Putting a rocker in my Sumos?

[sandflea]

Wow! Looks awesome!

[junglejim83]

how does this effect the integrity and stiffness of the ski?

I skied the new gotama and loved them with the rocker. Thinking about a purchase. But if I can get my hands on some older skis and rocker them that would be money.

Any reason this wouldn't work with older gotama like these http://www.volkl.com/ski_05/gotama.html

[booner]

Edit for the rocker on my DHs relaxing to a 5/40 both tip and tail. Pretty confident it will stay there, as the first time I did it (yesterday) was the same today before redoing them. I'm gonna work the tip rocker a bit more to try to get closer to 10mm and leave the tails as they are.

[XtrPickels]

What Happens if you add tip rocker only to a "normal sidecut" ski and the rocker begins at a point narrower than the tail width?

Does that cause your dimensions to be (making these up):
105tip - 90waist - 110tail

Would this cause the ski to behave weird? Is this a non-issue because the sidecut engages more toward the tip / a wider point as the ski is layed over?

I'm thinking about rockering some Prophet 90's for all mountain fun

[mountain_man]

What Happens if you add tip rocker only to a "normal sidecut" ski and the rocker begins at a point narrower than the tail width?

Does that cause your dimensions to be (making these up):
105tip - 90waist - 110tail

Would this cause the ski to behave weird? Is this a non-issue because the sidecut engages more toward the tip / a wider point as the ski is layed over?

I'm thinking about rockering some Prophet 90's for all mountain fun

It will change the turn radius.

You obviously want to select rocker points that will keep your radius the same. Eg: if the ski is, 130,100,120 rocker points should be 120,100,110. I think I've got that right. Really your only rockering for looseness and float. If you bend right you should still be able to tip the ski on edge and get full edge contact, a the rocker will be like the ski is pre-flexed. THis is only really in regard to all mountain rocker, not pow rocker because your aiming to achieve different results.

[gunniride]

Anyone else experiencing a slight change in the flex after doing this? Seems like the couple pairs I've played with have compromised the integrity of the tip flex a bit (no metal: Fischer 106s and BH Districts). Overall pretty happy with the results though.

Best photo on here in a while:

[sandflea]

I just did my Double Helix's, I have pretty much the same rocker on mine that booner got on his. I'm psyched to get these out in some powder.

[booner]

I just did my Double Helix's, I have pretty much the same rocker on mine that booner got on his. I'm psyched to get these out in some powder.

I tried to get a bit closer to 10mm in the tip yesterday, but could only get another mm making the tip 6/40 and the tail 5/40. I put a lot of force on the tips and basically got nowhere

[sandflea]

I believe 6/40 and 5/40 is what I got... hopefully it won't revert back any, I'll have to check tomorrow. I did get a small wrinkle in my topsheets(I used high heat). My Live Lifes have about 7mm tip rocker, so if I can get the DH's to that point I'll be satisfied.

I tried to get a bit closer to 10mm in the tip yesterday, but could only get another mm making the tip 6/40 and the tail 5/40. I put a lot of force on the tips and basically got nowhere

[El Chupacabra]

My Sumos are clamped down now. I generally used the Hjorleifson/booner approach, but my Harbor Freight heat gun died soon after I got started.

I would up using Mrs. C.'s 1875 watt hair dryer for most of the heating, and left the skis clamped down overnight. I'll post pics later today of the before-and-after rocker -- hope this worked.

[Bird Blaster]

This stuff looks great.

I can't wait to get home to try it on my gold 190 goats. I'd like to get some tip rocker on them just to improve the crud busting and give a bit more float in the pow. I'd be happy to achieve the rocker that booner got on his DH's

[El Chupacabra]

My Sumos are clamped down now. I generally used the Hjorleifson/booner approach, but my Harbor Freight heat gun died soon after I got started.

I would up using Mrs. C.'s 1875 watt hair dryer for most of the heating, and left the skis clamped down overnight. I'll post pics later today of the before-and-after rocker -- hope this worked.

Results: nada.... maybe 1mm change? I guess I didn't heat them enough.

I'll buy another heat gun and try again.

[sandflea]

Just measured my DH's, I got 7/40 tip 5.5/40 tail.

[doughboyshredder]

I think you're all being kind of retarded, but if you insist, heat the ski from the top only. The expansion / contraction properties of glass, will work with you instead of against you if you heat from the top.

