Ok, so I'm a big dude, 6' and 320lbs. I'm doing whatever I can to get in shape.
I'm looking into bikes, and have not ridden since I was a kid and know basically nothing about them. So, while I read the threads, I don't really understand the why of things. Like why have wheels with lots of spokes? Or a certain diameter of wheel, etc.
So, explanations would be great, just general pointers to look out for.
I intend to buy my first bike, preferably used since we have tons of used bikes in the area.
For instance, there have been a few nice trek bikes (4500, 800, etc) that have come up for sale here.. but what do they mean by 18" frame??
How do I know what to look for?