Looking for the most efficient kit

[hadley]

Hi all. I am a high school teacher and I believe actions speak louder than words, so I am researching which system to install on my specialized hard tail mountain bike. I have front shocks and would like to retain them for ride comfort if possible. Therefore, I am looking for a rear hub. I have a 20 mile commute with the last 5 miles gaining nearly 1000 feet on each end. You got it, the ride starts fast and ends slow. I often run into 30 plus mph winds. I live in the colubia gorge. Yes it makes the ride east great with that tail wind. I need to keep the price down, but the quality up. I am open to Lion or NiMH. I have considered NiMH to start with and then swiching over to new batteries as the morket on batteries changes. I realize this my not really work because of the high weight factor. I don't mind putting components together.

At this point I calculate I need about 380 Watt hrs. So probably need at least 10.7 Amp hrs at 36 Volts or 8 Amp hrs at 48 volts.

What should my shopping list include and what is the contact informatin.
Motor
Controllor
Battery
Other

Thanks in advance.

 

[pwbset]

At this point I calculate I need about 380 Watt hrs. So probably need at least 10.7 Amp hrs at 36 Volts or 8 Amp hrs at 48 volts.

What should my shopping list include and what is the contact informatin.
Motor
Controllor
Battery
Other

Welcome! Yummy.. I like hill climbing builds! Climb 1,600ft on my commute... it's a bitch. Here's my opinion:

Motor: 4011 or a 5305. 5 Series will add 10lbs, but will be oh so much nicer on that climb and cutting through those winds. Is your hard tail steel? If not you'll need a torque arm... probably should get 1-2 of those anyway.
Controller: 72v40a minimum. 36-48v is going to feel pretty wimpy and slow for that kind of climb and winds. Kinda depends on the motor you get.
Battery: Lithium. Period. With that kinda climb and those kinda winds you'll regret if you don't go that route. Are you a science teacher by chance? Class project... build the teacher a battery pack. 8) Tool packs are popular/affordable choices, but require tinkering. Ping packs likely won't deliver 40a sustained. LiPo will get you there, but may also 'splode on you. if cost is a super duper issue you could get some high drain rate NiCads in a pinch as they will deliver the goods amp-wise, but won't last long. That 380w/hrs? Add at least 20% to what you think you need. I originally thought I could do my commute in around 300w/hr and I'm averaging more like 400w/hr.
Other: Good luck finding stock. Your timing may be perfect as the ebike.ca online store is supposed to open back up in a couple of days with renewed stock. electricrider.com or poweridestore.com may also have something. Ebike.ca probably has the best reputation and best pricing.

 

[Drunkskunk]

Welcome to the forum. Looks like you have a good project lined up and you've done some research on the motor and placement. That leads me to my first question, how did you decide on 380 Watt hours?

You could do 20 miles on 380 WH of battery, at 12-14mph, no wind, and no hills. It would actualy be a good size battery for it, as a 4012 would drain 280-300 watts to do it at those speeds. I's done that exact setup before. But I'm stressing the No Wind, and No Hills, pedaling to assist the motor.

To climb 1000 feet in 5 miles, with a 30 mph headwind, you're going to need significantly more power. Thats 1 foot climb every 26 feet of road. I get a (very) rough figure of 250 watt hours just to climb that hill at 10mph

There are still too many unknowns to recommend a battery, such as your weight, the bikes weight, the bike's unpowered efficiency and the speed you want to travel at. I'd take a wild guess though, that you would want at least double that, probably more.

 

[Anonymous]

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[hadley]

Welcome to the forum. Looks like you have a good project lined up and you've done some research on the motor and placement. That leads me to my first question, how did you decide on 380 Watt hours?

You could do 20 miles on 380 WH of battery, at 12-14mph, no wind, and no hills. It would actualy be a good size battery for it, as a 4012 would drain 280-300 watts to do it at those speeds. I's done that exact setup before. But I'm stressing the No Wind, and No Hills, pedaling to assist the motor.

