Darkhorse MOW crank at .002???

[Bafflingbs]

I may not be understanding exactly what was being shown to me, but, my inde sent a video of him measuring crank runout at the end of the pinion shaft, at .002. The file is to large to attach here, but, it’s of the crank being rotated, and the gauge touching the very end of the pinion (left side, I believe). When I bought this very expensive piece of equipment, I was under the impression that it would be under .001? In fact, the tag accompanying it, from Darkhorse, shows .0008- .0005 Am I missing something?

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[Bafflingbs]

A picture of the measurement, from the video:

[Ohio HD]

Maybe try a different gauge, one of higher quality and reads in tenths.

[kd]

Darkhorse measurements will be taken in quality V blocks and the unit will be very gently rotated.  Your measurement is taken installed in the crank main bearings and that usually requires a tool (like a socket and bar) to rotate the assembly.  Because they have clearance for oil etc. that can allow movement or deflection from the method used to rotate it. If the pistons, rings and barrels are installed this deflection will be even more exaggerated.  How is it being turned?  You don't say what year the wheels are or whether or not it has timkin drive side bearings. If so, they need to be fully assembled to the proper clearance to stabilize the unit. With the gauge still installed you will be able to simply push or lift on that pinion shaft and see this movement in the bearings on the dial gauge.

This is posted in the right place for John to see it.  He will likely respond with a more folsum explanation that you can understand.  He will likely need to know the things I mentioned, how far the unit is assembled and the method used to rotate and measure the pinion shaft deflection. I suggest you try to find out and add it to this thread.

[Bafflingbs]

Crappy or not, it still shows more than .001 Not trying to bash anyone, I’m just trying to understand why it shows so much runout. I specifically bought the Man-o-War crank, because it’s supposed to be the very best. Not saying it’s not, understand, I just don’t know enough about this, and want to understand. My OCD is really in hyperdrive on this

[Bafflingbs]

Darkhorse measurements will be taken in quality V blocks and the unit will be very gently rotated.  Your measurement is taken installed in the crank main bearings and that usually requires a tool (like a socket and bar) to rotate the assembly.  Because they have clearance for oil etc. that can allow movement or deflection from the method used to rotate it. If the pistons, rings and barrels are installed this deflection will be even more exaggerated.  How is it being turned?  You don't say what year the wheels are or whether or not it has timkin drive side bearings. If so, they need to be fully assembled to the proper clearance to stabilize the unit. With the gauge still installed you will be able to simply push or lift on that pinion shaft and see this movement in the bearings on the dial gauge.

This is posted in the right place for John to see it.  He will likely respond with a more folsum explanation that you can understand.  He will likely need to know the things I mentioned, how far the unit is assembled and the method used to rotate and measure the pinion shaft deflection. I suggest you try to find out and add it to this thread.

Thank you very much for your detailed information. I’m not sure how it was rotated, as I wasn’t there to observe. I do know that the Timken conversion was performed. As was the blueprinted cam plate. (Zipper’s)

[Ohio HD]

My point is this. That gauge may have very high repeatability, but the tolerance is probably +/- 0.001". So if that's the case, and the real measure is near 0.001" and not 0.002". Then a gauge reading in tenths may very well measure out at the 0.0008" they show.

I've used several DH cranks, all measured at or within a few tenths in the motor cases that the accompanying tag states. Before determining that there is an issue, measure with another gauge, one with higher tolerance and finer readout.

The quality of the tool will give the quality or lack of quality in the measurement. 

[HD Street Performance]

Measuring shaft TIR is easy if you have access to a "Dial Test Indicator" (NOT a Dial Travel Indicator) with a resolution of at least 0.0005 in. (0.0001 in. is preferred).

[Bafflingbs]

My point is this. That gauge may have very high repeatability, but the tolerance is probably +/- 0.001". So if that's the case, and the real measure is near 0.001" and not 0.002". Then a gauge reading in tenths may very well measure out at the 0.0008" they show.

