I did my longest ride yet yesterday: 10.1 miles. I've had my Trek now 5 weeks and at the beginning couldn't do 3 miles. A combination of new seat, tougher butt, better pedals and some learned technique has really helped in the endurance department.
Started at 1825', went for 1.25m to 1705', then 6.3m to 2205', the rest from there on a different route back to home at 1825'. I don't know what's considered steep or tough, but for a 51-year-old, 225lbs, riding for just over a month, I'm pretty darn happy.
I do wish I'd done a couple things different on the bike: probably would get an FX now instead of a DS. Certainly would have done a different bar than the composite Iso-Zone one. The LBS sales guy even said I should re-think the bar change. I don't listen well. The bar was supposed - and does - to reduce vibration and hand numbness, but it's made in a way the precludes use of any bar-end attachment. So no mirrors or bar-ends. (unhappy face) Oh well.
On the plus, I originally wanted an MTB-geared crankset since they usually have a 22 low end, instead of the 26 on mine. What I found yesterday is that I went into 1st gear only once (which is normal - I do it for the entire uphill!) and only for about 200 yards. By the time I reached the top of my climb portion, I was either in 5th or 6th. Spent most of the time yesterday figuring out that going up a few gears is actually easier on me than riding in 1st the whole trip.