SunSurfer
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Posts posted by SunSurfer
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A detailed construction description of the final 2010 version, ridden for 7 full days in New Zealand's South Island is now available for anyone who doesn't feel able to afford a plate right now, when the technology is new and still being refined.
In time the price points may come down, the advantages and disadvantages will be better described, and the longevity of the different designs will be clear.
I have had an absolute ball thinking this design up, and creating it in my garage. It has happily filled a summer between snow seasons. More than that, my experience of riding a plate gave me an even bigger smile than I would normally get from snowboarding.
Along the way I have had particular encouragement and useful hints from fellow plate designers, Lowrider & Sean Martin. Thank you.
E-mail:
aj dot mckenzie at clear dot net dot nz
for the .pdf.
Have a great Northern Hemisphere winter 2010-11!
SunSurfer
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Do any US vendors have plans to sell the pre P-tex'd snowboard inserts +/- purpose built countersink drill bits +/- UPM templates for people to convert their old 4x4 insert boards to UPM?
SunSurfer
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I've had about 10 days on the plate equipped Riot.
For the trip I made to the South Island I made new caps for the slide slot. These were made from layers of 3mm aluminium and a layer of snowboard base P-Tex. The aluminium was freshly abraded immediately before application of the epoxy. The P-Tex was abraded and flame treated immediately prior to epoxy application and clamping.
These photos are lit to try and show the extent of the wear on the UHMWPE and P-Tex bearing surfaces of the slide unit I rode for about 7 full days riding in the South Island. One cap unit shows more wear than the other, I don't know why, and the wear is most extreme at the lateral (outer) side of that cap. This was my heelside, the left side of the board, and the side of the green base unit nearest the lens.
The P-Tex shows more wear than does the base unit's abrasion resistant UHMWPE (even UHMWPE comes in different versions and colours).
For those of you with eagle eyes, yes, the slide was the rear unit on my plate.
Although this is not the way most pundits would have you mount a plate, I deliberately chose this way after observing the way the snowboard responded to sudden shock loads in a bench test setup. Essentially, the whole board moves/vibrates with the shock independent of whether the slide unit is mounted at the front or rear.
I decided I would rather have the most solid (hinge only) mount under my front foot. Only time will tell whether it makes any difference to performance to have the slide unit front or rear. From the photos of the Canadian Olympic team boards it seems the jury is still out on this one.
SunSurfer
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Everybody loves to go fast but the truth is SPEED KILLS. Its up to you to know what your comfort/skill levels are. Don't ever assume that these plates are a bandaid for poor perfomance, improper riding technique and a improper stance.
Think Snow!
Kinetic Energy = 0.5 x mass x velocity x velocity
Nah, it's the sudden STOP that kills you!
When I was riding my plate equipped board (Riot Supercarve 180) I would ride, as always, up to the limit of what I perceived as acceptable risk. That's a combination of speed, sensation of balance and being in control, and surrounding traffic. Actually, that's what I did on my board without a plate too (Coiler AM 177), and before I ever even thought about plates.
The skiers I was riding with commented that despite the speed I was going that everything appeared to be in absolute control, and that I could clearly turn at will. There was no arm flailing, or anything else that suggested I was being thrown off balance.
An isocline plate extends the range of snow conditions and speeds that a competent rider will, be in control, be able to carve if they so desire, extend the time that their quadriceps femoris muscles stay unfatigued enough to maintain good control, and still follow the Snow Responsibility Code.
In the end, whether you drive a Toyota Corolla, a Humvee, a Lamborghini Countach, or a WRC Subaru on public roads, the rules of the road still apply. What you do on a racetrack is entirely different.
The effect on snowboard torsion will depend on the torsional stiffness of the plate. I could still easily traverse slopes, sideslip, hockey stop, and adjust edge bite and release in the turn by the same degree of movement that I needed on the unplated board I was riding for comparison. My plate was made from a 1996 Hot Logical snowboard. I don't think we're going to see plates built and MARKETED that are so rigid as to be able to prevent that kind of control.
There are going to be moments when you lose control and fall, just as there are when you ride an unplated board. Because you are likely to be moving faster at that time the consequences are going to be more severe, as both Snowman and the KE equation point out. Mass is less important than speed, and the plate will add perhaps 2-3% to the total mass of rider and board.
Buying and using more body armour isn't necessarily the solution. At more than about 50 km/hr any immediate deccelleration to 0 km/hr is going to do serious damage to you, armoured or not. We can do those sorts of speeds easily on an unplated board.
Better to considerably increase the distance ahead of you that you look for hazards in, and slow down when you spot them.
SunSurfer
(A separate OT thread might go on which board matches which vehicle!)
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The Breasts are on the Table.
If they're really resting there, try looking at
http://www.bravissimo.com/default.aspx
SunSurfer
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Sounds like what is really needed is a series of demo days, where riders can try before they buy. Identical boards, with and without plates.
SunSurfer
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Don't compare plates that are designed to have the rider above the board with their feet on a stable plane with the older shock absorbing systems that still result in the rider's feet changing angles with every bump and turn.
The design concepts are completely different.
