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My only thought is that "just fine" is not quantitative.  Most of us would say the same for our pivoted tonearms.  Anyway, you raise an interesting question: what difference does it make tracking warps with a pivoted vs a tangential tonearm? Why would skating force and the application of AS make any difference?  Answer for me is I don't know.

@lewm 

When you wrote AS I read A$.

There should be no skating force with a linear tracking (tangential) tone arm, except some side force has to drag it across the record. I am somewhat familiar with the Holbo deck which has both an air-bearing for the tone arm and another for the platter.

@asvjerry

Traversing a vertical warp momentarily increases the tracking force, then decreases it as the stylus goes downhill.  With a pivoted tone arm, the skating force is proportional to the tracking force.  In the extreme when the stylus gets airborne, it will be pulled away from the center by the anti-skating device, which tangential tracking arms do not need

No, you are correct, RB, there should be no skating force with a tangential tracker.  The only side force would be to overcome any friction in the carriage, and there is always some of that, which is why the best LT tonearms in my opinion float the carriage on an air bearing.

And you've answered the question.  Warps throw the balance of skating force vs AS out of whack, momentarily. I'd never thought to worry about that, so I won't start now.

The issue with tangential tracking arms of the air bearing or ultra low friction variety (e.g., Clearaudio) is that the arm does not have the mechanical advantage of a pivot/fulcrum, so considerable force is imparted on the stylus/cantilever to pull the arm assembly sideways across the record. 

In some cases that force is much higher than skating forces and there has been reported damage to cartridges.  There are ways to make pivoted tangential tracking arms.  The earliest used a sensor to detect when the arm is no longer tangent to the grooves and a motor to then move the arm/pivot assembly to again achieve tangency.

There are modern versions based on Thales circles, that has a conventional arm attached to a base that rotates to move the whole arm into a new position to achieve tangency (Reed T5, Shroeder LTA), these arms achieve tangency and virtually no skating forces while minimizing other adverse consequences.  

There are also straight arms that have not offset angle at the headshell.  The tracking geometry is WAY off with these arms, but, skating force is substantially less than that of arms with an offset angle.  I have heard some examples and I was quite surprised that the lack of any attempt to get close to tangency of the cantilever to the groove did not seem to hurt performance much.

Larry, That is an interesting idea, but I don't get it. The force applied to the stylus/cantilever would be to counter the force of friction between stylus and groove, and here, with a tangential arm, we have a cantilever that is always tangent to the groove across the entire LP. So the friction force would only vary according to groove tortuosity, ideally.  The carriage end that holds on to the arm wand has the same job as the pivot bearing does in a conventional pivoted overhung tonearm, to resist friction or stylus drag. For much of the time (except for two moments when the stylus passes through the two null points on the surface of an LP, if your pivoted tonearm is set up properly), with a conventional arm, the cantilever is not tangent to the groove, which imparts a side force on the cantilever. I would think that's "worse" than with a tangential arm.

Properly designed tonearms that have zero headshell offset also underhang the pivot. That's a huge distinction from tonearms with an offset headshell that overhang the pivot. In order to minimize TAE, Lofgren, Bearwald, Stevenson, et al, introduced the overhung tonearm and headshell offset, regardless of the effect on skating force. You are correct that the resulting high TAE of an underhung straight tonearm does not result in audible distortion. But you say it doesn't hurt performance "much".  I'd say it does not hurt performance at all, and in fact there is much to be said about the at least equally excellent performance of underhung tonearms with zero offset. (And I've said it elsewhere so won't bore you with my rationale.)