Electric Bikes - backpack foldable electric pedal bicycle.

I travel a lot to many cities for business. I always have free time to see the local, but walking won't cover a lot of ground. Bicycle is too big for me to lugging around the airplane. So I come up with a design that I can fold the bike and carry like a backpack about 4 years ago. But lithium battery cost too much and the in wheel hub motor is too big and heavy. Now I think is the good time to start this backpack electric bike. According to my design, The length of the bike is 20 inches and 10 inches diameter when you fold it. The total weight is about 25 lbs. The micro hub motor is 24 volts, the battery is lithium LiFePO4 at 24 volts and 15AH. The design have some unique features that no other bikes in the world have. Such as :

1) conceal battery. ( you cannot see the battery on the bike, it give the bike a simple, nice clean look )
2) height adjustable (The bike frame change the height and the length to accommodate any rider)
3) 12 Volts outlet to charge or power GPS, cellphone, laptop, mp3....even jump start your car.
4) Unique look ( I got this frame design from one of the alphabetical letter)
5) The way the bike unfold is also unique ( 2 seconds to deploy )
6) Unique non-bearing steering system.

I want to build the best foldable bike , so I need your of your input some features that I miss. Such as regenerate brake ( ultracapacitor ? flywheel ?....). The most import question of all is will this bike successful in the market place ? The cost to build this bike is about $400, retail will be $700. Please tell me anything wrong with this project. Thanks in advance

I know you want to build your own, but that's a whole lot of work, and I applaud it, but there's quite a mess of little folders I'd look at first.


http://www.jb-electricbikes.com/pro/16-light-weight-folding-electric-bike.htm


http://khadrasolar.com/products/E-Cycle%20Sport%20(silver).jpg (http://khadrasolar.com/products/E-Cycle%20Sport%20%28silver%29.jpg)

Oh no, I couldn't build even an unicycle, never less attempt to even try build this hi-tech bike. all my inventions is produce by the expert in their field. All I have is a drawing and ideas to create this bike. I have a close business friends in Vietnam, they own the biggest bicycle factory in Vietnam. They will handle the production and build the bike according to my plan. I just need to know what's else does this bike needs ? Will such a bike will do good in US ? or europe market? Since you guys are expert in bike, that why I need your specific advise because the start-up cost of this project is about $100,000. I still need to search for other partner too. I have other 50 more inventions, you can see some of them at http://inventorspot.com/forum/viewforum.php?f=32

Your project sounds extremely ambitious. A 24V15Ah battery weighs something like 8 pounds, and very few folding bikes are less than 17 pounds without battery and motor. $400 production cost is also very ambitious, especially when the wholesale price of the battery is probably $120 or more.

Micro hub motors are a great idea (I assume you mean a geared hub motor). 12V power outlet, also a great idea. Fit it in a backpack, also a great idea. (Lots of people want to travel by bike sometimes, by bus or train sometimes.)

Many people would be happy to pay $1000 or $2000 for all of these features, but most new companies are never able to add so many features to what is already on the market and still keep their product reliable and price-competitive. Achieving a reputation for reliability is another thing that's necessary for your new product to become accepted.

Thanks for your advices, I have a lot of technical people to help me out. I have a lot experience dealing with the China supplies for five years. I will make sure the bike is up to USA standard. I made my first millions dollars from my invention that relate to video games. It cost me about $80,000 if I produce my invention in the US, so I produce in China for $15,000. Anyway, back then I joined the video games forum, hundred of people share their advice. Those people really help me out and they also become my customers and wholesale buyers.
If I can produce the bike exact as I describe above, quality up to USA standard, the retail price between $700 to $800. Will you buy this bike ? Please help me out any advice or just enter yes for I will buy bike or no I'm not interest. I'm really appreciated. Thank you in advance

If you could truly build the bike as described and get it to dealers here in the US or via online sales originating here instead of overseas then I think you could sell many of this type of bike to travelers, yachters, private plane owners and commercial passengers, commuters, and the RV crowd.

But it is not easy as you know to launch a new product and although 250w is the max in Asia here we are allowed up to 750 in most cases. So perhaps you might want to enlarge the w some to give it a little extra zing for getting across the busy intersections in the areas this bike will be made for? And forget about regen as the range of this bike will not be enough to gain any real benefit from it.

You will need to enlist the help of a distributor here obviously that can accept container loads and get them out to the dealers that they either already have or set up specifically for this product. If the bike shapes up like you are planning I know I would take a couple! Good luck and keep us posted. If you could come back with some more detail via pictures or drawings that would help us to better visualize what you are up to. Don't worry about anyone taking your project on here as it would cost 10 times that amount!

