Where to start project

aqua zombie

New Member
Sep 11, 2012
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1
Athens Ohio
I have built one of these china doll bikes in the past. Life caught up and it hangs in my garage with pride. A friend of mine was kind enough to give me a china doll bottom end because he had bought it and had plans that he never got round to. Long story short... I don't know what I have, other than a china doll bottom end. He told me it was a "balanced dax bottom end". Soooo... wtf is a balanced dax bottom end? I was going to get a top end for it and could not figure out what i need. Looks like there are a few flavors out there when going about this. Ultimatly I do not want to not pedal, at all. So I was looking for hotter cylinder, and head options. Possibly a jackshaft and some gearing. (That is baisicly the rout I took with the motorbicycle that I built.) You all seem to have come a long way since I have put one of these together. I decided to try and research the ole dax balanced bottom end, and I'm here for the shortcuts obviously. To sum this up, do I need more info to identify, and after that what top end combos will work with this thing?
Also In advance, thank you to anyone who reads this and posts their 2 cents. I feel like I'm asking a lot, especially about not having to pedal, but please keep those 212 predator comments at bay to start. I'm considering that as well. lol.
 

Tyler6357

Well-Known Member
Mar 15, 2012
1,293
292
83
Santa Barbara, CA
Duane from Thatsdax got out of the business. However, most of his china girl engines were PK80's with the short connecting rods, they require the 47mm piston with the low wrist pin. The rest of the top end is stock using 8mm head studs. This one
 
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aqua zombie

New Member
Sep 11, 2012
24
0
1
Athens Ohio
DAX is a older vendor... I'm not sure if he's still around anymore.
I advise you to just put that engine on the shelf & go with a 212 if you don't want to pedal at all. ;)
Yea I knew that was coming. I had such good success with the last one though. The jack shaft drove a strumy 5 speed with the drum brake. I got it on the cheap and it’s gearing would pull me up hills. My kid has one of those Coleman mini bikes with the 212 predator and I can race up hills on it. I love the idea of the lighter weight China doll though.