If you have RSI, I would strongly consider going with a 7000 series. I am not sure you can get relief with a flatbar hybrid like the FX series. However, if you have your heart set on the 7.2FX, try a stem with a higher angle like a 105 mm with 17 deg Rise. Now, you can probably put a 45 deg stem on the FX, but it will affect the power transfer efficiency in your pedaling. I think the 7.2 comes with a 100 mmm 10 deg. Also try gel padded gloves and decent had grips such as Ergon brand.
Frame size - based on your height and inseam, you should be in the 22.5"
Sizing or Fit is extremely important because if it's not right, injuries will happen sooner than later. If the fit is right, your less likely to get injured. Also if the bike feels good, you are more likely to ride. You can really get messed up with injury if you 1. Don't have a bike that fits and 2. Ride too much too soon.
At the higher stem angle, it may put more strain on your knees because your working the quads more than the gluets. Remember to get the saddle height right, and don't mash the higher gears. In other words pedal faster with lower gears - less strain on knees.
Try to find a LBS with a certified fitter and pick their brain and be sure the bike fits you before plunking down the visa.
Also be aware of a recall on some TREK hybrids and make sure the store has it covered. Here is the link.
I hope that helps.
Last edited by MorganRaider; 09-11-09 at 08:27 PM.