Do slalom skis “wear out”

[Skiphreak]

My alpine skis will be coming out soon. It’s generally believed that an alpine ski will lose its intended performance characteristics around 100-150 days of skiing. Certainly there are numerous other factors that lead to degradation of an alpine ski (terrain, skiing style, maintenance). But, it got me thinking about my waterski…

Do slalom skis “wear out” or lose there intended performance characteristics over time and use?   Assuming it’s properly cared for and maintained, would frequency of use alone wear out the life of a slalom ski? And if so, is there a commonly accepted belief how long a ski lasts before it’s worn out?  

[aupatking]

I once talked to a pro skier friend who used to be on one brand of skis that does their mold/press at a lower temp, longer cook time. He said his skiing went to garbage for a few months and he couldn’t figure it out. I’m not remembering the exact circumstances (maybe he borrowed a friends ski) but he got on another of the exact ski and there it was. Skiing was back to normal. He said his ski had basically gone dead. He has since been on a different few skis of a higher temp shorter press time and says he won’t go back. 
I don’t know that the build method was the ultimate cause, but I have heard that it happens. I’m waiting for my ski partner’s 2017 Senate to die on him so I can catch up. 

[thager]

Of course they do! Wink,wink!! 

[Nando]

I don't know- quite a few years ago I was working at a pro tour event and was doing some background skiing for a TV spot.  A Connelly rep was giving me a hard time about the age of my ski- it was about 5 years old.  He flex tested it and the numbers were exactly as it left the factory (the ski was not originally intended for me and the flex numbers were written on it under the binding).  Best of all, I got a new ski from him 😃.  I always assumed that skis went soft after a few years, but none of my old skis ever did- at least not when I had access to a flex tester... 

[Horton]

@Skiphreak

The short answer is “Absolutely yes”.

The long answer is a bit murky. Every composite part has a life cycle. Every time you flex a composite part you are stressing the epoxy matrix that holds the fibers in place AND the bond between the fiber/ epoxy outer skin to the core material. Over time and cycles of flex and rebound the epoxy matrix and the bond to the core materials will degrade by some percentage. The carbon fibers themselves will last nearly forever unless they are stretched or compressed too far and then they fail catastrophically.

In addition to the epoxy matrix and the bond to the core is the core itself. When a ski is flexed the top of the core is compressed and the bottom is stretched. After doing this thousands of times the middle of the core will degrade due to the shearing stress.

Water skis stiffness is measured by finding the force required to deflect the ski .1 inch over a span of 12 inches and doing so at 4 standard places from the tail of the ski. This is the standard for testing new skis.  This is the standard but it is not very rich data. It just measures one metric. This method defines how a ski will flex when it is new but does not reflect the changes as the materials degrade.

How fast any ski degrades is mysterious. There are skiers who swear it does not happen. As far as I know, no one has ever found a dependable way to measure it. What we do have is a lot of anecdotes.

Personally, I once had a ski go from AMAZING to junk in less than 10 rides. I have ridden at least 100 skis over the years and have only seen this once. Some of elite men's skiers will go through 2 or 3 skis in a season.

Eddie Roberts told me a story more than once about skiers riding one ski for a season and then getting the EXACT same ski from the factory and insisting that it was so much better than the old ski. Insisting that Radar had changed something. The fact was that the old was more damp and less springy. The new fresh ski was unquestionably better.  

So yes I firmly believe that skis break down. How long does it take? It depends.

[vtmecheng]

I have no knowledge on how fast a ski degrades. It makes sense that it would have to simply by the forces applied and flexing it goes through during every pass and the materials of construction.  The bending results in tensile and compressive stresses that have to be high, along with shear stresses at the laminate interfaces.

This is a funny topic where I ski because of a guy who used to ski with us. He loved telling other skiers that their ski brand is crap and already broken down, no matter the age. I got a new ski once and on my second set he told me it was broken down already because that brand is crap. Now, whenever someone PBs we inevitably say, "you would have gotten through that pass but your ski is just broken down." Makes for a good laugh.

[Skiphreak]

Thanks guys. I'm using this thread as ammo to throw at my wife when I buy that new ‘24 Senate! 

[The_MS]

Yes

[eleeski]

Wood skis and early urethane core skis do structurally degrade with time and use. Modern skis, not so much.

Waterskis are not designed for huge flexing displacements - the flex is very subtle. An overloaded ski is likely to break, not get soft. This is quite different from an alpine ski.

