I've been meaning to post my thoughts on the Cycle Hire bikes but not got round to it until now. So here goes:
Undocking the bike is simple enough. Stick the key in the slot, wait for the green light and then give the bike a good hard pull. If it seems stuck, chances are you're not pulling hard enough. Docking is the reverse operation: a good hard push and the bike clunks into place, and you get the green light.
The saddle adjusts easily enough via the quick-release lever. No other adjustments are possible though.
There's a luggage carrier on the front that works well and I rather like. My 25-litre rucksack fitted in just fine, and seemed secure with the bungee cord attached.
The controls are simple enough. Front and rear brake levers on the bars, and a twist-grip for the 3-speed hub gear. There's also a bell underneath the left grip, operated by a thumb-wheel. It's a bit fiddly and on one bike didn't work at all. Front and rear lights come on automatically courtesy of a dynamo hub. The rear lights are rather too low down and the front light twinkles but I suspect doesn't make the bike very conspicuous to drivers. There's a helpful notice on the middle of the bars: "Watch for left-turning vehicles".
The brakes are drums inside the hubs. This makes them difficult to damage. However, they cannot be adjusted by the user, and seem to have a tendency to bind. One bike had a very weak front brake. That's a serious safety issue. On other bikes, the brakes worked with a heavy squeeze of the lever, but had no real 'bite'. However, you're rarely going fast enough for braking to be an issue. The drivetrain and tyres are all well-enclosed, so there's little chance of arriving mud-spattered or oily.
The gearing is low. I found little use for the bottom two gears, and top is only good for maybe 12-13MPH before you're wasting energy spinning the pedals too fast. Even downhill, the bike seems determined to resist anything more than a sedate pace. Getting your tie to blow over your shoulder like the cartoon Boris would require a significant headwind. A bit of a change of mindset is needed if you're used to riding a normal bike: you have to relax and take it slow. Until I figured this out, I found myself using a surprising amount of energy to no good effect and getting quite sweaty even on a cold day. I think there is a safety issue in the lack of speed. When I ride, I like to get ahead of the traffic and 'take the lane'. That style of riding is not really possible on this bike. On one occasion I found myself wanting to make a right-turn, but found I couldn't accelerate fast enough to get into the right-hand lane.
The bike rides more like a Rolls-Royce than a Ferrari. It's unfazed by rough surfaces, potholes or kerbs, and rides serenely over pretty much anything, although it's rather unsteady on loose gravel. The bike is very heavy at 23kg. For comparison, your average road bike tips the scales at 9 or 10kg, and even a steel-framed full touring bike like the Dawes Galaxy is 14kg or so. So this is like riding two bikes at once. I've seen some reviews claim you don't notice the weight. This is rubbish. It's not immediately apparent because the gearing is so low, but in top gear you're aware of the mass on even the slightest incline. The weight seems low down, so the handling is quite stable.
For me, an average-height rider, it was difficult to find a comfortable riding position. The bars are too close, so you either have to lean back or adopt an 'elbows out' position. The saddle I found fine, although on some bikes it seemed softer than others.
Because of the charging structure, you need to keep your journeys below half an hour to avoid usage charges. This means that if you don't know your end-point, you have to start worrying about finding a docking station 20-25 minutes into your ride. It's possible to undock another bike five minutes after docking your previous one, if you want to dodge the usage charges on a longer ride.
There seems to be no real cameraderie among Boris Bikers. My salutes were met with stony-faced stares. That's Londoners for you. Boris Bikers are a diverse bunch - suited business people, casually-dressed folk, some have helmets and high-viz gear, some are young and some old, and both genders are represented although I think more men than women.
In summary, if you don't have your own bike in town, this is the next best way to get around. Yes, the bike is a big blue barge. Yes, the weight and the riding position would be annoying on a longer ride, but it's fine for short journeys, which is what it's intended for. The lack of acceleration and top-end speed is annoying and could get you into trouble, but you can take this into account when you ride. It's a great alternative to tube or bus travel, being usually faster than both and more fun. A normal bike offers a much better riding experience, but for one-way journeys or where you don't have your bike in town, it's fine, and you don't have to worry about lights or locks, or the Friday-night-out dilemma of whether to risk overnight bike theft or ride home a teeny bit the worse for wear.