Originally Posted by Kevindale

Thanks! My wife started with 520s because they were on a used Gary Fisher she bought (used as a commuter, not a mountain bike). A year later I got the same, since they'd worked great for her, and were dirt cheap. Then she ended up putting them on her road bike. They've been fine, but if we get into real off-road riding I was already planning on going to 540s on those bikes. I'm gradually shifting the road bikes to A600 and A530, simply because I like the looks, which is worth the slightly decreased utility of only being one sided.