The Bike design is to be bare minimum to the bone so I achieve close to the feather as possible. That why I came up is the letter X. I call this bike is Xcell. X stand for expandable and also is the shape of the bike. Cell stand for battery cell. So together Xcell stand for progress.

I'm 100% sure that I can arrange the factory to build this bike. This bike project is easier than the car transformer design. If you see the movie about the car that transform to a robot, but my car only transform to a truck. Basically, want have a car and a truck for the price of one.

1) drop the regenerate brake.
2) option for bigger motor.

The reason that I choose the micro hub motor because I still want Xbike to retain the look of non-electric bike. The motor will be on the back wheel. But I will use bigger motor as option.

So far, you guys really gave me very meaningful. advise. But if you see something with my design, please let me know. Thanks

I like to have this project like community project, everybody work out all the bugs or option. Better do it now than retool or redesign later. It will waste time and money. I'm sure give you guys a discount when the bike arrive on the market. Again , if you see anything wrong with my design please let me know. I'm very grateful.

if you could make a bike that fit into a backpack, I'd buy it as long as it was less than $2000

Another question. I was in Vietnam when I designed this bike, I was design the bike base on 160 lbs weight for the local rider. If I was gonna sell American, 160 lbs is not gonna cut. it. What is the maximum ideal weight ? 200 lbs ? 225 lbs? 250 lbs ? This will determine for extra strength of the bike. Aluminum will be use for the frame of the bike.

In the USA market you should probably design to support 225-250 lb rider. Lighter riders over here will usually not choose to buy an electric assist bike. If a lighter weight design fails, then it will get a very bad reputation as being poorly made and will be tough to sell.

1. Give up the Back Pack idea ---- Dahon, the largest folding bicycle manufacturer made a double-ply back bag and it was a horrible idea. A folding bike has far too many sharp points that will dig into your back making it useless to carry for even 50 feet. If you decide to fill the bag with cushion or some kind of fabric, it becomes too large and heavy to carry around. The bag itself without any support was too large and cumbersome and takes about 10 minutes (Or more) to fold and unfold.

A better idea is to design the bike so that it "rolls" once folded. The Brompton and Strida bikes are good examples of folders that roll once folded therefore making it easy to transport at airports, malls etc. Trust me, you do not want to carry 27-35 pounds on your back for any length of time. This is not a set of books but a very heavy bicycle. I carried my 27 lb Dahon folder once for 150 feet and my back and arms were hurting for days!

2. Dahon/Sparc --- Dahon tried to sell a folder with the Sram Sparc a couple of years back. It didn't sell. Giant offered a very good (non-folding) electric bike for several years. It was a solid product all the way. It didn't sell well. You might want to send a letter to Josh Hon at Dahon bicycles and tell him your ideas. I'm sure he'll give you the full story of his attempt at an electric folding bicycle.

3. Chinese Delivery men --- The only people I see riding electric bicycles in New York City are Chinese delivery men. Seriously. This is your customer base and if you can find a way to sell E-Bikes to these low wage workers, you might have a viable business plan.

3. Chinese Delivery men --- The only people I see riding electric bicycles in New York City are Chinese delivery men. Seriously. This is your customer base and if you can find a way to sell E-Bikes to these low wage workers, you might have a viable business plan.


I liked your other points, I think the OP is fighting an uphill battle, but I hope he wins, as it would benefit us all as customers.

But perhaps the OP intends to sell his product to places besides New York City, where electric bicycles aren't even technically legal.

Another question. I was in Vietnam when I designed this bike, I was design the bike base on 160 lbs weight for the local rider. If I was gonna sell American, 160 lbs is not gonna cut. it. What is the maximum ideal weight ? 200 lbs ? 225 lbs? 250 lbs ? This will determine for extra strength of the bike. Aluminum will be use for the frame of the bike.

Hey thien63, there is already a fold-up electric bike on youtube. It's small enough to fit in a bag but not in a backpack.

Hey Thien63, what if you built an electric bike that folds up to look like you are rolling around luggage. Have you seen those luggage cases that roll around on wheels. What if you did that, it would probably be a bigger success.

Yes, I got it already, that's the invention #7 . I called the motorized carry-on suitcase. You can look at the descriptions http://inventorspot.com/forum/viewtopic.php?t=2516. Other my inventions also posted there too.

$800 max, supports 250 pounds rider and 50 pounds backpack.
power to get uphill more important than speed.

$800 max, supports 250 pounds rider and 50 pounds backpack.
power to get uphill more important than speed.

+1 on the torque!
The only reason I am considering electric assist is for the very steep 2km climb up to my house, with an average slope of 25% and often closer to 30%!!!
I have not heard of any electrically assited bike capable of this climb. Torque is important, for sure, but maybe not for everyone. I say offer options, and thus increase your market!
for example, offer several different motor options, some may want a mini to disguise the fact their bike is electric. others may just ned to climb a mountain twice a day (like me)
Backpack not important, comfy bag that can go on trains is!
If you can produce this bike for 800 bucks, and it will get me up the hill, I will want one!!

