SCR Question for the Engineers

[RCrobar]

 

 

What is the maximum angle a snowboard can be tipped up on edge and still carve a turn? 

 

 

At some point the tip and tail contact edge points, as the base of the board approaches a 90 degree angle in relation to the snow, would be too high for the center part of the SCR to remain in contact with the snow.  Basically the tip and tail put the center of the board too high and it can't touch the snow and can therefore can not carve a turn.

 

If a maximum angle can be determined, does this maximum angle remain the same for a board of 'similar' length and flex if one has a 13m SCR vs the other with an 8m SCR?  The distance the from the snow to the center of the board changes as the SCR changes; can there be a finite 'maximum edge angle' for any given SCR? 

 

A stiff vs soft longitudinal flex, combined with very soft vs very hard snow would play a big roll in the maximum edge angle a board could be tipped up at and still carve a turn.  I am not sure how to factor this into the question other than perhaps just look at quality solid firm snow with a nice quality HB carving board, that we all would love to ride.  For the sake of a good discussion, maybe we should forget about ice and powder, etc as this could lead to a gun fight:)

 

Thank you in advance for your thoughts.

Cheers

Rob

[TLN]

I think that board

1. Almost never reaches 90 degree.

2. It rips through snow. Tips dig into snow deeper, then board center. If center touches the snow, that pretty much means that other parts of board dig though the snow 3-4cm deep which is enough to hold the rider.

3. Obviously that 8m board will hold edge a bit less then 13m. But you have to put more force into 13m board to go tight radius.

4. Talking about stiff/soft board and snow: harder the snow - softer board you need. You want board to bend a bit more and touch the snow.  More skill you have - stiffer board you can ride.

[Neil Gendzwill]

Flex, camber and the fact that the board cuts into the snow play a part, so this is a complex question.  If you tip a camber-less board up on a hard surface at any angle without flexing it, only the tip and tail will be touching.

Edited November 4, 2016 by Neil Gendzwill

[queequeg]

the quality of snow surface probably has a fairly profound effect on this. Unless you're carving on proper east/coast chalk/ice a good ~1.5 inches of your deck is buried while carving.

Edited November 4, 2016 by queequeg

[drschwartz]

Agree with TLN. Board cannot physically get to 90 degrees. Your knees and lower leg prevent this. Depth of the carve in anything less than ice keeps the entire board in contact with the snow. I think the common issue of board "chop" has more to do with not getting enough edge hold due to a low board angle rather than how deep the board cuts into the snow.

[RCrobar]

Thank you for the comments so far.

Maybe, for discussion sake, it would be easier to imagine that the rider is a super human, peak of their game racer, riding on ice as flat, hard and smooth as a freshly flooded skating rink where a super sharp edge is penetrating the ice by a few mm!

For the record I don't believe that a board can be tipped to 90 degrees and carve.  My gut feeling is that a board can get to the mid 80's and still carve.  I am not really concerned about edge hold, more the idea of whether or not there is a finite number for the angle a board can be tipped on edge.

I was hoping someone can calculate this to get a ball park idea.

This edge angle curiosity is partially inspired by boot out issues and calculating just how much boot over hang you are able to have and still carve a hard turn with no boot out.  I have read a few board charts that recommend a given boot size with a given board width that I don't completely believe they are accurate.

Rob

[Neil Gendzwill]

Boot out is more of an issue in soft snow than hard. The further you can drive that edge in, the closer your boots get to the snow. 

[Corey]

I think the limiting factors are:

1. The reduction in normal force pushing the board into the snow/ice.  As you tip further and further, you are also putting less force down into the surface, so the edge either doesn't cut a groove, or pops out of the shallow groove.  Cue good ice riders, that keep the body as upright and/or compact as possible while also tipping the board as high as possible in an effort to increase that normal force.  At least, that's my theory after a few should-have-brought-my-skates days.  

2. In your perfect scenario, only the tip and tail are touching at 90-degrees.  The board bend/turn curvature (1/radius) would represent a y=1/x graph, where it shoots off to infinity as you approach the 90-degree mark.  

 

In practice, I'm pretty amazed how little boot overhang can cause issues on good snow.  A few years ago I had issues with the top buckle on my front UPZ boot levering the board out of the snow.  A ruler passing from the edge to the buckle suggested something like 85-degrees (yeah, right!), but in reality I was cutting a trench as well that lowered that dramatically.  

[ursle]

When the board at speed with nothing else touching the snow is carving, the camber curve is reversed, the board bends "shortening the size of its radius turn when not weighted", even on ice it can be tilted up on edge, if 90 degrees washes out drop down to 89, in softer snow the tip and tail will dig out the 2-5 mm discrepancy, if yer angles are in the 50's don't bother, no boot out allowed.