Resins can harden with time. An old ski might get stiffer as it ages. Maybe more brittle and weaker but most skis have a pretty good margin built in so that old ski still won't break on you. Certainly not go soft as it ages.

Any event that overloads a ski can degrade a ski. I've seen skis get run over by cars - despite looking OK, they might be suspect. I've seen black skis left in full desert sun. Resins, cores and even the rocker can be affected by the heat (we kicked off some carbon prepreg just by leaving it in the sun - it got to 170f! Enough to melt anything.). Don't leave your skis in the sun!

If your ski is not abused, it will give you years of good service.

With that said, new skis rock! New designs incrementally chase performance improvements. Old skis do undergo slight changes. The bottom texture wears down. Edges soften slightly - including the rope wear on the top edge which has a subtle but real performance effect.

Most importantly, a ski grows stale. Those quirky tendencies that kept you really engaged are now accepted and no longer helping you. You get too comfortable on the ski and quit pushing the edgy limits that score those extra couple of buoys. A new ski will force your skiing to improve.

Ski design has improved over time. A modern ski will score more buoys than an older ski. It will turn quicker with more stability than an older design. The new ski is worth it!

Eric

PS New trick skis offer even more performance benefits. Definitely upgrade your trick ski with a new one.

[buoyboy1]

I had a old X-5 and skied on it for about 3 years.  I began to struggle with it on my two hardest passes and became very inconsistent..  Would have a great feeling pass then a horrible one.  I put it on my flex machine and it was within a pound or two at every measuring location as compared to when I bought it.  One thing the standard flex test machine is unable to measure is torsional flex.  I sent to to someone that skis better than me and he had the same conclusion.  It was still a good feeling ski at 28 and 32 but 35 and shorter was nearly impossible.  I also imagine just because a ski flexes close to original numbers the speed of which an older ski rebounds slows down with age.  Any time I get a newer ski of the exact same make I am surprised how much better the newer one feels and performs.  

[Horton]

@buoyboy1

I said it before and I will say it again... A flex machine is a good metric for a new ski but does not measure ski deterioration.  

[MitchellM]

They must decay in some way over time.  The bigger question is how this would affect performance for the average skier.

I'm a decent tennis player.  Tennis raquets are made with similar composite materials, and they definitely do fatigue over time.  A tennis raquet likely takes more physical punishment than a water ski, but my raquets are usually "dead" after a year of play.  This is a very noticeable and well described issue in tennis.

[Horton]

@MitchellM This is an interesting question. My guess is a small changed to slalom skis results in a bigger change than in other sporting goods like tennis rackets or golf clubs.  This goes to my larger theory that slalom skis are at more technical than any consumer sporting goods. I have wondered if ANY sport has flex or dimensional tolerances as tight as water skis. 

I assume that when you get to the Olympic level even the brooms used in curling are super critical so I can hear the counter argument.

@AdamCord I know you want to chime in....

[tru-jack]

1 hour ago, Horton said:

This goes to my larger theory that slalom skis are at more technical than any consumer sporting goods. I have wondered if ANY sport has flex or dimensional tolerances as tight as water skis. 

@Horton  I would suggest alpine skis are.  Certainly not science based, but I'll never forget my daughter being absolutely amazed seeing Regina arrive at the malibu open in Milwaukee with only 1 slalom ski.  She was a U16 division 1 alpine ski racer at the time and she was used to seeing the pros, (world cup) alpine racers show up with 10-20 plus pairs of skis, and if it's a multi discipline event they bring 30 plus sets of skis.  to be fair, they have 3 or 4 types of ski (like slalom, trick and jump), and the skis will be waxed for different temps and selected the day of the race.  https://www.nytimes.com/2018/02/21/sports/olympics/mikaela-shiffrin-skis.html#:~:text=PYEONGCHANG%2C South Korea — Mikaela Shiffrin,with 70 pairs of skis.

 

[pcmcon729]

Snow ski construction couldn't be any more different from a slalom waterski.  @Horton is spot on about the limited info flex testing will provide.  REBOUND (dymanic) of the ski is far more important. This is far more difficult to measure.  I have had a well used 2 year old ski, "flex tested" at the factory, to be returned with the note that it matched the specs when new, only to ski on a brand new duplicate of the ski, and a completely different experience. Speed and rebound!  

[Horton]

okay I feel a little silly now. Yes, I should have known snow skis work way more finicky. I was more thinking tennis golf badminton curling pickleball... More the point I have always assumed the tolerances were tighter than elite automotive racing.

