Be Self Sufficient
As far as I’m concerned there’s a few rules you must follow as a road rider on the roads of the UK. And I’m not talking about The Rules. Or even The Highway Code. The later being a given and the former being a thing of personal choice.
But these rules really, really matter if you’re going epic.
You may be riding as a group of friends, with a club or solo. In all cases you should be prepared to look after yourself in a wide range of mechanical and other eventualities. This means carrying a minimum amount of “stuff” with you to be ready to deal with those eventualities, as well as simple things like having a back-up plan if it goes fundamentally wrong. Like that time my rear wheel rim failed in the middle of The Peak District.