You mean the sealing ring on the bottom of the headset cover? If it's flapping around, it might bind up and cause a bit of drag, but probably not enough to notice. The loss of a good seal at the point seems to be a non-issue if you have cartridge bearings with their own seals, unless you spend a lot of time riding underwater.
You mean the sealing ring on the bottom of the headset cover? If it's flapping around, it might bind up and cause a bit of drag, but probably not enough to notice. The loss of a good seal at the point seems to be a non-issue if you have cartridge bearings with their own seals, unless you spend a lot of time riding underwater.