I don't have a dedicated commuter and just use what I feel like for the day. My Orro Terra C gets the most use for commuting I guess. Below is it set-up for wet weather/winter riding with 32mm pirelli cinturato velos, mudguards, and my bar mitts. I use a 6 litre saddlebag for my work clothes and shoes and a hip pack for keys, lunch, and other bits.
Here it is in summer mode, with 40mm Hutchinson Touregs and a full frame bag, which has a 3 litre hydration bladder in it. In the summer, I will quite often extend the ride home with a 25 mile+ gravel route.
Sometimes, I take the summer road bike if the weather is nice (50-50 split between this and the Orro during nice weather). I can even fit my coffee in a bottle cage. Sometimes I use a small backpack, and other times I will use my 6 litre saddlebag for my change of clothes/shoes.
And a couple of times a month during TT season, this is used to commute on. It is not the most practical commuting in a skinsuit and aero helmet, but it can be quick. I either take my clothes in a small backpack, or take double the day before and leave a set at work.
