Actually Keven, the Rollermatic's rollers are built very well and are more than capable of withstanding those speeds. You have to see and feel the mechanism in person to understand fully how it works, whether it be a solid-tub Rapidry or a 1-18 (which is basically a slightly modified, belt-driven Rollermatic). They look much more complicated in pictures/diagrams, trust me.
The weak spots were like Greg said, the agitate arm, shaft, and wheel, and the spin clutch linings. Personally I think the Rollermatic/1-18 spin clutch is way too small (think coke-can) to spin-drain as well as get the tub up to speed, especially if it is a heavy solid tub! In the short time I've been on here, I've heard of quite a few 1-18s and Rollermatics that spin very slowly or don't even spin at all. Definitely the Achilles' heel of the machine. Never say never, but my 1978 1-18, which has had 27 years of use, still has a very strong spin clutch. I guess it all depends on the machine...
Now the agitate arm/shaft/wheel on the other hand; those are just plain FLIMSY! If a 1-18 is excessively loud on agitation (like mine is), then that's the culprit. They seem to get louder over time, and usually the quiet ones have had extremely low use. To give you an idea of how flimsy the parts are, my agitate arm is pretty nicked up from when I had to drop it to get my impact wrench on the tub nut, and I stripped the threads out on the agitate wheel when I tightened the bolt up so I had to use some blue Loctite on it. They could definitely use a replacement in the future...
--Austin
