Sidecut Radius

Yeah I agree that it's easy to go too fast and ruin your carve that way. I always try to carve as slow as possible but what I'm after is getting as close to the slope as possible and with as high edge angle as possible which doesn't really follow the rules of carving as such.

That brings me to another topic that is kinda related to that chart and that is flex. If you think about a turn with 90° edge angle and flat camber, the "turn" would be straight line regardless of the scr. Now in reality what happens is that when you initiate the turn and you haven't reached extreme edge angles yet, the board will flex according to the scr and that flex will later determine the turn shape.

I asked Bruce to build me a board with this philosophy and it works great. My board has camber though, I just used flat in the example above to better illustrate the point. It's rather stiff and has 16m scr with only 136cm effective edge so not much sidecut depth. The problem is that if I lose the decamber during the turn, I'm screwed since I relied on that shape to continue the turn.

One might argue that carving using flex isn't real carving though since it doesn't follow the "rule" of that graph. I still really like the graph.

Hi guys! I have a question regarding sidecut radius and snowboard specs.

The longest snowboard I've ridden is 163cm long, with a 28.5cm waist width, 143cm effective edge, and a 10-12m sidecut radius.

I'm 174cm tall and weigh 74kg, 38 years.

I've had about 100 days on the snow in the last 3 years, focusing solely on carving.

I am touching the snow with my rear and hand during heel side turns, I don't know precisely but there is a significant board angle in the turn.

I don't ride fast when I carve. I enjoy mellower terrain, blue and some red runs for carving. 

Do you think it would be too much for me to ride a board that is 172cm long, with a 26cm waist width, 155cm effective edge, and a 15-16.5m sidecut radius?

It's a Gray Desperado Ti Type R (VIw). Here it is in the picture as well.

 I am mostly worried about big sidecut radius of around 16m.

Or do you think that something smaller 160-165cm, with sidecut radius around 12m would suit my hight, weight and slower riding better? 

I’ve topped out at a 10m SCR, so I’m no help, but I am intrigued.  

What’s your mondo/boot size? With a 285 waist I assume you’re in soft boots… and now considering going down to a 260 waist?  

Sorry to go off on the width tangent, but I really am intrigued!

My Stranda Shorty has a 260 waist and I wear mondo 260 boots (287 outer length).  I like that it’s relatively fast from edge-to-edge at speed, but at higher edge angles I do get some heel and toe drag.  With the longer SCR you’ll have even less width under foot.  Are you going to hardboots at steeper angles?

16m is a big board.  If the stiffness is right for your weight and ability it could be a super stable ride but you're likely too light to make it a tight turner.

I'm more concern with the waist width though, as @board-doctor suggested.  My wife's custom Coiler has a 260mm waist and she rides mondo 23 boots!  Plus, her 9m sidecut is going to make the board wider underfoot than this 16m for the same waist width.

If you buy it just know that it's probably not an everyday board, but it will be a riot on the best days if you don't boot out!

That is one very interesting board at least on paper. I agree that the width will be a problem for low binding angles. What I propose is something like this:

That's 260mm waist Nidecker Tracer 161G with modified AT boots. I don't recommend that specific boot model though since I have cracked two shells with that setup. Hawx Ultra XTD is better. In any case I really liked that setup while the boots lasted. Here's a video of me riding that board with modified Hawx Ultra XTDs:

I'm pretty sure it would be a blast to ride that Gray with a similar setup. The problem with the Tracer is the deep sidecut depth. It needs soft conditions for high edge angles. That shouldn't be the case with 16m scr (I do ride 16m board most of the time now and it's great for high edge angle carving if the flex is right for you).

I also have a 174 length board with 16m scr and 247mm waist. I ride that board with AT boot setup as well:

That's a hardboot board though. That one carves even icy conditions with high edge angles no problem. Boots don't have the springs installed in that pic but now I'm using same spring than in the Tracer photo.

@board-doctor

My mondo boot size is 27 (EU 42), I've been on soft boots, with higher binding angles F39 / B30. 

