I want to build an Electric Bike

K

Khoazy

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Im 15 years old, and I want a project to do over the summer. I am thinking about building an electric assisted bike, but i have no clue how to build one. I wanna learn how though. Hopefully you could list the parts that i need. I own a Trek 7.2 FX and i am hoping to convert it into an electric bike that:
- Goes between 30mph and 40mph
- can last for about 20 miles
- costs under 150 dollars
- capable of going over small hills (foot assisted of course)

Any help would be appreciated. also, what are the negatives of owning an electric bike, and how hard is it to maintain? Thank You!

(moderator edit: merged your duplicate threads in different forums into the one that already had replies. Please only create one thread per subject; it might take time to get replies, so have patience. If necessary after a long enough time (a few days) you can reply to your own thread to "bump" it back to the top if no one replies to you, in case it just got missed.)
 
Im 15 years old, and I want a project to do over the summer. I am thinking about building an electric assisted bike, but i have no clue how to build one. I wanna learn how though. Hopefully you could list the parts that i need. I own a Trek 7.2 FX and i am hoping to convert it into an electric bike that:
- Goes between 30mph and 40mph
- can last for about 20 miles
- costs under 150 dollars
- capable of going over small hills (foot assisted of course)

Any help would be appreciated. also, what are the negatives of owning an electric bike, and how hard is it to maintain? Thank You!


(moderator edit: merged your duplicate threads in different forums into the one that already had replies. Please only create one thread per subject; it might take time to get replies, so have patience. If necessary after a long enough time (a few days) you can reply to your own thread to "bump" it back to the top if no one replies to you, in case it just got missed.)
 
Best thing to do would be to lurk around the forums for a while to see what others have done. Check out the ebikes photos and video section and http://evalbum.com/ to see other peoples creations. I can tell you right now that building a bike that's capable of what you want for $150 is impossible, but don't get discouraged. Start off small and upgrade, thats what I'm doing.
 
"You'll shoot your eye out kid"... :lol: Seriously though, this forum can be highly technical and end up confusing (and frustrating) at first glance. Maybe check the .PDF I attached which was written by ebikes.ca (one of the most respected vendors of ebike components in the world). It is a very nice primer for people new to building ebikes, it will give you the big picture. Also the ES Wiki has a lot of info in dictionary style format.

Good luck and make sure you wear a damn helmet at those speeds you want! :DView attachment Ebikes_Basics_Guide_Web.pdf

I should add that you would probably have a a hard time finding any bicycle that can hold-up to 30-40 mph (ebike or pedal only) for $150.00
Closest thing you can get to any kind of ebike for $150 might be a Walmarter for like $400. If you want to build it hit up a fellow ES'ers called "Wesnewel" (I think his nick is). He is an expert at dirt cheap (ahumm...cost effective) builds.
 
For $150 it simply isn't possible to get the components you need to get those speeds and the range your looking for...sorry..welcome anyways


KiM
 
First, I recommend reading up on batteries, motors, controllers, chargers here:
http://www.endless-sphere.com/w/index.php?title=Main_Page
and though you don't want to go as fast, I sitll recommend reading all the linked threads here
http://www.endless-sphere.com/w/index.php/I%27m_a_Noob_and_I_Wanna_Go_50MPH
because there is a lot of important info and discussion for you in those threads.



As for the build itself: you *could* do part of it for that budget, possibly even for nothing, but you'll need a lot of DIY skills and a number of tools to do so. But because it would be very DIY, there is no parts list. You'd first need to learn a fair amount about electric bikes (motors, batteries, controllers, mounting hardware, etc.), then see what you can find locally at thrift stores, yardsales, or on Freecycle.org or Craigslist.org for free or really cheap.


But: It's highly unlikely you're going to get the speed you want (nor would I recommend it, as it is most likely not legal in your area, and it is probably not safe with what you might be able to build with that sort of budget). You could possibly get the *range*, but unless you can find batteries for essentially free that are not SLA (lead-acid) then it's going to be very heavy (i.e., it might end up weighing more than you do), and you wouldn't get that range at anything like the speeds you're after.


See my old blog at http://electricle.blogspot.com for my own learning experiences in a similar project (with different goals).

See my CrazyBike2 and DayGlo Avenger threads here on ES for info on how those have turned out since I stopped updating the blog much a while back.


Now, if you find all the right bargains, or parted out old ebikes, you might be able to build a more modern and simpler type of ebike that could do the range you're after for something resembling your budget, without as much DIY, but again it probably will not be capable of the speeds you want.
 
Khoazy said:
Im 15 years old, and I want a project to do over the summer. I am thinking about building an electric assisted bike, but i have no clue how to build one. I wanna learn how though.
Click to expand...
At the top of the page is a search box. Underneath it is a question: Using Google Search? click 'yes'
Type 'Trek 7.2 FX' in the search box. Press enter. There will be everything about Trek 7.2 FX listed, in history.
Pretty cool, huh? You'll have to excuse me for saying cool. I'm like a million years old.
 
