Larry

Putting on skis
Skier
Joined
Feb 15, 2017
Posts
82
Can you guys enlighten me on turn radius of skis. For instance, I have older Blizzard Bushwacker in 173. I think they have turn radius of 18 on them. The newer ones(2019 and up) I think have much shorter radius of about 15.5( I think).

If the construction is close to the same, why are a lot of newer skis going to a shorter radius? Thanks
 

Jeffc7

Booting up
Skier
Joined
Apr 26, 2017
Posts
54
Almost always, size changes turn radius. For example, a 160 (15m), 170 (16m), 180 (17m) etc. There are a few skis where the turn radius is the same for every size, but it’s uncommon. Most 80-100mm waist all mountain skis range between 16-19m, at least in the skis my size. Except for the new Line Blade, I haven’t noticed more skis with lesser turn radius as a trend.
 

Cheizz

Craving camber
Skier
Joined
Aug 15, 2016
Posts
698
Location
The Netherlands
In general, skis with a shorter sidecut radius take less input (edge angle, bending) than skis with a larger sidecut radius to carve the same turn in the snow. So - again: all else being the same - the shorter sidecut radius makes for more effortless turning. For Blizzard, as an example, giving their Brahma a smaller sidecut radius leads to a bigger group of people that can ski them. The lazy cruising type (such as myself) who doesn't want to have to work the ski all of the time can now consider the Brahma too.
 
Thread Starter
TS
Larry

Larry

Putting on skis
Skier
Joined
Feb 15, 2017
Posts
82
@Cheizz, I would probably call my type of skiing "lazy" too in that I try to push hard but I have lousy technique. I never learned how to properly do pole plants. I really just hang my poles down and sloppily try to carve using bad technique but it is what it is now.

That being said I remember doing a demo of Rossi 88ti about 5 years ago. I think they also had 15.5 radius. They felt very "turny" to me in that if I wasnt paying attention every second the skis seemed to want to turn too easily instead of me trying to engage the turn on my terms.

In general, does a shorter turn radius help those with proper technique and allow those with a poorer technique to perhaps use a slightly longer turn radius and wait until the skier initiates a turn?
 

Philpug

Notorious P.U.G.
Admin
Pugski Ski Tester
Joined
Nov 1, 2015
Posts
24,500
Location
Reno, eNVy
Remember there are many ways for a manufacturer to measure radius. Contact point. Dimensions. Weighted/unweighted. When we are dealing with multiple tip/tail rise and rocker designs, unless we had an independent lab measure all of the skis the same way, there is no way to actually compare one ski to another A percentage of these radius numbers are for marketing, there is as much as, if not more inconsistencies here as there is in boot volumes.

Don't get hung up in exactly a 14.5m radius verses say a 15.5m or 14.2m. I am not saying all but many manufacturers can (and will) use creative licensing when it comes to publishing numbers. The only area that there is more consistancy is with race skis where there are FIS regulations.
 
Thread Starter
TS
Larry

Larry

Putting on skis
Skier
Joined
Feb 15, 2017
Posts
82
@Philpug , I guess the old adage of demo, demo, demo is really true in this case. So many skis sound interesting and different and me only being 5'8" and 150 also puts me in the upper ski length for ladies too. So i have even more demos to try. I'm still partial to Blizzard so maybe ill start there. Bushwacker, black pearl 88 or 98 even
 

Philpug

Notorious P.U.G.
Admin
Pugski Ski Tester
Joined
Nov 1, 2015
Posts
24,500
Location
Reno, eNVy
@Philpug , I guess the old adage of demo, demo, demo is really true in this case. So many skis sound interesting and different and me only being 5'8" and 150 also puts me in the upper ski length for ladies too. So i have even more demos to try. I'm still partial to Blizzard so maybe ill start there. Bushwacker, black pearl 88 or 98 even
Yes and no. Unless you are demoing all of your options on the same day in the same conditions with the same bindings and the same tune, demoing can create more questions than it answers. This is discussed in this article: What does it take to demo a ski?
 

Wilhelmson

Out on the slopes
Skier
Joined
May 2, 2017
Posts
1,939
Does the actual sidecut of a ski roughly equate to the stated radius?
 

Philpug

Notorious P.U.G.
Admin
Pugski Ski Tester
Joined
Nov 1, 2015
Posts
24,500
Location
Reno, eNVy
Does the actual sidecut of a ski roughly equate to the stated radius?
In can and usually does. I am sure you have heard us say that ski skis shorter turn or longer turn that stated.
 
