On my Trek Portland daily ride for the TDF Challenge...which I don't ever seem to win by the way.... I was coming down Bailey Hill enjoying the ride.  The sweat finally drying on my face before it starts to sting my eyes and on arms before it drips to my hands and makes holding the brakes slippery, I turned the corner onto Spencer Creek, about 1/4 in I passed a fellow cyclist-looked like a commuter to me, he was on an old StumpJumber with commuting tires, in cycling shorts but a t-shirt and had a pannier on stuffed to the brim.  I passed at about 19mph and said "Hi" as I went buy not to suprise him too much.  I looked in my mirror and there he was, a ways back, I could barely see the black figure.  Peddaling away, comfortably, in my own little world I glance back to view traffic and there he was still there peddaling and peddaling, gaining some ground-What the heck?  So I kick it up a notch-but then hit the little hill at Pine Grove where it slows me, he starts gaining more ground.  I continue on down the little hill and he falls out of sight again.  Must have turned off I think to myself.  Once again comfortable with my pace.  Some other riders on the other side of the road pass "Look strong" I hear in my head JV, my S. O. and riding partner always says when other riders approach, it brings a smile to my face.  I wave and continue to pedal on at my comfortable pace.  Another glance in my rear view mirror on my helmet shows that black figure creeping up on me again-"What the heck, is this guy following me?"  I turn a corner here, a corner there, up a bump, down  a bump, up again and I look back and there he is again.  I think to myself, if this 50ish year old man had a road bike he could kick my 'you know what'.  Why would you carry all that gear with you on a ride in and out?  I start going up the ascent to the top of Gimple hill, I see glass in my front tire and pull over to brush it off (no gloves on), and the man dressed in black passes me on his Specialized StumpJumper!  An old Mountain bike should not be passing me on this road bike with all these gears...but alas it did!   I must have become his training challenge for the day as I saw him again a couple of miles down the road headed back to the office and this time I fell in behind him, and he was only riding about 14 miles an hour then.   The moral of this story... never under estimate the strength and speed of a bike twice as heavy as yours!