small front tire; large back tire

[Black]

A 25mm is already a bit of a wide tire for a road bike. A 25 on the front and a 28 on the back sounds fine, although it's not a big enough size difference to affect your rolling resistance much.
I always ran 28s front and back on my commuter hybrid with 700c wheels.
And 25s on my road bike since there's not much tolerance for wobble where the chainstays meet the frame.


I agree with the strategy for a mountain bike-- I run a ~2" knobby rear and a 1.25" "city" tire on the front. Mostly for snow but it works fine in the summertime.