You can do one of two things.
1) Draft my wheel
2) Wear headphones when you ride
I do not have a policy statement on helmets. If you do not wear a helmet it doesn't impact me - if there is a crash and a helmet would have helped you, it would not have helped me, but a helmet is not a crash avoidance tool.
Headphones, on the other hand, block your ears, which are a crash avoidance tool, especially in a paceline. If you choose to wear them and don't hear a car honking, that's your problem. If you choose to wear them and don't hear me shout out "SLOWING" and run your handlebars up my ass, that's my problem.
This lecture was applied this AM on the google ride when I found someone on my rear wheel. When we pulled up at a stoplight, he pulled up next to me, took out an earbud, and said "It's much easier behind you". I read him my policy statement. Amusingly he said "Well then I'll just have to drop back or go ahead". Which was fine by me. The SF2G route is an obstacle course, frankly - there are more crashes on that ride than on the Noon Ride which is run at a much higher pace by more aggressive riders. I'll attribute this to the bollards, potholes, bike paths, mini-ramps out of parking lots, bridges to nowhere, and other assorted visitors from a Japanese TV Game Show focused on contestants physically injuring themselves.
If you're on my wheel and you can't hear me, then I have to be extra vigilant in pointing out the potholes and the like with hand signals, and taking my hands off the bar may not be what I want to do in such situations.
For those about to ride, we salute you
5 days ago