the high power stuff, but not always choice one for low power. You could shave the cost by buying only 5 ah, but then you'd inevitably hammer the cells with deep discharges and just have to buy more.