Ebike build specifications

[Exiged]

Hi Everyone,

First off I have done a lot of searching on here before posting. So I have done some due diligence. I am very mechanically inclined and do a lot of fabrication etc but I lack some of the electrical experience as far as specifying the proper components. I am starting from scratch and haven't purchased a bike yet so it will be from scratch my budget is to keep it below $3500 or so. My fav ebike so far is Kiplers super commuter. I want to build this bike as stealth as possible like his and also very reliable.

Bike
Looking for a road bike but it prob needs to be a mountain bike frame with road bike wheels and tires for reliability. Something close to Kiplers frame but not in Carbon Fiber? Would appreciate suggestions on this. If choosing a low weight bike is needed so I can carry more batteries that's fine. Piecing a bike together is fine.

Distance
I am looking to build an ebike for a long distance commute (40miles each way) Some good size hills each way.
I will do this about twice a week. (I know a motorcycle would be a better option but I am doing this a reduced carbon footprint project). I am able to charge batteries at work and be closely monitored for safety (lipo.). I will pedal assist the whole way to the best of my athletic ability.

Speed
I would "like" it to have an "average" of 30mph. Will pedal assist but not sure that will help achieve 30mph or not.

Commute
All public roads, all paved, some decent hills (no mountains)

Battery
This is the hardest part for me to figure out (brand, volts, size, amp, etc). I would like to make the batteries as stealth as possible without putting the battery in a triangle bag. I think this is a big tell that it's an electric. I was thinking a seat bag and maybe a handle bar bag with batteries in both locations. I am also willing to carry a battery pack in my bag to switch it out half way to the destination.

Motor
I would like a low noise stealth motor so I am guessing a hub drive unit is on order. I just don't want any cogging so the bike can still be ridden with no batteries on board.

Controller
Would need some help on this also I do love how kipler modified a smaller unit to work.

Thanks in advance for any help on this.

 

[Exiged]

Oh and I'm 5'11 190lbs.. Bike will only be driven when it's above 50 out

 

[Drunkskunk]

Welcome to the forum.

To go 30mph, you're going to need 800 to 1000 watts of output on flat ground with no headwind. An athelete in very good condition could maintain 100 watts output, meaning the motor would need to make 700 to 900 watts to keep that speed at 30mph, in ideal conditions.

That just isn't reasonable for a stealth bike for 40 miles. You would use 900 to 1200 watts each way, in ideal conditions. The world is never ideal, so you would end up using more. And you shouldn't run a battery dry. It's best not to discharge it below 20% capacity, so it would need to be even bigger. and Lipo batteries degrade quickly with time, so your battery would need to be even bigger to compensate for the 10%-20% loss of capacity per year.

At 20mph, we say you plan your battery size around 36 watt hours per mile. 30mph uses around 2.3 times more power, so that gives us roughly ~80 watts per mile. If you're an Athlete who can handle riding 40 miles without tiring, you can knock 10% off that, but lets start with 80wh/mile. That's a 3200 watt battery. at 48 volts, that would be a 66 amp hour battery. That's right at 50 pounds of Hobbyking Lipo. Possable, but you would probably need to build your own frame to hold a pack that size. Everything would need to be upgraded to handle the extra weight, and You bike would be more motorbike than bicycle. Your budget would likely be just a fond memory in the rear view mirror. Costs would approach the costs of a used Zero Motorcycle.

If you drop that cruising speed to 20mph, the battery gets much smaller. a 1440 watt battery would do it. However, your pedal power stays the same, and is now a much bigger fraction of the battery. you could knock about 1/3 of it's size off. This bike could still mostly be stock bike parts, and you could probably stay in budget.

And if you slow down just a bit more, somewhere around 17 to 18mph, where you're giving it a 50/50 effort between pedaling and the motor, you knock the required battery size in half, to a nice 720 watt battery. That's very manageable. Far too big to be stealth, but would fit in a full sized frame bag. It's still going to be a bit too heavy for a road bike, but a good MTB with road tires would handle this. You would have money left in the budget.

As for motors, there are plenty that can handle cruising at 30mph for hours on end, but they wouldn't be what I'd recommend for pedal assisting at >20.

