Some Ideas on building a 5000w E-bike

Some specifics of my first-time e-bike project,

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  • 26" wheel with a 5kw hub motor.
  
  • 50 mph max on flat ground, to start off with. The power level seems to be capable of 70, but that will be for another time. Overbuilt = durable.
  
  • I'd like to be able to cruise at 30mph for 60 miles, just to toss a number out there. I'll more likely vary between 20 and 35, with the occasional blasts to 50. More details about the expected range below.
  
  • I'll be using a pair of Shimano Deore hydraulic disc brakes, 203mm rotors. Though, I might use the Saint model, for its downhill-specific use. I need to be able to stop this thing at 50, because, well, that's important.
  
  • Rider weight is a feeble 135 lbs. Fully built, I am expecting around 200 lbs with me on it.
  
  • Terrain is flat, flat, flat. With the occasional 3% grade, except for Clermont and Mount Dora. I will go out there from time to time. I'll be on pavement 95% of the time, using a hardtail. I'm probably going with Maxxis Hookworm tires and thorn-resistant tubes. Tire choice isn't chiseled in stone yet.
  
  • I'm comfortable with spending $2000 - $2500 for just the motor/battery/controller, and other motor-specific items. I'm a bike mechanic in a retail store, so all things bicycle are negligible.

This is going to be a new toy, not transportation. Though, that might change depending on my experience with it. I'm only 15 miles from work, but this is Orlando traffic we're talking about.

Orlando is backwards a hell in terms of cycling safety and regulation. Most motorized bikes on the road here are walmart huffy beach cruisers with coaster brake only, rigged with a 50cc gas engine leaking fuel, spattered with dirty exhaust, ridden by a guy with 3 DUIs, at 40 mph in the bike lane.

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About the expected range : I used the e-bike simulator to get a number, based on tweaking some custom specs that seemed to be close to my build. I used the:

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  - Clyte 40100 motor
  
  - 96V , 26 Ah battery
  
  - 80 A controller
  

to approximate the power levels and speed potential (5kw, 50 mph max, 26 Ah). Playing around with the throttle settings, I found that cruising at 30mph will go 60 miles, which is pretty amazing for that battery (if my custom tweaks in the sim are accurate). This setup seemed to be in the range of the motor and battery I found here:

Motor Kit

Battery

This is the online store for a factory that produces them in mainland China (god I love the future). I have been seriously considering this kit. This post of my project idea is also a sanity check, before I spend any money. Anyone here would know better than I would:

Is this a good deal? Is this junk?

If I need to call the manufacturer to get more info on the products, what questions should I ask them?

Are the battery specs on par with what I should be using (72V 26Ah) ? I'll get two of them if so.

Can anyone direct me to a superior product(s) with the same build goals?

Any input is much appreciated.

Yeah,, at 30 mph, he'd be able to pedal up 10% of the power needed, if even that. And he'd need a giant front chain ring to pedal at all at 30 mph.

At 20 mph, he can pedal up at least 20-25%,, At 18 mph, a solid 30%.

1500 wh of battery can get you 60 miles, at 18 mph for sure. That's 72v 20 ah,, 48v 30 ah,, For really big range you start having to build a frame that carries it.

I built this, to easily carry 4000 wh. But right at the moment, I only own about 3000wh.

That looks like a QS clone, and a Sabvoton controller, which seems like a good combination.
It will likely be insanely powerful for a 135 lb rider.
You could shave some weight by going with a smaller DD hub like a MXUS 3K-Turbo or even a 35mm Leaf or Edge motor, and still meet your desired goals. Just make sure to get a high Kv motor (11 to 15 RPM per volt) and a 80A 4110 controller.
A 72V battery that can output 80A will be the more difficult task. Stick with Samsung 25r cells or LiPo if you can charge and maintain it safely.

Why do you want all that power? 5000w could cause you to be harassed by police.

lester12483 said:

Why do you want all that power? 5000w could cause you to be harassed by police.

Click to expand...

