Regarding Leonid Kuzmin’s Thesis on Skis being Faster without Wax
I am sorry to have to write this. Everybody who works in the ski industry has way too much to do and too little time to do it in the winter. My colleagues have chosen to ignore this thesis which we all figured would simply go away after people read it and thought for themselves. However, what seems to be happening is that people are being taken by the medias’ repeat running of headlines that refer back to this thesis keeping it alive and also lending it credibility. I also think that refuting this thesis will probably result in less bother over the long term as it has generated many individual email inquiries. Hopefully this will put it to rest. For this reason, I have elected to spend some precious time and address this sensational thesis. The thesis in question can be viewed at this link: http://epubl.ltu.se/1402-1757/2006/03/LTU-LIC-0603-SE.pdfI can start off by saying that throughout the world, there are national teams and clubs that devote a great deal of money and energy to ensuring that their skis are the fastest that they can make them. This involves a great deal of ski, structure, and wax testing. The entire elite ski racing world waxes its skis. The only exception to this is when the snow is exceptionally dirty and greasy (as in Thunder Bay World Championships in 1995). In these specific conditions, we realized that skis glided faster if they had never been waxed because they stayed cleaner. Again, this is only in the most dirty snow – which often times is trucked in from airports or fishing docks.
I’m going to number my comments so it is easier to follow each point.
1. Kuzmin starts by identifying a “mantra” and then saying that it is not true. The first thing that he says is that ski bases do not become impregnated with wax. His reasoning for this conclusion is that a hydrocarbon wax molecule is larger than a water molecule, so how come we haven’t seen water enter a ski base? This is his reason that wax does not enter a base.
The funny thing is that we do know that wax enters a ski base. At Toko we use a thermoanalyzer. We can wax a base and then measure exactly how much wax is in the base. We can even see how deep the wax has penetrated by slicing off 1/1000m pieces off and analyzing it. This is how we came up with measuring the effectiveness of ironing waxes (temperature versus time) as well as comparing the effectiveness of ironing versus treating skis with a Toko Thermo Bag. We know that wax enters a ski base. This is a fact.
Others have ended up with the same conclusion by weighing a ski before and after waxing, scraping, and brushing and coming up with a quantifiable weight of how much wax enters the ski base.
So, how come we don’t see water entering a ski base?
What Kuzmin doesn’t address is the need for heat to expand the base. If a ski base was heated up and then hot water poured on it, a small amount of water would enter the ski base…only to be squeezed out again when the base cooled off and contracted again. We skiers experience this when we prepare our skis inside in a warm room for an event in very cold conditions. We then go outside and then notice that the bases have become “white” because the wax in the base has been pushed out as the base contracted in the cold weather. Of course water does not get solid enough to be retained by the base and effectively become part of it. Clearly this water logic is very primitive and belies a lack of very basic knowledge of waxing.
2. The second statement that Kuzmin makes is that glide waxes do not protect a ski base from abrasive wear. His reasoning for this is because a ski base is harder and more resistant to abrasion than ski wax, treating a ski base with ski wax would only make the base less resistant to abrasion.
Let’s apply this logic to the world that we are all very familiar with. When our ski is dry, it is easily abraided or scratched, right? When we apply moisturizer to our skin, it becomes more resistant to abrasion. How can this be if moisturizer is so much softer than skin? Consider wood furniture and furniture polish again and come up with the same idea. The softer treatments do help protect against abrasion as well as restore, which is another key function of ski wax.
OK, let’s take a closer look at how Kuzmin’s methods. He used a Sand Slurry test to measure the abrasive effect on test materials. This involves putting Ptex and chunks of ski wax in a barrel with coarse sand and water for several hours and then evaluating the amount of abrasion on them afterward. Because Ptex is many times more abrasion resistant than any ski wax (block obviously) on the market today, “the idea that glide wax application protects the ski base from abrasion is clearly absurd”. Actually, in truth, Kuzmin never even did the test, he just quotes that Ptex is clearly more abrasion resistant than ski wax. What could have been done is compare waxed Ptex to unwaxed Ptex and then that would have given some data, but that was not even done.
