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johnstewart

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Posts posted by johnstewart

  4. BTS options on new boots? Modding Raicles?

    in Hardboot Reviews

    Posted

    I'm a big dude (~220lbs). Ride pretty hard (main stick is a 184 Coiler race board).

    The weak point in my gear is my Raicle 123's. I had a ton of spare parts because I got a bunch of these shells on closeout (I sold a few dozen pair here at $25 a pop), so I've stuck with them, since I have endless spare parts.

    I put BTS on 'em last year, and right away it was awesome, but now it's clear a major design problem with them is causing me grief.

    The pivot point at the ankle, if it's cranked down, won't allow the boot to flex on that pivot... making BTS useless.

    With the hex bolt loosened a bit to allow it to pivot, it also allows the shell to ride up and down, effectively screwing up the cant and prevents the boot from being stiff side to side.

    I've had it. I don't think there is a solution with the 123's.

    The Head Stratus Pros seem to be damn popular around here. Seems like they work with BTS, so I won't lose that investment?

    Unless anyone has an idea for how to deal with the craptastic pivot on the 123's, I think I'm going to make my wife unhappy and pony up for some new boots.

    I'm in Madison, WI... I don't think there's anyplace closer than Colorado to try these suckers on (let me know if there is!).

    Any input appreciated; thanks!

  6. Breck status?

    in Colorado

    Posted

    How's Breckenridge right now?

    A buddy has a line on some free lift tickets next weekend; thinking of burning some frequent flier miles to get out there for a couple of days.

    Is it worth it?

    This may be my last chance to get out west for a while (in Wisconsin); kid #2 is due in March.... but if the place isn't covered very well, would prefer to save the money!

  9. Handicapping a race

    in Racing

    Posted

    It's part of a bigger league; each team gets points for each gold/silver/bronze NASTAR each week.

    But as I mentioned, to compare NASTAR handicaps seems to have issues in that if you just subtract the delta between handicaps the fluctuation of the "bad" racers easily overwhelms the data.

  10. Handicapping a race

    in Racing

    Posted

    So we have a Monday night race league at Tyrol Basin, a little pimple of a hill just west of Madison, WI.

    Ten of us are on the team (two skiiers, the rest boarders).

    It's a lot of fun, but generally there's not much competition... the rankings amongst ourselves is usually the same. I'm a second slower than the guy above me and 1-2 faster than the guy below me, and so on.

    What I'd like to do is devise a way we can all throw a buck in a pool and compete in such a way that we all have a shot.

    So one way might be:

    - Average the last 2 race times. You get a bonus based on the difference from the fastest guy on the team, strictly based on time.

    So for example (using actual numbers from our first race this season http://www.nastar.com/index.jsp?pagename=raceresults&race=72605&year=2010)

    Tim: 20.49

    Brett: 20.71

    John: 21.21

    Aaron: 25.8

    Rochelle: 32.5

    So the bonuses for the following week would be:

    Tim: 0

    Brett: 0.22

    John: 0.72

    Aaron: 5.31

    Rochelle: 12.01

    ... and then the winner would be whomever is fastest after subtracting the bonus.

    The course (of course) is slightly different each week, so by using time instead of handicap you're not comparing apples to apples... but if you use handicap, the delta between people is much huger. For example:

    Tim: 23.21

    Brett: 24.53

    John: 27.54

    Aaron: 55.14

    Rochelle: 103.25

    So by simple subtraction the handicap bonus would be:

    Tim: 0

    Brett: 1.32

    John: 4.33

    Aaron: 31.93

    Rochelle: 80.04

    ... so simply subtracting this from the handicap and the deviation would be quite high. As the boarders are better, the handicap is more stable, but as you get slower, it changes a lot more. So I like handicap to keep the comparison more fair, but how to deal with the higher fluctuation?

    The goal is if a rider has a good night, they should win. But I don't want it to be random, either.

    Just sort of brainstorming here, so any suggestions, please speak up.