5000w watts on tap is more than enough for a police chase

You already have the frame?

Pedaling along at 30 mph would net you about 10% more range. I do it for miles at a time. It does not require a huge chainring. I run a 53/11 top gear, and can easily keep up at my typical 80-90 rpm cadence.

That battery pack from EM3ev would be way better than the one you linked to. And 60 miles would certainly be doable, if you can stay in a tuck on an upright.

At 18-22 mph, I am an eccentric old guy to police, and other road users. At 30 mph, I am a mildly annoying, curiosity. At 50 mph I'd be a threat to their self image, and possibly a terrorist.

30 mph requires 40 wh per nile, so you need a 2400wh battery minimum for 60 miles. Personally I'd use at least 30ah of 24s lipo. I'd pair that with a mxus 4503 motor and a minimum 3000W controller.

My bike doesn't require anything like that much power. With me pedaling along at 30 mph, I typically see 24 Wh/mile.



This simulation shows my motor, my actual tire diameter, my average battery voltage over a 48 amp hour run, and my actual gross weight, without pedaling.

And totally inappropriate for what he wants. Yeah, with a recumbent you can do 30 mph on <18wh per mile and not pedal at all. But on a standard mountain bike it will take ~40wh per mile at 30 mph.

He mentioned disc brakes and hardtail. I didn't see any mention of a mountain bike. He could go with this bike.

http://www.bacchettabikes.com/bike/giro-a26/

They are even located in Florida. He would probably be better off with their older cromo steel version, for an e-bike, like this one.

http://sanantonio.craigslist.org/bik/5886987586.html

But hey, why think outside the box?

Come on guys.. 60mph with a hardtail and just disc brakes on mostly pavement

Does pavement have the same meaning as in the U.K?

If you spend a lot of time above 30-MPH, wind resistance will have a major effect on your battery range. Max range per battery will be around 20-MPH...

Hey, thanks for the responses, everyone. I'm sticking with these specs for the build. It's just the way I want it. Part of the fun will be testing its range capabilities regarding speed, and other factors. I'll get another, duplicate super-battery when the funds allow. I'm very impressed with how far and well-developed this tech has become. I remember one the the first eBikes at the REI I worked at in Redmond, WA back in 2001.

I once rode a 150cc Vespa up to 50 mph. The wind was ripping the tears (of joy) right off my face. That was an amazing experience, that really stuck with me for 12 years. Out of all things to spend money on, this ebike project is it. I haven't been this excited about something in probably forever.

eTrike said:

For battery, this is a much better option: http://em3ev.com/store/index.php?route=product/product&product_id=252

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Oh yeah, that thing is way better. I need a BMS, so I'll get a different one from them. I imagine I can get some more Ah out of a customized unit. Thanks for the link!

teslanv said:

It will likely be insanely powerful for a 135 lb rider.
You could shave some weight by going with a smaller DD hub like a MXUS 3K-Turbo or even a 35mm Leaf or Edge motor, and still meet your desired goals. Just make sure to get a high Kv motor (11 to 15 RPM per volt) and a 80A 4110 controller.
A 72V battery that can output 80A will be the more difficult task. Stick with Samsung 25r cells or LiPo if you can charge and maintain it safely.

Click to expand...

Insanely powerful is right up my alley. I'll likely detune it in the beginning. I'd like to have a platform to build on, rather than needing to replace major parts like a motor. But, I'll look into these, thanks!

I'm concerned about batteries that might explode into a fireball. The LiFePO4 seems to be the best option. I'm also new to proper recharging practices, so I'd like a battery that's more forgiving, more or less.

lester12483 said:

Why do you want all that power? 5000w could cause you to be harassed by police.

Click to expand...

