Need to rent bike

[mpro]

New to the D.C area but the biking is better here,
A friend from out of town is coming and would like to rent a mountain bike for day.
Does anybody know of a reasonable but good place to do this in the d.c area.
I am from rockville.

[jon_baler]

You could go to Race Pace in Columbia, and then go ride Patapsco.