Road debris get into seat post hole what to do to prevent?

[nz6666]

When ride in rain, road debris can get into seat post hole. I can feel the friction when I slide the seat post in or out of the frame. If I remove the seat post I can see or feel the stuff with my hand. They may get in from under the frame, where there is a opening to the ground. I have the problem on both a Brompton and a Dahon since they both have the similar opening at the bottom. Strangely this only happens when riding in rain so not sure why they don't get in when it's not raining.
Do you have this problem as well? How do you deal with it or prevent it? For my dahon, it's easy, I can just pull the seat post out and clean the seat post, and use a long stick wrapped in rags to probe into the seat post hole to clean water or debris. For Brompton, I have to remove the saddle first, not the thing I want to do after every rainy ride.

 

[Nibor]

one of these?
http://www.wiggle.co.uk/fizik-seatp...|pcrid|71714705102|pkw||pmt||prd|5360605556uk

 

[Brommyboy]

Dirt gets into the hole at the bottom of the BB part of the frame. This has to be kept open to allow the seat post to protrude when folding the bike. The simplest solution is just to give it a wipe occasionally with rag or balled paper towel. If you park the bike and then lift the front so that it stands with the saddle on the ground and the bars in the air, you can easily see what you are doing. The wiggle ring will not work, as the dirt comes in from below, not down the seat tube.

 

[nz6666]

The only thing I can think of is pre cut some duct tape and stick them somewhere on the frame. When it rains, just peel some off and use that to seal the hole, stick it back to the frame when folding is needed.

 

[chris folder]

Hiyeah when you slide seat post up/down you can sometimes hear gritty sounds bits inside frame rub against post also that's what causes the scratch marks on seat post

 

[Ian H]

It's mostly the muck flung up by the front wheel. On the Airnimal folder I used to own, I fitted a flexible plastic flap just in front of the bottom of the seat tube – cut an appropriate shape out of a milk carton and zip-tied it to the frame. You may need to experiment with the shape.