Alf, instead of responding to 'insults' that are not insults by insulting someone...why don't you explain this statement:
"I install my Ultra Torque cranks so there is zero gap in the Hirth Coupling..."
How do you do that?
When the joint is tight...it's tight. It is axially as short as it is going to get and it is radially aligned. No user that tightens his 10 MM fixing bolt has any 'gap' in his Hirth joint.
The mesh length can not be adjusted.
"Apparently, someone in Vicenza decided that a torque of 60Nm will hold everything together without completely flattening the Wavy Washer.Apparently, someone in Vicenza decided that a torque of 60Nm will hold everything together without completely flattening the Wavy Washer."
The assembly is designed to with clearance for the largest possible combination of bottom bracket shells and individual part tolerances. THAT is what is causing the noise.
Let me re-type that:
The clearance of the properly assembled crankset per factory instructions in any bike frame is what is causing the noise. It's a poor design. Due to end play in the assembly. It has nothing to do with the Hirth joint. Other manufactures have run into the same issue.
There is nothing you can do to the Hirth joint short of using a 5-axis CNCmilling machine to re-cut the female tooth form deeper to remove that clearance. Do you understand that? It is...what it is. You can torque the bejeezus out of that joint and linearally it will only move tenths of a thousands as you overload the fastener and the draw surface/thread...resulting in pictures on the web C60 and I are familiar with.
The clearance can only be removed by shimming a cup (or both cups) outboard if you have external cups or by moving the PF cups outboard or by shimming between the cups and the bearings.
No one cares about the Q-factor. We do not set our cranksets up going by a pedal spacing spec. Especially if it's off by 0.1 MM / four thousandth of an inch!!! Or even forty thousandths of an inch. Where you're getting this...we have no clue. Honestly.
Is the 'gap' in your Hirth joint the air space at the root of the tooth form? The space between the tip of the male tooth form and the base of the female tooth form? If it is, I would really like to know exactly how you eliminated it. Otherwise, there is no gap in the installed Hirth joint.
I hope you take none of this as an insult because none of it was intended to be insulting. It's just that neither C60 nor myself...both of which are obviously engineers in real life...can not understand what you are getting at.
BTW, the last 34-1/2 years I've spent on drawing boards and CAD screens after getting my Journeyman's card as a Tool & Die maker. I have just a little experience with this sort of stuff and after these few brief discussions with C60, here in this thread, it is obvious to me that he is also very much familiar with metrology and tribology and the design elements of his crankset.
"I install my Ultra Torque cranks so there is zero gap in the Hirth Coupling..."
How do you do that?
When the joint is tight...it's tight. It is axially as short as it is going to get and it is radially aligned. No user that tightens his 10 MM fixing bolt has any 'gap' in his Hirth joint.
The mesh length can not be adjusted.
"Apparently, someone in Vicenza decided that a torque of 60Nm will hold everything together without completely flattening the Wavy Washer.Apparently, someone in Vicenza decided that a torque of 60Nm will hold everything together without completely flattening the Wavy Washer."
The assembly is designed to with clearance for the largest possible combination of bottom bracket shells and individual part tolerances. THAT is what is causing the noise.
Let me re-type that:
The clearance of the properly assembled crankset per factory instructions in any bike frame is what is causing the noise. It's a poor design. Due to end play in the assembly. It has nothing to do with the Hirth joint. Other manufactures have run into the same issue.
There is nothing you can do to the Hirth joint short of using a 5-axis CNCmilling machine to re-cut the female tooth form deeper to remove that clearance. Do you understand that? It is...what it is. You can torque the bejeezus out of that joint and linearally it will only move tenths of a thousands as you overload the fastener and the draw surface/thread...resulting in pictures on the web C60 and I are familiar with.
The clearance can only be removed by shimming a cup (or both cups) outboard if you have external cups or by moving the PF cups outboard or by shimming between the cups and the bearings.
No one cares about the Q-factor. We do not set our cranksets up going by a pedal spacing spec. Especially if it's off by 0.1 MM / four thousandth of an inch!!! Or even forty thousandths of an inch. Where you're getting this...we have no clue. Honestly.
Is the 'gap' in your Hirth joint the air space at the root of the tooth form? The space between the tip of the male tooth form and the base of the female tooth form? If it is, I would really like to know exactly how you eliminated it. Otherwise, there is no gap in the installed Hirth joint.
I hope you take none of this as an insult because none of it was intended to be insulting. It's just that neither C60 nor myself...both of which are obviously engineers in real life...can not understand what you are getting at.
BTW, the last 34-1/2 years I've spent on drawing boards and CAD screens after getting my Journeyman's card as a Tool & Die maker. I have just a little experience with this sort of stuff and after these few brief discussions with C60, here in this thread, it is obvious to me that he is also very much familiar with metrology and tribology and the design elements of his crankset.