First conversion; hills on a budget

[rosemaryflowers]

I've got a chromoly frame Specialized Rockhopper I want to convert and am looking for some advice. I'm just learning about e-bikes - been reading this forum for a couple hours and still working through the wiki, so my baseline level of knowledge is still beginner.

I live in Seattle and have been wanting to go e-bike because of the hills. I love to ride but hate the hills. And I live on a hill with 21% grade, though I can avoid that one, there's still probably ~10-15% grade around me I can't avoid. I have no speed requirements - just looking for an affordable set-up that helps me up the hills. I imagine the longest distance I'd ride round-trip would be ~ 40 miles, but only using the assist for maybe 1/4 of that. I don't plan on hauling much, perhaps some light groceries in panniers. I am 5'6, 150 lbs. I plan on upgrading to disc brakes. My wheels are 26".

My budget is preferably $800 or less.

Any advice to get me started? HUGE thanks!

 

[flat tire]

Your battery will eat up a lot of that budget, even if you "think" you will only use assist for 1/4 of the ride. Why do you say that anyway? Is a lot of it downhill or something?

Consider a mid drive that makes use of the bike's gearing if you need both extremely slow climbing for sustained periods as well as decent top speed on flat roads. A 1000W 8fun could easily have you cruising at 30 on the flats and climbing the steepest hills around. You could also use a geared hubmotor which might be a little simpler and less expensive, but it will have less versatility as far as climbing torque and top speed and the handling will be worse.

 

[rosemaryflowers]

I just checked Google maps and realistically most of the time I'd be riding under 10 miles RT. The longest is more like 30 miles and that wouldn't be often. Most of that trip I could handle without an assist.

 

[flat tire]

A basic e bike will easily have you cruising at 30 with no pedaling. Once you experience that I doubt you'll want to travel at ~20 or less while working your ass off.

 

[ddk]

I've got a chromoly frame Specialized Rockhopper I want to convert and am looking for some advice. I'm just learning about e-bikes - been reading this forum for a couple hours and still working through the wiki, so my baseline level of knowledge is still beginner...

I was perusing amazon yesterday and notices one can purchase a BBS01 or BBS02 mid-drive for about $450 and a 36V 10Ah lithium battery for about $200. Add a charger and Bob's Your Uncle or some other weird Australian meme that has nothing to do with this advice -or- otherwise known as: just meets your budget goal.

What you have in mind is very doable.
I rode an i-zip sporting one or two crap lead acid batteries for many, many (many) miles without ever using the motor except assisting on stiff hills.
But it was an i-zip so I had to walk it up +15% grades lol.

 

[dogman dan]

For a hub motor. Get a rear geared 500w rated hub motor. Not a direct drive. Geared motor means an internal planetary gear system allows it to freewheel normally, while a direct drive motor will resist slightly when you pedal motor off. The motor rating is 500w,, but for the steep hills you have, you will want to run 48v, which means your actual system power is likely to be at least 1000w

Or do the mid drive, which does shine best on hills. This is because the motor actually uses the bike chain, allowing the motor to have the low gear. A hub motor is essentially stuck in one gear.

Budget,,, double it. sorry. but that's the way it is for a good BBso2 kit or a good geared motor kit and a reliable battery that is not shipped illegally.

Didn't say 800 bucks is impossible, just hard to do and meet your particular criteria. Cheap DD kit from amazon, and a cheap battery is what many folks would put on a steel MTB. Then they would ride it with the power on at all times.

https://www.amazon.com/Lithium-Battery-Discharge-Electric-Lockable/dp/B01K3UPUQU/ref=sr_1_7?ie=UTF8&qid=1473079060&sr=8-7&keywords=36v+10+ah+battery
200 buck battery on amazon? hmm. here is one.


How can that thing ship from the USA at that price? How can it ship that fast from China without an illegal flight?

Specs are interesting for that one. is it 10000 mha (10 ah) or 2850 mah?

 

[MikeSSS]

Hub motors are not the best choice for Seattle, a mid drive like the BBSHD is the better choice. I'll talk about hub motors first and then the mid drives.

Hub motors, like the MAC, are available in different numbers of wire turns. 6T is for high speeds but not for climbing. 12T would have less top speed but would be the far better choice for a place like Seattle, a place with lots of steep climbs. Then there are large diameter hub motors, like the Magic Pie, large diameter has more low speed torque and therefore more climbing ability than small diameter. The motor in a large diameter hub has more leverage than that in a small diameter hub.

