I am doing a bike ride called the Tour of Flanders on Saturday 4th April (one of the Spring Classics of the pro racing calender, the professionals -Wiggins et al - do it the day after). It's 239 kms (150 miles) cycled in one day, over some steep hills on cobbled roads. I am doing it for 'fun', it would be a bonus to raise some money for MSF.
link to event website: http://www.sport.be/rondevanvlaanderen/2015/en/