28mm is fine and is still a good average size for most road bikes. The current fashion for adventure bikes is driving that wider but the vast majority of road bikes are still in the 25-28mm range. Personally 28mm + an inch or so of suspension is fine for me on some pretty lousy British roads, I find both gearing - even at 58x9 - and aero are bigger blockers. Would love to see an official Birdy with drops or bull bars where the fold isn't compromised.

Minor grumble - I note Pacific Cycles birdies invariably are sold without mudguards - which would be unworkable for me in Rainy Britain - what do you do in Monsoon season - for those of you who get Monsoons or a local equivalent.