building a motorized bicycle, need help deciding on which motor should I buy?

[Cylon]

Agreed but I couldn't imagine how slow a 49cc 4 stroke motor would be lol. It would work tho thats for sure.....Bummer you want to pedal so bad you could fetch a honda ruckas for 1300 or pay butterbean to build you a custom bike

 

[butterbean]

Any bike I would build would have pedals for one, and for two, how fast a 4 stroke can go depends on the gearing. A 49cc won't do 45, but 35 isn't out of the question and that's before redline. Show me a stock 2 stroke with stock gearing that can hit 35 before redline. Fastest I ever went was 33 on a long straight with a tail wind, pushing it hard at WOT.

 

[raindroptree]

I have looked at motoped before and I love the bike, but it is extremely expensive for a very low speed. That is definitely not my only other option. A motorized bicycle is a simple machine and because of this, there are always other options. I agree with Butterbean.

 

[Cylon]

Any bike I would build would have pedals for one, and for two, how fast a 4 stroke can go depends on the gearing. A 49cc won't do 45, but 35 isn't out of the question and that's before redline. Show me a stock 2 stroke with stock gearing that can hit 35 before redline. Fastest I ever went was 33 on a long straight with a tail wind, pushing it hard at WOT.

 

[butterbean]

Raindrop, let me give you a basic rundown of my current build. It's not what you are looking for, but it will give you an idea of the level I try to build at. As stated before, I built my own wheels but for what you are looking for, pre-built wheels are probably fine and maybe even cheaper or the same cost as any I would build because I charge more for wheel building than anything else. Anyway. The front is a motorcycle drum and the rear is a moped drum, both laced to 24" steel bicycle rims with 11g spokes. I built my wheels very heavy duty because I am a heavy person and I need strong wheels. I am using hydraulic motorcycle forks. Again, probably too heavy for your needs but I want your to get an idea of the quality of parts I use. I'm using a moped headlight bucket (bucket is just another word for housing) and motorcycle handlebars. The frame is a 1956 Roadmaster boys frame, American made, brazed, double top bars, very strong. The seat is a cafe style moped seat from a moped website called treatland. The rear hub is also from treatland. I have a double legged kickstand. I built my own lighting system, which uses front and rear LEDs with circuits I wired myself that allow them to be dual intensity. This means I have high and low for my headlight and the rear is a tail and brake light in one. I am using a 12v sealed battery to power the lights, which is charged by a tire driven 12v generator wired to a scooter rectifier. The tank is of unknown origin, but its big and plastic which is lighter than metal and won't rust. I recommend a plastic tank if you can find one. I will ask my buddy who I got this tank from if he can find any more if you like. Not much else to say about my build I don't think, that gives you an idea of how I build, so if you want me to build you a bike I won't charge you hourly I will charge you one flat rate but wheel building is extra, but also a flat rate. Again, send me a private message if you want to discuss it. Should you choose to buy pre-built wheels, I will inspect them for no extra charge. The only other requirement is that I test drive the bike before you pick it up, to make sure its all put together properly, safely and reliably.

 

[raindroptree]

https://m.youtube.com/watch?v=ZxdBklphn1Y

https://m.youtube.com/watch?v=G2VGjvF0z_A

I keep going back to these guys... they built some really good motorized bicycles. I have no idea what parts they have though. They have top speeds over 60mph. .. though I have a feeling that they are going to cause new laws to come out... lol.

 

[butterbean]

Cylon, that video doesn't prove anything. No proof that your engine is stock or that it has stock gearing, and the camera is shaking so bad I can barely read the speedo. Aside from that, it doesn't prove that two strokes are faster than 4 strokes. A four stroke or a two stroke, properly geared, can CRUISE at 35 without even going WOT. It's the gearing for either engine that makes a difference. I recommend a 4 stroke because they last longer.

 

[raindroptree]

the thing is, you can build pretty much whatever you want.... here is a video to prove this ... https://m.youtube.com/watch?v=J3766FEkaqQ

 

[Cylon]

Cylon, that video doesn't prove anything. No proof that your engine is stock or that it has stock gearing, and the camera is shaking so bad I can barely read the speedo. Aside from that, it doesn't prove that two strokes are faster than 4 strokes. A four stroke or a two stroke, properly geared, can CRUISE at 35 without even going WOT. It's the gearing for either engine that makes a difference. I recommend a 4 stroke because they last longer.

Read the comments on the video the maker put on there

https://m.youtube.com/watch?v=ZxdBklphn1Y

https://m.youtube.com/watch?v=G2VGjvF0z_A

I keep going back to these guys... they built some really good motorized bicycles. I have no idea what parts they have though. They have top speeds over 60mph. .. though I have a feeling that they are going to cause new laws to come out... lol.

There using the standard china girl http://www.ebay.com/sch/i.html?_fro...C0.A0.H0.TRS5&_nkw=motorized+bicycle&_sacat=0

Some are using expansion chambers from what I saw and I saw some gt2 frames, I bet some of them are just using cranbrooks

 

[butterbean]

https://m.youtube.com/watch?v=ZxdBklphn1Y

https://m.youtube.com/watch?v=G2VGjvF0z_A

I keep going back to these guys... they built some really good motorized bicycles. I have no idea what parts they have though. They have top speeds over 60mph. .. though I have a feeling that they are going to cause new laws to come out... lol.

I belong to that guys Facebook group. I don't think they are going 60 though, not on kit two strokes. Even the lightest riders haven't gone over 55 yet with some very serious mods, those guys are hefty like myself and their motors sound pretty stock to me. But they do build some quality bikes.