Little bump on Hydrodynamics

[Corne]

Hey Guys

 

I can get a 2020 NRG for a good price but at a cost...it has a little bump at the back right next to the fin

Do you think its worth it considering a ski is all about its hydrodynamics?

How much would that bump influence it do you recon?

 

 

 

[Bainesster]

Probably depends on your level of skiing, recreational skier probably wont notice, competition skier may not notice but wouldn't be ideal for their application

[vtmecheng]

Looks like someone drove the fin screw insert in too far or drilled it a bit deep. If so, I would probably take out that insert, fill with marine JB weld, and reinstall the insert. That way the JB weld helps hold things together from the inside. It would have to be a really good price for me to even consider.

 

Edit: Looking again, that may be a little too far outside of center for the screw insert.

[MattP]

Send it to @eleeski for disposal

[klindy]

I'd be more concerned about why the fin looks to be offset in the slot as much as it is. It may be the slot isn't centered but looks odd from the picture.

[Brewski]

Fin looks silly off set? Fin too thin? Slot cut too wide?

[Corne]

Thx for the response guys.. appreciated.

The fin offset is just the angle of the photo so lets stick to the hydrodynamics

Also I don't think it's a screw causing the bump(seems to far offset wise) but a flaw in the molding process ( I can always ask the supplier)

 

The question that remains (come engineers :D ).... is it worth to pay half price for this ski vs the hydrodynamic effect of the little bump??? :D:D:D

[Bruce_Butterfield]

My guess is it is simply an air bubble that got trapped when everything went into the mold. At half price its a steal. I would sand it down flat. If it is an air bubble just fill with a little epoxy and sand flush.

[BraceMaker]

Agree with @Bruce_Butterfield would probably disagree if it was right between the two binding plates where it could indicate a structural problem - but I can't see a ski letting go if you fixed that zit.

[wawaskr]

Buy it and sand it flat if it bothers you. There would be no structural implications.

[Rednucleus]

Half price ?? Whack it with a hammer and ENJOY!

[eleeski]

As @MattP stated "Send it to @eleeski for disposal". Someone will get years of awesome performance out of that ski.

 

Honestly, I wouldn't even fix that until you are searching for some change in the ski in a couple years.

 

Don't leave it in the sun is the only real concern.

 

Eric

[Corne]

Thank you all

Much appreciated

[DW]

@Corne - Will it have a hydrodynamic effect on the performance, yes but probably not noticeable and you actually don't know if it could be a beneficial help. The bigger effect will be mental not physical. At a big discount, well worth grabbing it, then if you ever 'question' your ski, fix it as noted.

[Corne]

I'm not familiar with the molding/construction process of a ski so I'm wondering if it's a hollow bubble or a thickening? If it's a bubble it might start cracking open once the ski is taking stress flexing back and forth in the course don't you think

[eleeski]

You are worrying way too much about a tiny bubble. Keep the ski out of the sun and it will be fine.

 

It's not an aircraft spar which will go through millions of load cycles. Even if it were, the bubble is way out on the ski and not heavily loaded. Structurally, the chances are good that the ski will outlast you.

 

Skis are typically skins of carbon or fiberglass cloth wetted with resin and sandwiched over a foam core. Pressure is applied in a mold to form the desired shape while the resin cures. A defect in the mold can cause a thickening bump but that doesn't look like a mold defect.

 

Your bubbles are probably voids in the lamination. Somewhere after it was out of the mold the bubble formed. I've had skis that molded in trapped air bubbles, been too little resin and not bonded to the core, overheated and pulled the skins from the core, and been dinged. Lots worse than that - and haven't caused a break.

 

To repair that bubble, I'd cut a hole in the top of the bubble, work some epoxy inside, heat it, clamp it and add some more heat. If I overtighten the clamp, some filler might be needed to level things out once everything has cured.

 

The last bubbles I fixed, I used Gorilla glue (a foaming polyurethane glue). The Gorilla glue flowed more easily into the void but I had to put water on the repair to get it to cure. Clamping was not called for in this case as my voids were collapsed - not sure that the Gorilla glue would have cured under clamps. My repair looks OK. I will have to see how it lasts vs epoxy.

 

Eric

[OldboyII]

Do not buy. It will be itching you non stop. You will get magnifying glass and caliper to control size of the bulb and will always suspect that something goes wrong during you turn etc.. I am almost serious :)

[Corne]

@eleeski so much information, clearly you know what you are talking about, thank you for all the info much appreciated!

 

Thing is I don't live in the states so no one will have the skill or knowledge to fix it if something does go wrong. I'm also paying 3x more for any ski (exchange rates) which makes this even harder and not something I can take a chance on

 

@OldboyII I think you are right haha

 

I think I'm better off going for a brand new Radar Lithium Vapor /w bindings than the bubble NRG R1 /w bindings at the same price

 

Thanks guys

 

[eleeski]

The only reason to buy a ski is "will it make you ski better?". A minor blemish is not important. Nor is a fancy new name brand.

 

Demo both skis. Both are excellent skis and work well for certain skiers. But preferences are very personal. Try before you buy - even if you have to pay a little more for that privilege.

 

Maybe that old Monza or Sixam suits you better than the latest and greatest. Try lots of skis to see what you really like.

 

If you like the Evo with its defect, ski it until it breaks (if ever). By then, all replacement Evos will be old and cheap.

 

As long as the ski suits your style, it's the skier - not the ski! Enjoy whatever ski you get.

 

Eric

[skialex]

@corne where do you live? I have an Evo s 66” with about 10 sets on( you can not really tell it had any use) and one that has no use at all. Both at very good price and no import tax if you are in Europe. I can send you some pictures when I go home.

[Corne]

That's the problem

 

@eleeski yes I want a ski that makes me better but how do I know, my only reference is a D3 Fusion that I skied once and loved hence looking at a D3 but so expensive

 

I live in South Africa

 

No demo programs available, I'm forced to buy a ski blind so I either buy a blem at a very very good price or a new one.

 

I might be able to resell these although our market is limited (specially on high end skis) and not lose too much money worse case scenario. Selling a blem with a print defect would be much easier than one with a bump on the ski side specially considering our exchange rate. A $1000 ski will cost me $3000. How do I resell that here if it doesn't work for me specially if it has a bump on the ski side of the ski :/

 

I wish I was in the states...D3 program here I come haha

 

@skialex I weigh 220 lbs will need a 68"

 

All I want to do is ski better, but our exchange rate is making that so hard :/

[eleeski]

For 3k you can visit the USA, go to a ski school, demo lots of skis and buy one or two. It would be an incredible experience as well.

 

Any top ski can work for you. The right setup will do a lot. Maybe you will have to move bindings around by a few cm but if you are "stuck" with a ski you should be able to make it work. All the high end skis have someone who has proven the skis performance potential. So you can too.

 

Choose a ski, loyally stick by it and enjoy.

 

Eric

[dvskier]

@eleeski You’re exactly right. If I were living outside the USA I’d fly to Orlando and demo all of the skis I was interested in. Then buy 1 at a discount and fly home with it avoiding the import fees. It would mitigate and risk of making the wrong choice.