Stance Width vs Perception of Board Stiffness

[fluxgame]

I was thinking about this on the lift this morning, was curious what others thought. I'm a very lightweight rider (135 lbs/61kg) and have found nearly every board I've ever tried a bit too stiff for me. I've always ridden used boards though, so I just chalked it up to most boards being made for much heavier riders. At the same time, I've settled on a very wide stance width (21.25"/54cm) relative to my height/inseam (5'8"/172cm & 31.5"/80cm). It's always felt most comfortable to me and really allows to me move around well on the board. I'm wondering though, if my wide base coupled with my light weight is making boards feel stiffer than they should. It makes sense, conceptually, that it would require less pressure to flex a board with a narrow stance than with a wide one, but I've never seen this discussed. Is it just a non-issue within the constraints of the insert pack in the board?

[SunSurfer]

@fluxgame The general principles have been discussed in another thread, but I'd have to search for it.

In general terms you're correct, not because the board is stiffer, but more because the further your feet are apart the less longitudinal flex bending leverage you exert. In effect you seem "lighter" to the board. Consider the two extremes, a) all the riders mass concentrated at the centre of the effective edge with b) the same riders mass split evenly between two points at either end of the effective edge. With b) the rider can jump up and down all they like but there is essentially no bending force exerted between the two outer contact points at the end of the effective edge.

The original discussion was around whether sliding hinge isolation plates made boards stiffer. No they don't. But by spreading the contact points for the riders mass further apart, they make the rider appear lighter to the board.

"I need to buy a new plate for my snowboard. It's cheaper than Ozempic!"

[Rob Stevens]

Have you narrowed your stance at anytime to confirm your feelings?

You’d be right in thinking the way you do, but there are techniques that wide stance carvers can use to make up for diminished bend in the board. 

With pressure easier to manipulate between the feet, you can ollie into the new turn to change edges and tip the board over aggressively early in the turn. A mellower version of leaving the ground to go from turn to turn would be pivoting on your back foot to close the turn and change edges. 

Edited March 20 by Rob Stevens

[ShortcutToMoncton]

Hard boots? 
 

21.25 seems pretty damn wide for hardboots at 5-8, but your inseam is pretty long….

 

[fluxgame]

1 hour ago, ShortcutToMoncton said:

Hard boots? 

Yes, should have mentioned that I suppose. 

1 hour ago, Rob Stevens said:

Have you narrowed your stance at anytime to confirm your feelings?

Haven't yet as it's just something that occurred to me. Season is pretty much over here, so probably won't get a chance to give it a proper test, unfortunately.

1 hour ago, Rob Stevens said:

A mellower version of leaving the ground to go from turn to turn would be pivoting on your back foot to close the turn and change edges. 

If I'm understanding correctly, I think I do this on medium terrain, but it isn't something that's within my confidence level on steep stuff. Also, doesn't fit with my goal for clean carves.

2 hours ago, SunSurfer said:

With b) the rider can jump up and down all they like but there is essentially no bending force exerted between the two outer contact points at the end of the effective edge.

Exactly my thought process, though much more clearly stated.

2 hours ago, SunSurfer said:

The original discussion was around whether sliding hinge isolation plates made boards stiffer.

That explains why I've never seen this discussed, I wouldn't have been inclined to read a discussion on plates.

Overall, sounds like I should give a narrower stance a try. I'll have to see if I can find a sweet spot between being able to move on the board and making more use of my weight to bend it.

[Rob Stevens]

59 minutes ago, fluxgame said:

If I'm understanding correctly, I think I do this on medium terrain, but it isn't something that's within my confidence level on steep stuff. Also, doesn't fit with my goal for clean carves.

The back foot pivot isn’t like the front foot version. 
When you do it on your front foot, the tail does go out wider and takes a different path. 
A pivot on the tail does not break the carve, happening as you’re carving from the back foot to the tail and lifting the front foot to a higher line. The track you leave in the snow would not show anything less than a carve. 
 You can also do this as a centre pivot between the feet at the edge change as the board goes flat, to lose speed or make a quicker edge change. As this largely happens in the flat phase, like the tail pivot, you would not be able to see anything other than a carved track. 
These are hard to do, hard to spot, but very effective at tightening a turn without relying on bending of the board at the centre of the turn via edge angle, or the type of more centre-of-the-board pressure a narrow stance allows. 