That depends on 3 things: when you ride it, where you ride it, and how much respect for the law you have. In my experience with overpowered vehicles, you can play with them quite a bit at the right times and places, along with a dose of self-control. Police around here are more interested in car/motorcycle racing, and the gas motor bike guys doing 40 in the bike lane. I've met and talked to many of them, being in the bike shops. You have to have some blatant disrespect for the law in view of police to get stopped. And even then, you'll have to carry on a bad attitude with them to get into trouble. If you're some dude on a bike with no noise, who has a happy, cheerful attitude, then no problems. For the most part.

drew12345 said:

You already have the frame?

Click to expand...

I was thinking of using a Trek 4300 aluminum mtb frame. But, at closer inspection of the slotted axle and torque arms on the motor, I'll really need a steel frame with horizontal dropouts. +200nm of torque might punish the 4300 too much, lol.

Warren said:

He mentioned disc brakes and hardtail. I didn't see any mention of a mountain bike. He could go with this bike.

http://www.bacchettabikes.com/bike/giro-a26/

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Bacchettas are nice! I don't want a recumbent for 5kw, though. I know the handling of a hardtail mtb and roadbike well.

brumbrum said:

Come on guys.. 60mph with a hardtail and just disc brakes on mostly pavement

Does pavement have the same meaning as in the U.K?

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Not just any disc brake ... one that comes equipped on freeride bikes going 50 downhill. Locally, pavement = asphalt. Never gravel, sand, hard-pack dirt, grass, etc, as long as I can avoid it.

spinningmagnets said:

If you spend a lot of time above 30-MPH, wind resistance will have a major effect on your battery range. Max range per battery will be around 20-MPH...

Click to expand...

Yes, this is true. I imagine it'll be around 20~30 most of the time. I regularly hit 30 on my road bike many times per ride, so I definitely know what it takes. I'll probably be pedaling with it the whole time, since I don't know any other way to do it.

hypertoric_amplituhedron,

"Bacchettas are nice! I don't want a recumbent for 5kw, though. I know the handling of a hardtail mtb and roadbike well."

On a recumbent, you wouldn't need 5kW for the speed you want, but it has been done, more than once, and at least 13 years ago.

http://www.evalbum.com/476

https://endless-sphere.com/forums/viewtopic.php?f=6&t=36048

And my favorite.

https://www.youtube.com/user/FASr7/videos

He is on this site, and still at it after six years in traffic.

https://endless-sphere.com/forums/viewtopic.php?f=6&t=14842&hilit=Russia&start=600#p315445

Use a QS 205-H50 v3 with an 18 fet 4110 controller, not expansive, very smooth spinning, efficient... and both able to be upgraded to much higher performance if/when you want to.

Saint brakes, at 50 Mph you won't regret.

Hardtail is OK if pavement is very nice. On mine field streets that we have here, I couldn't build a hard tail for 50 Mph.

brumbrum said:

Come on guys.. 60mph with a hardtail and just disc brakes on mostly pavement

Does pavement have the same meaning as in the U.K?

Click to expand...

NO !...Pavement in USA means ashphalt road surface.
Pavement in UK means pedestrian sidewalk.

Warren said:

On a recumbent, you wouldn't need 5kW for the speed you want, but it has been done, more than once, and at least 13 years ago.

Click to expand...

My god, popping wheelies on a recumbent .... that's a lot of torque! Well, don't get me wrong. Doubling the range for whatever build is an attractive feature. It's the handling characteristics of a 'bent that I don't want for high speed. I just feel like they're too twitchy. But, that seat would be way more comfy after an hour.

MadRhino said:

Use a QS 205-H50 v3 with an 18 fet 4110 controller, not expansive, very smooth spinning, efficient... and both able to be upgraded to much higher performance if/when you want to.

Click to expand...

Are you talking about this thing? : https://wholesaler.alibaba.com/product-detail/QS-Motor-205-Electric-bicycle-kit_60525698534.html

This looks a lot more professional. The link I provided in the 1st post looks like a mimic company that's jumping on the craze. Usually, they will model themselves after the real deal, who I've been trying to find. If this thing is upgradable, then I guess 3kw is a good start. Watching some vids of this power level makes me realize it's what I'm looking for.