[booner]

Finally got to ski the DHs the other day, but only in about 4" of new. They skied just how I thought they would...skied a hair shorter, no difference in hard/groomer performance (except, since they ski a bit shorter they are a bit more comfortable), and the tips rise up a hair in the fresh stuff just enough to keep the shovel on top. There is some tip chatter at full speed in the skied off shit, but it's only visual...you can't actually feel it and it doesn't affect performance at all. The rocker didn't relax any more either...even after using them. It's still 6/40 and 5/40.

[El Chupacabra]

How long did you heat the topsheets?

I have a replacement $7 heatgun from Harbor Freight, and might give this another shot. I also just might wait until summer and leave the skis clamped together with a block of wood in between, all summer, in the hot storage shed.

[booner]

How long did you heat the topsheets?

I have a replacement $7 heatgun from Harbor Freight, and might give this another shot. I also just might wait until summer and leave the skis clamped together with a block of wood in between, all summer, in the hot storage shed.

About 5 minutes, just enough to get em really warm/just to the point of being hot. I used a fancy hair dryer so the best I was gonna do was get them sort of hot, which is what I was after anyway. I'd be afraid to get them more than a little hot. I think things would start to melt, which would be a really bad idea. I ended up doing 3 rounds of heat/bending/cooling, and left them clamped for 2-3 hours each time.

[sandflea]

Just got on mine today and came to the same conclusion as booner did. I'm pschyed that it could be done that easily.

[Like a Boss]

What Happens if you add tip rocker only to a "normal sidecut" ski and the rocker begins at a point narrower than the tail width?

Does that cause your dimensions to be (making these up):
105tip - 90waist - 110tail

Would this cause the ski to behave weird? Is this a non-issue because the sidecut engages more toward the tip / a wider point as the ski is layed over?

I'm thinking about rockering some Prophet 90's for all mountain fun

DO IT! Then tell me how you did it so I can do it to mine. Line P90 with tip rocker = Swiss Army Knife of skis.

[willmtbike4food]

It will change the turn radius.

You obviously want to select rocker points that will keep your radius the same. Eg: if the ski is, 130,100,120 rocker points should be 120,100,110. I think I've got that right. Really your only rockering for looseness and float. If you bend right you should still be able to tip the ski on edge and get full edge contact, a the rocker will be like the ski is pre-flexed. THis is only really in regard to all mountain rocker, not pow rocker because your aiming to achieve different results.

Somethings telling me 120-100-110 is a much longer turn radius than 130-100-120. I'm not sure I can explain why, but I'm pretty sure it has something to do with the waist dimension remaining the same... Can anyone elaborate?

Booner - did you lose some (any? all?) camber when you did it? The side profile you show of the tips looks similar to the profile of my Praxis Pows, but I'm not familiar with the Double Helix, so don't know what the profile looked like to begin with... Any thoughts regarding putting a thinner piece of wood underfoot to retain the camber?

[booner]

Booner - did you lose some (any? all?) camber when you did it? The side profile you show of the tips looks similar to the profile of my Praxis Pows, but I'm not familiar with the Double Helix, so don't know what the profile looked like to begin with... Any thoughts regarding putting a thinner piece of wood underfoot to retain the camber?

DHs are flat to begin with, and have a hair of early rise...contact points were about 3 inches inside of tip caps. Now they're about a foot in. I don't think the camber would have been affected had there been any.

[willmtbike4food]

Cool - thanks, and nice work!

[XtrPickels]

DO IT! Then tell me how you did it so I can do it to mine. Line P90 with tip rocker = Swiss Army Knife of skis.

I attempted and got no where. Maybe I didn't leave them clamped long enough or have enough bend to begin with. I literally made no change at all.

[Like a Boss]

I attempted and got no where. Maybe I didn't leave them clamped long enough or have enough bend to begin with. I literally made no change at all.

How did you heat the skis? I'm wondering how the metal matrix layer on the top of the Line P90s affects this process. You didn't end up kinking it? Any ideas on this from ski-rockering veterans?

[Conetucky]

So I'm not an expert in composites but I have some experience and a strong engineering background. A few things that can be done to minimize delams (visible and non-visible). First, you should really be heating the entire area for an exposure time of much longer than 5 min before applying any forces to them - think ramp up from room temp to maybe 200deg over 30 min. Then apply rockershape under a steady temp for approx an hour to an hour and a half and ramp the temp back down.

(similar to the we repair composites)

This is just my best guess - i dont have any rockering experience other than the skis i did in highschool with a blowtorch which was a disaster. Take it or leave it. My steady-state temp is low enough that you will get in the range of gelling the epoxy but not high enough to melt the ptex off.

Note: Skis that have carbon or fiberglass are going to be rocker-converted much better than skis with wood in them.

Thats my 2c.