 

[wesnewell]

http://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
Forget stealth. Not going to happens with an ebike that will do 40 miles at 30mph. You can also forget pedaling at 30mph unless you put on a very large chain ring 52T+ and a 11T rear sprocket. But yes, you can build one that will do 40 miles averaging 30 mph if you don't mind spending a lot for the battery pack. A 48V 1000W motor kit can be had for <$300.
http://www.ebay.com/itm/26-Electric-Bicycle-Motor-Hub-Kit-Front-Rear-Wheel-Ebike36-48V250-500-800-1000W-/291119531800
But, you'll need ~2.1Kw worth of 52V battery pack to do 40 miles at 30 mph. Basically 40ah of 52V 16s lifepo4, 40ah of 14s rc lipo, etc. getting 40ah of 14s rc lipo on a bike will be a challenge, but can be done. It will weigh ~30 lbs. Lifepo4 will weigh up to 50 lbs or more and be a lot bigger. And it's not going to be comfortable either. if I needed to go 40 miles at 30 mph, I'd look into a tadpole trike. Withe lower wind resistance you could cut the battery size in half. And it will be a lot more comfortable to ride. Drawback is the initial cost of a decent trike, but you will get a lot faster top speed if you need it also. Play around with the simulator for different configs.
http://www.ebikes.ca/tools/simulator.html

 

[Exiged]

Thanks guys!

I really appreciate the input! What would 40ah of 14s rc lipo look like? How many packs of which ones? The battery portion of the build is really the hardest part for me to understand on a regular bike. I realize it might not be possible for the 30mph but before dismissing it completely i would like to get a rough idea of the size and weight of each one. I haven't considered a trike but that might be a good option. A 20mph goal is probably more realistic.

 

[motomech]

25 mph is kinda a "sweet spot" for a lot of Ebikes in terms of reasonable size pack, safety and comfort.
You can pedal along at that speed with an easy to fit 50T/11T sprocket combo.
Costs from this point go up exponentially.
IMO, speeds in the 25 to 30 mph range, for most roads, requires a decent quality Full suspension mountain bike.
Motor and battery wise, 30 mph is not hard to achive.
But the range for are talking about is a challenge. For Lipo, smaller than a "breadbox", but considerable weight.
Nice thing about Lipo is, it can be split-up.
Still, 40 Ah of Lipo is going to require some advanced pack building and charging techniques.
Doable, but you will likey need to spend some time reading here.
But hey, what else to you have to do that would be a better use of your time? :lol:

 

[Exiged]

Thanks for the input! I think I would be really happy with 25mph. I have done a lot of searching through the battery threads and I'm still having a hard time figuring out what it would take as far as how many of which battery packs etc. I guess I should have paid a little bit more attention in science class! I haven't purchased a bike to start with yet so a suspension MTB is an option. Any suggestions? I have built a few lotus race cars so I have the mechanical part down just figuring out amps, voltage, and lipo is a bit of a challenge for me.

And I am serious about this project not just "tire kicking"

25 mph is kinda a "sweet spot" for a lot of Ebikes in terms of reasonable size pack, safety and comfort.
You can pedal along at that speed with an easy to fit 50T/11T sprocket combo.
Costs from this point go up exponentially.
IMO, speeds in the 25 to 30 mph range, for most roads, requires a decent quality Full suspension mountain bike.
Motor and battery wise, 30 mph is not hard to achive.
But the range for are talking about is a challenge. For Lipo, smaller than a "breadbox", but considerable weight.
Nice thing about Lipo is, it can be split-up.
Still, 40 Ah of Lipo is going to require some advanced pack building and charging techniques.
Doable, but you will likey need to spend some time reading here.
But hey, what else to you have to do that would be a better use of your time? :lol:

 

[motomech]

Thanks for the input! I think I would be really happy with 25mph. I have done a lot of searching through the battery threads and I'm still having a hard time figuring out what it would take as far as how many of which battery packs etc. I guess I should have paid a little bit more attention in science class! I haven't purchased a bike to start with yet so a suspension MTB is an option. Any suggestions? I have built a few lotus race cars so I have the mechanical part down just figuring out amps, voltage, and lipo is a bit of a challenge for me.

