st_lupo

I second giving Topaz a try. Another thing to keep in mind is that YouTube absolutely destroys certain video formats (I'm looking at you 1080/24). Converting to 60fps seems to get handled by a better set of transcoders/parameters at YT. Filming with 360 cams and reframing to 1080 always leaves a crappy ish result. I only use the 360 module on my Insta360 one rs for certain shots, but the video is sooo much better with the 4k module.

I think Ruroc has you covered, mate.

I can only assume that is another new scale: douche froggery?

I've heard lots of good things about The Treeline. My next book needs to be something silly though

Yes and no (IMO). There are multiple ways to pump a track, but this is a really great article that describe the physics of maximizing acceleration on pump tracks. Angular momentum. This sin’t the most intuitive description, but it is pretty much bang on, and covers why you can even accelerate in banked turns with no change in elevation. Where you push/pull to get the most bang for you buck is probably slightly different from what most people think. https://m.pinkbike.com/news/how-to-pump-your-bike-physics.html?pbref=p

Thread will self destruct in 5, 4, 3, ….

Poor riding and general cluelessness aside, I’m actually really taken aback by his cavalier attitude towards crashing into a kid. Posting a YT video that is essentially: “Look at my cool video of me tackling a kid on the slopes” wtf!?!

That dude is a technicolor superman. He sensed the straight liner starting their run, and managed to turn around and tackle the culprit before they could hurt anybody. A regular hero if you ask me!

That's some level 80 shamanisn there! I can't wait to use it: just stare pensively off into the horizon and say "no... not really" and leave a pregnant pause for the remainder of the lift ride.

I'm picturing Walter White and Jesse Pinkman on a snowboarding trip to Sante Fe. Should have asked that person if they liked riding strapons?

This would make a better sequal to that 90’s Sega game: Road Rash.

I agree on this, but then the conditions you just highlighted look pretty soft and dry. That is absolutely fun and teaches how to balance pressuring the board while also being dynamic and compliant over a choppy surface and is one of the conditions where carving boards still have an unfair advantage over most things (imo). Based on John's description of the freeze/thaw cycle at Aspen and the photo from Soft Boot Surfer, I am imagining shitty uneven grooming early in the evening that freezes into ballistic plate through the night with 2 to 3cm square edge steps, yowtch.

Imagine what happens if you are charging down a run at 40 to 50 mph and discover that one of your boots is no longer connected to the board. Then imagine how much torque that board is going to put on the one leg that is still attached. Then imagine this happening while your velocity vector is pointing off to the side of the run into the trees... This sport doesn't tolerate marginal equipment. At the very least, to have fun, you have to trust the gear that you are riding.

Yeps. Plays a bigger role at faster speeds, but is still present at lower speeds.

So that thread on Aspen is kind of a bummer. How is the typical groom for everybody else and what equipment (if you know) does your hill use? Our local hill uses a Pistenbully (600?) and the area is small enough that they are able to groom everything 7 days a week.

It doesn't just effect terminal velocity but acceleration as well

All things being equal the crumpled paper will not fall to the center of the earth at the same rate as the crumpled lead of identical shape. Gravity (as in 9.8 m/s^2 or 32.2 ft/s^2 for those that are measurement system challenged) is an _acceleration_ that effects all things on earth equally, and not a _force_. The force of gravity would be F=mass__kg * 9.8, which is obviously greater on the lead (heavier) object and less on the paper (lighter) object. Given that both objects in this thought experiment have an identical geometry, they both have the exact same drag at a given speed. Since the lead ball has over 16x the mass of the paper the drag force is nearly negligible compared to the paper ball. For example: F_gravity_paper = 9.8 [m/s^2] * 1 [kg] = 9.8[N] F_gravity_lead = 9.8 * 16 = 156.8 [N] velocity_paper = velocity_lead (at our initial conditions) F_drag_paper = 3 [N] (just pick a number, at some speed it will have this much drag) F_drag_lead = 3 [N] (same geometry and speed as the paper ball) F_resultant_paper = F_gravity_paper - F_drag_paper = 9.8 - 3 = 6.8 N (working to accelerate the paper downwards) F_resultant_lead = F_gravity_lead - F_drag_lead = 156.8 - 3 = 153.6 N (working to accelerate the lead downwards) F_resultant_paper = mass_paper * acceleration_resultant_paper ----> acceleration_resultant_paper = F_resultant_paper / mass_paper = 6.8 / 1 = 6.8 [m/s^2] F_resultant_lead = mass_lead * acceleration_resultant_lead ----> acceleration_resultant_lead = F_resultant_lead / mass_leas = 153.6 / 16 = 9.6 [m/s^2] And, all things being equal, the lead ball will in fact have the higher terminal velocity because the drag at terminal velocity for both balls needs to counteract their gravitational "force" (which is 16x larger for the heavier lead ball). Since drag increases with the square of the velocity, this means the lead ball will have a terminal velocity that is 4x larger than the paper ball. From a purely mechanical sense (minus the rider's capability), yes it is! But the basic idea is very simple. This! This is what separates good courses from bad courses and makes things exciting! However, I'm not completely convinced (again in the purely mechanical sense) that performance on ice should favor either the heavier or the lighter system. The edge hold needs to resist the centripetal force of the turn, (m * v^2) / r. I don't know exactly how the edge-hold force would be described but I'm pretty sure that for "idealized" edge hold on ice (the gouge through the ice doesn't buckle) that it is roughly linear with the rider's mass (something akin to force due to friction), ie f_edge = mass*ideal_ice_hold coefficient. In this idealized case the the turn radius winds up being independent of the system mass (and edge length for that matter) and radius_min = (v^2) / ideal_ice_hold I'm guessing that when riding "on the edge", ice and packed powder act in a very different and non-linear fashion (buckling. etc), and in such a case, the system weight, edge length, etc suddenly plays a much larger role.

