Threadless Headset Parts

[MartynWheeler]

Hi,
Just pulled the forks off my specialized secteur road bike. It has sealed cartridge type bearings in the integrated headset. I noticed that there is an extra seal between the bottom bearing cartridge and the crown race (a flattened rubber type seal) - my question is: is this normal? What is its purpose given that there are seals on the bearing cartridges? Is it just another layer of protection? It is just that most assembly diagrams of threadless headsets don't seem to include it.

Thanks,

Martyn

[Brucey]

it is an additional seal, because one isn't enough on bikes with no mudguards. Quite a few bikes have them like this.

cheers

[Valbrona]

Some integrated headsets have these seals and some don't.

These are the seals you find on the work surface in the kitchen after you have re-assembled your fork and tightened up the headset bolt.

[RogerThat]

The seals are often ineffective. I've taken to buying an outsize rubber 'O' ring and using this as an external sock seal. I've taken this through winters ( I don't ride with a front only a rear mudguard) and the bearings are protected beautifully. And the best news, they're only 10p each from my local hardware store!

[MartynWheeler]

Thanks for the help. This forum is brilliant!