To climb 1000 feet in 5 miles, with a 30 mph headwind, you're going to need significantly more power. Thats 1 foot climb every 26 feet of road. I get a (very) rough figure of 250 watt hours just to climb that hill at 10mph

There are still too many unknowns to recommend a battery, such as your weight, the bikes weight, the bike's unpowered efficiency and the speed you want to travel at. I'd take a wild guess though, that you would want at least double that, probably more.

First Question: How did I come up with this number of 380 Watts. I borrowed an Bionix PL350 which has a 350 Watt Motor,36 Volt Lion Battery and rode it to school and was impressed with how much it helped out. I can peddle one way, but both is a pain in the bicycle seat. Secondly, I did calculations from ebikes.ca and was trying to follow their guidelines.

From ebikes.ca
Motor Type Rough energy usage
Minimal Assist, (using motor only on hills, slower ~30kph setup) 6-8 Wh/km
Typical Assist (~40 kph with pedalling, motor on all the time) 9-12 Wh/km
Power Hungry (either no pedalling, or hauling a load, or going really fast) 14-20 Wh/km

Now take your trip distance, multiply it by the appropriate watt-hours/km from the table above, and you'll get the total minimum watt-hours required for the trip. Take the watt-hours you've estimated and divide it by the voltage, and you now have an estimate on the minimum amp-hours you'll need from the pack.

I used 32 km(20 miles) times 12 Wh/km to give me 384 or 380

I weigh 205, The bike is 28 lbs, It is a mountain bike with high pressure commuting slicks on for efficiency, The speed I want to travel at is probably 20 to 25 on the flats and 10 to 15 up hill. I should say the wind reaches its maximum only on three exposed corners and three 1/4 mile straight aways.

From your experience sounds like 750 or 800 watts are closer to what I need. I should say I was completly stoked to climb the hill at 10 mph instead of 6mph on the Mountain Bike or 8 on the road bike. I like the part where it is asisting me, but I am staying in shape. Currently I try to ride one way as often as possible, but I would like to be able to truely commute.

Thanks for your ideas.
I hope this helps

 

[pwbset]

I used 32 km(20 miles) times 12 Wh/km to give me 384 or 380 ::: The speed I want to travel at is probably 20 to 25 on the flats and 10 to 15 up hill. ::: From your experience sounds like 750 or 800 watts are closer to what I need.

Just for your reference/research I'm averaging 35-50wh/mi at grades between 8-20% - "power hungry" maybe, but it's realistic when climbing. I'm doing pretty much exactly the speeds you're talking about above and I'm peaking 2,000+ watts and averaging 1,000+ and I peddle a lot. This is all with a slow 4011 motor, but it's over volted to 84v so makes up for speed that way. Sounds like you like exercise etc. etc. so maybe the lighter/cheaper 4 series would work for you as well. If money isn't an issue maybe just get a Bionx kit or an Ezee kit.

 

[hadley]

I'm glad to hear that it is usuall to pedal hard. That sounds like great fun on your bike. Unfortunately, money is an issue. My goal is to put it together for around $800 dollars. I am interested in sodering or wiring my own pack together. I could get ahold of old power tool batteries. I am a woodshop and material science teacher. The issue is getting the smart charger components together. I would love to be able to solder the batteries together with my students. What are the health risks. Well, that is a dream at this point.

The Bionix is lame with the 20 mph speed limit. The Ezee looks interesting. I will what ebikes.ca comes out with in the next couple of day.

Thanks for the real experience.

 

[mvadventure]

Being familiar with basic computer operations I googled "colubia gorge" and figured it was "Columbia Gorge". This means quite simply that you're likely in the Pacific Northwest. Since I live in Florida which is about as far away from the Pacific Northwest as you can get and still stay in the same country and since the closest I've ever been to the Pacific Northwest is a long weekend in San Francisco I have no claim as to local knowledge.

But I do know it rains a lot there. It is raining a lot here in Florida right now with hurricane season upon us. Rain is not good for hub motors (at least Crystalyte), front or rear. Rain is not good for controllers. Rain will short out a motor and or a controller faster than you can turn the switch off. Quite frankly rain is not good for electric bicycles but some kinds of motors can handle it better than others.

