An interesting phenomenon...

[hafte]

With respect to camber. As I have mentioned before I have three pairs of skis made and they are stored out in the garage/shop. They also kept most of their camber while the temps were cold out. A friend came over with a couple of pairs of Scottybobs he wants to use for a side cut on a new pair. Well they are two different generations of the same ski only the newer pair has less camber, almost flat, while the older air has more camber which he says he likes. So, I say “like this pair of skis?” and pull out the Big Labowskis. The stiffest most cambered pair I have made so far. They had, last time I looked, 15 mm + of camber in each ski. That measurement was taken just after the ski season in april. Now in the heat of the summer they measure more like 7-8mm of camber. Talk about a thermal expansion in one material or an other!! I was kind of shocked. I really didn’t expect to see that happen. I’m intrigued to see what happens when the temps drop again this winter.


Hafte

[skiguy]

The Scottybobs have been Manufactuered by different manufacters almost ever year. I would bet that the limited few that are producted in their Silverton factory are the ones which hold their camber. Last year they started making them in China and I think next year they will be made in China again.

[hugocacola]

thats the problem of china, the manufacteurs or "brand builders", they send their designs to china and can not control the production...every pair of skis or snowboard must be made with paxion and quality control...

[RoboGeek]

which brings up an interesting topic - how do you store your skis? Mine sit right here in the shop, propped up in the corner (I'm staring at them now!). I have them strapped at the top and bottom, with a towel shoved in between right under the front binding. With the heat cycling they go through out here, I think they actually grew some camber from storing them that way

[hafte]

I store them standing on end against a wall or lumber shelf but not strapped together. I haven’t done that since the days of double cambered skis. I don’t store my factory skis that way any more either and will have to take a look at them to see how they are faring. All of the skis are out in the uncontrolled environment of my garage/shop.

I have never really taken notice of my skis during the off season. That’s a resent development since I started making my own. I just thought it was a curious development and I’m interested to see what will happen when the temps drop. I was also wondering if anyone else has witnessed this.

RoboGeek, how do they look when you unstrap them and lay them side by side on their sides with the bases together? Have they actually changed one way or the other? I’ll try and get out and take a picture. I think I have a before pic from around march also.

Hafte

[RoboGeek]

I originally had them loose in the corner. The shop hit a few 100+ days and I looked at them then - they seemed flat compared to what they used to be. So I set it up as described and the camber is back to what it used to be when I first sat them there, plus a few mm possibly.

The temps are regulated in here now and the ski's seem to be back to normal now.

[bigKam]

when waxing skis with a hot iron, the temperature gradient across the thickness of the ski causes the skis to lose camber, but when cooled the shape returns. could this be your case with the warm summer temps? but if your skis are the same temp throughout, then there's no temperature gradient. now, it could be that it's not the gradient that drives the shape change, but the difference in coefficient of thermal expansion of each material. this is probably true.

i don't remember reading this about your skis, but did you heat-cure the epoxy? if so and if done correctly, the camber should be fixed.

if the epoxy was not 100% cured, then over time and the slight increase in temperature can trigger the relaxation.

have you considered wrapping your skis with a nice bag with icewater or take them up to the end of one of the canyons where the air temp can be 20-30 degrees different to see if they "snap" back into shape?

kam

[hafte]

Here is a picture of the skis and how I have been measuring the camber.
The skis on the left are Blizzard Titans with ~16mm of camber. Next is the Doods then the Big Lebowskis (BL), and my third unnamed/unskied pair. The BL’s had as much camber as the Titans in March. The doods seem to be about the same as when they were made.




The Doods and the BLs were both low temp cures at ~80F for 8-10 hours. The doods had a 110-120F post cure for 4-5 hours. The BL did 110-120 post cure for ~10 hours. The post cure was done by making the space in my curing tent smaller and placing two heaters in the tent. So the air heats everything ski, form, etc. After that the skis came in the house for a week or two before they were taken down to the shop to have the bases ground and the edges sharpened.

I’m not that worried about them. It just seemed like an interesting occurrence. It’ll be interesting to see what happens when they get cold again.


Hafte

[Greg]

I think I posted this before, but my second pair of skis, the Better Rockets, have gone from having camber to having serious reverse camber. I am not sure if this is from use or not, but my extra pair which also had camber, and has never been skied, has a very strange camber. I don't remember if they were that way when I pressed them, but they basically went from a few mm of camber to a few mm of reverse camber, just from standing.

This is obviously a very complex topic, and I would be curious to hear what other people have experienced.

[Holymountain]

I've made ski with no camber for a powder use and after 15-20 day of uses I obtain a reverse camber, I don't no why,
It's not due to the wood who want to come back to his first form because they have no camber.
So it's really good topic if somebody have an idea...