We all know that when we wax a base with blue wax, scrape and then brush it out the result is a far harder base than when we wax it with yellow wax. Why is this? Because blue wax is really hard and brittle. In fact, blue wax appears to be harder and more brittle than a graphite base (4000 electra for example). It only follows that the introduction to this brittle hardness to the ski base (addition really) would make the ski base more resistant to dry friction which both abraids a ski base and slows the ski.
3. His third point is transparent base material is faster and better than black base material. (He refers to it as graphite base which is how it is commonly known, but in actuality, black bases do not contain graphite, but carbon or soot). He then shows a chart from the Ptex manufacturer IMS Kunststoff AG where the chart shows the wax absorption of the bases (then he says ignore this because bases don’t absorb wax – why show the chart then?). Of course this whole point has nothing to do with his thesis or premise, he just wants to make a point that black bases stink.
In actuality, the ski industry knows that transparent bases are better in very wet snow than graphite bases. We know this. We also know that transparent bases are better for promotion because we can write graphics on the bottom of skis that makes for very cool looks and great exposure. The problem is that we also know that except for in very wet snow, black bases run better than transparent bases.
Notice that ski manufacturers such as Atomic and Germina used to make transparent based (6000T) skis specifically for very wet snow. This is nothing new and I can assure you that the manufacturers are aware of the fastest base materials in any given condition. There are other issues. When a ski manufacturer orders base material from a supplier, you have to basically order it in miles of material. This effectively eliminates base material that is good for racing in only a specific condition. Kuzmin writes, “Why ski makers only produce X-C skis with a graphite base is one of the biggest mysteries in the ski business”. Something can be a “mystery” to an uninformed person and a simple concept to an informed person – think about it.
4. Kuzmin then goes on to give what he calls a history of skiing and then of ski wax. One thing that jumps to my attention is how disdainful he is of wax companies. He then goes on to describe the foundation and evolution of Swix (in a very critical manner). This is a strange thing to do because there were a number of wax companies in existence before Swix, of which Toko was one, but not the first. He then describes how pathetic the waxes were even as late as the mid 1940s. He even writes “Swix was born in 1946. These waxes are known as the second generation of waxes, though there was still no division into kick and glide waxes. Skiers used the same waxes as kick- and glide- waxes. Sometimes a softer wax was applied on the middle of the skis. From that time until the present all kick waxes have been and are instances of Swix a la 1946. Nothing revolutionary has happened since in this field”. What he is saying is that our current kick waxes are the same as the glide waxes of old and also that kick waxes have not improved at all over the past 60 years.
My nine year old daughter could pick this one apart. First, in 1940, Toko had a very popular and famous glide wax line out called 1-3-5 wax. This was a hydrocarbon wax that offered a harder wax for cold (1) and a medium wax for around freezing (3), and a softer wax for warm (5). This theme continues today in Toko’s Blue, Red, Yellow colors which is a testament to the concept of simplicity and function. The waxes themselves were similar to today’s hydrocarbon glide waxes except the paraffin was not as pure and there was no synthetic additive in them. Of course they are nothing like the kick waxes of today as these waxes were slippery, not sticky! They resembled candle wax which of course does not resemble a stick of kick wax.
I should add great developments have occurred in the areas of binders and dirt resistance of waxes for warmer temperatures (klisters and silver hard waxes) especially over the last decades. It is true that there has not been a revolution in kick wax for the colder and easier-to-wax for conditions.
5. Kuzmin then makes the point that “the development of Fluorocarbon additives and Perfluorocarbon powders was hailed as a radical turning point, as a third generation of waxes.” And adds, “It is hard to see it (the development of Fluorocarbon waxes) as a radical turning point, or that there is any reason to call Cera F (Perfluorocarbon powders) the first wax in a new third generation of waxes. It all looks like an exemplary case of a promotional gimmick”. A promotional gimmick? Any experienced racer knows that to start a race in wet snow without a Perfluorocarbon overlay is to resign one’s self to a poor performance – everybody knows this! How could he possibly say this even?! I have to wonder what this guy is trying to achieve – what’s his agenda? (I really don’t know, I’m not being rhetorical).
