Whilst at a 100 mile time trial yesterday I was amused to see a slow moving cyclist coming towards me in full Sky kit, dark mirror glasses wearing earphones, he was probably doing around 11 mph and riding a little too far out into the road, anyway a time triallist moving at at least 25 mph was catching him very quickly and shouted to warn him he was passing [it was a very busy A road and noisy so the overtaking rider didn't want to have to pull out too far into the traffic], now most cyclists would glance back and either pull into the side or move close to the verge while the racing cyclist went past. Not this guy, it was clear he was oblivious to what was going on in the world around him. Nobber.
