Please help me push the limits of whats possible with ebikes

I have a need for an ebike that is pretty ambitious

230lb/105KG Rider
160km/100mi route mostly flat no stops
Desired speed 50km/h 31.25mi/h constant with decent pedaling

What kind of bike would I need to accomplish this feat

I realize it's sort of on the edge of what possible.

Budget is up to 5000$ for an ebike that can do it.

I would very much appreciate any and all help

For *this* forum, that's not really all that ambitious.

You should take a look around; there are a few ways to accomplish what you want, including both existing bike frames and custom building your own, or using trailers for the batteries or even a generator.

With $5K I could build one that would go 300 miles non-stop, except maybe to take a leak. For only 100 miles, under $2k without pedaling.

100 miles on one charge is definitely possibe. It's going to get harder though at that speed, since wind resistance just goes crazy the faster you go. So the battery gets almost twice as big to do that ride at 30 mph, vs 20 mph.

So a recumbent might be a good start. Also you may go ahead and consider trailering some of the huge battery, particularly if you only need 20 mile range for much of your riding.

But it could be done on a "regular" 26" bike like this. 48v batteries. Three 48v 15 ah pingbatteries, or even three 48v 20 ah.

The motor needs to hit 30 mph at 48v, and you say pretty flat, so the 9 continent 2806 will do it. 20 or 30 amp controller. 30 will get you rolling a bit better.

If not trailering that 50 + pounds of batteries, then you will have to use a front hub motor. 50 pounds plus motor all in back will be horrible. If trailering, you could perhaps carry a smaller battery in the frame, and trailer about 40 pounds of battery.

The bike itself is going to need a really strong frame to pack that kind of weight around. So if an upright bike with no trailer, you'd have to be looking at tough stuff like full suspension bikes in the downhill category, or no suspension bikes built for panniers like a surly long haul trucker, or best of all, longtail cargo bikes like yuba mundos, surly big dummy, etc.

Bet approach though, should be a recumbent with one wheel trailer.

I agree with most comments, that this goal is definitely not pushing the limits of what is possible. Building a clean looking bike that handles nicely and can do that range though, is somewhat a challenge. I wouldn't like to pull a trailer or carry a backpack full of batteries, but with Lipo one can carry quite alot of Ah on a bike without too much compromise.

I use this setup for long rides, as much as 24 bricks of Lipo onboard, and nice handling on or off road, at much faster than your target speed.

Thanks for the quick responses.

A Semi- or fully recumbant would make me nervous I think it would attract more attention from trafic cops.

Same deal with the trailer but a little less so.

If possible I may go with the trailer.

Also im wondering how effective pedaling can be in saving energy can you slap on 10kph by pedaling or 1kph Id love to get some exercise out of it and also lighten my potentially massive battery mass

adding speed on top of your already maxed out bike speed? hardly...

helping the motor out, yes.

but remember, at 45km/h, which is what i cruise at 48V i'm using about 700watts per hour....pedaling would add 100watts and reduce load on motor to 600watts.

so are u helping? sure...but not a lot.

Bitmaximus said:

Also im wondering how effective pedaling can be in saving energy can you slap on 10kph by pedaling or 1kph

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Red_Liner740 said:

adding speed on top of your already maxed out bike speed? hardly...

Click to expand...

Right.

You'll be using approximately 900 Watts (output) to cruise at 50kph. If you could add 100Watts through pedalling, that would take you to 52kph.....

Let's say you'll need 1200 Watts, allowing for system efficiency.

160km at 50kph would take 3.2 hours.

3.2 x 1200 = 3840 Wh.

A battery of that size, with a specific energy of 125 Wh/kg, would weigh 30 kg.

This is entirely possible, and EASY within the budget. It would require a whole lot of battery somehow being mounted onto the bike, which you are really going to notice. But its quite possible, and wouldn't even be that hard.

