the itch, the urge, the desire for change. all true bike nerds get it. geeking out on swapping out parts and reconfiguring machines that run perfectly fine but don't suit the mood at the moment. addiction, affliction, neurosis....
ah, the joy of owning a surly crosscheck. current configuration of slicks, full fenders, porteur rack, and a fixed gear drivetrain make it the ideal commuter. jump on and pedal to work; done deal. it's been in this configuration since july when i built it up to replace my car vs. bike damaged frame. and it's almost exclusively been ridden daily leaving my pacer parked in the garage.
but then the mood swings and ideas arise. a fan of scorching for years now, the thought of returning to a dedicated dirt fixed go-all fat tired crossish rig is appealing. pull off the rack and fenders, swap out the tires for larger volume, and add a couple of teeth to the rear cog.
so lets do some gearing math here. 40t/16tx27"=67.5"; my ideal road gear when slogging clothes, food, etc back and forth to work. i've pushed larger gears in the past but it's easier to ramp up the rpms and spin instead of bogging down working like a dog in the hills or when doing battle with an incessant headwind.
now for dirt applications you'll want something even lower, say high 50's or low 60's. 40t/19tx28"=58.9". spinny yes, but when riding in the rough it keeps the cranks turning over. also handy for towing a kid trailer which i've sadly been neglecting to do enough of lately.
and in regards to tire choice, i've had good results with running a knobby front (schwalbe marathon cross) while still favoring a semi-slick commutery rear (vittoria, conti, panaracer). traction is compromised but not as bad as you'd imagine. plus tire life expectancy is greatly extended as the inevitable paved miles add up especially when you're reluctant to always driving to the ride.
so i'll make the changes above, fender up the pacer for wet weather duty, and most likely write up another rambling post in a couple of months when my riding tastes vary again. winter is getting closer and commuting thru it calls for a different setup...
.