Frame building advice

Be sure your welding is sound and has good penetration. Be sure to measure everything five times before cutting. Be sure everything is straight and true and always take welding distortion into account as you go.
A jig is always a good idea if you plan on doing more than one. There are several plans available to build your own. Google ''adjustable frame jigs''
Use good material strong enough for it's intended job. No conduit or water pipe.
 
Here's what I did for a one off frame without a jig. Make a full scale drawing on piece of plywood or masonite. Cut spacer blocks of different thickness to support each piece.

Check your geometry. http://calfeedesign.com/tech-papers/geometry-of-bike-handling/

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2.5" conduit coupler (actually closer to 3") from home depot. I needed something big enough to accommodate a coaxial shaft arrangement.
 
Any suggestions for cutting the a arm off a hardtail and incorporating a shock behind the seat post so as to leave room for motor but creat a soft tail for trail riding?
 
Soft tail needs to have a jack shaft were the pedal sprocket is to work right so the chain stays from a floppen. May still need a spring tensioner besides..........Curt
 
Soft tail needs to have a jack shaft were the pedal sprocket is to work right so the chain stays from a floppen. May still need a spring tensioner besides..........Curt

Im in the works of putting together a beast... its gonna be kind of a cross between a down hill mtb and a hill climb dirt bike... probly going to use a 60 tooth rear sprocket in attempt to maximize torque... just going to suck to have to sacrifice the speed...
 
60t sounds excessive, my bike with a reed valve pulls good wheellie's with a 44t on a 26" wheel.
I'm working on a full suspension bike without jack shaft by lifting the swing arm pivot to be inline of the sprockets.
 
Nowsee thats exactly what i had in mind! But with the 44 on the bike ive got now (26") has no balls for climbing hills on the trail... i figured i would sacrifice a little bit of speed in exchange for the steep hillclimb capabilities... on a side note... a buddy just turned me on to a 125 honda 4stroke kit with full shift trany and kick start for like $200-$250... ought to get 85mph+ from that bastard :-D have any of you guys thought about throwin kits together and seeing how they go on craigslist? Im thinkin of ways to fund my newfound hobby :-D and i figure the practice in putting these together cant hurt lol
 
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