I'm not sure it is the momentum that makes changing direction harder. Removing the rider's skill from the equation and looking at the physics: the centrifugal force needed to change direction is linearly proportional with mass; and while I'm not sure, I would guess that edge hold is also a linearly proportional to mass. So I think that from a purely mechanical sense, the potential for performance in the technical disciplines would in an ideal situation be independent of the system's mass. (Or perhaps the increased rotational inertia of a heavier rider has a larger effect?) However, given that the rider's ability and agility is a part of the equation in a race, lighter seems to correlate to body-agility, which then impacts the total biomechanical system and likely dominates technical disciplines in being quicker edge-to-edge? (In speed disciplines I would assume that body mass will play an increasingly important roll and heavier = faster to an increasing degree).

WTF!? How do you ass up grooming that bad unless you are trying to f- it up? I can't imagine that the ungroomed slope was worse than this? How are you supposed to drag your hand on the ground without breaking a wrist? And a hip, and a rib, and a collar bone, and your neck? This horror story, pics of the Vail lift lines, and friends telling me about traffic from Golden to Summit County in the winter really take the edge off of not living in CO anymore.

Absolutely, but then the drag coefficient becomes a variable and the math becomes a lot less clear. Just found this link: https://www.scirp.org/journal/paperinformation.aspx?paperid=76068 that attempts to statistically correlate various body-type parameters with skiing performance. (Warning: tons and tons of jargon that goes beyond me). It could be confirmation bias but a couple of sentences stand out: >>> Irrespective of gender, skiers specialized in TECH events differed in anthropometric data in comparison with SPEED specialists. Further univariate analysis showed that SPEED specialists had a higher body weight, BMI and sum of SF corrected for body height than TECH specialists (Table 1). <<<

Highly simplified highschool math follows… (forgive the handwriting, decades behind a keyboard has destroyed what little handwriting skills I had to begin with )

This has always confounded me too, but my quick, shoot from the hip (no racing) take is: heavier riders do have an advantage. You see this practically on the slope and in theory. You even see this in Galileo's experiment. NASA, in fact has a wonderful experiment where they drop a bowling ball and a feather in an evacuated chamber. Boom! Both hit the ground at the exact same time! Wonderful! But in everyday life, we know the bowling ball will drop faster, precisely because (like you mentioned) drag plays a factor. Given to identically shaped objects, your drag force is going to scale based on the cross sectional area, Your inertial force is going to scale with the mass of the object. For simplicity we examine a sphere (other objects roughly follow this). A sphere's cross sectional area scales with the square of the radius (r^2), whereas the mass scales with the cube of the radius (r^2), so when working out the equations of motion, the the inertial component (helping to _maintain_ speed) is going to grow faster than the drag forces (working to reduce speed) as a function of size. Additionally, the drag force is going to grow with the square of the riders speed, becoming increasingly important (and differentiating) at higher speeds. The ideal candidate would actually be a _denser_ rider: small rider (low drag) with a lead belt (high inertial forces). One thing that does work in the lighter rider's favor is the drag of the snow on the board, which is proportional to the rider's mass. But I'm not sure of the magnitude of that force relative to aerodynamic drag.

Those graphics are so cool! Spelling Coiler in Minecraft blocks makes it ++ !

I'm pretty sure TPU is better than PVC, but I can't find any seamless TPU laminate gloves. I would have loved it if somebody would thermoform a TPU "pocket" that you could glue/sew on existing mittens that was formed such that all of the exposed seams were moved to the back side of the mitten and wrist. It's the exposed seam along the finger-tips that always get eaten up first for me.

Wound up getting tangled in my own tracks that day. How it started How it went...