RockerBlocks Up Close

[SkiJay]

I’ve been playing with a full set of RockerBlocks this week, and here are a few notes. First off, they are as nicely made as you’d expect from D3. Their beautiful anodizing is even color coded so you can easily tell who is using which version at your next tournament (except for that guy who sprays his flat black because he's hiding his secret setup from everyone who doesn't really care anyway). Best of all, the adjustment screws and clamping bolts now all use the same 5/32” size Allen wrench.

 

There has been some talk about the amount of stress these RockerBlocks put on the screws that fasten them to the ski. This is simply not an issue. The amount of screwdriver torque required to draw the tail tight with even the R-60 takes little more than two fingers. You are screwing into properly anchored inserts in the ski, and all of the forces applied during skiing are in the direction of reducing the strain on these mounts. Nothing this side of the airlines is going to cause a structural failure, period.

 

In the following pictures, I've fastened the front of each RockerBlock to the ski and left the middle and back screws out so you can see how much difference there is between the three different models. In practice, the ski's tail isn't drawn into as much rocker as might be suggested by the amount of space visible between these blocks and the ski. As stiff as these RockerBlocks are, with no fin clamped to the block, they also flex meeting the ski about half way.

 

R-30

R-45

R-60

One thing is for sure, RockerBlocks are no gimmick. They alter turning enough that pretty much any skier will notice the difference. It’s pretty subtle during the pre-turn, but the turn at the ball went from easy with the R-30 to too easy (for me anyway) with the R60 on the pre-production 66” Helix I’m trying (awesome btw). However, therein lies the opportunities. What if you like to run your fin as far back or as deep as you can, but losing the ability to turn aggressively at the ball is the limiting factor? Perhaps adding additional rocker will let you run your fin even further back or deeper while still turning hard. Traditional thinking has it that skiing on the next size up is good for speed, but harder to turn. What about the next size up with an R-45 or an R-60 RockerBlock mounted so it turns like a smaller ski without losing it's big ski cross-course speed?

 

Things that make you go hmmmm . . . .

[xrated]

I didn't understand a word of that, but they sure are pretty

[ozski]

Nice post Skijay, I've got my Quest to the point where I'm not thinking at all about setup and now this. R-30 is stock correct? If I go for the R-60 then is it going to cost me speed?

[SkiJay]

@ozski Yup, the R-30 is the stock block, and will likely be preferred by most skiers.

 

Theoretically the R-60 would make the ski a bit slower, but in practise, probably not enough that you'd notice. The acceleration and speed of a ski are affected by the bezels, flex, torsion, side-cut, rocker up by the rear foot, and even running surface. The last 8" of rocker is only a tiny component of the ski's speed.

 

The more significant trade-off with tail rocker is how solidly the ski hooks up at the finish of the turn. A ski that is hard to turn is easy to stop turning. A ski that turns too easily is harder to stop turning (think fin too shallow). If the ski gets too turn-happy, it can kill your speed and form by delivering too much angle off the ball and even be prone to spinning out. But in the right hands, it can hook the skier up sooner after the ball and deliver an earlier and longer acceleration phase, meaning higher speed, more width, and more space.

 

Everything is a trade-off and all skiers are unique. The only way to know if a rocker change will speed you up or spin you out is to play with it.

[Waternut]

Out of curiosity, do the rockerblocks makes a 0.030", 0.045", and 0.060" gap at the back of the ski? It looks like more.

[mwetskier]

@Waternut -some one who gets this stuff better then me says it looks like ' ' the fraction of degrees of angle the radian lines describe from each end of the block over the arc of the blocks bottom surface ' '. which is total greek to me.

[Steven_Haines]

@SkiJay, thanks for the information/explanation of the Rocker blocks. Have you skied them enough to have settled in on a certain one? Since all this Rocker block info has come to light, I decided that I'd like to try one for myself. So this winter I took an old HO block and turned it into an R45. I just started my ski season last week, but got a chance to try it for two sets. I have only tried it in my old MPD so far, but I could definitely feel the ski slide a little bit more at the finish of the turn. I now have it mounted in my S2 and am anxiously awaiting my next rides!

I've been thinking about the theory of the block a lot since riding it last week and was wondering if it would enhance your offside turn if you were to machine a block to create twist (thinner on one side than the other) in the tail rocker section of the ski like a Nano Twist? In my mind, it seems like it could be very effective in tuning a skis turning radius. Am I all messed up in my thought process?

The reason this is appealing to me is that I find that when I first start tuning in a ski, I always end up boots and fin back from stock and the fin shorter and deeper than stock. On the S2 I like that type of set up also, but I find myself not completing my toe side turn as well as I'd like. If I make the fin longer and shallower, the ski turns harder but I have a tendency to blow the tail out on my harder passes.

So...could this be another way to enhance our skiing?

[mrpreuss]

Does Nate use one?

If so, which one.

[Waternut]

@mwetskier I think I understand that but I can't imagine any skier would be geeky enough to use that as a basis for their naming of parts. I recently got a 2013 D3 Quest and had some time to measure my own which I believe has a R30 (someone correct me if I'm wrong). I measured a 0.027" gap at the end of the ski with the rockerblock installed. Could be a 0.3 degree angle taper but the gap seems more plausible. Hopefully, I'll be able to try out this ski soon. I'm starting to get the itch.

[mwetskier]

@Waternut -if you understand it your smarter than me. i was just repeating what i was told.