[eleeski]

Slalom ski flex is measured in millimeters. Loads are smooth on and off compared to almost every other sporting product. Snow skis have impact and huge flexing displacements at a much higher rate - even for a non competitive bump skier. And racers load their skis enough that they have to sharpen the edges after every run. Watch Mikaela Shiffrin running slalom gates to really see equipment get worked. Tennis raquets smash the ball on every hit. Bicycles get every road defect directly transmitted as load.

Waterskis have it easy. Water is so much softer than ice, a smashed tennis ball, or pavement. Water damps vibtations nicely. Water spreads out the load across a lot of the ski. Structurally it is about as easy as it gets. 

I make my skis as stiff as possible (for my weight constraints - I'm a total believer in weight reduction). Rebound has never been relevant to any ski I've built - not compared to weight and stiffness.

So why do skis suck as they age? Testing doesn't show any measurable degradation.

Rocker changes? Flipcore skis (wooden core snow skis with the cores pre loaded by the molding process) lose a lot of the livelyness that makes them fun as the skis age. But I'm not sure of any wood core waterskis. However, pre loads are possible in the molding process for waterskis and a ski might move over time (and heat). 

Some skis don't get all the mold release removed before sale. A quick wash with Ajax cleanser will take care of that. Usually that improves the ski's performance - your results may vary. But nobody waxes their waterskis and skis better. Any mold release will be gone quickly - before most complaints of a ski "breaking down".

Some skis come with a carefully chosen texture on the bottom. This texture can wear and change the "feel". I like a 40 grit scratching across the ski. It needs to be renewed a couple times per season for me. Note that many (most) skis have very smooth bottoms and 40 grit textures might not work. 400 grit? Other skis have a sandblast texture molded in. Not sure how to refresh that except by buying a new ski.

Edges do wear. Travel rash, handle dings, rope abrasion of the side from getting up, binding movement, fin movement - there are so many factors that one can actually feel. I'm not sure that it "ruins" a ski. A lot of it is mental.

I struggled in my last few slalom rides. Frustrated, I examined my ski. I found that my travels had damaged my wing. Between rounds of the tournament, I found visegrips and straightened the bent wing. Solid round next round and back home had the best practice set of the year. Sometimes it really is an equipment problem.

But not a broken down ski. I pulled out a ski that I gave up on a few years ago and loved it. It is my first string ski now. Too often we blame the equipment when that's not the issue. 

Buy a new ski if you want it. Not often can we buy buoys so temper your expectations.

Eric

[liquid d]

Spend the money! Enjoy the honeymoon! Life is short baby!!!

[Mastercrafter]

.... What a flex tester can't test is compression and rebound rates, and I'd have to imagine that has as much or more effect on feel and performance of a ski than actual spring rate and stiffness. A new ski is likely to be more crisp and feel more alive than a ski with 1000 sets but I'm not sure we have the equipment to test it. Going back to the race car analogy, suspension setup (compression and rebound, along with spring rate) makes a world of difference. 

 

 

[BrennanKMN]

I do agree, that skis degrade over time. However, at what point does it matter for most of us? 

I would argue that for the vast majority of us it really doesn't matter. You're far more likely to see an improvement in your skiing from a new ski due to newer technology vs. a 'non warn out identical ski'. While I have zero data to back any of this up, I would find it very hard to believe that someone skiing at the -15 to -28/32 level would notice any true difference. If they did I would argue that it is mental and a blind test would need to be performed.

I ski 40-60 sets a year. I try and use a ski for 3-5 years. After that I believe I can benefit from the advancements in new skis. Not that my ski is so warn out that I need a new one.

[The_MS]

Lots of factors go into a ski breaking down. 
Amount of time spent baking in the sun           
Any handle shots to the ski or tip of ski?        
Time in hot cars                                                
Number of sets                        
line lengths skied

ect   

 

 

 

[Horton]

@BrennanKMN

it is a spectrum.

At 15 off. meh. Whatever.

By 32 off a dead ski sucks.

At 38 off or shorter it is absolutely a thing. It is absolutely worth a number of balls.

[DW]

@tru-jack - it was noted that Mikaela picked a ski outside her allotment for a specific discipline, it was from one of her competitor / Atomic teammates stash.

In addition to the characteristics noted for a ski degrading, fin box stiffness or degradation / change will also have a significant effect on ski performance.  JTH - at the elite motorsport level, specifically F1/Indycar etc.  the tolerances are down to thousandths for numerous measurements (shocks, aero, ground clearance).  Relating to skis, numerous stories of a team / driver changing the chassis to fix a recalcitrant car.  I've experienced that very thing in a formula car.  Or maybe no matter what the sport, humans simply whine about something and yes sometimes its mental. 

