How old is too old for a ski?

[eleeski]

While @vic has a good point, resins are a fraction of a ski's strength. Depending on the materials chosen and the design and quality of the layup, the loads will be carried primarily by the fibers not the resins. So whether the resin stiffens or softens, the properties of the ski won't change much.

 

Graphite tends to fail catastrophically. It's fine until it breaks. It doesn't behave like other common materials (especially plastics) that weaken and soften before failure. Whether the resin stiffness over time or softens with loading, it won't substantially affect the graphite's properties - and the feel of the ski.

 

I would have said that once everyone moved away from Clark foam's polyurethane cores, that core failure was not a factor. The success of Goode's carbon core suggests that perhaps improvements in the cores are possible but my PVC cores have yet to cycle to failure or noticeable change.

 

"Wisdom" that is based on wood skis or old resin rich glass skis with urethane cores does not apply to modern skis. After a few hundred thousand hard turns, a modern ski might fail - but it will be obvious.

 

Eric

[thager]

80

[Goode9700]

I am on a 14 year old Goode 9700 and still skis great. I have tried skis but never seem to gain a bouy or I loose in consistency, so stay on the ski. I still remember with the Goode 9100 the talk was it would not breakdown since full carbon, then after a few years and sales down, the next ski came out and the talk was they breakdown. I am sure they break down but if the ski works, keep skiing on it, I am not convinced they break down much if at all. Its in the MFG best interest to keep the story going that they breakdown.. It works, a few bad sets and a slalom skier jumps on a new ski and buys it because of initial success, then after a month his bouy average is the same or maybe skiing less consistent and jumps on old ski if he did not sell it yet.

[vtmecheng]

As an engineer, this is an interesting discussion. Composites are not my area of expertise so I don't have much to add. One thing did came to mind. While the static deformation may provide information on how a single dynamic force will deform the ski, how the ski rebounds may also influence its feel. When loaded dynamically, I'm visualizing that the ski will flex and oscillate. The frequency of that oscillation could change how the ski feels and reacts to inputs.

 

This could be pure crap, I haven't spent much time thinking about all this.

[Pullhard]

Internet research shows material life for carbon fiber & resins (lifetime), fiberglass (50 years), and plastics / foams (1000 years). High stress applications for these materials include automotive, boats, mountain bike frames, etc. Even though water skis are stressed during use, they are used seasonally, often not used because of upgrading, mostly used in fresh water, and kept inside out of the elements. Any ski, if well cared for, should last a long time. To prove otherwise would require extensive testing of identical samples, using mechanical means in controlled conditions, and statistical analysis of the results.

[vtmecheng]

@Pullhard I can't comment on the cycles to failure of carbon and resins. I have seen carbon fiber mountain and road bikes fail catastrophically. It's rarely a pretty picture for the rider. In many of these cases, the bikes were high end models from companies who know how to lay carbon. My point is, the materials may be fantastic when perfect but flaws occur during manufacturing. Even small ones can lead to lowered strength and ultimately failure.

[Pullhard]

Agreed. I work in an industry where material flaws are a major concern and we inspect for them. Even super alloys and titanium can have flaws that can be catastrophic. From what I read on the MB's, most of the failures were from the old designs. They are saying now CF frames don't fail. Same for automotive. Slalom ski's don't take anywhere near that kind of abuse so should last as long as the owner still likes the ski.

[TEL]

I bumped this post I have been skiing on a 2018 D3 NRG It now has an excess of 250 sets on it. I Have another Identical Ski that has never been skied on same identical bindings Same exact fin settings and wing angle. All I can say is the new ski is more sensitive. Meaning coming in my pre-turn it just wanted to turn, I ran over a few buoys everything else felt about the same. Second set I just had to be more relaxed and not push the ski and I skied fine. I run 22 -32 battling 35off.

 

[MNshortliner]

@TEL are the bindings on the unused ski also unused? If they are not used your boot may just be stiffer, there for, more responsive to your ski until they get broken in.

[TEL]

Actually the new binding is on the old ski I have about 75 sets on them , the old binding has a new liner and was just repaired.

[MichaelGoodman]

Would be interesting to have a flex test done on both

to compare the results.

[MISkier]

I flex-tested mine at 2 ball the night before the State Championship tournament last month. 7 years old and 400-500 sets by a 39 off skier before I bought it 3 years ago and put another 200-250 sets on it. It was interesting to pull my old 9500 out of the closet and ski my tournament round without reacquainting myself with it.

 

 

[BobF]

Interesting observation on the two NRG's. Would've also been insightful to have them both flex tested side-by-side when new. I'm not sure that current production methods allow for the "exact" same ski to be created every time. Correct me if I'm wrong.

I've always said that if I demo a ski that gets me another pass first time on it, I'm taking that magic ski, not another one like it.

[Broussard]

@TEL As others have mentioned your "experiment" includes two variables, the ski and the bindings. You should use the same exact pair of bindings on both skis to compare them.

 

Also, unless you have data to prove otherwise, the skis might not have had the same exact flex numbers when they were brand new.

[mike_mapple]

its pretty hard to make a handmade ski to be an exact replica of another, you can get it pretty close, but you will always have a variable.

 

also, I have not made a ski in a few years so this could have changed. I would assume the adams would have the best insight into this.