Thread Starter
TS
Larry

Larry

Putting on skis
Skier
Joined
Feb 15, 2017
Posts
82
Thanks @Philpug what makes it harder for me too is that prefer a generic 88-98 ski width because I might be one of the few who would Never want to ski powder but stay on about 4-8" of soft hard packed. I'll take a long groomer run any day over powder.

Use skiing Cornice (groomed part) top to bottom gondola at Mammoth for an example...
 
Last edited:

JFB

Getting off the lift
Skier
Joined
Nov 11, 2016
Posts
173
Worth mentioning here is that sidecut radius describes the shape of (the edge of) the ski, not the turn. Turn radius is influenced by sidecut and a whole bunch of other factors.

OK, I have been accused of being (or perhaps accurately described as) a word weenie......
 

Philpug

Notorious P.U.G.
Admin
Pugski Ski Tester
Joined
Nov 1, 2015
Posts
24,500
Location
Reno, eNVy
Thanks @Philpug what makes it harder for me too is that prefer a generic 88-98 ski width because I might be one of the few who would Never to ski powder but stay on about 4-8" of soft hard packed. I'll take a long groomer run any day over powder.

Use skiing Cornice (groomed part) top to bottom gondola at Mammoth for an example...
This is where I have mentioend many times over, "don't get hung up on the numbers". If you read "What's the best ski?" there is a section in the center that compares four 88 mm skis. Almost every one of these skis have a turn radius within a meter or two yet all react on the snow very different. That article was from a few years ago but is still true today.
 

David Chaus

Epic & Ikon because I’m indecisive. Or am I?
Skier
Joined
Nov 12, 2015
Posts
2,752
Location
Stanwood, WA
^^^^ This is especially true with the shapes of the tip and tail. A ski with a very gradual tip and tail taper will have a surfier, less precise feel to engage the turn, which has it advantages in bumps and crud. A ski with a hammerhead-type tip with little-to-no taper and a flat tail will engage edges better (by this I mean quicker, more firm from initial engagement and will hold that edge as long as you tell it to). This is great on groomers, but makes the same ski a little hooky in crud and require more effort to navigate bumps and off-piste.

Then you add in the flex at the tip and tail (and everywhere else along the skis) being different on these two hypothetic models, and they don't feel similar at all. And both of these hypothetical skis may have the same stated turning radius, made by the same brand.
 

Paul Lutes

Out on the slopes
Skier
Joined
Jun 6, 2016
Posts
573
Remember there are many ways for a manufacturer to measure radius. Contact point. Dimensions. Weighted/unweighted. When we are dealing with multiple tip/tail rise and rocker designs, unless we had an independent lab leasure all of the skis the same way, there is no way to actually compare one ski to another A percentage of these radius numbers are for marketing, there is as much as, if not more inconsistencies here as there is in boot volumes.

Don't get hung up in exactly a 14.5m radius verses say a 15.5m or 14.2m. I am not saying all but many manufacturers can (and will) use creative licensing when it comes to publishing numbers. The only area that there is more consistancy is with race skis where there are FIS regulations.
Very disturbing. Nightmare inducing, even.

IS NOTHING SACRED?!?!?!?
 

jmills115

Out on the slopes
Skier
Joined
Apr 25, 2017
Posts
746
Location
Salt Lake City, Utah
Remember there are many ways for a manufacturer to measure radius. Contact point. Dimensions. Weighted/unweighted. When we are dealing with multiple tip/tail rise and rocker designs, unless we had an independent lab leasure all of the skis the same way, there is no way to actually compare one ski to another A percentage of these radius numbers are for marketing, there is as much as, if not more inconsistencies here as there is in boot volumes.
@mishka spent 3 or 4 chair rides explaining this to me as I was asking him questions about his Mad Russian skis at Alta in January.
It only took us one stop to continue talking at the top of Supreme in 0° temps to realize waiting for the next chair was a better idea.
 

oldschoolskier

Out on the slopes
Skier
Joined
Dec 6, 2015
Posts
2,220
Location
Ontario Canada
Something else that needs to be remembered with turn Radius is risk.

The smaller the radius the greater the risk at higher speed of catching an edge (tune not withstanding). This is most noticed on shorter length skis.

So the idea zone for speed vs turn ability vs risk is somewhere between 16+m and below about 20m. Larger to smaller from this range shifts the balance.