Big wheels--not those 20 inchers that a lot of foldies have--would be a wish for me.

Reachable handlebars. The few foldies I've seen have handlbars that seem too far forward.

What I'd really love is a full size comfort/cruiser style electric foldie. Heavy, but doable if I could wheel it with a handle when folded, like rolling luggage.

A basket/ pannier set-up that is quick and easy to remove when folding the bike. Maybe a pannier system where the panniers would convert into some type of backpack, while the bike folds and rolls behind.

Hmmm, i disagree on the whole big wheels thing. i just happen to believe small wheels are better: better acceleration, more control of the bike, better poprtability, and just as fast as big wheels. this iw why Moulton chooses 20" wheels and are considered the best riding bikes ever!
an integrated rack system would be nice, or how about this?: a pannier-type bag that attaches to the bike for carrying stuff and then de-taches when folding the bike and turns into the carrying bag for the bike!

In Moulton bikes a lot of engeenering spent on Suspension. Otherwise small wheels kill your tuches

Hmmm, i disagree on the whole big wheels thing. i just happen to believe small wheels are better: better acceleration, more control of the bike, better poprtability, and just as fast as big wheels. this iw why Moulton chooses 20" wheels and are considered the best riding bikes ever!


Really? I always thought the little wheels would move the bike more slowly. I've only test ridden one, and I was only in a parking lot. It felt funny to me, and it didn't seem like I could get a whole lot of speed out of it.

small wheels accelerate faster than big wheels, this is just physics. so in an urban setting for example, with lots of stopping and starting, a small wheeled bike will be faster overall.
bigger wheels maintian higher average speeds over long distances, but this can be easily compensated by gear ratios, meaning you can get the same gear inches, same distance traveles per turn of the cranks, as on a big wheeled bike. It is true that over rough road, smaller wheels transmit more vibration to the rider, as pointed out by abu phinus, this can be eliminated with good suspension or simply running bigger tyres, like Big Apples.
small wheeled bikes have toured the world, and I regularly log 80 - 100kms in single day trips on 20 and 24 inch wheeled bikes. check out the folding bike forum for more discussion on the relative benefits of running small wheels

small wheels accelerate faster than big wheels, this is just physics. so in an urban setting for example, with lots of stopping and starting, a small wheeled bike will be faster overall.

Although 20" wheels have some compelling benefits, the difference in acceleration isn't enough to entice many people to switch

I estimated the energy required to get two wheels up to 25kph. A 20" BMX wheel tire weighing 1420g (with wheel) takes 33 joules of energy. A 1750g, 26" mountain bike wheel took 66 joules, a difference of 33J. These are moderately heavy wheels for road use and I assumed all the weight was at the circumference, thus favoring the smaller wheel in this comparison.

33J may appear significant - it is more than 1% of the bike's kinetic energy (2400J for a 100kg ebike with rider). However, most of the work in riding is battling wind resistance and other forms of drag. It takes about 160 joules per second (watts) to maintain a 25kph pace, so the 33J needed to accelerate the larger wheel amounts to only one fifth of a second lost in getting up to speed.


bigger wheels maintian higher average speeds over long distances, but this can be easily compensated by gear ratios, meaning you can get the same gear inches, same distance traveles per turn of the cranks, as on a big wheeled bike.

If it were truly possible to compensate by using different gear ratios, you would see small wheels in use on racing bikes.


I regularly log 80 - 100kms in single day trips on 20 and 24 inch wheeled bikes. check out the folding bike forum for more discussion on the relative benefits of running small wheels

I don't mean to knock small wheels. For ebikes with hub motors, they should offer some significant improvements in efficiency due to their higher RPMs.

I had a prototype of a full size electric bike that will sell less than $800. But for now, I like to built the first electric, backpack, foldable, adjustable bike in the world. I think that I will get lot of free publicity and then I can start to produce the full size electric bike

sign me up for the beta testing!

Many Americans are way over weight so force them to lose it if they want your bike. ;) However, Americans tend to be relatively tall due to all the hormones in their food supply, so you should probably compromise at a rider weight of 225 lbs.

Many Americans are way over weight so force them to lose it if they want your bike. ;) However, Americans tend to be relatively tall due to all the hormones in their food supply, so you should probably compromise at a rider weight of 225 lbs.

Force your customer and be eaten by competitors:bike2:
Electric bike will have more customers with overweight people .
I bet one would find more customer in range of 225 to 250lb, them in 200-225lb.
(I am personally 220, but i would also have backpack with 20-30 lb)