I'm currently starting to build a new chopper/freak bike, and thought I would do a build log.
The idea for this bike is pretty simple. I want a bicycle that looks like a hillclimb motocross bike (ie long swingarm). To do this, I'm simply adding a box section rear end to a BMX frame, and mixing in some MTB components.
This was my MSPaint concept sketch:
Parts I'm starting with:
-K2 Rake chromoly BMX frame 21"
-bmx bars (above pic)
-3 piece Diamondback unsealed cranks (Powdercoated gunmetal, also in above pic)
-.243 Racing Freeride dropouts w/ disk mounts, derailleur hanger and chain tensioners
-Rock Shox Jett fork (60mm? Elastomer?)
-Haro polished Frontload BMX stem
-Kink 44T sprocket
-26" MTB front wheel
-20" 14mm axle BMX rear wheel
-mismatched V brakes with Gorilla brake booster
-10' of box section steel tubing
Where I'm at:
I've purchased the Box section (1.5" x 0.75") tubing from our local metal supply, and cut it into 2.5' sections. Yes, the rear stays will be that long.
I've cleaned up the 243 dropouts to remove all welding from the previous stays and make them a uniform thickness.
The rear end is chopped off the K2 frame, and I'm still cleaning up what is left of the stay welds.
I'm trying to figure out the geometry of the rear end at the moment too.
I want it to be spaced 120mm. I think this will give me the greatest range of adjustability, in terms of rear axles. I may have to squash it down to fit a 110 BMX hub in there, or spread it out to fit a 135mm MTB rear axle.
At present, I've got an old BMX rear wheel, with a 14mm axle. The picture of the dropouts shows them being held up by a 14->10mm flatted axle, but I won't be able to use the 243 chain tugs with it. Plus, the flat spots are spaced at 110mm.
I'm going to keep the stay bridges far enough away from the dropouts that I can fit a 26" wheel in the back as well.
I am also trying to work out the bottom bracket height.
As this bike will mostly be for cruising/goofing around, I think I'll keep things slack.
I'm going to try to have the seat stays along the same plane as the top tube.
Oh, and as far as colours go, I think I want this thing to be bright.
I was originally thinking something like safety orange, or flourescent orange, but I've got a friend who is trying to convince me to go with Kawasaki green (as he's got a Kx-80 number plate).
I'll update this thread when I make some more progress =]