I've been mostly riding snowboards with waist width from 27.5 - 28.5 cm, with 10-12m sidecut radius. 

Many Japanese carvers ride Gray Desperado Type R so I was thinking about trying one. It would definitely be a new experience riding narrower board with longer sidecut.

Thanks for sharing your experience with the Stranda Shorty!

I am not switching to hard boots. 😊

@wild-cherry

Hey James, thanks a ton for your input! You've definitely given me something to think about regarding waist width.

I'll try to test it out if I can, to be sure that I'm not booting out.

I guess if I first get to try your JJA, I wouldn't be as interested in Gray anymore. 🏂

@xargo

Thanks for the setup pictures and your video on Nidecker board looks great! 

I am riding soft boots with steeper angels and Flow NX2 Fusion bindings, but I should probably test the board first before buying it to be sure that there is no boot out. 

@damir You're welcome! My advice is to do a Fuego test: https://www.extremecarving.com/forum/viewtopic.php?t=7172

With as steep angles as you have, the Gray will probably work great. I did an improvised Fuego test with the Tracer. 260mm waist like the Gray and mp27 Malamute boot with 30deg angle. Gray will be slightly narrower due to that 16m scr though:

Not good enough for extreme edge angles with extended legs and/or soft snow but should get you really close to slope.

Now I'm feeling strange after having to drink two cans of olive oil.

@xargo

Wow! Thanks you so much for testing it out!!!

That would barely make it. Looks like those few centimeters more means a lot! 

Man, some of these threads drift a lot.

There was a lot of good sidecut discussion in the prototype thread.

The above physics is a static model that doesn’t really work at higher edge angles.  I found this interesting FEA paper for the geeks.

The turn radius doesn’t go to zero, and it’s different in different snow…

https://www.researchgate.net/profile/Peter-Federolf/publication/224891596_Parameter_Study_using_a_Finite_Element_Simulation_of_a_Carving_Alpine_Ski_to_Investigate_the_Turn_Radius_and_its_Dependence_on_Edging_Angle_Load_and_Snow_Properties/links/0c96051ab59577fbb0000000/Parameter-Study-using-a-Finite-Element-Simulation-of-a-Carving-Alpine-Ski-to-Investigate-the-Turn-Radius-and-its-Dependence-on-Edging-Angle-Load-and-Snow-Properties.pdf?origin=publication_detail&_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6Il9kaXJlY3QiLCJwYWdlIjoicHVibGljYXRpb25Eb3dubG9hZCIsInByZXZpb3VzUGFnZSI6Il9kaXJlY3QifX0

Posted by: @board-doctor

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The turn radius doesn’t go to zero, and it’s different in different snow…
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Interesting stuff! Doesn't come as a surprise though. I'm pretty sure that gaussian fit only applies to that specific ski ridden by that specific rider in specific conditions. The important thing is that it's the flex pattern of the ski/snowboard that the major determining factor of the turn shape with high edge angles. In any case the graph shows really well how the gaussian fit looks like it's going to settle at around 8m when going for 90° edge angle. That number will be mainly determined by the flex. I'm doing around 10m (or maybe a bit less) radius turns with a 16m scr rather short effective edge (136cm) board and that thing is pretty stiff.

It's actually pretty interesting how that graph seems to start at around 14.2m which is pretty close to my 16m and the gaussian fit goes pretty near or a bit tighter to what I'm getting...

Howe et al varied the SCR by the cosine of the angle and I really don’t think that is correct.  If you consider the boundary condition of 90 degrees, the calculated SCR goes to zero, but it really doesn’t.  The projection of the sidecut actually goes straight (infinity).  I think it should be the projection of the SCD that follows the cosine function as the board is angled… starting from the max (physical) depth, going to zero.

That ‘physics of a carved turn’ just doesn’t seem right.  

Thanks to @riotsupercarver for diving into this…
https://carversconnection.com/community/prototype-prototype/the-jasey-jay-anderson-working-title-carving-snowboard/paged/5/#post-599