Did I ever show you all how clean my 212cc predator build came together?

panmines

Active Member
Joined
May 28, 2015
Messages
115
About a year ago I needed to build a tough off roader bike in order to support my true passion hobby of exploring abandoned mines, many of which have derelict roads/paths leading to them perfect for motorized biking. My goal was to create a simple and lightweight off-road bike with lots of power. I decided on using a 212cc predator because of how cheap the engines are and I wanted to challenge my newly found welding skills. In my research, there are only three bike frames than can comfortably fit one of these giant engines my favorite of which was the Electra Cruiser 7D. The bikes are pricy, but I was able to snag one on craigslist for only $100! I simply welded a 1/4" steel plate to the frame along with a chain tensioner. I was planning on keeping pedals, but I ran out of time and settled on braising a 1" steel tube to the frame for foot rests. Looking back, I think this was the better decision because keeping pedals, an extra chain, and a rear freewheel cog set would have added complexity and a few extra pounds. I also had to offset the torque converter and mounting holes on the engine. I bought a new back wheel with disc brake rotor mounts and mounted the biggest rear sprocket you can put on a bicycle frame (68 teeth). The last step was switching out the rigid front fork with a 1" threaded suspension fork with 180mm disc brakes.


The result is an extremely simple and light build with perfect chain alignment. It has extreme amounts of torque at the rear wheel, 148ft/lbs. to be exact.

Proof:
(8.1 ft/lbs. @ the shaft) X (torque converter gear ratio: 2.7) X (torque converter sprocket to rear sprocket ratio: 6.8) =148.716 ft/lbs.
8.1x2.7x6.8 =148.716

It weighs just over 100lbs. with a full tank of gas and fits nicely on my rear platform style bike rack. The gas tank is a Whizzer aftermarket part and holds over a gallon I believe.

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Tight Fit:
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BONUS PICTURE:
The first abandoned mine I rode the bike to: the Arlington Silver mine of Conconully, WA
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FNTPuck

Well-Known Member
Joined
Jul 2, 2018
Messages
883
212s look sooooo much better horizontal compared to vertical.

For longevity and strength, I'd brace the motor plate with a square tube connecting the seat post to the down tube, and run a seat post all the way bottomed out with rosette welds to reinforce the post.

Nice build! Acceleration must be nuts with a TQ converter and that huge sprocket.
 
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