    Also, an enhancement might be to include more races in the the past for bonus calculation... but we don't have a lot of data points; only 6 races per season (and not everyone raced last year).

  11. Park City this weekend

    in Utah

    Posted

    So... snow, I hear?

    Headed out west for the 1st time in a couple of years. Going to get a couple of days on the hill Sat/Sun/Mon. Not sure on Sat/Sun, but had planned on Park City on Monday (the last time I was there was the best carving day I've ever had).

    Was just trying to fit my 182 Coiler in a borrowed snowboard bag... doesn't really fit well (but better than mine).

    But if there's a bunch of snow, then maybe I'll just leave it home and only bring out my ATV. I really love that Coiler, though.

  15. Racing Jersey?

    in Racing

    Posted

    I don't want a full-on race suit, but would like a little padding on my upper body to help with hitting gates... especially in the kidney area.

    Any recommendations for snowboarding racing gear?

  19. Mes '09

    in Great Lakes

    Posted

    i'm gonna find out, tommorrow, if i work wednesday.

    I'll probably be out there either way though, cause hopefully johnstewart will sell me that donek he's got for sale.

    I'm gonna try to be working chair 2 again, though, so i can watch you guys make smiles in the snow.

    Jack(Dave?) - didn't get yer emails about the board. Some very small chance I'll make it to MES this year... new kid, company I've worked for for the last 14 years is on the rocks. But if anyone from Madison is going, I could send it up with them.

    Anyone here planning on going to MES from Madison, or anywhere nearby?

  20. Donek Axis / Axess 177

    in For Sale

    Posted

    Jack - didn't get your emails, not sure why; drop me a line at john@johnstewart.com directly.

    I don't think I'm going to make it to MES. Some very very small chance I will. I'll ask around Madison and see if anyone plans to go from here. If I can manage to send it up, $275 would be fine.

    This is actually the board I rode the last time I was at MES!

  22. Straight and fast stability issue

    in Carving Central

    Posted

    I would posit the reason you get better purchase with underinflated tires is not directly the friction of the surfaces together, but the fact that the knobs can get into nooks and crannies, and stay there.

    Likewise on a snowboard, the larger surface area helps you plane over the slush, and a smaller board would sink in and get stuck... but the friction between the snow and the board is the same.

  23. Straight and fast stability issue

    in Carving Central

    Posted

    Right; this is idealized. In the real world you do have other concerns. For example, with an edge, you may have the effect of the snow being compressed causing melting of the snow under the edge, whereas you might not if the entire board base is flat.

    But my point is just that when people think about friction, they often assume that a wider area will mean less friction, but that's not true... it just affects these other outside influences in various ways.

    On a car, a big wide tire grips the same as a narrow tire... the reason drag racers use big wheels is not specifically for this reason, but other concerns (heat, durability, etc...)

  24. Straight and fast stability issue

    in Carving Central

    Posted

    This is just for fun, because I really could care less and I'm bored. It will make me exercise this brain of mine.

    I will give you that the coefficient of friction for UMHW may be less than the metal edge material, but lets take into account the amount of the meterials in question. I'm going to be generous and say a single edge is 2.5mm wide. This amount of material is so minimal it isn't worth including in the equation.

    However, my base I'm going to say is apoximately 200mm wide on the average. Slightly on edge I'm going to say aproximately 50mm of base material is in contact with the snow. Running flat I would have four time the material in contact with the snow, that four times the friction. It doesn't matter how low the coefficient of friction is, it's still four time more. Friction is the enemy when it comes to speed.

    Ah, this is a common mistake when thinking about friction. The increased area in contact has nothing to do with it.

    The only thing that matters is the coefficient of friction and the normal force (it's been a while, but I'm pretty sure this is the force perpendicular to the surface). You can have a surface are of an square inch, or a square foot, and the friction will be the same. The area of contact doesn't figure in at all.

    http://www.school-for-champions.com/science/friction_equation.htm

    The reason is that as you increase the area in contact with the snow, while there is more in contact, the force that each section is being pushed on is less by a proportional amount.

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