Edited March 20 by Rob Stevens

[fluxgame]

4 hours ago, Rob Stevens said:

These are hard to do, hard to spot, but very effective at tightening a turn without relying on bending of the board at the centre of the turn via edge angle, or the type of more centre-of-the-board pressure a narrow stance allows. 

Thanks for the clarification, that makes more sense, conceptually at least. I'll certainly have a go at it, but I'm doubtful that either are within my skill level right now though.

Edited March 21 by fluxgame

[TWM]

For me, a wider stance feels like a more stable and controlled means of bending the board; a wider stance, with deeper knee bend, affords more fore / aft leverage from the (hard) boot over the board, and more stance stability to drive turns and angulate more aggressively.
 

For me, a relatively narrow stance — while it places more weight closer to the board’s center — stands me up too tall, compromising the body mechanics that allow me to exert leverage over the board. And so, for me, narrower stances make boards feel stiffer. 

Edited March 28 by TWM

[SunSurfer]

@TWM The actual effect is measurable and reproducible. It's not just a "feeling". I did actual measurements with boards and different distributions of the same weight to confirm the result.

The length of board between each of the rider contact points AND the outer ends of the effective edge is essentially a lever with the riders mass acting with gravity to produce a bending force. The shorter the lever, the less force to flex the board as a whole.

[fluxgame]

@SunSurfer I think the issue at play is one of riding style? With a relatively passive riding style, when one simply uses gravity to bend the board, having a shorter stance obviously makes it easier to bend the board, as your experiments show. However, with a very active riding style, where the rider actively uses the legs to bend the board between the feet, a wider stance should afford more leverage to do so, since the lever is inverted.

I experimented with this recently and found that I was able to narrow my stance slightly (54cm->52cm), but that any narrower and my ability to bend the board greatly diminished. I think it may be a two-fold reduction via pure mechanical advantage and also compromised body mechanics as @TWM mentions (I also felt very stiff and locked in place with the narrower stance).

I think I've adopted the (hyper)active riding style out of necessity since the boards I've been riding simply don't bend much underneath me when ridden passively and skid more often than carve when put on edge. However it's really tiring to ride like that all the time and (to me) can feel a little frantic. I've been seeking out a more relaxed ride feel. Now, I think the answer is that I just need a board made to an appropriate flex for my weight.

[TWM]

15 hours ago, SunSurfer said:

@TWM The actual effect is measurable and reproducible. It's not just a "feeling". I did actual measurements with boards and different distributions of the same weight to confirm the result.

The length of board between each of the rider contact points AND the outer ends of the effective edge is essentially a lever with the riders mass acting with gravity to produce a bending force. The shorter the lever, the less force to flex the board as a whole.

That's certainly an important factor to consider in stance width. But then, why not ride a 10 inch stance?

I just went through this exercise last week on a new-to-me and quite stiff board.

A narrow stance was preventing body mechanics necessary to aggressively pressure and drive forward and laterally into the boot. And, by standing me up too tall, it limited me from getting the board higher on edge, into a deeper flex.

A wider stance changed this with body mechanics that allowed powerful leverage through the boot and stability and balance to get the board higher on edge.

So, for me, given other important variables to consider, widening my stance yielded deeper board flex.

[SunSurfer]

@TWM I absolutely agree with you about wider stances and the extra stability and power they bring to riding (up to a point, in my experiments with stance I've found where too long is for me).

My point is only about the physical response of the board to mass distribution and gravity in a static measurement.

I suspect, but do not have the equipment to show, that the result is similar in a real carved turn in firm snow. The pressure pattern on the board base is much more complex there, compared with the static flex measurement.

A thought experiment suggests to me that having a significant length of board beyond the points where the riders mass is attached to the board is essential for the correct flex curve to develop in the board. Having a plate that put the contact points at the ends of the effective edge (the longest possible stance) might even result in  a camber type curve in a turn making the board impossible to ride!

[RRrider]

I am going to test this out today.  just widened the stance, and am bringing my screwdriver with me for on slope adjustments

 

[RRrider]

10 hours ago, RRrider said:

I am going to test this out today.  just widened the stance, and am bringing my screwdriver with me for on slope adjustments

 

For me. Hard boots, zero rear offset, 60/55, and 21.5 separation of bindings (I’m 5’8” with 31” inseam) was a noticeable improvement.  Stable is the clearest word i. An think of.  Will try it again tomorrow.