I want to build a bike

[Mindfreak]

I really want to build an Electric(or gas) Bike. It has been my dream for a while to make one myself, to go through the long work and get the satisfaction of making something that works and is my own.
But, I have no idea where to start!:smallredface:
Does anyone have suggestions of where I might be able to find cheap parts, good books to read about it, things I should know and tools I should own before I try?
I want to try to be as cheap as possible, but I am willing to buy tools that I would need.

[Mando Knight]

Things you should know:
Mechanics of Materials
How to read off the material properties of various alloys
Basic electronics
Basic machine design (which also depends on material mechanics)

Tools you may need:
Arc welder (depends on your construction materials)
Pneumatic hammer and other such power tools
Tools for cutting and shaping steels

[thubby]

i would highly recommend fixing a junker before doing anything from scratch

[factotum]

Well, the primary things you're going to need are a motor and a battery pack, so I'd do some research into that area! A car starter motor would work, but the battery would be big and heavy and you wouldn't get much of a range...

[Generic Archer]

Well, if you're planning on using an existing frame it'll need a lot of modifications to support the motor/engine and to cope with the loading.
You can't realistically do this with aluminium so steel and a welder are a must. As well as the knowledge to use them to make reliable and strong joints.

Agree that some knowledge of mechanics will be required, though it'll still be a bit of trial and error. I'd suggest building the frame from scratch, but it's not a task I'd want to attempt.

Dane

[Serpentine]

You could try checking out an organisation like The Bike Shed (http://www.thebikeshed.org.au), see if there's one in your area of just contact that one for advice.

[Mando Knight]

Well, if you're planning on using an existing frame it'll need a lot of modifications to support the motor/engine and to cope with the loading.
You can't realistically do this with aluminium so steel and a welder are a must.

Well, you can't weld modifications on with aluminum, but if you use the right alloys and build with the right shapes you'll be fine. A decent steel would be much cheaper than getting the right aluminum, though.

[shawnhcorey]

Well, you can't weld modifications on with aluminum,...

Actually, you can but you must be a very, very good welder. :smallsmile:

[Mando Knight]

Actually, you can but you must be a very, very good welder. :smallsmile:

Alright, technically, you can weld aluminum alloys, however, since most structural aluminum alloys are heat-treated to increase their strength, the heat-affected area around the weld will have significant strength loss, as the application of enough heat to create a weld will cause the metal to anneal, effectively making it "forget" the prior strengthening treatments.

[inky13112]

I have a gas bike, cost ~300 to make, and is awesome to ride and was fun to make. They can be a bit of a pain to maintain at times though, so be forewarned.

To elaborate, there's alot of things that can go wrong and an HT motor like most gas bikes have isn't the most reliable, so you need to be ready to do regular maintenance, and take good care of the bike.

Any basic tool kit should serve you pretty well, I used a drill, wrenches and a screwdriver to build mine. You certainly don't need to do any welding. Wouldn't have even needed the drill if I had chosen a different chasis for it.

Speaking of which, I got a real cheap bike from wal-mart, you really want a steel frame because the stress you're putting on the bike is far more than they were designed for. A good aluminum frame will work too though.

The motor I got is a skyhawk gt5, which is a Chinese made two stroke engine with an alright reputation. Most gas bikes use a 2 stroke like that one, which requires you pedal start, (which is useful for the legality issues you can run into) use a gas/oil mix, (the ratio debate rages on) and can fit in the bike frame. The other option is a 4 stroke, which is pull start, separate gas and oil, usually larger and so back mounted, is arguably more reliable, and is more expensive. I've never used one of these so I can't say much. They are fairly cheap from any of a number of online stores, which unless you want to try converting a weedwacker or something, you'll probably have to get the parts from there.

For a new person I recommend you get one of the kits, they have everything you need to motorize a typical bike frame. A 2-stroke kit can cost from 150 to 300 or more. Look into the reputability of the vendor before buying though, as the kits frequently have broken or missing parts, bad motors, etc. This isn't a problem if your vendor is decent, as they'll replace anything that came bad in the kit. (look for a warranty, but some vendors don't honor theres so be careful)

There are a couple gas bike forums you should look at, they have a wealth of information, those reviews I talked about before, and plenty of people way more knowledgable than I to help you out.

If you're willing to put in the effort for it, a gas bike is definitely worth it. Since you said you're looking to build a bike, I assume that means you're looking for a bit of a project, so I'd definitely recommend you go for it.