How does this kit look? Anything to change? I can't tell if that's the 4110 controller you mentioned. It's too bad they don't lace to a 26" rim yet, but no worries. I'll just ship it off to J&B for a build.

"It's the handling characteristics of a 'bent that I don't want for high speed. I just feel like they're too twitchy."

This is based on your years of recumbent riding experience?

Picture taken while riding no-hands.

https://endless-sphere.com/forums/viewtopic.php?f=3&t=78828&start=25#p1174665

You do know that the current land speed record on a bicycle is now held by a recumbent at 86.65MPH?

http://www.recumbents.com/wisil/whpsc2016/speedchallenge.htm

I didn't see the upright streamliner record in Indianapolis, but I did see it race against streamlined recumbents at the State Fair track, in Milwaukee, back then.

http://bentrideronline.com/messageboard/showthread.php?t=91768&page=2

hypertoric_amplituhedron said:

MadRhino said:

Use a QS 205-H50 v3 with an 18 fet 4110 controller, not expansive, very smooth spinning, efficient... and both able to be upgraded to much higher performance if/when you want to.

Click to expand...

Are you talking about this thing? : https://wholesaler.alibaba.com/product-detail/QS-Motor-205-Electric-bicycle-kit_60525698534.html

This looks a lot more professional. The link I provided in the 1st post looks like a mimic company that's jumping on the craze. Usually, they will model themselves after the real deal, who I've been trying to find. If this thing is upgradable, then I guess 3kw is a good start. Watching some vids of this power level makes me realize it's what I'm looking for.

How does this kit look? Anything to change? I can't tell if that's the 4110 controller you mentioned. It's too bad they don't lace to a 26" rim yet, but no worries. I'll just ship it off to J&B for a build.

Click to expand...

The kit is the easy solution, yet a good start. The seller can upgrade, you need to discuss.

Experienced builders do prefer to buy the motor alone, in its best version : qs 205 h50 v3 that means with 50mm magnets, alu stator with extra copper fill and upgraded phase wires. You can find it in ES "for sale new" qs motor. PM Vito, I believe he still selling it for 273 $.

We use a smaller controller that is neat to mount on the bike frame in full air flow. You will also find threads about them 18fet 4110 controllers in the "for sale new" section of the forum. They can deliver a lot of current when upgraded to their best, but 5 000w is within the stock spec, and pretty low for both the motor and the controller. I feed well above 20 Kw bursts and they are running pretty cool.


For the rest, throttle, switches, etc... they can be found cheap in a good variety, many sellers have them or you can order with the controller. Wire and connectors for harness, voltage monitors, etc... are found at Hobby King: 8 ga silicon wire and big gold bullet connectors. Many of us are using 75 A Anderson connectors for they are safe and reliable to disconnect frequently.

Good luck with your first build.

Warren said:

This is based on your years of recumbent riding experience?

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Yes, that's exactly it. I love recumbents (also worked at Catrike), but I don't have a lot of miles on them. I certainly don't want to go 50mph on one . I've ridden many, either a customer's tune up or a new assembly. Some were very smooth riding. But that's still 50 miles compared to 30,000 for an upright road/mtb.

MadRhino said:

They can deliver a lot of current when upgraded to their best, but 5 000w is within the stock spec, and pretty low for both the motor and the controller. I feed well above 20 Kw bursts and they are running pretty cool.

Click to expand...

Really? Well, let's say I wanted to run my bike in the quarter mile. I'd like it to do around 70 mph tops. It'd be neat to go back out there again with something different. Plus, I don't have the 11 sec beast anymore, so I gotta build something cool. Do you think 5kw is enough to do it? I'll be using a 17" moped wheel, with probably a 2.25" wide tire. That's about 23.5" diameter, which needs around 1,000 rpm . How would I achieve that? Is it as simple as using the 30*4T (11.39kV) running 88V? I know it's important to have enough torque to push it up to those speeds, too, which I guess is where the amps come into play.