^^rough estimate...for what you describe, you'll need:
to use a different bicycle or small motorcycle.
to 'invest' $2000-3000. Pretty discouraging but money is money.
Some guys really figure out how to do it cheaper, but they are usually geniuses.
 
A motor kit alone will cost you close to $300. A battery that will go 20 miles at 20mph will cost $200-$400 new. Expect to spend at least $500. There's are ways to do it a little cheaper, but requires some battery skills/knowledge.
 
Hi Kid

Register your general location so you can better tap into the locals with tons of left over parts. You could use the LBS, local paper or something like craigslist or ebay to find local junkers /parts bikes also. Some worth it and some not so much. Check out the RC folks also for stuff to use if your handy and can build adapters / brackets. Be patient and stuff will drop into your hands very reasonably. You will learn a bunch more this way also and possibly turn it into a side line that can help pay for college.

cheers
 
Wait 1 more year then go where ever your heart desires. 8) That's because your now able to get a job!

That's assuming the minimum legal age to work is 16 in your area. Some places let you start working sooner.
 
I know this is an electric forum, but if you are looking for a 30+ MPH bicycle with good range for cheap it is hard to beat a gas motor. Get an older 90's steel hardtail mountain bike from Craiglist, get a decent quality (non-eBay) 2 stroke 50cc or 66cc bicycle motor ($200 - $250), if you have some money left over pick up a good used suspension front fork, and there ya go. They are cheap and fast, but usually require a good deal of mechanical know-how and constant maintenance (which is why I switched to electric).

But you will definitely attract a lot more attention on a gas bike, and depending on the laws in your area, it is probably illegal for a 15 year old to ride one.

If you want to go with a DIY electric build, as Wes said, $500 is about the minimum you will spend and even that will be hard to reach 20 miles at 30+ MPH. You would probably be using a lot of lead SLA batteries that will be very heavy and wreck the handling of the bike, and overall might not end up being the best experience. If you go with 48V and 15 - 20AH of LiFePO4, you are looking at $400 - $600 for the battery alone.

One thing you might want to consider is a used, lower powered prebuilt bikes, like the eZip Trailz: http://www.walmart.com/ip/Ezip-Trailz-Men-s-Electric-Bike/15773448

You can find them used on Craigslist for around $200 and the SLA batteries for them are cheap. You may need to add a second SLA battery pack to get the 20 miles out of it, depending on how much you want to pedal. Changing out one of the sprockets on the motor side (very easy to do) will get you about 23 MPH. So not the speed you were originally asking for, but budget friendly and less likely to get you problems with law enforcement.
 
$1000 is a reasonable estimate for getting to 40 mph. But for only 10 miles at that speed. Slow to 20 mph, and the same battery would go 30 miles.

Why wait to go to work, you got all winter. Till legal, you have to create your own job rather than go get hired at the restaurant, but that's a valuable life skill you'll use over and over once you learn it.


Start by building a 30 mph bike, using Wesenwells formula. Buy your batteries after you scrape up the cash for the motor kit. Batteries don't keep on the shelf all that long. It can be done with a pretty cheap used bike, but look for a strong steel one. 30 mph is plenty really. 40 mph will just get the cops on your ass, and oh joy, the cops will know and hate you when you get to driving. Perfect. I did that, and it was no fun for about 5 years.

I see no reason why you can't be rolling by spring. Just go get money.
 
You might also consider some real home building, but aim for about 15 mph. That's just about doable for $200 if you have the bike. $100 is for cheap batteries, scrounged stuff. The rest goes into some kind of junkyard motor.
 
You might also consider some real home building, but aim for about 15 mph. That's just about doable for $200 if you have the bike. $100 is for cheap batteries, scrounged stuff. The rest goes into some kind of junkyard motor.
 
Nothing but encouragement for your ebike build. I'd recommend sticking with your specs, but upping your budget. Do odd-jobs, ask mom & dad & family for help, begging if you need to, and save, save, save. Get your budget up to what it'll take to build what you really want. In the meantime, do the research as suggested. Learn all about the various options for motor, battery, etc. Best!
 
Hi, welcome to the sphere.

I started off doing this on the cheap and was able to put something together which I thought was quite satisfactory for the money. A thread on my build can be found here: http://www.pedelecs.co.uk/forum/electric-bicycles/11818-project-ghettobike.html Hopefully it will provide some encouragement.

My build has long moved on from the last post in the thread however. A word of warning - E bikes are very addictive and you will find yourself in an endless circle of improving and refining your ride.

I do think that considering your budget, your goals are far too ambitious. For your money, you are only going to achieve 15mph. If you are to aim a bit higher, 30mph really does feel like plenty once you're bombing along. In my hands, 40mph would be plain dangerous :)

The one thing I have learnt in the last year I have been working on my build is that everything is about compromises. If you can budge on any of your first 3 goals, then you will stand a better chance at reaching target.

So, which of your first 3 goals are least important to you?
 
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