Tänkte kontakta tillverkaren:
http://www.emw.de/E_web/aa_technical_foams.htm
för att fråga om svenska grossister för Poret men blir osäker på om det ska vara polyether eller polyester, På en gammal tråd på trikeslistan talar man om polyethylene:
Poret filterfoam (was: RE: [trikes] alot of replies) karl.auer@id.ethz.ch karl.auer@id.ethz.ch Thu, 09 Nov 2000 10:53:59 +0100 (MET)
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Hi Jon.
On 08-Nov-00 Jon Loldrup wrote:
True. I'm trying to get a slab of Poret 10PPI filterfoam to make a replacement seat pad, will let you know if it makes a difference. A Challenge seatpad cut in half to replace the lower seat pad on my Windcheetah made a big difference to comfort, so I expect great
things
when I replace the back pad as well.
How did it change comfort (better I suppose, but can you describe
what
became better?) I haven't heard of "Challenge seatpad" or "Poret
10PPI
filterfoam " before, do you have an URL?
The standard seat pads are absorbent, so riding in the rain is a squelchy affair. They also have very poor air circulation properties, so one gets a very sweaty back. They are hard to clean and take a LONG time to dry out once they get wet.
This filterfoam is the same stuff used on Challenge bikes. It is an open-pore polyethylene foam technically called Poret, and comes in various grades, ranging from 10 pores per inch (PPI) to 100PPI or more. The coarsest version is the stuff Challenge and probably a few others use. 15PPI would be softer and probably still OK; anything finer would still have a cushioning effect, but the flow of air through the material would be much decreased, and the tendency to hold water when wet would be increased. Water just falls through the 10PPI stuff. Getting it clean is just a case of squirting it with a hose or under a tap, and shaking it dry.
Ed Deaton at Fools Crow Cycles sent me a Challenge seat pad, which I brutally assaulted for Experimental Purposes. That is, I chopped it in half (crossways) and laid the two bits across the bottom part of the Windcheetah shell to replace the supplied lower seat pad. There wasn't enough to make a replacement back pad as well.
The result was very pleasing. The foam sits neatly in the shell, and deforms to the shape of the rider. On the other hand, it doesn't flex much - which means that you are not dumping pedalling energy into the seat pad. Even when compressed by my 100kg, air can move freely through the pad - at speed, I can feel air moving under me, scooped up by the lower lip of the shell. Because the pad shapes so well to the rider, it lessens the tendency for the rider's body to slide forward. The foam adheres naturally to the Velcro strip in the seat shell too, so it sits firmly where it's placed and attachment and removal is very straightforward.
My plan is to get a larger sheet of this stuff and cut a single shaped pad out of it to fit into the Windcheetah shell and replace both the lower pad and the back pad. I expect the airflow to continue all the way up my back, which would pretty much eliminate the sweaty back problem.
I'll let you know how it works out when I get the stuff and have tried it out properly. One possible issue is the 50mm thickness of the material - it may affect the effective rider position and/or lift the upper body too far out of the shell. It may be necessary to shape the thickness of the pad, not just the outline.
Regards, K.
Finns någon kemist i salongen?
olaf