So...during your initial period of decision making it is my humble opinion that you seriously need to consider the fact you will get caught in the rain. Fortunately Endless Sphere has lots of folks willing to offer opinions and even some facts. They have pulled me out of catastrophe on numerous occasions.

Rain aside I ride a simple steel six speed beach bike with a Phoenix Cruiser (Crystalyte 5340) front hub motor, a Crystalyte 4840 controller and use LiPO4 48 volt 20 AH batteries monitored by a "Watts Up" meter. It literally destroys all local hills. My hills are of course bridges but the bridges over the ICW are more than 65' but I can't begin to quote slope angles, I just know they're steep. If I keep the speed down to <20 MPH my range seems to be unlimited as I get tired before the batteries do. My longest trip has been about 33 miles with two bridges and average speeds >20 MPH but not much more. The batteries were reading almost 52 volts at the end of that trip.

But...a couple or three or four weeks ago coming back from the golf course I got caught in a horrendous downpour. First the throttle locked in a wide open position and since I have only rim brakes and was on a bike lane (not path) on a busy two lane road it was getting hairy. Turning off the controller meant pedaling my 230 pound body and 80 pound bike into the wind while wearing a waterproof rain suit in 85 degree heat. Top speed was 5 MPH at this rate and the fatigue factor was extreme especially since I'm an old fart and use my pedals mostly to keep my feet off the ground.

Finding shelter after about fifteen minutes I thought everything would be OK but all I proved was that sometimes simply thinking is like simply wishing cause moisture, probably through condensation, had entered the controller which in turn shorted out EVERYTHING. You simply, try as you might, cannot pedal a shorted out hub motor. It's like having a 40 pound weight on one side of the wheel with the brakes on. I wound up pushing the bike 2.5 miles to my mother-in-laws house. The fun factor was negligible, the transportation factor non existent. The wet factor however was 100%.

$400.00 later I'm back on the road but with much more respect for the rain. Hills aside and I'm sure you have hills worse than I saw when I was a kid going to school in Scranton or when I lived in the mountains of N. Georgia, rain or moisture is needs to be a serious factor in your decision making.

However as you undoubtedly learned the pursuit of the EV Grin is worth the effort. Good luck, have fun and don't use cheap batteries.
Mike

 

[hamblin10]

Just remember that going over 20 mph eats your watts exponetially. The power drain becomes HUGE! I use about 350-400 Wh on a 8 mile commute to work at 20 mph without peddling on fairly flat roads.

 

[dogman dan]

Yeah, power hungry is the rate of use for 20 to 25mph. You will need a 20 ah lifepo4 battery or equivilant. And more like $1200 minimum. A few months ago it could be done for a thou, but not today. But it is worth it. However, my wife scored a 150 cc scooter at a garage sale for $650 last week. It did take all summer to find the good deal on one, but $600 or so will buy insurance and all the gas for a year, making it cheaper than my ebikes by far. The scooter is real fun, but I'll still prefer the ebikes in good weather.

 

[Drunkskunk]

Hows that scooter compare to your bike? I've found my Ebike much faster and more powerfull than most scooters around here, and it is much faster than my 50cc moped.
Then again, 100mpg on the moped, and $50 insurance, thats 13,750 miles worth of gas and insurance for your $600

 

[dogman dan]

The wifes new scoot is a 150cc Roketa tahiti. It rides weird to me with the 13" wheels, very different from all the motorcycles I've owned. It performs a lot like my old CB 125 honda with a top speed of about 65 and comfy speed of 55. But it's noisy, stinky, etc. I feel a bit more vulnerable since you are not able to hide on a bike trail for most of the ride, so more vigilance is needed for 100% of the ride. Still very fun, mileage checked out at 63 mpg at 50 mph. New retail is close to the cost of a middle of the road lithium ebike. One year old and with only 3500 km on it it was a bargain. Oddly it had no issues that needed fixing when the first owner uncrated it. I calculated its cost at about 16 cents a mile on $4.00 gas. My ebike, so far is at about 8 cents a mile. Riding it in the summer will be much better than heaving a heavy ebike on the bus bike rack to keep from killing motors in the summer. She will ride it most of the year.