I've used several DH cranks, all measured at or within a few tenths in the motor cases that the accompanying tag states. Before determining that there is an issue, measure with another gauge, one with higher tolerance and finer readout.

The quality of the tool will give the quality or lack of quality in the measurement.

I got ya, most likely you’re right, and at the very least, it’s still better than I had. Thank you

[rigidthumper]

IME, it's not uncommon for cranks to have less TIR when measured in v blocks, than when measured in the cases.

[kd]

The fact that it has timkins also supports the need to be properly assembled for clearance before this test.

[Bafflingbs]

IME, it's not uncommon for cranks to have less TIR when measured in v blocks, than when measured in the cases.

LOL! I don’t even know what “IME” or “TIR” stands for

[Ohio HD]

IME, it's not uncommon for cranks to have less TIR when measured in v blocks, than when measured in the cases.

LOL! I don’t even know what “IME” or “TIR” stands for

What's LOL mean?   

IME - in my experience
TIR - total indicated reading.

[Bafflingbs]

IME, it's not uncommon for cranks to have less TIR when measured in v blocks, than when measured in the cases.

LOL! I don’t even know what “IME” or “TIR” stands for

What's LOL mean?   

IME - in my experience
TIR - total indicated reading.

  Thanks!

[Bafflingbs]

The fact that it has timkins also supports the need to be properly assembled for clearance before this test.

Therein lie’s the question

[Hossamania]

Run it for 5000 miles and measure again, same gauge. No change, no worries.

[Buglet]

   These measurements don't surprise me as ever body has there own way of measuring and reasons why one person measuring is different then another. 

[Bafflingbs]

I think I’m just going to take Darkhorse at their word, and trust their measurements are more correct than Made in China gauge.

[Ohio HD]

You can always call John Dahmer at DH. He'll set your mind at ease. He takes all inquiries seriously.

This is an article he did with Hot Bike a few years back.

https://www.hotbikeweb.com/motor-tech-bottom-end-theory

[Bafflingbs]

Thank you

[Darkhorse]

As someone said, post it here and John will see it and reply - funny how that happens (just not always in a timely fashion as a lot is happening right now).  My first response or question actually is how is the indicator being supported, I can not see in the picture supplied?  It does seem to leave some question in stability of indicator?  We use the Feuling plate so there is NO ability to destabilize the indicator while measuring.  I would be more than happy to discuss with you if you wish?

Thanks guys, John

[kd]

  That was my thought too.  There appears to be a pair of vice grips in the pic and that style of "adjustable" mount (segmented snake arm) or simply using them for clamping the base absolutely does permit deflection in the mount.  The gauge also does not appear to be perpendicular to the surface being measured and if that is so the measurement taken will consequently be longer.  For interest sake, it would be nice to see a shot that includes the full view of the set-up.

[Bafflingbs]

I spoke to my builder, and confirmed what some have said. He even thinks it may be his gauge. I’m going to chalk it up to A.) my lack of experience B.) his gauge and C.) the method of how he measured. The bike is back together, and, is running smooth. I am very happy. I did have to have the sprocket pulled, however, both the original and the updated sprocket, were too noisy for both he and I. I really wanted it to work out for me, as I love the concept. But the neutral knock was very loud. It was tested both with and without, and ultimately not a good fit for me.

[Darkhorse]

While we will always return our Man O War product if a customer is not happy with how their bike performs, I do have to say our motorsprocket is not the root cause of the neutral rattle as H-D calls it, but more of a issue within the H-D trans.  H-D has upgraded the countershaft 1st gear with one that resolves the neutral knock as I call it.  My 19' M8 is quiet as a church mouse in neutral, amazing quiet with our Man O-War motorsprocket which is very encouraging.  My 12' was not which really had me puzzled for quite a while

[Bafflingbs]

  In any case, my bike runs better, and feels better, than any other bike I've EVER ridden!!! It's definitely on par with an M8, for smoothness