And I am serious about this project not just "tire kicking"

25 mph would reduce your battery pack to maybe 30Ah(wesenwell would know better).
That still means Lipo. It's not the size, but the weight that demands it go into the center triangle. It would be too much for a rear rack.
Full suspension bikes with an open triangle are the Holy Grails around here and there are some threads on the topic, worth looking up. My Rocky Mountain linked below is a good example.
If you could keep the Lipo packs down to 12S(close to 48V), that would allow you to use the Thunder 1220 charger and a single(cheap) server power supply. Good, since you will need two, one @ each end of your commute. I think 12S would be close to 25 mph with the DD motor(wesenwell?). There are lot's of ways to get to 12S/30Ah of Lipo, but I still think bricks of Turnigy 6S/5000mAh(20C) from Hobbyking are the best value. That would be 12 bricks.
Opinions vary on how high a quality doner bike is needed.
Many use Wallyworld bikes without problems, but I like 4, 5, 6, etc. year old mountain bikes of good quality.
Often, they are hardly used off-road and after they are a few years old, they are out-dated as far as the hardcore MB crowd is concearned. The beneficaries are us Ebikers because you get alot of high tech hardware for the money. For example, I purchased my 2007 Idrive(again, linked below) in mint condition for $600. Less than half the MSRP because it was 4 years old and considered too heavy for serious mountain bikers. But weight is a non factor for an Ebike and the suspension and brakes, still good for off-road, are heaven on the street.
Again, I'm sure wesenwell will be back and I suggest you search his posts for some guidance in the mean time.

 

[wesnewell]

If 25 mph is fast enough then you don't need 14s lipo. 12s will get you about 28mph top speed on the 48V 1000W kit. And 30ah of 12s will be enough for 40 miles at 25 mph. It will take about 60 cubic inches, or 10"x6" in that config, weigh about 21 lbs, and cost about $500 including a bms and charger.

 

[dogman dan]

Bottom line here for 40 miles going pretty fast is that you will need to carry a lot of battery. Like 48v 30-40 ah.

On most regular bikes this can be a bit of a problem, with your ass hovering over the rear wheel, adding even more battery weight back there sucks. Yes, put as much as will fit in the frame triangle, but then you lose some stealth. Only e bikes carry the battery there.

What you need is a longtail. It will be much much more comfortable to ride long distances, and it will easily carry up to 40 pounds of batteries. With your weight more in the center, carrying a lot of weight in panniers still balances nice, and the bike handles much better.

And, the big panniers typical on cargo bikes will hide a huge hubmotor, getting you stealth in a way. Yuba mudo, Surly big dummy, ODK, Edgerunner, etc. You could hardly do wrong to get the stoked edgerunner from Grin.

But you can also build your own very nice longtail on the cheap. Here's one I just put together on a very small budget. This hundred buck bike

Became this. It rides extremely comfortable, even with 1500wh of battery aboard. Comfort is going to be a big deal on a daily ride that long.

Picture section has a thread on the bike.

 

[Exiged]

That thing looks like a ton of fun. But probably very suspicious if I am cruising by the boys in blue on that going 25mph. I really like the trike idea as well but I'm thinking that might cause some unwanted attention...

Bottom line here for 40 miles going pretty fast is that you will need to carry a lot of battery. Like 48v 30-40 ah.

On most regular bikes this can be a bit of a problem, with your ass hovering over the rear wheel, adding even more battery weight back there sucks. Yes, put as much as will fit in the frame triangle, but then you lose some stealth. Only e bikes carry the battery there.

What you need is a longtail. It will be much much more comfortable to ride long distances, and it will easily carry up to 40 pounds of batteries. With your weight more in the center, carrying a lot of weight in panniers still balances nice, and the bike handles much better.

And, the big panniers typical on cargo bikes will hide a huge hubmotor, getting you stealth in a way. Yuba mudo, Surly big dummy, ODK, Edgerunner, etc. You could hardly do wrong to get the stoked edgerunner from Grin.

But you can also build your own very nice longtail on the cheap. Here's one I just put together on a very small budget. This hundred buck bike View attachment 1

Became this. It rides extremely comfortable, even with 1500wh of battery aboard. Comfort is going to be a big deal on a daily ride that long.

Picture section has a thread on the bike.

 

[dogman dan]

Get the moped class registration for your e bike, and you can go 30 mph in CA.

Bottom line, 80 saddle miles a day, you can't be doing that on a bike that steers all funny because you overloaded it. It will fatigue the hell out of you to ride a shitty handling bike with too much battery weight loaded on.

This is not coming from a guy who never did an 80 mile day on an ebike. I got the t shirt.