Again as @Philpug stated these are only guides not absolutes.
 
Thread Starter
TS
Larry

Larry

Putting on skis
Skier
Joined
Feb 15, 2017
Posts
82
@oldschoolskier , from my only one experience(Exp 88) trying a radius of less 16, I noticed that it wanted to turn quite easily when I wasnt ready.

Like I said, I'm more of a "lazy" skier when it comes to technique. I think my Blizzard 8.0ca at 172 is 17 radius. I realize other things play into it now but mentally(w/o demoing) that I'm afraid to try anything less than 16.

I look at specs for a 170-175 88-98 lightweight ski that has a radius over 16 is few to pick from
 

Philpug

Notorious P.U.G.
Admin
Pugski Ski Tester
Joined
Nov 1, 2015
Posts
24,500
Location
Reno, eNVy
@oldschoolskier , from my only one experience(Exp 88) trying a radius of less 16, I noticed that it wanted to turn quite easily when I wasnt ready.
Thant has less to do with the radius than the shape of the ski. As I referenced in the "What's the best ski" link. The flaired tail of the Experience 88 locks into a turn. The new version of the ski with the same name is much more tapered at the tip and tail, yet a tighter published radius. the current 88 is actually much easier to ski and is less likely to turn when you weren't ready.
 

mishka

Getting on the lift
Industry Insider
Joined
Jun 15, 2016
Posts
267
@mishka spent 3 or 4 chair rides explaining this to me as I was asking him questions about his Mad Russian skis at Alta in January.
It only took us one stop to continue talking at the top of Supreme in 0° temps to realize waiting for the next chair was a better idea.
HAHA I hope my explanation was informative and something helpful.

on OP subject
turn radius only part of "package" not to mention it can be misleading and manipulate all depend how it measures.
to simplify and put in perspective. Main components of the "package" not the new order of importance:
tip shape and profile
central/sidecut section shape/radius and profile
tail shape and profile
ski construction
this components EQUALLY IMPORTANT to how ski preform and feel. looking at one component not gonna get you anywhere to understand whole "package"
 

François Pugh

Making fresh tracks
Skier
Joined
Nov 17, 2015
Posts
3,196
Location
Great White North (Eastern side currently)
For traditional short radius turns (not arc-2-arc carved turns of any radius short or long) you have an extra degree of freedom, but for carving arc-2-arc turns on hard snow the range of turn sizes you can make at any speed and on the speed of a turn of a given size is limited.

The (centripetal) turning force is that needed to accelerate the mass of you and your equipment around the turn, F=mV^2/R, where m is mass, V is speed and R is the radius of the turn. Besides the turning force, you also have gravity (mg) acting downwards. The net force is the vector sum of the forces acting on you and your equipment.

Where the extra constraint comes in is that the size of turn the ski is designed to make is roughly (it's an approximation) dependent on the tipping angle of the ski, R = Rs * Cos(theta), where theta is the tipping angle of the ski and Rs is the side-cut radius of the ski. In order to make a clean carved turn, the vector sum of the net force cannot go past perpendicular to the base of the ski (critical angle critia for non-slip). I'll spare you the math, but the results are clear: Tip the ski up too much and the ski will dial up a turn with a too-small radius, and that radius at that speed will demand a higher centripetal force so that when the net force adds up it will be too horizontal and you will not be able to carve that turn at that tipping angle and the ski will slide sideways; ski too fast and the centripetal force will increase too much and the net force will be too horizontal and the ski will slide out. You don't have to be at the critical angle; you just can't go past it, so angulation allows you to ski more slowly, but ski too slowly and you will require too much angulation (e.g. me in a quest for speed skiing like a pretzel on one (the outside one) of my SGs making a clean turn at the top of the lift on an eastern hill so as not to lose any speed).

It's all related. Well-designed hard snow skis are designed (including how stiff they are, what the side-cut radius is, damping needed, and everything else) so that the side cut radius and the range of speeds and turn shapes dialed up matches the expected range of g-forces for clean carved turns at their design speeds. Short side-cut radius for SL, long for DH, about 15 m for the typical recreational skier, longer for speed freaks.

What I've stated above is for hard snow and for arc-2-arc turns. For traditional short radius turns and for deeper snow I find taper and rocker profile play a critical role.

EDIT: if someone has access the the critical angle gif it sure would help the explanation.
 
Last edited:

Members online

Top