i don't want to be harsh but surely trimming a few pounds would be more beneficial than wearing an aero helmet?
Interestingly, it's possible that the improvement in Cd.A from trimming your bulk actually makes more difference on typical domestic TT courses than the change in mass.
Interestingly, it's possible that the improvement in Cd.A from trimming your bulk actually makes more difference on typical domestic TT courses than the change in mass.