6. Kuzmin writes, “It is uncertain why skiers stopped using a kick wax along the full length of the skis, but instead began to use glide wax on the front and back (“tips and tails”) of the ski. It was probably because the companies that produced the first plastic skis were Kneissl and Fischer, whose managers had much more experience of alpine skiing.” Evidently, Kuzmin thinks that skiers are really stupid. I believe that skiers stopped using kick wax along the full length of the skis was because it worked better to use glide wax on the ends and kick wax in the middle only. I can tell you that this is why I started doing it this way. Also, I seem to remember Elan and Rossignol having early “plastic”. The green and black top sheeted Elans and then the next year the navy blue top sheeted Rossignols.
7. Kuzmin then writes about Stonegrinding (referred to as SG), “The first impression of SG was not very pleasing; the ski did not glide at all. A very material- and labour-intensive processing was developed to get the skis to run acceptably after SG. Moreover, because the machine and wax makers made huge amounts of money by introducing the new equipment, they convinced the X-C community and themselves of the superiority of SG machining.”
I’m not sure what planet Kuzmin was living on during the 90s, but on planet earth, this is not at all how it happened. First off, the stonegrind manufacturers and the wax manufacturers are entirely separate. The “wax makers” did not introduce any new equipment as a result of Stonegrinding. Additionally, Stonegrinding was an instant success where it mattered most – in the elite racing field. There was no “convincing” going on at all. I was on the US National team and was also aware of every single national team driving and flying all over the world to get ground by some of the early masters of stonegrinding. Many of the national team waxers were stonegrinding experts out of necessity as this is a developing art and racing was where the great development was occurring. My estimation is that 95% of all ski medalists (Alpine, Combined, Jumping, Biathlon, and Cross Country) in the 1992 Olympics skied on stoneground skis. Most had their skis stoneground specifically for the Olympic races about 1 month before the events. Now of course the technology has improved such that a Stonegrind can be applied cleanly enough for a skier to race on it the next day (with the proper waxing – penetration and then hardening before applying the waxes of the day).
8. Kuzmin then notes that all of the testing (waxed versus unwaxed) was done on skis scraped with a metal scraper. We all know that metal scraping is an art that takes skill and patience (as compared to peeling a base to flatten and eliminate unwanted structure before stonegrinding). I have a personal knowledge of Kuzmin’s metal scraping prowess as I had the bad luck to have to work on his wife’s skis before the American Birkebeiner around 2002. The ski bases were dried-out, scratched up (he scraped them dry as compared to scraping them and using a soft wax as a lubricant), torn (as compared to cut), and simply horrible and slow. I spent 3 late nights working on her skis starting completely over – metal scrape, dehair, wax, structure etc. She ended up having excellent skis, but only as a result of my undoing all of his horrendous work. With this being the case, I can only assume that all of the skis that he scraped were scraped equally as bad and that all the skis were probably equally as slow because the badly scratched, torn, and simply very slow finish on the base was certainly the dominant factor in slowing the skis down.
9. Kuzmin then talks about how bad Stonegrinding is again – how the skis don’t accept wax after Stonegrinding and how the roughness of Stoneground bases and steel scraped bases are very similar. It is a fact that skis take in a ton of wax after having been Stoneground. Otherwise, the finish of a Stoneground base varies greatly depending on the desired finish. Generally the finish of steel scraped bases is very poor – hence the needed development of Stonegrinding. Sorry to give such simplistic responses on these two points, but the logic is so primitive, I can’t justify spending any more time on it. I assume that you the reader can see this too.
10. Then he talks about how Stonegrinders a limited to applying longitudinal patterns on a ski and how this is perhaps OK in warm temperatures, but in cold temperatures a transverse (lateral) structure would be better. Come again?? This is simple lunacy. In cold temperatures, particularly with cold powder snow structure needs to be kept at a minimum. Furthermore, this is the type of snow that any horizontal (or lateral or transverse) scratches will make a difference. This is one of the only conditions where the horizontal structure will make a dramatic difference. Anybody who has skied in these conditions knows this.
