 Poster: A snowHead
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Whilst preparing my Volkl M5 skis for my trips this season I noticed that towards the tips and the tail the base is not completely flat but slightly concave from around 1" in from each edge, this must have been done in the factory as they have not been on a grinding machine. Why are the bases profiled like this as I have never come across this before on all the Volkl skis that I have owned.
This is particularly noticeable when removing the wax with a 5mm Perspex scraper and I have to use a 3mm thick one to be able to bend it to get into the concave section to try as best I can to remove the wax. Even after skiing for a week I can still see the difference where the wax has not been fully removed even though I used a nylon brush followed by a horsehair brush after waxing.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Some skis will have a slight concave shape at the contact point of the tips, I think this is what you are describing. The ski is designed this way to allow the edge close to the tip to engage slightly quicker.
This will give you a more demanding and sharper handling ski.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Thanks for you informative reply and yes that is what I was referring to.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Not saying it is what has happened in your case, but in my experience some composite kids skis can go concave from waxing with an iron. I noticed it the first time I did a pair I had 5 pairs of same ski. Did the first with an iron and noticed it was concave, checked others and weren't. Did second pair and went concave the same. So did the others with hot air gun and brush and were fine. The two that went concave I clamped down on a surface table and heated tops slightly and they went back flat. I do adult skis all the time, probably wax over 100 skis a year for dry slope so I am experienced at it. No idea how much effect the concavity has on the performance of the ski. I do all the kids skis with hot air gun and brush method now, works just as well and doesn't use as much wax.
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You'll need to Register first of course.
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| valais2 wrote: |
| @Tykebike, I think the answer from NoMap is confusing camber with concavity in the base (to which you refer). It is a recognised issue see |
I think this is something different and not confusing camber and rocker. If you consider rocker and camber to be longitudinal, i.e. along the length of the ski then some skis, particularly powder skis can have a convex or concave profile horizontally. A convex profile is used to help shed snow in wetter conditions. Similarly some skis have concave areas at the tip and tail were the camber starts and ends. The idea, I think, is to make it easier to engage the edges on wider skis icier conditions. I have seen it on multiple pairs of Elan skis straight from the manufacturer, although I think that also might relate to a lot of Elan skis being left and right specific, so each ski has a definite inside and outside edge. I personally don't like it as it makes servicing a pain in the ass.
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@NoMapNoCompass, very bizarre, never heard of such a thing. And I don't understand the mechanics either (shedding snow when wet?)
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Convex base is essentially horizontal rocker. One ski that I can immediately think of that has this feature is the DPS Spoon, on the shovel.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Yes it looks like that but not as long. How do I add a photo into my posts - usually from a photo stored on a Macbook Pro rather than directly from a phone?
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That is convex though, i.e. base lower at the edges, higher in centre, rather than concave which is lower in centre higher at edges which is what you originally described. They will give the opposite handling characteristics to each other.
To post an image you need to host it somewhere. e.g. https://imgbb.com and the get a link to the jpg and place it within [img] and [/img] markup
Last edited by Ski the Net with snowHeads  on Wed 5-04-23 9:03; edited 1 time in total
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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If you put the bases of skis together and look down between the tips, how big is the gap in the middle?
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Ive just been fettling them for winter storage and measured the concavity of each ski at between 6 and 8 thou over a distance of approx 12" at the tip and tail (but not including the tip itself).
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More than you could grind then. I found a thread elsewhere that suggests it is quite common on volkls. I just checked 10 different pairs, völkl deacons has the most but not as much as you, then Salomon Wipro had slightly less, various unused and used junior skis all had some, Id say about 0.5. Only ski that was completely flat to the eye were Rossignol hero st ti.
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You know it makes sense.
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Your Mantra’s shouldn’t be concave in the tips and tails but unfortunately loads of them (and other models) are like this now. Shame.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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@crosshatch, why is it happening? Never heard of this before
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Poster: A snowHead
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It seems to be worse on the large scale production skis, not so much on top end. Only thing I can think of is that they are getting base grind in production before the core is fully cooled and set.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Quite an odd one this - I was just moving some skis around this afternoon so I thought I'd have a quick look. They included Stockly SL and GS, Head SL, some old Salomon twin-tip park skis, my almost-completely worn out Salomon Rocket2s and my wife's Rossi something 100mm all-mountain/powder ski. Not a single one of them had this concavity. The Rocket2s showed a slight hint of daylight between them but inspection confirms that it's old damage and not a consistent gap across the width.
