This is one of those practices that I hate to see. Its a stupid thing to do on nearly any route. If you're on a quiet, segregated cycle route with very few other people I don't particularly care (like someone speeding on a completely empty motorway - don't ask me to get het-up about that). But this is something I encouter quite often in Cambridge, and I hate it. I hate it. I hate it.
I've been rear ended by other cyclists five times in Cambridge. Once was a guy who who came off his bike on a wet drain cover and slid into me - can't really blame him. Another time was a bloke who planned to plough straight through a red light I was stopping at - a complete plonker who only just swerved enough to clip me rather than really crunch in to me. Third one was a woman who was so intent on her mobile phone conversation that she rode in to me. None of those caused any damage to me or my bike.
I've been hit by cyclists riding with umbrellas in one hand, twice. One of those was a woman who rear ended me as I stopped due to the presence of a fire engine in front of me. Big, obvious, static red fire engine, not moving at all, flashing blue lights, attending a building that had been hit by lightning in the ongoing storm. If she hadn't hit me I wonder if she'd have hit the fire engine. Knocked my chain off, it jammed and left me with a three mile walk home in the rain. Second one was on Kings Parade - I slowed down so as to not ride in to the back of a car that was slowing up in front, another cyclist rear ended me and knocked me off. She simply couldn't stop in the rain with only one hand for one brake and an umbrella in the other.
Its an oddly common phenomenon here in Cambridge - riding with an umbrella. Typically its students, riding pretty normal student bikes - usually mountain bikes that have seen better days, not usually with the tightest brakes around, rather than perhaps bikes with back-pedalling brakes or even high quality disc brakes. And its terrifying, I can confidently predict seeing three or four coming off their bikes with brollies every year. I'll see several hit or nearly hit pedestrians as they hold their brollies out in front of them, and very often in the narrow canyon like streets of Cambridge freak gusts of wind will blow them in unpredictable directions.
But there are other bad habits you see among Cambridge cyclists. We get a lot of 'racer' types here, especially with the new autumn term. Usually blokes - younger guys, undergrads who want to get up later and then weave rapidly left and right through the commuter peloton with little regard for others. We've also seen plenty of single speed and fixie bikes come in to Cambridge in recent years too - and many of them are ridden by numpties who will slowly, slowly creep past you at a juncion, past the white line, past the light, anything to avoid actually stopping.
Oh, and then there are all the cyclists who queue in the feeder lanes for the advance stop lines. So you'll be stuck way back in traffic behind cyclists who probably want to turn right across the traffic while the box at the front remains annoyingly empty...
Annoying, irritaing, bothersome... But step back for a moment.
Does any of this matter? Think about it, I've been hit by other cyclists, from behind, 5 times. The worst damage was a jammed chain. I see similar things happen every year, usually in autumn - the worst injury I can remember seeing as a result was a skinned elbow. And those fixie riders wibble-wobbling slowly through the lights, I can't honestly say I've ever seen any of them get hurt. Those folk who queue in the ASL on the left of Downing Street to turn right, blocking me getting to the junction where I want to turn left, I can honestly say the worst they've done for me is stopped me getting through until the lights change next time.
Hell is not other cyclists. Other cyclists can, perhaps, get right on your tits sometimes - but lets be reasonable. Worse things happen on the roads.