How to true a crank

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Tioli
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How to true a crank

Post by Tioli »

This is the way I did it.

Bottom of page 26 from the signature link or bottom hear:
http://www.trials.com.au/forum/viewtopi ... 303#p37303
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
pumpguy
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How to true a crank

Post by pumpguy »

To answer your question about where to measure the runout, it depends on where you support the assembly.

You have it supported on V blocks where the bearings reside. Others support the crank assembly out at he ends with cone pointed steel centers fitting in the drilled dimples at each end.

When supported on V blocks like you did, as you say, the maximum run-out will be at the ends of the shafts. When supported between centers, the maximum runout will be where the shafts meet the wheels.

I expect the factory measures the runout between centers, and show runout dimensions where the bearings reside. If you ever see an old Harley factory type crank truing fixture, it will have hardened steel centers at each end, and runout indicator needles to ride on each of the bearing diameters.
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Tioli
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How to true a crank

Post by Tioli »

that's what confused me. As you say if you use cones on the ends measure in the middle and if you support in the middle measure the ends.
The manual clearly shows support in the middle and measure in the middle. A little out on the gear side but nowhere near as much as at the end of the flywheel shaft.
Seems like the tolerance in the manual is a lot more forgiving.
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
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