I have three* bicycles, a road bike, a mountain bike and a town / hack bike**.
The one that is used most frequently (as opposed to the one that does the most miles or takes the hardest knocks) is the oldest, cheapest and ugliest of the three, a hack bike in the classic sense. It has mudguards, a rack, 28mm semi-slick tyres, a single-speed converter and security bolts on the axles. It also has a coating of grime so thick that it serves its own anti-theft protection purposes, but it's a few things away from a perfect city bike.
So what might a perfect city bike look like?
Well, one thing you can guarantee is that it would look nothing like the various ridiculous concepts that get splashed around every now and then. Take this one. Please just take it. With that much fancy carbon-fibre on show you can guarantee that if you don't someone else will. As long as it's not raining of course, because there are no mudguards. And as long as there's nothing to carry (no rack). And it's full daylight (no lights). And...
I'll stop there, you get the picture.
So, again, what might a perfect city bike look like?
I think there are a few constants that would be welcome anywhere:
Integrated lights. Good ones, one that will do a job both to be seen by and to be seen, built into the bike so as to be theft-proof and running off a dynamo with a back-up battery for the traffic lights.
An integrated lock. I don't want a d-lock swinging off my handlebars and taking chips out of the paintwork, worse I don't want to arrive and realise that I've left my lock at home.
A belt drive. Whether linking to a hub-gear or a single-speed (we'll come back to that) a good city bike is one that you arrive on clean and presentable (or at least as much as you left the house). I want a nice clean belt-drive (this at least the bad-example above does get right) and I want it enclosed as much as practical. If I forget my bicycle clips I don't want that to mean that I need to buy a new set of trousers because of chain marks all down the right leg.
Some kind of secure compartment on the bike where my emergency toolkit can live without needing to stuff my multi-tool, pump etc into my pockets every time I go to the pub.
Integrated mudguards. This should be optional, not everyone lives in such a god-forsaken climate, but if you're selling a town bike in northern Europe then full guards, with mud-flaps should be there as an option.
An integrated rack. Again optional, but a key job of a proper city bike is to be able to transport stuff around. Personally I don't like cycling with a rucksack, give me somewhere for my stuff.
Security bolts on the wheel QRs. I don't want to be un-hitching a wheel every time I lock up, sorry, I just don't.
Tubeless tyres. Possibly a bit controversial this one, at the moment there isn't a lot of choice in road tubeless road tyres but, having switched to tubeless on the mountain bike about 5 years ago and not having had a puncture since, I'd like that same confidence in my city bike please.
Disc brakes. Again this is potentially a bit controversial but better modulation and more consistent braking in the wet is worth, to me at least, a slight weight penalty. Also brake pads are much cheaper to replace after a crappy winter than rims...
So if those are the constants, what are the variables?
Firstly I see two types of geometry being required; a sit-up-and-beg Amsterdam-style option for those who prefer to be upright and relaxed, and a more aggressive, compact set-up for those who like to go and play in the traffic and take a faster route (my preferred approach).
Secondly there is the variable of local geography; places like Cambridge, or York, or Amsterdam can be easily tackled on a single-speed bike. The topographies of Sheffield and Durham however, require gears.
Finally there is the matter of climate and all-year cycling; for some a full set of racks and mudguards is essential, for some lucky buggers (living in LA or Seville perhaps) rain is simply not worth worrying about and wet-weather protection is simply unnecessary mass.
From these variables I see a line of 8 bicycles being derived: two geometries, each offered in a hub-geared and single-speed version, with all 4 of these available in a fair-weather*** or all-weather flavour.
Below are some sketches suggesting how such a machine might look and work. Feel free to criticise the artwork but know that in doing so you are missing the point...
Integrated lights:
Front and rear would have two LEDs, a flasher and a constant. Both rears and the front flasher would be set up to disperse as much light as possible, the front constant beam would be correctly set up to light-up the road and not on-coming traffic. I think a 300 Lumen high-power and 150 lumen low-power should be sufficient for open roads and lit roads respectively.
Integrated lock and retention point:
A cable lock permanently attached at one end with a spring-retention mechanism to help with re-coiling the cable. The lock is designed to loop around a fixed object and lock on itself. I know it's not as secure as a D-lock but it has practical benefits and the lock you have with you is always better than the one you left at home. The rubber strap on the top-tube stops the lock head rattling around and is designed to be replaceable in the event of it perishing.
Bottom-bracket locker:
Simple bit of bent aluminium, attached to the frame with some security-head torx or allen-bolts. The lid lock is the same as the one on the main cycle lock so only one key is required. Large enough compartment for a spare-tube, a multi-tool, some instant patches and a couple of CO2 cannisters with an adaptor. Again not perfectly secure, but nothing is.
Initial thinking, Frame options and seat-tube cluster:
A basic upright frame and a compact variant. The kick up at the back of the compact top-tube is to ensure the rear light remains clear of any panniers or racks. The seat-tube cluster is designed so that the frame has a naturally compliant nature to offset the necessary size of the bottom-bracket area. Heavy use of hydro-forming is required but this can be done quite affordably now.
Throughout I have attempted to balance the requirements of integration with use of standard components, hence the lighting wiring doesn't go through the bars and stem, the rear light isn't built into the seat-post and the option remains to have a version without mudguards and rack so that standard after-market parts can be used.
I suspect you might not be able to hubs that have a dynamo / disc and gear / disc combo yet but I believe this will come along fairly quickly.
Looking at what's currently easily available it seems that Gazelle appear to be the closest I can find to this kind of approach but some bits really don't feel that integrated and the locks aren't really fit for purpose. They do seem like nice bikes though.
Anyway, that's my thoughts, what are yours?
* Well, 3 1/2 if you count my share of the tandem.
** This is widely recognised as the minimum number of bicycles by the way, if you were wondering.
*** N.B. Mounting points would still be included on the frame and forks of course.