1200 Watts is about what I would say for 50 kph. I would never want to assume pedal power into a calculation as to if I will make it or not. Its not all that hard to just put a little bit more capacity on than you need, and worry less. I would say you would be shooting for closer to 5kWh of nominal battery capacity, at something like 20-24S... That way, even when the battery degrades, you will have enough power to make the trip without any pedal power. No reason to punish the battery when you can just strap some more on. It should be easy to get the rest of the system do what you want, it would only be a battery issue, which is just going to be a bit tricky mounting. With this kind of capacity, you would be shooting for the lowest cost per kWh, since discharge rate would be almost meaningless. Obviously Lithium would be the only way to easily get this kind of capacity. I would say the best bet would be 48 Turnigy 6S LiPo's... They can be purchased for $43.02 from the US warehouse, you should be able to get free shipping and 1% off. Thats $2044.31 for the 5.328kWh battery, which should be able to take you about 120 miles at 50 kph. This number can go up significantly with lower speed, and also with very low rolling resistance and pedal power.

http://www.hobbyking.com/buddy.asp?code=4BF101B4-920F-4428-A1DE-02ECA8EEC69F

The motor/controller to be able to handle 50 kph for the 100 mile trip shouldn't be an issue. Just about any higher power motor can take it, but drill some holes in the side anyways, and the controller requirements are not high. Mounting 48 of the Turnigy LiPo to a bike is 'possible', but its going to be a mess to wire it up. You would probably want to shove like 10-20 of them on a rear rack, tape the rest to the frame. Total cost should be easily below $3k, excluding the bike.

I think given the range you want, budget is not the issue - but carrying the weight is. I would go with a longtail for sure- a Surly big dummy built up with extracycle bags holding 40ah of 48v will be heavy, but should do it. Then run a rear 9c or similar motor at 35-40 amps (you'll need the power to haul all that kit up the hills even if they are few). Longtails are also designed to carry more weight on the back, so the rear motor with rear mounted battery is not as big a deal. you could also try mounting some behind the seatpost. I'd put a short travel suspension fork up front and a really big disk. Rear suspension is nice at that speed, but with the longtail, it will take some of the sting out and a suspension seatpost would help too.

It would be a heavy beast for sure, but at least a cromo longtail frame is designed for carrying loads. I think any normal mountain bike frame will handle poorly with the amount of battery you need for 160km.

Rhino knows what he's talking about.

The more info we have, the more we can help. Do you need that 100 mile range in one go? Or is it 50 miles somewhere and 4 hours there before you return.
Just slowing down some solves half your problems with range. As would being able to carry 50 mile range and charge awhile.

I can and do carry 100 mile range on a full suspension mountain bike, but that is figuring on traveling 20 mph to stretch range that far. The main thing is a frame strong enough to not wobble like mad when loaded down. At 30 mph, my range drops to about 60 miles. To go 100 miles at 20 mph, I'd be carrying a 36v 20 ah lifepo4 and a 48v 15 ah lifepo4 that together weigh 30 pounds. Then to get another 20 miles range, a 36v 15 ah in lipo. About 10 pounds.

For sure, to cram about 48v 50 ah on a bike, lipo would be smaller and lighter. But you can easily carry enough battery of any lithium chemistry on a yuba mundo, or similar cargobike. The frames are made with 100 lbs of cargo in mind. For me, a problem with that is I need suspension for a ride of more than 20 miles. I ended up recently making my own longtail, with a rear shock.

The pedaling is another thing that diminishes in being worth it as you increase speed. For sure, the motor will draw less power if you are pedaling hard enough to add 1 mph to your speed. Because of the increasing wind resistance at speed, by the time you are going 30 mph adding even 1 mph to your speed takes a lot more than the typical bike riders 100 watts. If you're very fit, you can definitely add to your range, but it's just a lot harder to do so at 30 mph, compared to at 20 mph.

So I find that pedaling at 100w adds a ton to my range when riding at 200-300 watts on the motor, as in below 20 mph. At 30 mph, it takes about 600 watts just to cruise, and my 100w added is not much. But in the right gear, I can get my motor watts to drop at least that 100W. I pedal mostly because on a long ride I get very uncomfortable if I don't pedal. And over a 60 mile day, even that 100w does add up.

Here is a pic of my long haul bike.