 

[USAEBIKECO]

My recommendation would be 48 volts and 40Amp hours for the battery. This will get you 30mph tops (depending on weight) and about 40 miles on a charge. You can always add on more batteries later.

1000 watt motor kit would work well

Get a bicycle with suspension.

Get really good Kevlar tires and thick tire tubes.

All of this for well under your $3500 budget.

 

[USAEBIKECO]

36V 40AH would likely get you 60 miles on a charge if you pedal with the motor. Top speed would be about 20mph.

 

[Exiged]

I searched on here for good suspension bike candidates for conversion but didn't see a good thread on it. I'm not able to register this as a moped and trying to keep it "under the radar". I'm going to start looking for a bike this week!

I also took the bike route to work and back today. The roads were in very good condition but their def are some steep hills but for every hill I climbed their was the same amount of decline after it not sure of this effects battery choice. Target goal is adjusted to average 25mph for 40miles. With moderate pedal assist. Their are not too many stop signs on the route as well.

 

[motomech]

http://endless-sphere.com/forums/viewtopic.php?f=3&t=32056&hilit=suspension+open+triangle

http://endless-sphere.com/forums/viewtopic.php?f=3&t=28151&hilit=suspension+open+triangle

http://endless-sphere.com/forums/viewtopic.php?f=3&t=59415&p=890498&hilit=suspension+open+triangle#p890498

http://endless-sphere.com/forums/viewtopic.php?f=3&t=57669&p=861191&hilit=suspension+open+triangle#p861191




http://endless-sphere.com/forums/viewtopic.php?f=3&t=28151&hilit=suspension+open+triangle

 

[Exiged]

THANK YOU!

http://endless-sphere.com/forums/viewtopic.php?f=3&t=32056&hilit=suspension+open+triangle

http://endless-sphere.com/forums/viewtopic.php?f=3&t=28151&hilit=suspension+open+triangle

http://endless-sphere.com/forums/viewtopic.php?f=3&t=59415&p=890498&hilit=suspension+open+triangle#p890498

http://endless-sphere.com/forums/viewtopic.php?f=3&t=57669&p=861191&hilit=suspension+open+triangle#p861191




http://endless-sphere.com/forums/viewtopic.php?f=3&t=28151&hilit=suspension+open+triangle

 

[Exiged]

Gents,

I know you suggested a full suspension bike but what are your thoughts on this Kona Bike and the battery locations. It has more of a mountain bike look to it than the big steel beach cruisers and won't look *too* out of place going 25mph..
Thanks again for the help so far. Awesome forum!

http://endless-sphere.com/forums/viewtopic.php?t=5328

 

[wesnewell]

Bikes just don't handle good with the batteries on the back. If you can't put them in the triangle, hang them over the top tube. It's almost as good as in the triangle.

 

[motomech]

Gents,

I know you suggested a full suspension bike but what are your thoughts on this Kona Bike and the battery locations. It has more of a mountain bike look to it than the big steel beach cruisers and won't look *too* out of place going 25mph..
Thanks again for the help so far. Awesome forum!

http://endless-sphere.com/forums/viewtopic.php?t=5328

IMO, 25 mph is on the borderline for a ridged w/ V-brakes.
Depends on the Road, never hit a pothole?
Then why not? It certainly has a big triangle.
There really isn't any downside to the suspension of a mountain bike when electrified except the cost.
But you are going to buy lot's of Lipo to stuff a triangle bag and two chargers, so maybe economizing in the donor bike might be necessary.
The other thing is, the right used ebike frame doesn't always pop up when you get a litebulb over your head.
I think I watched Craigslist for a month before I found my Rocky Mountain.
Meanwhile, are you studying Lipo?
I think you you are going to need some custom harrnesses.
I would suggest you look at icecube57's work and read his posts.

 

[dogman dan]

40 mile range at 30 mph, (to average 25 including all stops etc) will weigh about 25 pounds minimum. More if you chose lifepo4. two 48v 20 ah packs.

This is enough weight to make a bike like that Kona smoke handle like a pig if you carry it all in the rear. But if you put a triangle bag on the bike, then you kinda blow the whole stealth thing.

But you could ride 25 mph actual top speed on a lot less battery. Two 48v 15 ah. Now you could have both batteries weigh 9 pounds each, and carried lower in the panniers, it would handle tolerable. Other stuff you need like a tool kit, pump, etc can carry in a handlebar bag helping balance out the loads.

