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new to fourm, thanks for all the help so far

Posted: Fri Jan 29, 2010 11:04 am
by house
Hey all, I just wanted to post appreciation for all the help so far even if I just joined. I have been doing extensive research from your discussions.

Im rebuilding a spree for a family members B day "suprise present" It was wore slap out. Went with the 44mm BBK from Taz, (thanks man) and ended up milling the head last night with a steady hand and a dremel.

Everything was great untill I started to put the drive belt back on and noticed crank wobble, duha that was why the case was filed with grime.

Tonight I will fab up a crant stand, get a dial indicator fron Harbor Supply and try to tune the crank.

I havent read much about this on this fourm other than some refrences to "Rowe" products, it looks rather simple if you are patient. I will post again with pics in tec docs,

Anyway Im glad to have been turned on to you all and have caught some spark of what these little scoots are all about, please feel free to guid/ sugest because I am new to smaller motors.

Black Arts

Posted: Fri Jan 29, 2010 11:47 am
by Wheelman-111
Greetings:

Ah, the Black Art of Crank Truing. Not unlike lacing a bicycle wheel, really. It's known by many, practiced by few, done well by fewer still. Harley-Davidson cranks are made the same way as Sprees (Don't tell nobody... :surprise: ) only substituting inches for millimeters. All the guys I know who can do this are named "Lefty", have grey hair and not many teeth.

Besides the dental extractions and name change, you'll need a selection of dead-blow soft metal hammers, the aforementioned truing stand and dial indicators, a sharp eye and perhaps a nautical sextant, some of which can be found here

Might just be easier to source a known-decent one from a Forumista, but of course a lot less fun.

For an in-depth description of how it's done try this.

Good luck!

Re: new to fourm, thanks for all the help so far

Posted: Sat Jan 30, 2010 1:05 am
by house
Yep, you were right, this defiantly takes practice. I did ok for a first try, the journals were off in all 3 axies. I have no idea how this bike ran like this.

All in all it was a good lesson, thanks for the material, and tell Lefty he is a better man than I. I did improve it in the X/Y direction, I was initially getting .16, got it down to .08, not runable in my opinion so I will look for a new one.

Truing

Posted: Sat Jan 30, 2010 9:44 am
by Wheelman-111
Greetings:

First, that shows great initiative and good results.

One comment I have is that the nipple method of crank holding will introduce a measure of inaccuracy. As the crank spins, the points may wander a little bit. A little bit is a lot when the specs are to .04mm! V-blocks should be easy to find for less than $300 at HF.

Still, you turned a useless crank into a usable one and for that I applaud you. I'm putting your post into Advanced Tech when I get a chance.