Are linear tracking arms better than pivoted arms?

Excentric records kill all theoretical advantages of passive linear trackers. Doing simple math, you can see a side force as large as up to 1.0 gramm peak applied to the cantilever when say, 200 gramm of slider+arm mass is driven by 1 mm out-of-center record. Cantilever ealisy moves more than 1 degree from centerline under such force. In perfect world of ideal records, when the arm moves accross the record with virtually no acceleration, high lateral mass is a good thing, allowing needle to follow groves while the arm stays steady due to high inertia. From my personal experience with 120 g air tracker, 1-1.5 mm eccentricity is pretty audible, not to mention lead-out groove, where cantilever bouncing becomes scary.

Well, after starting this thread and reading everything everyone has written, I have decided to give pivoted arms another shot. After numerous emails with Dertonarm, I have decided to buy a Fidelity Research FR64s tonearm. I know Raul thinks the AT is superior, but based on its low resale value, I decided against it. If for some reason I decide I don't like the FR, I am confident I can get my money back. I am looking forward to all of the parts coming in (I bought the arm, a new TNT armboard from VPI, and a NOS Orsonics headshell). It is my hope that this combo will sound better than my ET-2 in all parameters. If it does, I will gladly sell the ET-2 and be done with linear tracking arms once and for all. Since the arm is coming from Australia, the headshell from Hong Kong, and the armboard from VPI, it will be awhile before everything arrives. It should be interesting and I hope worthwhile. There must be a reason why the FR64s has a cult following and the value continues to climb.

Livemusic, Good point about lateral mass. I have lately started using a Dynavector tonearm, which is deliberately designed to present a high mass in the horizontal plane. I can only say it is a great sounding tonearm with lovely bass response. However, I think the possible negative effect of high mass in the horizontal plane is ameliorated (at least) by the pivoted design of the Dyna tonearms.

In terms of trackability and distortions, not neccesary.
In terms of sonic performance, not neccesary.

I am inclined to think an air-bearing linear arm could sound better than a DC-servo one. There are some good designs during the past few years.

Dan

Mepearson, not to muddy the waters too much but I spotted a comment from Dertonarm that needs correction: the bearings in the Triplanar as good as you can find. They are custom-built by an aerospace bearing supplier, and are 3 or 4 grades higher in hardness and polish than the bearings found in the SME 5. There is only one manufacturer in the US than can make the bearing and they are the most expensive part of the arm as I understand it.