Geared hub motors often have 5 to 1 reduction, the motor spins 5 revolutions for each 1 revolution of the wheel. This gear reduction makes the geared hub motors better for climbing and for moving away from a stop, than direct drive hub motors. Because of the gearing, a geared hub motor can be smaller, lighter and less visible than direct drive motors. When choosing a geared or direct drive hub motor, look for a high power, watt, rating, it should be more durable than one with a lower watt rating.

Direct drive hub motors are simpler than geared hub motors, they may also be quieter too. Geared hub motors are typically smaller, lighter and less visible than direct drive motors. Direct drive hubs are more reliable, especially if brushless and sensor-less, the Aotema 36v hub motor is an example of reliable, but it is a poor choice for Seattle.

Hub motors are made to operate at a particular speed on flat land. If your climbing is done at a lower speed and a high throttle setting, then the hub motor will pull more amps of current than it should. This condition is hard on the hub motor and the battery. To climb with such a hub motor, you have to pedal really hard, to keep the speed up on the climb, and thus not kill the hub motor and battery.

Voltage: 48 volts is better than 36 volts. For a given power output, 48v will pull less amps or current than 36v. Amps of current cause the over heating and component failure problems. Problem is that 48v will also produce more power for some given amp draw and people use that extra power and so, in most use, people use the same or even more amps, when using 48v as opposed to 36v.

Sensor-less hub motors do not have Hall sensors, the Hall sensors are a failure point. If a Hall motor and it's controller are built to operate either with or without the Hall sensors, (can operate in sensor-less or in sensor modes), then these motors and controllers may continue to operate and be usable after the Hall sensors fail.

Now for the best choice: the mid drive motor systems drive the front chain ring, passing the power through the chain to the rear cog set. When you gear down for a hill, by shifting to the big cog in the rear, you gear down both the pedals and the electric motor. This is a very good thing. Steep climbs use a lot of power, lots of power is best provided by high pedal and motor rpm and thus lower pedal and motor torque. The motor will spin faster and thus draw fewer amps. Fewer amps is better for both the motor and the battery. Higher pedal rpm is better for the knees and the muscles, nobody needs permanent knee problems and the muscles recover faster from high rpm, lower force use than from the opposite.

Another thing, vendors like Luna offer the option of mid drive front chain rings that have fewer teeth and thus lower gearing. This option if the way to go for places with lots of climbing. Remember: smaller front chain ring gives lower gearing, and larger rear cog gives lower gearing.

It is possible to kill a mid drive and perhaps the battery too, on a climb. Just do the climb in a big gear, using low pedal rpm and high throttle. That will do it.

Gear down and spin up the climb, that is the way to use a mid drive and your legs too.

 

[wesnewell]

https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302

 

[ScooterMan101]

Dogman Dan has touched on the key points you want to follow,
to add to that.
I have experience with two hub motors, one small one, that you should not even consider unless you are very fit , a 36 volt /350 watt rated motor that I run at 48 volts,
and
The better choice for you , only if you do go with a hub motor , the Mac motor from em3ev.com
the Mac I have is a fast wind ( 6T ) and will go up hills, on a 48 volt battery pack, but it liked to go up hills less than 14% grade, ( 48 volt battery pack 11.5 amp hours = apx. 520 watt hours )
and even then it only liked to go up hills when I used 22-25 amps into the motor , meaning with a 48 volt pack the motor was now running at 1,056 watts to 1,200 watts .
for your hills in your area , you would want the ( 12 T ) version of the Mac motor. If you do go with a hub motor it is best if you know someone who can build/lace up a wheel for you, and true it , dish it, and take out any hop of the rim.
However
For where you live the BBS02 or BBSHD would be better. Luna Cycles LLC in the Los Angeles area has those.

Because of the distance you want to go, you should really only use a 48 volt or 52 volt battery pack, and one that is at least 13 amp hours. or in other words over 600 watt hours of capacity on up to 700-800 watt hours , so that you do not use most of your battery capacity , so that you can get better/longer life from your battery pack .
it is Best to buy a Battery Pack from an known and trusted vender , like Grin Technologies just north of you , there in Vancouver B.C. or em3ev.com
or Luna Cycles LLC. , Luna seems to have the best selection and reasonable prices right now.

Em3ev.com and Luna Cycles LLC, if you want to do the conversion yourself,
or
Grin Technologies, if you want a close by , excellent , vendor that can hook you up with everything you need, and has allot of experience with your needs.
Buying Local is always better in the Long Run, especially when you have such a great business ( Grin Technologies ) just up the highway from you, there in B.C.

