Any experience with the Sidas foam liners ?

[passeparici]

Hello,
Is there someone with some experience with the Sidas Foam liners ?
I was wondering if the Classic PU Race was not a bit too stiff to wear all day long.
There is the PU Comfort liner but it takes a bit too much space in my boots

 

[glencoe]

I’ve been using the full race liners for all skiing since 1994. I wouldn’t use anything else.

 

[otto]

I have been injecting Sidas liners since the early eighties. Stiffness in a foam liner is controlled by the chemical mix in the foam, ( ratio of catalyst to base % ), the amount of volume available between the foot size and shape and the shell volume, the amount of structure built into the liner itself ( like cuff reinforcement or pre-padding of the ankle pocket, etc ), and lastly whether you allow the foam to bleed out naturally versus clamping of either outflow or inflow of the mixed foam.

Inherently, the Classic PU Race liner has no pre-padding and the liner itself does not have any stiff structural additions. So the result you get from that liner is relative to the guy that does your injection, the foam mix, and the volume difference between your foot and the boot shell volume.

Good luck!

 

[Tony Storaro]

Yep. Been on PU Race for the last 2 seasons in my RS 130.
The experience has been mostly fantastic. Excellent fit and as I said in another thread- I love the fact that the tongue is removable which means you can move it up and down in the boot a bit for a better feel.

Not in love with durability tho, they get easily scuffed by the constant ins/outs of the shell as I prefer to wear them racer's style-laced up and after 2 seasons they started developing small cracks in the material in the ankle areas .

Depending on how grippy your custom insoles are, you may leave these in the boot and remove the laces.
Mine are quite grippy, so it is not possible to insert my foot in the liner while it is in the boot, but I prefer them laced up anyway.

All in all, very good liners.


And no, they are not stiff for all day use, they are super snug but very comfy.

 

[passeparici]

I have been injecting Sidas liners since the early eighties. Stiffness in a foam liner is controlled by the chemical mix in the foam, ( ratio of catalyst to base % ), the amount of volume available between the foot size and shape and the shell volume, the amount of structure built into the liner itself ( like cuff reinforcement or pre-padding of the ankle pocket, etc ), and lastly whether you allow the foam to bleed out naturally versus clamping of either outflow or inflow of the mixed foam.

Inherently, the Classic PU Race liner has no pre-padding and the liner itself does not have any stiff structural additions. So the result you get from that liner is relative to the guy that does your injection, the foam mix, and the volume difference between your foot and the boot shell volume.

Good luck!

Thanks, nice answer.
A question though : are the foam mix different for the Classic PU Race and the PU Comfort or it is in the guy doing the injection's hands ?
I assume you get something less stiff if you allow the foam to bleed out naturally no ?

 

[François Pugh]

Don't know much about Sidas liners, but my old foam liners are as stiff as they come and hard as rock. The fitter made them so by cramming extra foam into them at seam-busting pressure. They are now comfortable (long story, but I had to do the finishing work on them myself (removing the bottoms so the size 8 liners could spread out to fit my size 10.5 feet). My boots are not warm, but they are comfortable. I have no problem wearing them all day (except for freezing my toes). Although the ski boots are hard to put on and take off, especially when cold (boots are stiff too), they are very comfy when it's not cold.

 

[otto]

There are a couple of factors that have altered the world of foam. Up until about 10-12 years ago there was a chemical used in the process called CFC's. Perhaps someone familiar with this material could explain what CFC's are and why they are bad for the environment and for humans. That said when the CFC's went away it definitely changed the way the current foam mixes work. This is anecdotal on my part, however in my opinion, the non CFC foam does not seem to work as well. The current foam versions available from all the suppliers seems to have less horsepower for those of you out there that like the hard and positive feeling of your old liners. On the upside the newer foams are more comfortable and easier to get in and out of. Although that said, I would not still be in a foam liner without a heated boot bag. Perhaps because I am lazy or maybe it's just an age thing?

In the good old days of foam, you could play junior scientist with the mix of catalyst/hardener to the base. Repeatability was the big issue. Could you get two foam kits to behave the same way? With any luck and the foam gods smiling down upon you, maybe? Today's foams are way more consistent and behave better for the operator of the process. The downside is that it is harder to "customize" the customization of the foams kick speed and density. Playing amateur chemists, does not net you the differences you could produce in the CFC era.

To directly answers the OP's second question, I do not believe that the foam kits are different between the Classic and the Comfort. They use color coded and letters to match the foam kit size with the liner size. I believe the main difference is the liner materials between the two and the Classic comes with an injectable tongue and the Comfort does not. If you had a low volume or high volume situation, you could mix and match a larger or smaller foam kit to make a love match.

 

[Tony Storaro]

Perhaps someone familiar with this material could explain what CFC's are and why they are bad for the environment and for humans.

Right here!

CFC-11 or also Trichlorofluoromethane-widely used blowing agent for polyurethane foams.
Also very effective in blowing holes in the ozone layer and Johnny Polar Bear does not like that.
Hence-forbidden.

I would not still be in a foam liner without a heated boot bag. Perhaps because I am lazy or maybe it's just an age thing?

Objection, your honor! 2 seasons in PU race, never had a heated boot bag. Just ordered one for the ZipFits tho.
Room temperature is perfectly sufficient to put the foot in the liner, lace it up and then into the shell. No problemo.

 

[Funkendrenchman]

I find the new Sidas tongues to be softer than the overblown Sidas tongues from 10 years ago. That’s why I’m using my old tongue with the newer Sidas Classic Flex. I think the loss of “horsepower” is largely in the tongue.