212 build

old motorbike · Mar 22, 2012

Hi, I just bought a 212 predator while it was on sale for $99 at HF.
I know it's big sized and heavy, and probably should have spent the extra $40 for the 99cc, but here it is. I like challenges anyway. Bought a torque converter from e bay for 129. (I'm dumb that way) It's also on the heavy side.
A friend, who owns a bike shop is finding an old steel bike to use as I'm sure the frame will need much modification to work. My old aluminum bike wouldn't hold the engine.

silverbear · Mar 22, 2012

Yes, that's a lot of motor for a bike, but others have done it. Pretty amazing you got that for a hundred bucks. Take lots of photos. Good luck with your build/
SB

calvynandhobbs · Mar 22, 2012

I did the exact same thing. Walked into Harbor Freight on the way back from a ski trip to New Hampshire since there are none near me with the intention of buying the 99cc Predator and saw the 212cc for $99 so that's what I walked out with. I bought the same Torque converter for $129 too. It just arrived yesterday. I'm hoping to start my build at the end of April. I look forward to see how yours comes together. I've been jotting information down from all of the 212 builds I've seen and taking away lots of info.

5-7HEAVEN · Mar 22, 2012

Follow this 212cc build. Glenn seems to have it in there nicely:

http://motorbicycling.com/showthread.php?t=34506&highlight=212cc

Check out this bike. HUGE in-frame space!

http://www.americasbikecompany.com/Firmstrong_The_Chief_Cruiser_p/firm-chief.htm

I bought the same frame glennbo used, for my 6hp Robin build. Torque converter too, like you.

calvynandhobbs · Mar 22, 2012

5-7HEAVEN said:
Follow this 212cc build. Glenn seems to have it in there nicely:

http://motorbicycling.com/showthread.php?t=34506&highlight=212cc

I've read that entire thread and have it added to my favorites. It's a good one and I'll probably be stealing several ideas. I also have some information out of Scotto's build pulled out and a couple others. I just need time to start working on it.

old motorbike · Mar 25, 2012

Those are some great looking builds. Still waiting on the bike shop to find an old steel bike to use. This build will need to be beefy as the engine is heavy, also the torque converter.
Other than a spacer, (press fit), that first goes on the crank, (which I made a slip fit)
The drive bolted to the engine perfectly.

andrewflores17 · Mar 25, 2012

just knock out all the small things like throttle linkage what kinda tank you are going to use and anything else you can do until the moment comes with the bike best of luck .

mrleo · Mar 25, 2012

Nice buld. My honda gx120 turned out to be 13-1/2 wide what is yours? I put the gear on the cvt on the outside of the cvt in middle of engine so chain would line up. Is yours going to be way off center?Good luck.
Leo

old motorbike · Mar 31, 2012

Been doing some measurements. Engine and torque converter is 12" wide. will need to widen cranks.
14" long. Going to cut frame and weld in plates.
10" high. The sprocket is 3" to the left, so I'm running it to the back wheel on left side.
With the torque converter, I'm not sure what the starting ratio will be. It has a 10 tooth #41 sprocket. I'll probably start with a 40t rear sprocket and see what will happen.
Decided to just go with my aluminum bike and will start to cut and fit frame and plates today.
Using the standard frame mounted tank for now. Maybe use the stock exhaust if it will fit.

5-7HEAVEN · Mar 31, 2012

Thanks for the dimensions. This is with fuel tank, muffler and air cleaner removed, yes?

Are you running with or without governor? That will determine what your gear ratio should be.

mrleo · Apr 1, 2012

Iam going to not use the governor and i have a 44 rear sproket. I hope to drive it next week I will Let you know how it runs.
Leo

5-7HEAVEN · Apr 1, 2012

That's a start.

Another member is using 45t/10t gearing w/TQ-Verter and your engine. No complaints from him yet. Your gear ratio is 4:1, with effective ratios between 10.8:1 to 3.6:1.

FWIW, I'm building a 6hp 170cc Robin engine w/TQ-V. Rear sprocket will be 54-tooth/8-tooth. Gear ratio is 6.75:1; effective ratios range from 18.225:1 to 6.075:1.

Governor removed. xct2

old motorbike · Apr 2, 2012

Been doing some cutting and drilling !/4" plate aluminum for engine mounts. Cut lower frame for mount plates. Bottom will mount engine and welded to both down tubes. Front plate welded to bottom plate and top of down tube then to upper plate. Upper plate welded to top of frame down tube and front plate and bolted to upper engine. Output sprocket will be 1-1/2" too far off center so I'll make a jack shaft at the rear wheel frame.

culvercityclassic · Apr 2, 2012

Wow...are you going to weld that yourself? What's the thick-ness of that frame tubing? That motor is no joke and you need to really think if you trust this frame...If it was me it would have to be steel...

old motorbike · Apr 2, 2012

culvercityclassic said:
Wow...are you going to weld that yourself? What's the thick-ness of that frame tubing? That motor is no joke and you need to really think if you trust this frame...If it was me it would have to be steel...

You're right, I was going to do a steel bike and didn't find one I liked yet. I decided to cut the frame open to see the thickness and it's .060" and elliptical, not round 1-3/4" x 2-3/4" . I believe if gusseted and braced right it should hold.
My business partner is a pro welder and with the right prep. should hold.
Of course fabbing an engine that big on a bicycle is crazy anyhow. I'll need to ride it like grandma to keep from breaking the back wheel or anything in between. With the little cag engine I had on it, the handling was dodgy at best @ 35mph.
I build crazy things like this. My last race car was 110" wheelbase and went 9.0s @ 145mph. I built the whole frame-cage by hand with a glass coupe body. Or my 190 hp custom Busa.
I know that means little here. At 66 yo this could hurt or kill me. There's a lot of prep to do.

DFlanagan · Apr 2, 2012

culvercityclassic said:
Wow...are you going to weld that yourself? What's the thick-ness of that frame tubing? That motor is no joke and you need to really think if you trust this frame...If it was me it would have to be steel...

Wow that's scary..... May the force be with you!

5-7HEAVEN · Apr 3, 2012

old motorbike said:
You're right, I was going to do a steel bike and didn't find one I liked yet. I decided to cut the frame open to see the thickness and it's .060" and elliptical, not round 1-3/4" x 2-3/4" . I believe if gusseted and braced right it should hold.
My business partner is a pro welder and with the right prep. should hold.
Of course fabbing an engine that big on a bicycle is crazy anyhow. I'll need to ride it like grandma to keep from breaking the back wheel or anything in between. With the little cag engine I had on it, the handling was dodgy at best @ 35mph.
I build crazy things like this. My last race car was 110" wheelbase and went 9.0s @ 145mph. I built the whole frame-cage by hand with a glass coupe body. Or my 190 hp custom Busa.

I know that means little here. At 66 yo this could hurt or kill me. There's a lot of prep to do.

Actually, it means a lot. dance1

You've got skills.

old motorbike · Apr 6, 2012

Have been getting ready to weld in plates, cleaning and prepping frame. Ordered parts for jackshaft.
Here's the section of tube cut out, .070" thick.

mrleo · Apr 6, 2012

I like it a lot good job.
Leo

old motorbike · Apr 6, 2012

mrleo said:
I like it a lot good job.
Leo

Thanks a lot mrleo.

While fitting engine prepping to tack plates, I found the top plate moved the engine over 1/2" too far. Need to make another plate. Hope my welder can work on it some this weekend.
Anyone know how this engine vibrates? It may shake the bike apart. Wanted to mount on rubber mounts. Thought it may cause chain problems.

212 build

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