 

[bruincounselor]

15 hours ago, corey_dyck said:

I think the limiting factors are:

1. The reduction in normal force pushing the board into the snow/ice.  As you tip further and further, you are also putting less force down into the surface, so the edge either doesn't cut a groove, or pops out of the shallow groove.  Cue good ice riders, that keep the body as upright and/or compact as possible while also tipping the board as high as possible in an effort to increase that normal force.  At least, that's my theory after a few should-have-brought-my-skates days.  

 

Is this what we call Great Plains Style?

I finally have an explanation for my style.

[BlueB]

There is also the factor of board's twist. the edge angle on tip/tail will be less then by the bindings... 

[RCrobar]

Hi Neil

 

This comment of yours surprised me a bit, I 'think' I know why.

 

Quote

 

Boot out is more of an issue in soft snow than hard. The further you can drive that edge in, the closer your boots get to the snow. 

 

 

When I think of boot out, I don't mean that the boot/binding has simply touched the snow.  For me boot out means that the boot/binding has touched the snow causing the boards' edge to be lifted up and out of the snow, the edge of the board is 'kicked' out of the path it was carving and is no longer carving.

 

I personally have more issues with 'boot out' in harder conditions.

 

To illustrate, I'd would use a toeside EC turn as an example.  When experimenting with different amounts of the toe bail protruding past the boards' edge and carving in hard snow I have had the following experience.  I have done a toe side carve in good snow, good grooming that was on the softer side.  When going back to check the carving mark left in the snow you can see that the toe bail has also left a small trench in the snow.  On much harder snow, the same toe bail protruding set up has kicked the edge right out of the carve, causing me to go into a starfish, superman slide/crash.

 

For me personally I find the boot/binding touching in soft snow very annoying, but much more of a problem in hard snow.

 

Cheers

Rob

[RCrobar]

Hello

 

This thread and the question of a maximum board angle was inspired more by softboot carving.  I was researching a board purchase and asked a question of a very respected long time board company and was given helpful and thoughtful reply's from an employee that was a World Cup Board racer in the 80's or 90's.  This is one of the tips he gave with regards to setting up a softboot carver.

 

 

Quote

 

With the angles you describe, and your boot size it should be more than OK to ride the x, even if you hang over  (-(12 mm max on each side). And most important, adjust the bindings so you hang over a bit more on the frontside edge than the backside one, because you lean more in backside...

 

 

I have read many forum members here over the years tell new riders that you can get away with a bit of overhang when setting up your boots/bindings.  This made me wonder if this 'bit of overhang' translated into a maximum angle a board can be tipped over. 

 

From the replies it seems like this is too complicated of a question to get a definitive answer.

 

Thank you for your replies, they are appreciated.

Rob

 

[Eric Brammer aka PSR]

Somehow, most of my hardshell mounted boards have extreme p-tex wear from the edge to about 1-2 cm away from the edge. I literally am burning off the p-tex in this thin bandwidth, yet I ride 'on edge' most everywhere that is groomed, often at 50-to-70 degrees from flat (or horizontal). I can get to 90 degrees on some boards, but don't think I've exceeded that for more than a few seconds, ever. I guess the 'snow' I ride that's groomed is considered 'firm' by most. But, my sidewalls on my carving boards also suffer greatly, especially near the tip/tail areas. And the boots also show signs of 'burn' at the toes and heels. Livin' on the Edge!

 

Edited November 9, 2016 by Eric Brammer aka PSR

[BlueB]

How and why would one exceed 90? I'm not convinced it's even possible in a crash... 

[nekdut]

How about an off-camber multi-sloped run, like Ruthie's?  You could get to and possibly beyond 90 deg given perfect conditions and superhero technique.  

Edited November 9, 2016 by nekdut

[Eric Brammer aka PSR]

23 minutes ago, BlueB said:

How and why would one exceed 90? I'm not convinced it's even possible in a crash... 

I take it that you've never tried to do layed-over carves down a Super-pipe? Okemo's pipe is My design, literally from the ground up. I've carved it, on lines no one else (save, perhaps, Todd Brown) thought of. Doing a handplant at the base of the curve, while your board is above you, that's more than a 90* edge engagement; but, it's a move done in fractions of a second, so....

 

[BlueB]

We are talking board to slope surface, not body to the horizon. 

[BlueB]

Otherwise, I can do head below board carve on our 43% slope, when hero groomed. 

[west carven]

howdy RCrobar

silly question... you would auger into the snow...

 

[philw]

Well the force due to gravity is not normal if you are on any slope , hence you can contrive whatever with that . 

 

Thought experiment :just imagine you have a hugely wide board.  Then your angle could be over 90 to the snow, either because you're below the board or because your centripetal is enough to hold you there,depending on the line .

Soft booters run with overhang though and do not care . Therefore either they ride soft snow , or they ride slow , or they do not crank over that far . Those yawgoon chaos and Ryan do carve hard, but not ec I guess. .