[Jim727]

Interesting. Here are my thoughts:

First, the carrier beam deflection will load the #1-6 rollers somewhat differently, but to get 10x wear on rollers 1 and 6 the deflection would have to be severe and oddly shaped. I doubt that is it.

Second, contamination is something all track wheels live with - why would 1 and 6 be that much worse? I'd rule that out also.

Third, the mounting arrangement of the idler arms and connection to the rollers is unknown. Don't know about interactions there.

Finally, track slack. This is one thing that definitely loads rollers 1 and 6 more than 2-5, but 10x the wear? My guess would be that it's track slack compounded by the difference in slack from the inside of the track to the outside of the track caused by uneven surfaces and crawler turns. This would not only add the additional radial load on the roller wheel but also add twist and thrust loads to the roller axles, carriers, and wheels. Placing strain gages on the roller carriers should tell if this is the case.

Haven't gotten to do this kind of stuff since engineering school!