Hope something in here helps :smallsmile:






Electric bikes are lame. (JMHO)

[Nopraptor]

I've built myself a motorized scooter from scratch, its not really that hard. although to be fair I had a professional workshop to work in (yay metalworking dad!) all I needed was:
An arc welder ( you can also use an electrode one)
shaping tools
saws for various materials
wheels
raw material
chainsaw gas motor ( I call it "Da Chopper!" cookie if you get the ref)

[Mindfreak]

I have a gas bike, cost ~300 to make, and is awesome to ride and was fun to make. They can be a bit of a pain to maintain at times though, so be forewarned.

To elaborate, there's alot of things that can go wrong and an HT motor like most gas bikes have isn't the most reliable, so you need to be ready to do regular maintenance, and take good care of the bike.

Any basic tool kit should serve you pretty well, I used a drill, wrenches and a screwdriver to build mine. You certainly don't need to do any welding. Wouldn't have even needed the drill if I had chosen a different chasis for it.

Speaking of which, I got a real cheap bike from wal-mart, you really want a steel frame because the stress you're putting on the bike is far more than they were designed for. A good aluminum frame will work too though.

The motor I got is a skyhawk gt5, which is a Chinese made two stroke engine with an alright reputation. Most gas bikes use a 2 stroke like that one, which requires you pedal start, (which is useful for the legality issues you can run into) use a gas/oil mix, (the ratio debate rages on) and can fit in the bike frame. The other option is a 4 stroke, which is pull start, separate gas and oil, usually larger and so back mounted, is arguably more reliable, and is more expensive. I've never used one of these so I can't say much. They are fairly cheap from any of a number of online stores, which unless you want to try converting a weedwacker or something, you'll probably have to get the parts from there.

For a new person I recommend you get one of the kits, they have everything you need to motorize a typical bike frame. A 2-stroke kit can cost from 150 to 300 or more. Look into the reputability of the vendor before buying though, as the kits frequently have broken or missing parts, bad motors, etc. This isn't a problem if your vendor is decent, as they'll replace anything that came bad in the kit. (look for a warranty, but some vendors don't honor theres so be careful)

There are a couple gas bike forums you should look at, they have a wealth of information, those reviews I talked about before, and plenty of people way more knowledgable than I to help you out.

If you're willing to put in the effort for it, a gas bike is definitely worth it. Since you said you're looking to build a bike, I assume that means you're looking for a bit of a project, so I'd definitely recommend you go for it.

Hope something in here helps :smallsmile:






Electric bikes are lame. (JMHO)

that was actually pretty helpful, thank you.
I guess I can shell out for a kit, though combining a weed whacker engine with a bike would be fantastic!
Thanks to everyone for the helpful info!

[factotum]

Actually, I've just thought--forget about electric and gas, why not put a home-made turbojet on the thing? :smallbiggrin:

[Generic Archer]

Welding aluminium without a good, inert argon chamber will cause the welds to fail easily and randomly... I'd consider that not being able to weld.

And taking a drill to a thin aluminium frame? that idea scares me a little. it would radically detract from the strength, and a 'good' frame usually means a light, well designed one, optimised for weight, a hole would compromise the structure and could invite failure

[Tyndmyr]

Actually, you can but you must be a very, very good welder. :smallsmile:

I was gonna call this out, since my little brother has a profession of doing exactly this, yes. However, as I understand it, it's not the place to start welding.

A junker is prolly the best place to start, though, yeah. All projects tend to have mishaps the first time around. Best to do those with cheap things.

[Mando Knight]

Actually, I've just thought--forget about electric and gas, why not put a home-made turbojet on the thing? :smallbiggrin:

...Because that is significantly more work than either one? You can purchase small-scale turbine engines (http://www.jetcatusa.com/) (turbojets, turbofans, or "turboshaft" engines, you probably don't want a turboprop), but to get the power you want, you'll need to spend more cash than on a simple IC or electric motor. (For a 35 lb thrust jet engine, you'll need to spend over $5000)

Also, I wouldn't recommend making your own turbine engine unless you're already familiar with everything involved: the mechanics behind the turbine and compressor, compressible fluid dynamics, metallurgy, fuel/air ratios... (the last two are extremely important... a stoichiometric fuel/air ratio will wreck the turbine blade. You can come close with special nickel-based alloys and a few other metallurgical tricks, but in the end it's still a high enough temp that you'll be risking damage due to thermal strain.)