[tru-jack]

@DW do you recall the rumour at the 2018 olympics that Ester Ledecka won the super-g gold on borrowed skis. Something along the lines that she only had a few pairs of skis and they got misplaced. I recall it may have been Mikaela that lent the skis.  The other amazing feat was a gold in snowboarding at same games. Pretty amazing to win gold at 2 different disciplines at the same games. 

[Cooper_Trelawney]

Reading this thread and hearing about ski stiffness and flex makes me wonder about plates and bindings and if they limit the Ski from it's full performance potential (of course me, the skier, is the biggest limiting factor).  But what if plates and/or bindings flexed with the ski?  Or do skis just not flex in the central area where bindings are mounted?  Is this just a dumb thought?

[Horton]

@DW I always thought that a looking for differences of less than 5lb of force used to create 0.10" deflection across a 12" span was a pretty high bar. 

[APB]

On 10/27/2023 at 6:44 AM, Skiphreak said:

Thanks guys. I'm using this thread as ammo to throw at my wife when I buy that new ‘24 Senate! 

100% yes. and youll love it.

[lpskier]

Do slalom skis wear out? I’m not sure. 
Do slalom skiers wear out? Certainly. 

[Drago]

@Cooper_TrelawneyThe testers/designers use bindings with plates, so likely no big deal.

@tru-jackAlpine speed skis are different (SG and DH). Sometimes they will be several years old. When you hear Picaboo Street or Lindsey Vonn are using DH skis in Super G, it's because they are incredibly fast. Atomic owns the speed skis, they return to the factory after races. Mikaela, who I assume had #1 priority, decided not to start the super G, the other Atomic athletes stuck with what they chose earlier, so Ledecka got Mikaela's and flashed from the back for the win. (The track can also get faster and faster when the snow gets less sharp and glazed-over)

World Cup Alpine SL skiers probably use at least 10 pairs of skis a season (and several boots!) Alpine skis flex  more than 12 inches every single turn, obviously they break down quite a bit. (A SL course is around 50 turns). It would be interesting to know how much an H20 ski flexes when the greatest load is applied in water.

[Stevie Boy]

At the end of the day, does your ski still perform for you, as the ski softens, it may suit some people and be a little more forgiving than when it was new, if you have hit a slump that you cannot get out of, or you feel that the ski is less responsive you may consider that the ski is at fault, a difficult one, as change occurs, your body or technique will adjust accordingly and maybe difficult to detect a change until the ski is totally shot.

Lots of factors here, how you treat your ski, leave it in the sun or a hot car or put it in your bag damp/wet, may contribute to ski breakdown over time.

Somebody did explain to me that, when a ski breaks down, it can be good one day and not so good another day, went into some explanation about the fibres re-aligning, getting displaced and then re-aligning again, interesting but I do not know enough about carbon fibre to give a informed explanation.

[tru-jack]

@Drago I know all about the SL and GS skis as both kids ate through a minimum of 2 pairs of each and in their later years 4 pairs of each ski every year. My garage had more skis than local sporting goods store. They never got into downhill but a fair bit of super g and yes everyone wanted older skis as they’re full of wax and run faster.  Boots would get worn out at 2 pairs per year and in their mid-teens they would change through the season for a stiffer flex in the same size. My wife was never keen on new boots for the kids that were the same size. Fortunately after buying 8-12 pairs of skis for kids annually she’s been desensitized to new sports equipment and the odd slalom ski I order every other year doesn’t get noticed.   
 

[skialex]

@Stevie Boy I have flex tested some skis that had more than 500-600 sets.  Haven’t seen any softening. Not at all. I have only seen in some an increase in the time for the flex numbers to settle, compared to fresh skis. I don’t believe that a ski can become softer thus more user friendly for us mortals. 
I also believe that some skis don’t wear out at the same rate and riding a ski that you like a lot for some years after many sets, doesn’t mean that it’s done,  If it feels right… it feels right.

I have thrown away a ski that I loved for many years because it felt sluggish and to much work and when tried a fresh ski it felt much easier to ride.

[Horton]

I'll say it again. Whatever happens to a ski as it ages is not reflected in the standard flex test procedure. Skis certainly degrade with use but the standardized flex procedure does not show it.

somebody alluded to ski being maybe actually better after it's broken in. no no no no no no no no. there is nothing better about an older ski.

