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| Q&A: McKendry on Speed (1810 Posts)
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i agree 2
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On 6/16/2005
mike p
wrote in from
United States
(69.107.nnn.nnn)
this neck helmet-speedsuit connector is something i considersed a while ago, while pondering the fact that i cannot afford a doc. my personal thought is there would be no way for it to work. in order for the fabric to not vibrate in the wind (like a t-shirt at 50mph) it would need to be so taut that ur head would not be able to swivel or tilt. game over.
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Q&A's!
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On 6/16/2005 Jimmy.
wrote in from
United States
(207.200.nnn.nnn)
I agree Christopher!
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I Agree
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On 6/15/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
If you start with a light, strong, safe helmet that has good visibility, and whatever you're adding to it doesn't negatively effect the weight, strength, safety or visibilty, then you'd have a good result. The trick is to make the system smooth and aerodynamic while in a tuck, but without putting pressure on your neck or limiting your head's range of motion. The "Unibomber Helmet Hoodie" should also consider the area from the chin to the chest, but arguably to a lesser degree than the back. Don't forget that the "Donald Duck Inflatable Butt Plug" musn't be allowed to scrape the ground in when sliding the turns 8-)
Time to fair the board. Torpedo Tommy, reporting for duty!
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aero helmets and such
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On 6/15/2005
duane
wrote in from
United States
(68.15.nnn.nnn)
I would think that a well-designed soft cover for a snell-rated helmet (well chosen), could provide aerodynamics at least as good as, and probably better, than the doc go-fast helmets or the landingham helmet
Both of those helmets leave a big gap between the trailing edge and the shoulders that no doubt causes a low pressure area and loss of air at that point. The landigham is longer so a bit better here, but it was designed for a ski tuck where the shoulders are way forward. In skating hut-tuck position the shoulders are several inches back so leaving the big gap
what I'm talking about here is a speed suit that goes over the helmet. think lycra and spandex stretchy fabric like the olympic speed skating suits, only with a big head. no gaps and the fabric could be oriented to stretch taut between the head and upper body to leave effectively no neck and a smooth profile (some of this stuff stretches 400% one way and not at all the other direction)
not so hard to make, spandex can be glued together with elastic hot glue or sewed on any machine easily with elastic thread. In fact lycra streches so much that the stock speed skating suits might be convinced to stretch over a helmet, though probably not, and the fabric would be oriented wrong
note that such a gimmick is NOT banned for the Timeship races, and presents little extra weight, and no danger unless you mess up and allow the material to shift over the visor somehow
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Bearing and Axle Size for 97mm Flys
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On 6/15/2005
K-Rimes
wrote in from
Canada
(24.87.nnn.nnn)
Hey again Chris, I have a set of 97mm flys and they wreaked havoc when put on my stock randal DH's. Even on the mellow turns of Jake's Rash on the Danger bay weekend did they bend my axles to a healthy degree. 10mm axles are a viable solution but my main worry is that with such small diameter balls, will the wheels "top out" so to speak? I know that my 78 mm flywheels (Slid down from 83) top out at around 91 km/h when used with my tuck. I know I'm capable of 100 plus km/h when on 97's and 8mm bearings such as the Bones Swiss 6 which have larger balls and higher top speeds. Would a 97mm flywheel be noticeably slower when using 10mm axles and bearings? Does the large wheel diameter and small bearing diameter equal out to make my 97's run more like 90's or even 83's?
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Finishing that thought...
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On 6/14/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
...With a long history of skaters complaining about, and race organizers banning products that appear to provide a competitive advantage, it's unlikely that we'll see much progress in the near future. And in the mean time, putting a whale-tail on a Volvo doesn't make it a Porsche. It's a Volvo with a whale-tail.
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You Could
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On 6/14/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
You're asking if you could put a helmet inside a helmet, but I think what you want to know is if you could put an aerodynamic shell around a conventional helmet. I'm sure that you could. The question is why someone would want to do that. If you take something that is heavy and has poor visibilty for downhill, adding more to it doesn't really make sense to me.
Your question presupposes that aero helmets are not safe, and that conventional are safe. That's a false premise to begin with, and not a good way to go about getting a helmet that is both safe and fast. Here's what I suggest:
1. Understand the requirements for safety
2. Understand the requirements for speed
3. Assume that you can meet both requirements
4. Build your helmet from the ground up accordingly
Designing a helmet for downhill is very different than designing a helmet for streetluge or inline or gravity bikes, even though they are all gravity sports. Gravity sports racers are very interested in aerodynamics because thay don't have a gas pedal to stomp or a throttle to twist or an aerodynamic body to protect them from the oncoming flow of air. Typically racers who are in an upright or seated position while racing don't need to look up through their forehead (like a downhiller) or look down through their navel (like a streetluger). Some use mirrors instead of turning their heads. Some have helmets that quiet the wind and noise. Some don't have shields and allow for goggles with tear-offs because of the dirt and mud that blocks their vision.
Streetlugers often choose a "wedge" helmet that has a thinner chin bar (for downward visibilty) and an angled shield that brings air off their chest and over their heads more cleanly. They have headrests to help support the weight of their head and helmets. This is exactly the opposite of what a downhiller wants. Downhillers want to be able to see up through their foreheads and also from side to side. Downhillers have to hold their heads straight out while in a tuck, which puts a lot of stress on their necks. This makes fatigue one of the many safety factors. Therefore I believe that the best helmets for downhill are lightweight ones with excellent visibility.
