Need Recommendations and Help

Senjikua13 · Jan 8, 2017

Sorry if this was posted in the wrong area.

I'm currently working on building a motorized bicycle. I built one before with one of the chinese 4 stroke kits but this one is just much bigger that what i had originally imagined. I currently have a 212cc Predator Engine, I've heard they mess up spoke and didn't bother worrying about it because i have a sprocket mounted to my rear wheel. I'm attempting to jackshaft it, the problem is: I don't know gearing and so im hoping someone can help me out. the way I am attempting to jackshaft it is to have the drive sprocket on the left while the wheels sprocket is on the right. I really could use the help and wisdom of people who have been at this awhile. thank you for taking the time to read this

- Beach cruiser ~shcwinn
- 212cc Predator engine
- not much else is gathered except the kill switch and minor stuff.

TheNecromancer13 · Jan 8, 2017

How fast are you wanting to go?

Agreen · Jan 8, 2017

Mine is geared through a belt drive cvt to a 50t sprocket. Plenty of speed, remarkable torque, and seamless shifting is really nice. Look up the TAV2 or go kart torque converter.

TheNecromancer13 · Jan 8, 2017

If you're looking for how to set up the jackshaft, here are some pics of the jackshaft on my 125cc lifan bike, it might give you some ideas:

Left side view:

Right side view:

Including rear wheel sprocket (note that your rear sprocket would be bigger as the lifan has internal gear reduction while the predator does not):

If you're interested, here's the whole bike:

Senjikua13 · Jan 8, 2017

You've got a really nice looking bike. Is there a kit that you'd recommend or a site where I can order specific parts. If you could explain the gear reduction that'd be great.

TheNecromancer13 · Jan 8, 2017

Senjikua13 said:
You've got a really nice looking bike. Is there a kit that you'd recommend or a site where I can order specific parts. If you could explain the gear reduction that'd be great.

Actually, I've got 2 really nice looking bikes lol. The black one is nicer than the red one, although the black one is still unfinished (it's to the point where I can ride it though, and it can hit 65 mph!). If you're using a predator engine, the last thing you want to do is buy a kit. Predator kits are even more garbage than the 2 stroke kits. For information on gear ratios, read step 55 of my instructable: http://www.instructables.com/id/79cc-Motorized-Bicycle-From-Scratch/?ALLSTEPS#step55

For that matter, you might want to read the entire instructable, the only difference is that you are using the 212cc instead of the 79cc, pretty much everything else will be the same. Are you planning to remove the governor system btw? If you are (and I'd highly recommend it) that might be a bit different, but should be similar. And I'd also recommend using sturdier wheels than the ones shown in the instructable, personally I'm a big fan of mag wheels. My red bike currently looks like this:

The red one has teny rims, the black one has I don't know what, but they were from mbrebel.com.

Senjikua13 · Jan 9, 2017

I will take a look at the instruct able. Why do you recommend removing the governor? I bought a set of Max's but mine are a bit different than yours. I'll post a pic of then after I'm I get back over to my buddies.

TheNecromancer13 · Jan 9, 2017

The governor system's purpose is to prevent you from blowing up your rototiller or what have you by limiting the rpm of the engine to about 3600. Remove the governor, and you can turn at least 6000 rpm, and you'll go almost twice as fast. Also due to the clutch engaging around the 2800 rpm range, if you don't remove the governor you'll have a very narrow speed range.

Senjikua13 · Jan 9, 2017

I'm not truly seeking to speed it up but being able to seat around 30mph would be nice anything extra would be nice but not truly needed

TheNecromancer13 · Jan 9, 2017

If you remove the governor, then you can have it turn like 4400 rpm at 30 mph, and gear it lower so you have lots of power. Try a 13:1 ratio, that should give you plenty of power and a top speed of about 35. BTW why did you decide to use the 212 instead of the 79 if you only want to go 30 mph?

Senjikua13 · Jan 9, 2017

You said kits are bad and in your instructable you recommend GTC Jackshaft, it doesnt appear to sell just the jackshaft rod but a kit itself. Will it fit at 212cc compared to a 79cc?

What do you rate these brakes at? -> https://www.amazon.com/Shimano-BL-M...83985264&sr=8-11&keywords=disc+breaks+bicycle

TheNecromancer13 · Jan 9, 2017

When I said kits are bad, I was referring to the ones that claim to have "Everything you need to get your bike up and running" or some crap like that. The ones that have the stock rag joint sprocket and then tell you it will hold up fine to any engine, let alone a 212.

Come to think of it, I'm not sure if the GTC jackshaft will fit the 212 predator, I've only ever used it with the 79cc. I just sent them an email inquiry, I'll post when I hear back.

If it turns out that the GTC jackshaft does fit, the parts you will want to use are the jackshaft plate, the keyed shaft, and the 10t sprocket. You'll probably need larger than a 17t sprocket for the first stage gear reduction.

Senjikua13 · Jan 9, 2017

Thanks for your help on this. Reading over the instructable has made things a lot simpler. Ill have to show you my mounting plate when I get a chance. I am figuring out the amount im going to spend building this and boy its going to be fun avoiding cops haha jk. im going to try and get it registered.

TheNecromancer13 · Jan 9, 2017

I'm pretty sure that any gas powered bicycle is illegal in Florida, regardless of engine size. You definitely won't be legal on a 212cc. However, not being legal doesn't stop me from riding either of my bikes, and where I live, it seems that as long as you don't act like an idiot, the cops could care less about the size of your engine.

How much were you intending to spend on your build?

Senjikua13 · Jan 9, 2017

Well I'm just seeing how many pay checks I'd have to spend to get the dream setup and it's a Macargi stretched beach cruiser that I want for a base which is about 320 plus shipping or around 450 total. I've had one in j-Ville and i have gotten stopped a couple times once for being in a neighborhood after a person broke into several cars the night before and they said as long as it stays under 50cc it's legal

TheNecromancer13 · Jan 9, 2017

Just heard back from AGK, the GTC jackshaft does fit the 212 as well as the 79. Although if you're using a micargi stretch cruiser, why not just make your own jackshaft and save some money? The bike in the pictures of my homemade jackshaft is a micargi puma stretch. BTW, while the micargi frame is great for motorizing, the rest of the bike is extremely low quality, expect to replace wheels, fork, and bearings at the very least, and fabricate your own brake mounts.

ragdolldude · Jan 9, 2017

You may not hit your target MPH with the governor hooked up. Between a speedometer and a tach, you should be able to do your 30 mph without hitting your "red line" rpm. I'm going to pick up a build from KC in a couple of weeks. Nuvincii rear end which has a lower than normal gearing than a multispeed rear hub, with variable ratios that include an overdrive higher than normal. Even with this equipment, I can control speed between adjusting rear gearing and adjusting the throttle. 53cc HS motor, and this engine has produced about 43 mph without the engine fully broken in.

Senjikua13 · Mar 10, 2017

Okay long break between now and my last post. I'm trying to set up a jackshaft completely made from parts I need to buy. Problem is, I don't know what I'm doing. Nor do I know what to buy. I have a 10 tooth clutch and a 44 tooth on the bike as of now. What do you all recommend I should get and where should I get them
I proceeded to remove the governor from my 212cc predator engine. Just need lots of help now.

TheNecromancer13 · Mar 10, 2017

I'd still recommend a GTC jackshaft. Is your clutch for #35 or #41 chain?

Senjikua13 · Mar 11, 2017

It's a #41 chain

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