Still looks pretty normal, as does riding closer to 25 mph. Bike can still be built for 30, just saying riding a tad slower means carrying 10 ah less battery, improving handling and lowering cost.

Add a Cycleanalyst to the build of course, so you can fine tune your speed to each days weather. Ride 30 mph if the CA says you are hitting your target watthours per mile to make it.

You could also get away with adding a decent, but not too tall shock fork to the bike. 100 mm travel or so. This will lower the vibration on the bars and improve hand fatigue on that long daily ride.

 

[Exiged]

Yah I have been studying lipo and it looks like this will be the technology I will use (taking in all the safety precautions into consideration) . Very interesting technology. It took my a while to figure out how you can make 12s out of other 6s, 4s, packs and the lingo takes a while to figure out. Looks like it's 12 6s bricks to make 12s of 30ah or 18 bricks of 4s to make 12s 30ah. I'm guessing going with 6s is the tightest of the packaging. Any benefits to using the big 4500mah of 12s bricks? Other than less wiring and the higher C rate? These are $120 a brick at the moment.

Def will add a cycle analyst and anything else you guys suggest to make it more reliable so I'm not pedaling the last 10 miles with no battery life.

Is their a particular motor that uses less power to get the same distance?

 

[wesnewell]

I run 10ah 24s2p of 20C lipo at 40A. It's rated for 200A. 30ah would be rated at 600A, so there's no good reason to run more expensive lipo when you'll likely be using <1C discharge on it most of the time. When I was running 18s2p I used some real cheap 10C lipo and it worked fine too. As for the watt meter. I didn't like the complications involved with them so removed it from my bike and replaced it with a simple voltmeter. But that's just a matter of choice. A simple voltmeter used as a fuel gauge works great wired to the controller side of the battery connection.
http://www.ebay.com/itm/DC-15-to-120V-Waterproof-Red-LED-Panel-Meter-DC-Digital-Voltmeter-Two-wire-NIGH/141365876290

 

[Raged]

I think you're overcomplicating the battery. If you want 30mph start with 14S lipo, but don't go nuts up front. Start with 2P and see if that setup gives you what you want before you buy more for range. I prefer less cabling in a simple setup (personally went for 2x7S 5.8Ah bricks for 14S) but if I was to do it again, I'd go multistar 8Ah lipo in a 6S + 4S + 4S config for a higher density 14S setup and the shorter length of the multistars make putting them in front tube panniers easier. Solves the problem of a battery box design at the start and is re configurable when you find the right voltage / battery point.

Front tube pannier will also stealth it up if you're worried about police attention when they see a massive in frame battery box.

I'm also a big fan of geared motors. It keeps the bike feeling like a bike when you don't want to use power, has more torque off the line and and is physically smaller (you can hide it behind disc brakes). Trade off is you're not going to hit 50mph on one and people say they're more fragile. I absolutely beat on my 2014 model MAC 10T and haven't frocked it yet. Everything around it has broken... Pedals.... Ratcheting mechanism on my freewheel...3rd set of brake pads front and rear... Etc. I don't do jumps on my ebike though. Did it once and the weight makes me nervous =(

 

[motomech]

perhaps you didn't read thru the complete thread, but the goal now is 40 miles @ 25mph.
In general, I prefer gear motors too, but in this case the DD is the way to go.
Since he needs so much Lipo and 2 chargers, we are trying to keep the costs reasonable.
A DD motor will let him cruise @ 25 mph on 12S.
12S would allow bulk/balance charging without breaking the series connection with one of the Thunder 1220's;
http://www.hobbypartz.com/75p-1220-charger.html
2 of those with 2 inexpensive server PS's would be $250.
A quick ck. with Hobbyking shows a price reduction on the Turnigy 6S/5Ah 20C, which is about the best capacity per/dollar there is.
He needs 12S/30Ah or 2 bricks in series and 6 of those in parallel. Say, with shipping, $45 a brick or $540 for all!
So now, we are talking about $850 just for batteries and chargers!
Mister OP, are you sure you want to go Ebike? Long range takes big $$$
A motorcycle or gas scooter would be less expensive.
If so, he should contact icecube57 right away for custom harrness and Server PS's.