So what's going on to cause this? Is my sample just atypical, or is there something people are doing while servicing to cause it? I notice one poster earlier who put it down to hot waxing, which I could just about believe, but to my mind you'd need to be getting the ski almost hot enough to soften the whole base material - when I hot wax I'm always careful not to overheat it, as long as the wax is properly liquid for that fraction of a second while you're ironing it in it's good enough for me.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Sorry I made a mistake earlier, 6-8 thou is about 0.15-0.2 mm which you could grind off, correct me if I'm wrong. My volkls are worse than that.
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You need to Login to know who's really who.
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From this article...
https://www.thepisteoffice.com/index.php/1-tuning-advice/tuning-guide/9-base-tuning
"Caution: Many modern wider skis do have a slightly concave base towards the tip & tail which should not be ground flat – a 10/15mm flat section down the outside edges of the p-tex is all that’s required."
This is a design 'feature' on some modern skis - I am not a fan. As I said earlier, Elan skis I have owned had weirdness like this, more so on the asymmetric skis which have a left and a right and hence specific inside and outside edges. As a general rule if there are specific areas of concavity at the tip and tail close to the limits of the camber then it is by design.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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@under a new name, they are like it from new, straight out of the wrapper. Good light and a proper true bar will back this up. I’ve seen loads of skis like this from new over the years, including those made by Salomon, Atomic, Head, Nordica, Blizzard, Volkl and probably others too.
The factory grind/structure pattern on Volkl’s freeride skis (Mantra and Kendo for example) is quite smooth and plain (to look at and touch), compared to their piste skis which usually have a much more defined and diagonal pattern cut into the base.
When looked at closely, this smoother pattern on skis like the Mantra is consistent and uniform across the entirety of the base material (edge to edge, tip to tail), even in the concave tip and tail areas. This indicates that the concave spots have somehow occurred after the ski has been ground in the factory, simply because it wouldn’t be possible to grind an even finish on the base if it was “warped” before it was ground.
As to why they are like this, we can only speculate and guess, but I certainly wouldn’t believe a manufacturer trying to justify this fairly obvious defect with marketing BS.
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@crosshatch, how very odd. I must admit I haven't serviced my own skis since well back in the last century. And really not paid much attention since!
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| Tykebike wrote: |
Whilst preparing my Volkl M5 skis for my trips this season I noticed that towards the tips and the tail the base is not completely flat but slightly concave from around 1" in from each edge, this must have been done in the factory as they have not been on a grinding machine. Why are the bases profiled like this as I have never come across this before on all the Volkl skis that I have owned.
This is particularly noticeable when removing the wax with a 5mm Perspex scraper and I have to use a 3mm thick one to be able to bend it to get into the concave section to try as best I can to remove the wax. Even after skiing for a week I can still see the difference where the wax has not been fully removed even though I used a nylon brush followed by a horsehair brush after waxing. |
i’ve just received a pair of M5 mantras with exactly the same problem
I got them from a Ski shop (where I’ve bought a new pair of Scott skis) and they offered them to me for a really good price so I thought why not? They told me that a guy had insisted on buying them even though they assessed his skill level is too low to ski them properly. He then apparently skied them for one and a half days I decided they shop was right and returned them to the shop to sell on.
I’m now thinking that his issues with the Ski were possibly more related to the base and the edges. Having done a bit more research, I would expect a Ski with a concave base to be very gabby / twitchy. I haven’t tried skiing on them yet so I really don’t know. I’m wondering whether the original Purchaser just had some bad luck and wasn’t knowledgeable enough to identify the potential issue.
They are also a complete nightmare to wax. The first thing I had to do was to take off the storage wax that was all over them. Using my flat scraper I only get the first inch or so of wax either side all the way down the length of the base; not just at the tip and tail has been hinted at being a piece of possible deliberate design by John at the piste office.
Did anyone ever find out a bit more about this subject and whether the Mantras do come with a concave profile by Design (which would seem crazy to me) or whether this is just a factory production issue?
I service seven pairs of skis for my family and myself and none of them apart from these have any sort of curved base they are all bang on flat.
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It's common on many models - probably to help straight line tracking at speed (reduces the 'squirrely' feeling) when the ski is flat on the snow, ie when schussing.
Note that a flat section of the base adjacent to the edge is required as if the concavity goes from edge to edge the base is known been 'railed' which makes it difficult/inconsistent to roll the ski on/off its edge.
Here's something to play with if your skis have a bit of concavity at the tip (and which is a 2-man job): flex the ski at the tip and whilst holding the ski flexed put a straight edge across the concaved area and see if the base flattens - it probably will be.
To scrape a ski like this isn't an issue - simply start at the edge of the ski and scrape narrow strips (ie 10mm wide) working your way across the base to the other edge to follow the profile of the base. I scrape all skis this way as it's a lot this wearing on the thumbs compared to the greatly increased resistance when scraping the full width of the ski.
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