The simple answer is as little as possible. You’re going on a day trip, not a holiday, so you can leave the kitchen sink along with your cares and worries behind.
Most important is a helmet, you only have one head so it is worth protecting, says he in his most patronising way ... but while I’m here, just check it fits well. That it sits firmly and level on your head, your ears poking through the little triangles of the straps and you need to be able to get 2 fingers between your chin and the strap.
Next – water or something to drink. Leave the beer for after the ride, water is fine although I prefer squash of some type. I’d recommend one of the big bike bottles, fit a bottle rack if you haven’t one already, they’re only a few pounds from any bike shop.
Some food – Bring just enough of what you like, after all remember our rides are in the south east of England not Siberia and we do stop for refreshments and cake. I remember when leading youth rides, some poor lad was sent out complete with a thermos of soup, 2 rounds of sandwiches and a basket of bananas, his mother adamant that it was all totally necessary. His rucksack weighed a ton – I know I had to carry it for him!
On similar lines – think about clothing, you need to bring enough, easy in the summer and winter, more difficult in early spring when you should err on the side caution and wear an extra layer just in case.
Very important – bring a spare inner tube, worth checking it fits the bike and doesn’t have any holes in. Every cyclist has done it, replaced one punctured inner tube with another – yeah, you feel really stupid!
I bring a pump and multitool with me on every ride, so you don’t need to on our guided bike tours, just remember to take them when riding solo, especially on the bike trails. Worth remembering here that if your bike needs some weird spanner to release the wheels, (yes it’s happened to me) take it with you when ever you set off.
It’s always wise to bring money or a bank card, we will be stopping en route for coffee ‘n’ cake and occasionally you may need that unplanned train journey home.
As a general rule, if everything can’t fit in a small bum bag or your jersey pockets, you don’t need it, which brings me tidily onto my final point ...LESS IS BEST – remember that poor youngster forced to bring a 3-course lunch with him, every kilo on your bike has to be lugged up every hill and them there 'ills get tougher as the day goes by. So leave behind the bike locks, lights, folding table, kitchen sink, your cares and worries - you won’t be needing them!