Back in 1989, I actually played putting structure in my own ski bases with a file. One day, I put lateral structure on my ski just to verify my intuition (common sense) that it would greatly slow the skis. It did. The skis were horribly slow until I had them ground appropriately.
It seems that I test everything where Kuzmin surmises or theorizes about everything. I do not claim to be a smart scientist, but what I do know is irrefutable because I have experienced it. It is not theory. I test everything.
This is the end of the first part of his first dissertation. I’ll just plow on acting like the whole thing is one part to avoid confusion. I’ll just work from front to back.
11. In his next section, he slams Stonegrinding some more and says that a ski scraped with a steel scraper will be more hydrophobic than a ski that was stoneground. He did mention that the skis were waxed with Swix CH8 wax (not a very hydrophobic wax) and then, unbelievably, the skis were brushed with a Red Creek Steel Roto Brush using 4000 rpms. (Why would you do this to a pair of Nordic skis?? You might as well just throw them out or better yet, give them to the poor). Anyway, he then goes on to write how Stonegrinding makes a ski less hydrophobic compared to metal scraping and how wax needs to be added to increase a skis hydrophobic properties which then will attract dirt. My opinion is that the hair that he generated in metal scraping contributed to the water angle measured on the machine resulting in a high measurement. The stonegrind was almost certainly far cleaner (based on what I have seen of Kuzmin’s metal scraping I can say this was confidence) resulting in no “assistance” to the angle of the water drop. His hairy and torn-up metal scraped ski base never touched the snow this entire time – why not just jump on it and see how she runs??
12. In the Abstract of Kuzmin’s next thesis, he writes, “It is common knowledge that minimizing dirt on the running surface of skis improves the surface glide. Waxing usually improves the gliding ability of skis in the short term. But how does waxing affect pollution absorption in the long term? In this study a number of skis with a transparent base and a white background were treated by steel scraping and with different glide waxes. The gliding ability of waxed and unwaxed skis, the sliding surface whiteness and the hydrophobicity were tested and documented. Testes were performed before and after the skis had been used for different distances. It was observed that all the waxed skis (regardless of the wax used) absorbed more dirt than unwaxed and as result all waxed skis lose their glide ability sooner then unwaxed (dry) skis. General conclusions: Stonegrinding and glide wax application are far from an optimal treatment for skis if the primary goal is to minimize friction over a given distance”. Well, he finally got one right! I concur with this statement assuming he was testing in an extreme version of dirty snow. This is common knowledge among the racing community. It first came to light at the 1995 World Championships in Thunder Bay, Ontario. Skiers were skiing on brand new unwaxed skis because they stayed cleaner and thus faster longer. This was extremely dirty snow though which is rarely seen. Most times, such extremely dirty snow is trucked in from airports and fishing docks (you can imagine how much oil and other pollutants are in such snow). The lack of wax gives the dirt and grease nothing to stick to.
To follow up on this, of course a dirt and grease covered base will be less hydrophobic than a clean base. So, yes, a dirt free base is faster in general than a dirty base. However, this condition is extremely rare – we are talking about extremely dirty snow here. FYI – the waxed skis are faster until they become dirty. (Oddly enough, Kuzmin’s testing did not show a decrease in hydrophobicity as dirt accumulated on the base – go figure – must have been a lot of fish oil in that dirt or something).
FYI, Kuzmin roto brushed the hotwaxed skis again before testing with a Steel Red Creek rotobrush. Might as well throw the whole test results out.
Its strange, if you compare the meat of what he is writing about to the headlines, they don’t compute. Most of what he writes about in volume is steel scraping versus stonegrinding (and then a bunch of intelligent sounding re-writing of history).
Kuzmin has more work coming. He plans on testing more in cold temperatures. Hopefully, this information will encourage him to improve his work.