Until you have ridden an isocline plate design, that keeps the rider's feet on the same slope while the board arcs beneath, it is hard to believe what the converts like myself are saying.
SunSurfer
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Try looking here for up to date data
http://www.bom.gov.au/climate/current/soi2.shtml
Australian Government Southern Oscillation running data
SunSurfer
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Hi Nigel,
Unfortunately for a range of reasons (not injury) I won't be getting any more snow time this winter. Boards have been storage waxed and put away. Starting to think about how I might try and produce a similar UHMWPE block around the sliding axle as in Sean Martin's design for next season.
If you are interested I could e-mail or post some more photos of the version that was ridden in the South island.
Been riding with another carver this year at Turoa, and by chance caught up with them at Cardrona. Sorry to have missed you.
SunSurfer
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I have discarded the 5mm axle model. There was some minor deformation of the axle after a couple of days riding.
Having completed my holiday in the South Island, and having just seen Sean Martin's videos on destruction testing and his production version (Vendors Section), I disassembled my 8mm axle plate mechanism.
8mm axles remained true and round.
The fixed axle plastic block groove and locking plate showed no significant wear.
The sliding axle UHMWPE surfaces showed significant wear. In particular, the surface on the side nearest the plate had visibly lost some of it's thickness, with this most pronounced at the most lateral parts.
Sean's design has a plastic block around the sliding axle. By this means he spreads the loads on the sliding axle in a way that I am unable to achieve accurately in my garage workshop. His design is less likely to have such a significant wear problem.
My hinge/slide design works, but has wear limitations that will require regular checking and replacement of some of the bearing surfaces.
SunSurfer
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Been riding every day for the last 6 days, have a glass Coiler AM 177 and the 8mm axle plate equipped Riot Supercarve 180 as ride choices.
Days start out on groomed cord, and then as expected the snow gets cut up and lumpy.
My own carving is making progress, and have had the pleasure today of riding with a New Zealand carver, and a visiting US snowboard/ski instructor from Lake Tahoe, Dick Schulze, who is listed amongst the California hard boot instructors on the Bomber list.
Today have ridden non stop between 0845 and 1600hrs with a 10 minute lunch break. Having ridden both boards on fresh groom and later in the day conditions over the last 6 days, my choice is firmly for the plate equipped Riot. I have been carving all day, and the thing that strikes me as being most different from my previous days on the snow has been the lack of fatigue in my quads. Bear in mind these are 51yr old quads that get a moderate amount of road & MTB cycling to keep them in shape. By smoothing out the bumps I carve better, and with less effort. I don't notice the extra weight of the plate on the chairlifts. I am riding faster than I have ever dared before and feel more in control of my board.
I think there will be a small group of carvers who will not benefit from a plate. They only ride perfectly groomed cord at under 20 km/hr!
SunSurfer
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Lifty: It's a double decker!
Me: (large smile)
SunSurfer
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Just getting to grips with the idea and working through the possibilities .
A turnbuckle type device could adjust the tension. If that was at one end then clearance would not be a problem. The string/strap could be fairly thin in that direction, would depend upon what material was used to make it. Spar makers for yachts use steel wire rope and spreaders/diamonds struts to achieve similar ends.
My latest iteration homebake plate mechanism, with an 8mm axle, has a 23mm gap between board and undersurface of the plate.
http://www.bomberonline.com/vbulletin/showpost.php?p=310581&postcount=12
SunSurfer
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Isolation mechanism principles are very simple, a hinge at one end of the plate and a combined hinge slide at the other. Actual mechanisms and materials for achieving those principles vary widely and will have different wear characteristics. Plate stiffness, torsional rigidity, and binding placement relative to plate/board pivot points are areas ripe for experimentation.
Just mentally doodling here, could a plate be tuned for varying stiffness by attaching a bowstring like adjustable tension strap beneath the plate?
SunSurfer
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Summer time in BOL is like menstruation ...
Northern Hemisphere PMT!? (pre-mountain tension)
SunSurfer
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Where does those pics come from?
I have a WC Oxess on order with UPM inserts. So this plate would be fine....
Try the Oxess Facebook site Pictures page.
SunSurfer
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Just had an e-mail reply from the organising committee secretary and the venue for the snowboard PSL & PGS events is a terrain park, Snow Park NZ!
Looking on line at (not current snow coverage) photos of the park that show the general terrain the only reasonable course seems immediately beside the chair lift, about the same slope as the half pipe.
SunSurfer
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Took my cues from photos of the Apex Composites plate as used by the Canadian team. In addition B Karl plate axles are also set outside the binding plate centres.
Haven't tried axle under binding plate centre, but would anticipate less shock absorption in this position.
SunSurfer
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Back from 3 days of riding on a mix of snow / ice and boards. Both 5mm axle and 8mm axle units were used with no problems.
The plate used with the 8mm axle unit was made from an old, scarred Hot Logical carving board and is fairly stiff when tested by bouncing on it as per the video by Sean Martin. The aluminium insert inlaid into the plate has been both epoxyed and bolted to the plate. The epoxy must be applied within a minute or two of freshly sanding/abraiding the aluminium surface. The aluminium rapidly oxidises.
