I've started to bike again, this time around taking it a lot more seriously than I have before. I pulled my bike out a few weeks ago, and started to get used to it again. I have a few problems, that I'd appreciate some advice on:
Background:
* I'm a big-ass guy, 6'1" 280lbs, and I'm hoping that bicycling will help me shed weight (in addition to better eating).
* I got a
Trek 7000 as a gift from my dad in... '10? Maybe '09. It's been used sparingly, and as a result, had some rust issues. I read up a bit on bicycle maintenance, got some Naval Jelly, and cleaned my cassette and chain as best as I could. As far as I can tell, it's functionally OK.
* I've been riding half and half on paved trailed and gravelly trails. This has been mostly ok with my 7000, though I have had some wobbliness on moderately loose dirt/gravel trails. About 20-25miles (32-40km for the rest of the world) per trip, 3 times a week so far.
* I seem to average about 13-14mph on trails/sidewalk riding, which feels a bit slow. Not sure if my aforementioned slightly rusty cassette/chain have anything to do with that.
* I don't think that I'll convert to pure road biking or pure trail biking at any point, I enjoy being able do ok speeds on roads, while not having super thin tires which would make some trail biking a lot tougher.
Questions:
1) I'm concerned about my chain and cassette, I sometimes have issues with gears slipping (usually the lowest gearing). This is a 7-speed cassette... it isn't possible to upgrade to an 8-10speed without changing out my shifter, is it? If I have to stay with a 7speed, can someone point me to a good explanation "14-34" might indicate in the gearing? It appears that replacement cassettes have different ranges/ratios/whatever that is.
2) Is it worth considering going up to a Trek FX series bike? As far as I can tell, the FX line is a slightly different design with higher grade parts.