[Stevie Boy]

@Skialex + @Horton

I understand what you are saying , perhaps as @skialex suggests it's probably more the ski settling in or the skier settling into the ski, so the term softer would be incorrect.

I Agree with both of you Guy's

[Horton]

part of the reason why this subject is surrounded in mystery and confusion is because most of the time skis disintegrate at such a slow rate that the skier doesn't realize it's happening. It's the "frog in a pot of water" situation.

[ETskier]

I think a lot of it is the rebound rate deteriorates.  Haven't seen any measurement for that. @skialex was sort of on to that above.

[MDB1056]

Re- reading all of this again…..the simple answer is nobody knows . A lot of speculation, guesses, one metric comments, logical assumptions, anecdotal experiences, etc., but zero hard quants on multiple key metrics that support even a loose consistent lifespan model of any kind. 

I find that surprising from the industry considering a high level of consistency in modern manufacturing processes, and materials, yet the absence of data may also reflect a common reality that data may show very little degradation, which of course is not good for promoting buy new. Who knows….  Again the only constant here from reading is we don’t know.

[Horton]

@MDB1056 

[thager]

Hold my beer....... and yet Jeff Rodgers put up some pretty damn impressive scores a few years back on an unknown very OLD ski! 

[skialex]

@thager you could be right, or he might had a stash of some very old skis with not thousands of sets in them. Very impressive though. 

[MDB1056]

@Horton show us the quants. Absent hard data specifics cannot be confirmed. Sure we can all agree changes likely take place over time, but again specifically what when and why seem elusive at best. If the industry has data it should be made known. As again absent data it’s all admittedly speculation, meaning nobody really knows…. 
 

pandas….. meh 

[jjackkrash]

I don't see how some healthy skepticism about blaming alleged unmeasurable material changes for poor performance is triple panda worthy when the impact of bias on perception is a known scientific fact.  That seems to devalue the triple panda award.  

[Horton]

the way I read @MDB1056's comment, it sounds like he's questioning if ski performance actually degrades with use.

I do agree that we do not have a metric & we do not have hard data to measure any of the parameters. That does not change the fact that performance degradation after thousands of cycles ( turns & pulls ) is in the realm of common sense. It may not be scientific, but the anecdotal evidence is significant.

The only hard science I know on the subject comes third hand through Eddie Roberts from the University of Washington who did some electron microscope studies of micro fractures in epoxy matrixs around carbon fiber. The short version is yes the matrix changes after time and cycles.

 There also could not be and will never be a meaningful formula to calculate how long a ski will last because every skier loads a ski differently, every skier takes care of their gear differently, & every composite part is slightly different than every other.

[jeblanc]

Piggy backing onto what @Horton said about every skier loads a ski differently, common sense says that short-line skiers at the highest level are putting a lot more load than us recreational skiers.  I don't compete but I have regular access to a course.  I've used the same high end ski for the last three plus years and I'm not in any hurry to get a new one (this sport is expensive enough as it is).  But in a sport where there's constant innovation in the industry, I do sometimes wonder when it's time to start thinking about replacing my "old" but pricey equipment.

[Horton]

@jeblanc how much do you weigh and what passes do you run? How many rides do you think you take per year?

[jeblanc]

@Horton Looking back at the calendar this year, I would estimate I skied 40-50 sets.  I'm 160 lbs and generally ski -15 off/34 mph.  On a good day I push it to -22 off.  

[Horton]

@jeblanc you can tell your wife I said "you must get a new ski. It is critical!"

Between you and I, your ski is likely pretty fresh unless you abuse it with sunlight or run it over with the boat.

[Horton]

The conversation I wish we were having is about how to test skis for degradation. How does snow skiing measure rebound? If I am correct that the standard way we measure new skis is useless to measure performance decline then what is the correct method?

[Drago]

@Horton I’m not aware of any measurement of decline in snow skis' rebound. Mostly the pilot says, "These are dead". There are other variables prior to tossing a snow ski (no edge left, hit a rock...). Skis that don't work on ice can work in dry cold "aggressive " snow (Vermont--> Colorado).

*we're talking about elite-level racing here, not powder skis in Utah 

[Killer]

1 hour ago, Horton said:

The conversation I wish we were having is about how to test skis for degradation. How does snow skiing measure rebound? If I am correct that the standard way we measure new skis is useless to measure performance decline then what is the correct method?

You test old alpine skis rebound by skiing on new skis