[bishop8950]

@skijay, nice post

 

@mrpreuss, yes

[SkiJay]

@Waternut I did a rough measurement of the gap formed in the pictures above and they were roughly R-30 ~ .130", R-45 ~ .150", and R-60 ~ .180".

 

@Steven_Haines I've only skied on them a few days and am undecided between the R-30 and R-45 for the Helix, but that's totally personal. I've been skiing on a Nano One XT which has a very narrow tail, lots of rocker, and shallow stock fin depth, so it smears easily at the finish of the turn. The R-45 makes the Helix finish more like the XT which is what I'm currently used to.

 

On the other hand, my personal preference for any setup in general, which stems from car racing, is to avoid setups that make anything too easy. Too easy = reduced feel & less consistency. A skier with years more experience than I have would likely do better with a more sensitive setup than I can control. But I'm kind of liking that the R-30 needs me to be more deliberate with my technique because I'm still a bit of a bull in a china shop in the finesse and consistency departments.

 

Rockering one side of the block more than the other will also change the angle of the fin to the base of the ski which also means the wing will no longer be parallel to the ski's base--interesting concepts but kind of uncharted territory.

[ozski]

@mrpreuss - Nate used the stocker last year, when he was testing the new green Quest with us in November he was switching out the fin and block from his WR ski. I seriously don't think tail rocker was on his radar at the time. What I can tell you is that his setup is way different to what most people consider normal.

[mwetskier]

two of us ski on mapple skis and i was thinking it might be interesting to try this fin block but then it occurred to me that the rocker block wont fit other skis unless the mounting screws are in the same place. also the mapple block only uses 2 screws near each end so theres no pull down point in the middle where it would be needed the most.

[ral]

@SkiJay, can you tell us more about the Helix?

[ForrestGump]

@mwetskier Andy molds a lot of tail rocker into the last 6 inches of the 6.0 and 6.1 already. Which is why he puts the flat area on the top for the fin block to seat against.

[skistrom]

The curve on the bottom of the Rocker blocks is as follows:

With the top surface as level, R30 will have .030 gap at each end. R45 will be .045 gap each end and R60 will be .060 gap each end.

[Steven_Haines]

@SkiJay,

Thanks for the response! I never thought of the potential offset of the fin. But that brings up another question. How does Goode do it? Do they have a raised area on the top sheet to accommodate for that off set? And if they did, would that offset the fin in the other direction? I would think that their fin is positioned at a 90 in relation to the bottom of the ski the same way it would be if you were to machine a block to be thinner on one side than the other. Our dock is covered up with D3 products! We have one guy skiing an old 9700, so I'm just shooting from the hip when it comes to the construction of the Goodes.

I might try it by adding some type of shim on one side of my altered HO block. Could be fun...or disastrous!

 

@skistrom, I may be mistaken, but I believe that the 30 in the R30 is actually 15 thou off each end of the block so that you would end up with a total of 30 end to end. Again, I'm no expert! I just play one on the Internet.

[mwetskier]

@ShaneH -right but trying something new is not always about trying to add some thing that might be missing. some times its just about finding the limits at each end of a given parameter. my point was that some skis maybe even most won't be able to fit the d3 rocker block for those who like to experiment.

[bishop8950]

@ozski - Since the White Quest, the "stocker" D3 block is a 30 RockerBlock. Nate first tried a 30 RockerBlock before the Quest came out (90% sure that was on the yellow X7) and has used it ever since as far as I know.

 

@ral - I rode a 67" Helix last week and it felt great. I have little to add to what Seth has already said very well. Compared to my Quest, it was quicker side to side with less effort. I also felt some "easy to come by" extra width as I approached the buoy. It was only one ride and I need to spend more time on it to know if I will be on a Quest or Helix this year. The official word from D3 will be out soon.

[SkiJay]

@ral I can compare it to the Nano One XT if that helps. The Helix is a faster ski that rides higher in the water, with a flatter attitude, and more ski in contact with the water. The Nano One XT is a turning machine and is very forgiving, but it rides deeper and requires some effort to build speed. While the Helix is faster, it's not super-fast with the temperamental skidishness that usually comes with that. In fact, I would call the Helix the most forgiving "fastish" ski I've ever ridden. It can also turn really hard but still carry speed through the finish of the turn, then bolt toward the wakes with as much angle as you can stand. I'm used to my XT which is an asymmetric ski designed to help on the off-side. The Helix is symmetrical, but its off-side turns are still a breeze. While it can carve nice quick tight turns, the XT can swipe an even tighter turn, though at the expense of some exit speed. If you like the steady forgiving nature of the XT or Quest but want a little more speed off the ball, or less effort, you really must try a Helix. This is my fifth day on it and I like it more each day.

[ral]

I NEED one...

[ozski]

@Skijay - Helix photos please..

[SkiJay]

@ozski I can't help you with photos because it's a preproduction ski without the upcoming graphics.

[SkiJay]

After spending four days on the Helix with an R-30 block on it, I thought I'd go straight to the R-60 to see how much difference it made. The R-60 did make it carve slightly tighter turns and deliver a little more angle, but it wasn't as big a difference as I'd originally thought. I did spin it out a couple of times by getting over zealous, but for the most part, I really liked how tight it could carve without letting go. It feels a bit like the fin is .003" - .005" shallower while turning except it finishes with better hold at the end of the turn. If there was any loss of speed at all, it was imperceptible to none. Probably the R-45 would be where I'd settle.

 

My ski guest has a 2013 Fusion, and he jumped on the Helix for a set. His sense was that the Helix was a bit slower and more stable than his Fusion.