[LEAKYSEALS951]

Another big thing to check for with a used bike is drivetrain wear. Over, time, the chain stretches, wearing 1/2 moon divets/stretching into the cassette/ front ring teeth, and eventually the chain jumps straight over them when power is applied. Sometimes the wear gets so bad putting a new chain on the old cassettes makes matters even worse and you end up having to replace all cogs, chain, and front chainrings, which is expensive and ruins your day.

As for v brakes vs disc- I think it depends on where you live. If you are in a fairly flat area or only moderate hills, v brakes are lighter, simpler, and less maintenance. Get in a mountainous area with 1000+ foot descents and whatnot, and you might want to go disc brakes. I still have v brakes on my dinosaur- and have done a lot of long distance MTB races with them, and only on the long descents do I wish I had the disk brakes (like 10 mile descents and stuff).

Also, for any used full suspension bike, really examine the bushings for wear. A lot of them get super sloppy with age.