Thanks for the careful reply, maddslacker. The bike did arrive, and I built it up. Unfortunately, the large front chainring was trashed in shipping, and the rear brake rotor slightly bent so that it wobbles and rubs a little bit on the rear pads. SixFifty is shipping replacements.
However, I have gone out for a couple of short rides keeping the chain on the lower chain rings. Set the tension on the spd’s low — no problems there. Had one small fall when there was a sharp rise in the trail and I had my weight back too far. I’ve always pulled up on the bars climbing on the road, and adjusting to sharply changing terrain is going to be a challenge. Plus I’m way out of shape.
I took your advice and bought the book you recommended, Mastering Mountain Bike Skills, 2nd Ed. (I went for the kindle version — there’s a nice kindle app for iPad.) and am working my way through it.
The other thing that surprised me is how much the rear shock compresses on (absorbs…) my pedal downstroke. I’m going to have to figure out how to increase the resistence (looks like there’s a place to add air — can I use a floor pump?) and then fiddle with it.
Anyway, it’s fun. The trails around here are mostly used for hiking, horseback and x-c skiing. Lot’s of stretches I find a bit intimidating — I’ll have to snap some pix.