For a hub motor. Get a rear geared 500w rated hub motor. Not a direct drive. Geared motor means an internal planetary gear system allows it to freewheel normally, while a direct drive motor will resist slightly when you pedal motor off. The motor rating is 500w,, but for the steep hills you have, you will want to run 48v, which means your actual system power is likely to be at least 1000w

Or do the mid drive, which does shine best on hills. This is because the motor actually uses the bike chain, allowing the motor to have the low gear. A hub motor is essentially stuck in one gear.

Budget,,, double it. sorry. but that's the way it is for a good BBso2 kit or a good geared motor kit and a reliable battery that is not shipped illegally.

Didn't say 800 bucks is impossible, just hard to do and meet your particular criteria. Cheap DD kit from amazon, and a cheap battery is what many folks would put on a steel MTB. Then they would ride it with the power on at all times.

https://www.amazon.com/Lithium-Battery-Discharge-Electric-Lockable/dp/B01K3UPUQU/ref=sr_1_7?ie=UTF8&qid=1473079060&sr=8-7&keywords=36v+10+ah+battery
200 buck battery on amazon? hmm. here is one.


How can that thing ship from the USA at that price? How can it ship that fast from China without an illegal flight?

Specs are interesting for that one. is it 10000 mha (10 ah) or 2850 mah?

I've got a chromoly frame Specialized Rockhopper I want to convert and am looking for some advice. I'm just learning about e-bikes - been reading this forum for a couple hours and still working through the wiki, so my baseline level of knowledge is still beginner.

I live in Seattle and have been wanting to go e-bike because of the hills. I love to ride but hate the hills. And I live on a hill with 21% grade, though I can avoid that one, there's still probably ~10-15% grade around me I can't avoid. I have no speed requirements - just looking for an affordable set-up that helps me up the hills. I imagine the longest distance I'd ride round-trip would be ~ 40 miles, but only using the assist for maybe 1/4 of that. I don't plan on hauling much, perhaps some light groceries in panniers. I am 5'6, 150 lbs. I plan on upgrading to disc brakes. My wheels are 26".

My budget is preferably $800 or less.

Any advice to get me started? HUGE thanks!

 

[docw009]

Can't go wrong if you kick the budget up to around $1000 and get a Bafang BBS02 for $499 from Lunacycle and a battery for $450. The mid drive is the lightest weight compared to comparable hub motors. It will go slow. It can go fast. It will climb your hills in the lower gears with your feet up on the bars. And if you want to shut off the pedal assist and ride it like a bike, it pedals easy, albeit a 50 pound bike, so you might not go much above 12 mph. I've built a BBS02 equipped bike, and it would be my choice if I moved to Seattle.

On the other hand, if you roll the dice, can you get a serviceable hub motor and battery for your $800? I think one can, but it's not easy. Since the battery is the most important and expensive component, getting a Luna battery only leaves you $350 for a motor. Plenty of people here buy that $200 direct drive motor off ebay and go 20-25 mph for thousands of miles. Others have pointed out the tradeoffs of direct drive for hilly country. It's hard to find well known geared motors that are in the same price range. The safe recommendation is to spend $400 on a MAC geared motor kit, but even then you won't have the surety that it will climb like a mid drive.

Finally, everyone assumes you know how to take apart a bike and put on a motor. Not rocket science. Neither is it complex. Still one needs the proper tools, or friends with those tools. A couple of bike specific tools are needed too,

Hope you find something that works for you.

 

[flat tire]

OK here's an idiot's list so you can get the important points and avoid those gigantic wall of text replies:

Direct drive: unsuitable for your use case (hills) unless it's insanely overpowered ($$$)

Geared hub: cheap, simple compromise, if you get one that will climb your hills it will have a slow top speed, which really sucks when you're not climbing hills.

Mid drive w/ variable gearing: the obvious choice if you can swing it, bonus is better handling

Budget: better have some room to grow unless you are a thrifty (and lucky) classifieds user and total DIYer.

 

[thriftstorehack]

Hill climbing is always a big issue for me. I build on the cheap with electric wheelchair parts and lead acid batteries. The only bike that i own that will successfully climb the big hill is my homemade recumbent. The main reason is i have a 7 speed "transmission" on that bike. If i climb in high gear it pops the breaker. Running about 50% power in low gear it will go up just about anything at 3 or 4 mph.

The bike weighs about 140lbs with the batteries and i am about 200lbs.

Check out the recumbent trike build on my YouTube it may give you an idea or two.

 

[wesnewell]

At only 150 lbs, you won't have any trouble climbing hills with a cheap 48V 1000W DD motor. But for a 40 mile range, you'll need a 20ah battery pack if you want to ride at 20 mph. I can say this with certainty since I didn't have a problem when I weighed 270 lbs.