Sorry I'm a little late to post this but a friend of mine also owns a Trek 7300 and had similar problems with insufficient braking power and severe brake squeal. He ended up replacing the stock Tektro brakes with Avid SD7's and they've been far superior. I also replaced mine with a SD7 in front and SD5 in the rear and it's worked wonders on my Diamondback. I've logged about 300 miles since the swap and haven't had to readjust them or heard any squealing. They're only $20 for the SD7 and $12 for the SD5 at Jenson - I HIGHLY recommend them.