After you contact Vito at QS motor, someone will send you a mail with all the motor spec and the speed of all the winding turn count available. Select the winding that will make your desired top speed in the size of wheel that you plan to use.

Then, 5 Kw is making a bike aggressive enough for most. Above that you need to think about geometry and suspension to build a bike that has the handling characteristics required for that sort of power. Above 10 Kw, it is very easy to build a bike that is dangerous to ride because it doesn't handle, accelerate and brake neat enough.

hypertoric_amplituhedron,

Making a blanket statement like, "recumbents are twitchy", is kind of like saying Mexicans are murderers, and rapists.

My experience is just the opposite of yours. I worked in bike shops my last eight years of work, and checked out $5K tt bikes I couldn't ride no-hands.

I never made any record of my rides for the first 25 years, but starting in 1994, when I got my first cycle computer, through 2015, I logged 38K miles on pedal bikes. Two thirds of those were upright miles. I haven't ridden a pedal bike in more than a year. The last time was returning from the salvage yard, when I junked my car.

Since September of 2011, I have ridden 35,019 miles on electric assist recumbents.

The fastest I ever went on an upright was 44.0 mph, in 1997, on my 1972 Frejus, which I still own. This was on a descent with a tailwind, of course, as I never got over 30 mph under my own power on a bike in my life. I have done 40 mph many times on uprights, and recumbents, and the uprights always felt terrifying at those speeds, with my chin on the bartop, looking out the top of my watering eyes. The recumbents always feel rock solid, as I have my head up, and I am firmly planted in a real seat, going feet first, instead of perched on skinny rail, with my head out front, below ass height.

The fastest I have ever gone on a bicycle was 46.5 mph on my RANS Screamer, back when it was still a pedal tandem. It was totally relaxing...no drama at all. Now that it is a DD electric single, it has never gone over 36.5 mph, thanks to the back EMF above it's 32 mph top speed. However, my Linear mid-drive sees 40-44 mph on most rides, since it freewheels.

Hell, I even went 42.0 mph, on my rowbike, on a descent.

https://web.archive.org/web/20051224103727/http://www.rowvelo.com/images/PDRM0860.jpg

and felt much safer than on an upright.

hypertoric_amplituhedron said:

It's the handling characteristics of a 'bent that I don't want for high speed. I just feel like they're too twitchy.

Click to expand...

Which 'bent?

Every design will have different handling, just as with upright (or any other) bike.

I have two different designs, CrazyBike2 and the SB Cruiser trike, and I wouldn't class either one as "twitchy", especially as I get to higher speeds vs starting out. I've raced CB2 in various configurations on a kart track, and other than doing stupid things and wiping out (which I would've done on any bike), it was fun. Rode it's unpowered configuration at about 40mph downhill shortly after it was built, was nice and stable. (unfortunatley it's illegal to do that now that it has a motor on it, which is stupid).

(though certain versions of CB2 with different wheelsizes or other front-end changes that changed the handling significantly *were* twitchy or otherwise difficult, at various speeds).

One thing I'll say is that the only crashes I've ever had on CB2 were skid-outs on it's side, even in conditions that would've been a header on a regular bike (which I've done about every type of crash possible over the years, mostly when I was younger and dumber, mostly on gravel roads in farm country as a kid).

Only serious injury in any of the CB2 crashes was a fractured ankle that got pinned under the cranks on the kart track. Only other was some skin off an elbow, again at the track (the previous time). The other laydowns left me uninjured because the seat frame and handlebars protected me and allowed me to ride out the skid on the bike rather than skidding/flopping/rolling around on the road like I have on any of the regular bike crashes.

Recumbents are no problem at high speed, for it is exactly their comfort zone. It is at low speed when you need to be balanced and nimble, that they have poor maneuverability. It is pretty much the same handling effect as a chopper motorcycle.

A bike that you can control in all situations, is a bike that you are free to load the front or the rear at will with minimal body displacement. The more it is naturally loaded on the front or the rear, the more of a specific bike it is, for acceleration, speed stability, cargo, etc...