Front hub installed on an alloy shock fork, which is difficult and not recomended. But if I need to carry 50 pounds of battery and water in the back, it helps the bike balance. It can go 30 mph loaded down, but handling is compromised enough to prefer to keep it to 20 mph when it's that heavy. With just one 15 lb battery in the metal toolbox it handles fine. At about 40 pounds of cargo, it starts to flex enough, and rim brakes get inadequate enough to make it better to slow down when loaded.

My longtail, also more happy at 25 mph or less. A funky frankenbike, and surely safer at 20 mph than 30 mph.
It could go 100 miles I'm sure, and carry plenty. But 30 mph on this one would be asking for it I think. I have a battery up front, to help balance out the rear motor this time.

A real longtail, with a shock seatpost of some kind, and a pile of lipo is most likely the best solution, for hauling ass for 100 miles. On flattish ground, motor meltdown won't be a huge issue really. You should be able to cruise at 600-800 watts. So a good direct drive motor should handle that easy. That kind of distance, I'm assuming there won't be a stop sign every mile.

MadRhino said:

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Hey Rhino, is that a front-mounted battery pack like I use? Not many folks have caught on to this trick... Are you also as as I was by the handling improvement over a pannier/rear rack solution? 8)

-JD

Yep, I have 2 dirt bikes running, both with batteries in the front. I just add some on the frame when I need extra range. At high speed, that is most of my ride, I like the batteries mounted high. For slow technical, and eventually jumping, I plan to build a trial bike with batteries mounted low.

Getting some great ideas, thanks!

As for more info

Montreal Qc -> Sherbrooke Qc
People have told me its pretty flat
Obviously some if the travel will end up on the highway
But if you check the google bike route it seems like only 30km on highway

My goal for time is 3-3.5 hours
And it is "one shot" not much room for charging- in fact none.

Ive considered leaving a battery at a half way point at some store or
Something to swap with the batt on the bike but prefer not to.

From what im hearing from you guys I should need 1000W per hour to maintain a ~30 mph speed? So maybe I should shoot for 4kw capacity on the bike?

Heavy weight-> needs strong frame

So

Strong heavy duty frame
4kw total energy -> 4 x 48V 20Ah ping?
2-3 on back rack
1 in triangle or front mount like madrhino
Front wheel 9c motor 48V
30A controller?

I also want an anti police system 250W sticker/Removable Jumper to limit speed

How does this sound guys?

Sounds god awful heavy to me -_-

The numbers I got from the http://www.kreuzotter.de/english/espeed.htm are about 1500W continuous at the wheel(s) and 5 KWh of battery for an upright seating position on a standard bike.

I like Dogman's recommendation of a recumbent with a one wheel trailer.

I've got a 4kw-hr pack sitting on my desk that would do it without breaking a sweat, and it's definately fittable in just a typical pannier bag setup. Which if combined with a rear-hubmotor would make a bike that accomplishes what you want, and is totally stealth. (it would look just like a normal pedal bike with pannier bags.

If you want to look normal, a longtail bike is easily the best way to do it. Plenty of battery room with space for luggage/cargo too.

Options in addition to the ones a previous poster mentioned (Xtracycle, Surly Big Dummy) are the Kona Ute and the Yuba Mundo. I'd suggest the Mundo as it's strong, made of steel and has a 200kg total carrying capacity. It's also reasonably inexpensive, leaving more budget for the electrics.

4 kWh is a good pack size to aim for.

If you find your pack is too small, you can always travel a little slower. I've done over 160 km one day rides on less then 1 kWh though the average speed was much lower then what you aim for.

Something worth spending time thinking about is weight distribution. A normal bicycle with ~40 kg of battery and motor all over the back wheel might look stealthy, but won't handle terribly well. Comfort and good handling are important for long rides.

Bitmaximus said:

Montreal Qc -> Sherbrooke Qc
People have told me its pretty flat
Obviously some if the travel will end up on the highway
But if you check the google bike route it seems like only 30km on highway
-

Click to expand...

You're dreaming if you think that you can commute Mtl-Skerbrooke on the highway.
You might be lucky and do it once or twice, but the cops will catch you before long. They will not care about the power that you have. They will get you out of the highway, where bicycles, E-bikes and mopeds are not allowed.