Total weight of 8mm axle units and the plate is 1850 gram. (approx. 4lb 3oz)
The photos show the plate and hinge units after their first full day of use on hard packed black and blue runs that are narrow and crowded.
And yes, Lowrider, I was wearing an enormous smile!
First tries on a plate were back on the absolute beginners slope as I checked out that I hadn't made some major miscalculation and the whole thing wouldn't fall apart on the first ride. The feel is quite squishy and odd at low speed but no problem sideslipping/ hockey stopping even from the first run.
In the afternoon cut up crud/bumps it was like getting 18yr old knees/quads/reflexes riding the 5mm axle/plate combo (which is significantly softer, made from a non carving snowboard) on a 167cm Avalanche board made in 1997. Before trying it I'd been riding a recently acquired second hand fibreglass Coiler AM 177, 21cm waist, (no plate - I haven't had the courage to cut into its' base!) in the same snow. Plate equipped board was much better in this setting.
The 8mm axle plate was on my 180cm Riot Supercarve which got tried two days later. In between we'd had a day of rain and then freeze so the snow was now hard packed / icy over most of the upper mountain and slush on the narrow access trails back to the skifield base. By Colorado standards our runs are very narrow and crowded so a lot of turns get made!! Riding faster, and more sure footedly in those conditions than ever before, and again my 50+ yr old knees really didn't feel the strain I would normally have expected.
Heading to the South Island in 12 days time for just over a week of snow time in and around Queenstown/Wanaka while the FIS Junior World's are on.
Some minor tweaks will be made between now and then.
SunSurfer
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Joint replacement surfaces have been almost universally UHMWPE on medical grade stainless steel alloy for many years. These types of surfaces have the best track record for wear so far.
Recent advances for hip joints are steel ball femoral components onto highly polished, precision ceramic cups. It will be a number of years before it is seen how well these last. Some of the early model ceramic cups fragmented inside the patient once in use.
Increasing the bearing surface area also slows the rate of wear as point loads decrease.
SunSurfer
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Industrial strength looking plate Seb!
The durability of the pivots/bearings in these plates is going to be an emerging issue, especially after you pay $1000+ for one. Anyone designing them had better either source a sealed lubricated bearing that works well at sub-zero temperatures OR reflect/read up on why orthopaedic surgeons don't use steel on steel, or steel on aluminium, for their unlubricated hip joint replacement joint surfaces.
Kia ora, and welcome to Aotearoa.
Watch a little top class rugby series that is on at present between the best 3 nations in the world (Australia / New Zealand / South Africa - in alphabetical order, bragging rights before next year's World Cup will be decided by the outcome). Take care on our gravel surfaced skifield access roads. Best of luck for the FIS Junior Champs at Treble Cone in Wanaka.
SunSurfer
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8mm axle version now in progress. With a tiniest amount of shaving of the inside of the U-bolts on the 6mm rope clamps an 8mm axle fits snugly. M8 stainless bolts available locally in lengths up to 220mm, with smooth shafts for all but the last 40mm.
SunSurfer
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Traffic paint will get you very time, even more so if it's at all wet! Ask any road motorcyclist!
SunSurfer
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Use purpose built new inserts, pre-PTex'd available as below.
http://www.maislinger-snoli.com/nc/de/produkte/browse/1/select_category/25.htmlSnoli make the stuff, and a few places in Europe seem to sell it.
Drill a pilot hole from the top. Drill the base using the countersink to create the socket that matches the profile of the pre-PTex'd plug (7 or 9mm depth), thin layer epoxy, drive the plug home into the board. Wait for epoxy to set and base grind your board.
Haven't yet found any place outside continental Europe that sells the plugs, countersink, or snowboard mounting kit.
SunSurfer
Follow the quote above for more details and a picture of these inserts in use by a World Cup racer. I've sourced some from a company called Worden in France. The link from Tufty (a couple above my quoted post) to the inserts page on their site works.
I used a 16mm bit to cut the base hole, a 16mm countersink to accomodate the taper, and a 9mm bit from above.
Sunsurfer's Homebake UPM Plate Recipe.
in Carving Central
Posted
Had a few requests already. Nice to know people are interested. Although I took some care writing it, I know from past experience that having someone else read your stuff is the best way to find the typo's and ambiguities. Direct e-mail means I can get feedback and do any final editing needed.
I have a G-mail account, but had wondered whether the best place for the .pdf might eventually be as a tech article here on Bomber. This is one of the places, in the English speaking world, where people are likely to come looking for information about alpine snowboarding.
Recipe includes a list of the beyond basic workshop tools you'll need to do a reasonable job. I bought a second hand drill press, something I'd always wanted to have anyway, to drill the holes with adequate accuracy. A hand held drill is just not accurate enough on getting the holes vertical.
See Fin's comments when drilling holes in a Sigi Grabner board in the thread about 4x4 to UPM conversion.
http://www.bomberonline.com/vbulletin/showpost.php?p=313201&postcount=8
Email me either via the site or at the address above.
Best wishes
SunSurfer