Steve Birmingham asked with regards to my comment about dustcaps often not eing
> I've wondered about that, Is there any reason besides the few grams of
> weight for leaving them off for racing?
> I espacially wondered about bikes from the "Aero" days, with all manner
> of weird details to make them smoother,
> and then the crank dustcaps werent there! just looks weird on the aero
The more correct question is: "Is there any reason to ever use them?" IMHO, they serve absolutely no purpose whatsoever. I have heard people say that they help keep the threads of the cranks clean, but my personal experience shows this to not be the case. I have also seen more than my share of dustcaps that become permanent, and simply can no longer be removed without considerable work. Lastly, in the case that a crank bolt should ever loosen up on a ride and you don't have any tools with you, you can generally hand tighten the bolt so that you can get to destination. This is not possible if the dustcap is there. I do however subsribe to the use of rubber nib fillers for allen key fittings on brake center bolts. If you ride enough in the rain, these allen key 'holes' invariably get filled with grit and grime and can make the bolt inoperable.