I took a similar stance when a friend invited me to ride with her on the skyride ride (25 miles around south west London).
I turned up without a lit, only 25 miles at a steady pace on mainly quiet road, unfortunately it took some convincing to ride with them without helmet.
In the end they wrote down a quick disclaimer and got me to sign it (no responsibility if I crashed etc.).
I took a similar stance when a friend invited me to ride with her on the skyride ride (25 miles around south west London).
I turned up without a lit, only 25 miles at a steady pace on mainly quiet road, unfortunately it took some convincing to ride with them without helmet.
In the end they wrote down a quick disclaimer and got me to sign it (no responsibility if I crashed etc.).