Originally Posted by
ColonelJLloyd
I've asked about that, Eric, and was told it was to save time during a race if something happened and a crank bolt needed to be accessed for whatever reason.
Indeed. I've never raced but I can offer this anecdote. On an early ride with the Masi I stopped at a bike shop which has a back door to the Minuteman Bikeway. The proprietor and every employee had to come over and ogle it. Then the proprietor started telling me about all the bike he'd collected and restored, not just interesting models but the actual bikes used in various Olympic or world championship or TDF runs. (I'll take his word for it.) But one story was how he finally after a long search found the exact caps for his crank. Then he showed it to a buddy who asked why he bothered. The first thing any race mechanic did was throw them away because you couldn't service the crank quickly with them in place.
Okay, so it's just a second-hand story. It's the best I got.
I've been told I should keep them in to keep dust out of the threads. I've been told I shouldn't bother. Some of my bikes have them, some don't. I think. I should go check or else I'll have something else to worry about.