Maybe some of the trek fx's are lighter.

And as a 5'1 person with a "higher" car, even if it's only a subaru outback... I have no desire to lift a heavy bike on to it. I can put my titanium bike on the roof no problem, it's maybe 16 lbs and lifting it over my head and strapping it on isn't bad. I can take it down too. Both without a stool. But I am literally holding on to the chain stay and one of the bike tubes and holding it straight up over my head, arms fully extended.

Anything much heavier than that and I start worrying about the car in case I drop something. Lifting a 24 inch POS girls mountain bike on the roof to take it to my neice (damned thing musta weighed almost 30 lbs) was a pain in my neck and required a stool. As did a mountain bike (maybe 25 lbs?)

I use a hitch rack normally... and while I don't have a problem lifting 25 lb bikes on to it... It's a bit of a pain, because the arms of the hitch rack are above my shoulders and then because my bikes are small frame with water bottle holders, frame pumps, it's a bit difficult to maneuver into the arms because a bit of a tight fit.

I've got a fair amount of upper body strength and have no problem carrying heavy things... I just find it awkward lifting things over my shoulders or head over a certain weight, so I don't think the ops request for a lighter bike is unreasonable. And I find my surly annoyingly heavy at 25 lbs in comparison to all my other bikes.