Take a small appartment in Sherbrooke (for University I presume), then build a lightweight MTB and have fun in the surrounding mountains. :wink:

I've been thrown out of the #40 highway by the cops, with serious warning. Now when I have to ride the highway, I ride in the grass along the fence. It's fun and much faster than cars when it's traffic hour, but I wouldn't want to do it everyday as a commute. Anyway, that is illegal as well, but the cops don't care as much, and I can always escape though the first hole in the fence.

I was just thinking that myself. Didn't Justin have trouble with that on his crosscountry ride?

Since charging along the way is not an option, going lipo makes more sense than pings. Again, your speed goal is not so realistic for that kind of range, unless you are packing it on a longtail. But at 25 mph, three 48v 20 ah pings would get you there. Carrying them on a yuba mundo would not faze it that much. But bear in mind, a longtail is not expected to be pedaled at 30 mph. So like my bikes, 20 mph may be comfy, 25 tolerable, but 30 definitely sketchy.

So here goes, I'll be the first one to say what you really need is a small scooter or motorcycle for this task. Like a honda 150cc. If nothing else, because it's highway legal.

Also, nobody has factored in a steady headwind, whatever those are likely to be. If you want to maintain 30 MPH against a 30 MPH headwind that will cause the energy estimates to almost quadruple.

If you are going to carry that much battery I'd look into using both front and rear panniers like the lycra boys do when going on long road trips.

Like Oaknet, I also think that having your batteries over the front wheel make for a better handling setup

Under 10 pounds of battery on the bars is dreamy. Any more and you will notice a slower swing time when you need to steer quick. No slower than that of a regular motorcyce though. So it's just a matter of adjusting to the feel.

To carry all that lipo on a regular wheelbase bike, he'd want to pack about 10 pounds on the bars, 20 more on the mid frame, and only carry what he must in back. A front hub helps balance the back, but I won't call my long haul bike good handling when it has 50 pounds in those panniers. A rear motor and lots of battery up forward works best.

But he's still gonna get busted riding that freeway in Canada. He needs a motorcycle, or motorcycle conversion so he'll have a plate.

dogman said:

Under 10 pounds of battery on the bars is dreamy. Any more and you will notice a slower swing time when you need to steer quick.

Click to expand...

The motorcycle analogy is apt, it does feel different, heavy but with a more refined, planted control. 8)

I've run 25lbs up front, so far. The key is to have it hard-mounted, not sloshing around, and tightly packaged to the axis of the forks rotation. Steering response is snappier than a rear mounted battery because I am moving most if the mass of the bike with the handlebars, instead of translating that input through a flexing frame to a mass bouncing about in rear panniers.

After all, steering isn't a matter of how fast you can rotate the handlebars, it is how fast you change the mass's direction of travel. I can turn the handlebars very fast on my rear X5/30lb rear battery xtracycle, but I'd fall because the rear won't follow. With a front mount, I feel like the mass that needs to be turned is centered between my hands - because it is. The front wheel is always loaded for superior traction, and the battery gets the softest possible ride because it is directly connected to the stanchions.

I had a bad fall a few years back, swerving around a group of pedestrians (on the bike path, in my lane, backs to me ). I had a new build with a rear x5 and a @30lb rear pack. I swerved left fine, but when I tried to roll to the right, the underloaded front wheel lifted while I was looking right at it, and I dropped. I had done the same move on TF bikes hundreds of times, so I was surprised. I had a long time to think about it while my ribs healed and reasoned out that the problem was too much rear mass. I started working on a center battery, frustrated by the lack of room, then I saw a 50's show with a kid delivering bags of groceries in a front basket, and it got me thinking it was a great way to preload the front wheel and suspension.

When I look back at all the front-basket delivery bikes designs we've had over the last 100 years, it seems like heavy masses have frequently carried up front.

-JD

oatnet said:

...
I've run 25lbs up front, so far. The key is to have it hard-mounted, not sloshing around, and tightly packaged to the axis of the forks rotation...

Click to expand...

+1
I would add that having some weight high, well in hand, gives a very fine and quick control of the bike's balance at high speed.

Fitting the weight low creates a lever effect, and alot more displacement is required to shift balance, that is good for precision steering at low speed, but delay the balance shifting response at high speed.