The only downside to it, is with a wierd automatic tranny built right into the rear wheel, it will make it a bit harder to electrify later. I'm looking for my bike, a street legal 90-250 cc dirt bike for cheap, preferrably not even running. Then I could build an electric motorcycle capable of taking the fun cut to work. The fun cut is a power line road up and down the desert hills for 10 miles to get to the other side of town. It won't be cheap, but the fun cut will be worth a few thou in costs.

 

[DahonElectric]

I'm glad to hear that it is usuall to pedal hard. That sounds like great fun on your bike. Unfortunately, money is an issue. My goal is to put it together for around $800 dollars. I am interested in sodering or wiring my own pack together. I could get ahold of old power tool batteries. I am a woodshop and material science teacher. The issue is getting the smart charger components together. I would love to be able to solder the batteries together with my students. What are the health risks. Well, that is a dream at this point.

The Bionix is lame with the 20 mph speed limit. The Ezee looks interesting. I will what ebikes.ca comes out with in the next couple of day.

Thanks for the real experience.

You do know that you "can" disable the Bionx's lame 20mph speed limit? Even up to firmware 2.7, which is currently the latest.. I have mine disabled on my P-250HS version for the Dahon folding bike.

While Lithium is the best option period, there is a not so widely published fact that if you are depending on the capacity to stay constant for the rest of the year, then you will be sorely disappointed.
Lithium, unlike other batteries, loses capacity as it ages. It looses capacity as it sits in the boat coming from the Asia and it looses capacity as it sits dormant in the warehouse waiting to be picked. It is not so uncommon that you can buy a cheap Lithium pack from eBay solely because it has a bunch of old cells in it. Some of you have probably noticed by now that your lithium pack is loosing capacity even with a few charge/discharge cycles. It's also not uncommon to loose about 40% of its capacity even after 100 cycles or so. Sure it's light and sure it's got the voltage and the capacity to boot, but for how long..
And that is the reason why I chose the NiMH. Unless you have money to burn, go with Lithium. If you're solely thinking about saving gas money, goes with the less than stellar NiMH batts.

If you are solely into power pedal assist, think about providing more capacity than you would need to complete the whole commute if you plan on going Lithium, which means lots of moola. This is not a problem if you provide some or most of the pedal assist by your own power with the Bionx system, since you're not solely depending only on its electric power.

 

[Will]

I converted a hardtail mtn. bike using the C-lyte408 motor and a 48v Lith-ion @10.5a. I've regularly ridden a 22 mi route with a 850' climb and hilly the remaining miles so the total climb is a bit greater than the 850'. It takes 18 minutes to ride 3.5 mile up the side of Sand Mtn. (NE AL) pedalling fairly strenously with the motor. But, it climbs @11-13mph (pedal assisted) and cruises 17-21mph along the hills. If you're willing to pedal, the C408 with 48v and 25 or 30amp Crystalyte controller can do the job. The downside, 48v Lith-ion batteries can approach your $800 budget. You may do better with a 48v LiPo battery pack, yet if you go that route, I'd get 15amp hr. Being able to charge before riding back would be a near neccessity. A 20 mi. one-way commute is generally not a daily endeavor, unless your name is Lance. The C-lyte 500's would surely work, yet the C408 free wheels better, allowing you to pedal without the motor somewhat and isn't as weighty. Do NOT mix soldering, Lith-ion batteries, and students. The batteries have a serious, even explosive, discharge capability

 

[dogman dan]

As I creep up on 1400 miles on my cheap lifpo4 bought from Li Ping, I haven't had any loss of capacity that can be noticed. Sure, it's only been 4 months, and About 100 cycles but I dang sure haven't lost 40% yet. Or even 10% But that couldn't be cuz I don't hammer my battery way past what Li Ping rates it for.