Can a lightweight helmet be both strong and safe? Absolutely!
Don't most strong yet lightweight helmets cost more? Absolutely!
Is it worth the extra money? It depends on who you ask. For me, absolutely. For the casual or unsponsored racer, maybe not.
Here in the state of California, you can ride a motorcyle in traffic on the freeway at 65mph with a open faced DOT or Snell rated helmet. It appears that protecting the brain is more important than your chin. Some people say that there isn't that much padding in the chin area of some aero helmets. Some have more than others, but it's important to remember that positioning a conventional helmet for better visibilty can expose the chin area entirely, which means NO shell and NO padding. The conventional helmets with better visibilty tend to be the ones designed for goggles and not for shields. Drilling holes in a helmet to retrofit a shield can compromise the integrity of the helmet. So again, trying to take something that was designed for a different sport isn't really going to do what we want it to do.
Also consider that a Snell M2000 rated helmet requires 105 degrees of peripheral vision, 30 degrees of downward vision, but only 7 degrees of upward vision. It's about riding a motorcycle and looking ahead, down and around, but NOT up like we want it to.
Protecting the brain comes from two main sources, an outer shell that adds a load-spreading capability and prevents objects from penetrating the helmet, and a liner which absorbs the energy of an impact by crushing. There is nothing about an aero helmet that procludes it from having plenty of protective foam for a liner. There is a tendency to give up some of the padding that is used for comfort to keep a more streamlined profile, but that's a luxury that many can do without. And yes, there are some people who will build a shell without a protective liner but that's not a helmet - it's an airflow device that's worn on the head, and it provides very little safety.
I am convinced that the best helmets for our sport have yet to be created. There isn't anything about the shape and size of a well designed aero helmet that is inherently dangerous. At some point an oversized helmet could interfere with turning your head, but that's true with any helmet, aero or not. It will take a lot of time, a lot of money and a lot of guts to make a good helmet for us. There is a big risk in offering a helmet to people who are going to use them while bombing hills in packs on skateboards. Until someone steps up and makes a good downhill-specific helmet, there will be a series of trade-offs that prevent us saying which helmet is best suited to the task and which is the safest. With a long history of skaters complaining about, and race organizers ba
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Aero
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On 6/14/2005
Tyler
wrote in from
United States
(67.169.nnn.nnn)
Is it possible to enclose a "snail" helmet within a speed helmet? Would the integrity of the "safe" helmet still hold its merit?
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Aero Helmets
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On 6/14/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
An aero helmet is but one part of being aerodynamic on a skateboard. A good tuck, streamlined leathers, a speedsuit or having a lot of mass can kick ass on a guy with only an aero helmet going for him. Aero helmets can do a good job of passing air more cleanly over the head and past the shoulders, but the trailing part of the "teardrop" that you are trying to form has to join the air cleanly behind you, or you're not really gaining that much.
The faster you go, the more important the aerodynamics are. Nothing will ever compensate for poor riding skills, and it's important to realize that we're not going that fast, nor are we in an aerodynamic tuck while cornering in the technical parts of a hill. There are however, many race courses that have long fast bottom sections where better aerodynamics can mean the difference between winning or losing. Hot Heels, the DHX, Barrett Junction, Almabtrieb and Auerberg for example. Knowing how (and who) to draft is even more important, and the time when an aero helmet can help you most is when guys are riding away from each other, and trying to widen or close a gap.
People can argue about which features are more important than the others, but it's very important that you are comfortable in your helmet. "Comfortable" doesn't just mean that it feels good on your head. It means that you're okay with wearing the helmet while racing. If it doesn't feel right to you, you may not be able to skate as well or as safely as you should, and either of those are dangerous. Unfamiliar equipment is dangerous, and the time to be trying something out for the first time is not in a race.
I think that it's important to be able to see where you're going when you're racing down a hill. It's hard enough to see from a tuck as it is, and you don't want your helmet to have poor visibility when worn in its proper position. If the visibility is bad, people will either wear the helmet out of position so that they can see, or they will ride face down and take "peeks" at the road ahead. Lastly will they stand in a slow tuck, and give racers with good visibility an advantage. There is some super strong material that I use for my shield that literally never fogs on me. This is important to me because my shield is fixed and can't be opened accidentally or in a crash.
Light weight usually comes at a premium price when strength and/or safety are maintained. My carbon-kevlar helmet is very light, very strong, but not brittle like some carbon-only helmets can be. It's also more expensive than most helmets - expect to pay more than a grand (unpainted) for anything decent.
You'll want to have as much high quality impact-absorbing padding inside as you can, also fill in all of the areas where the helmet is farther from your head. One of the nice extra safety features that an aero helmet can provide is its ability to transfer the impact of a head on collision uniformly around the shoulders, chest and back. People have survived hitting trees at speeds that would have crushed the spinal cord of anyone wearing a conventional helmet. Make sure that your helmet has a good chin strap and fastener. One that allows you to breathe normally while snug and keeping the helmet in place.
Aero helmets aren't for everyone, but it was the first helmet that I ever used in downhill and so I grew to become very comfortable in mine. It has served me well, protected me well, and has been a part of my quiver from the very beginning. I like how they look, and they can intimidate uneducated riders. Don't expect an aero helmet to be the magic bullet or to give you superhuman strength. It's just one of many clubs that you can have in the bag. I bring mine to races and will sometimes use it for qualifying and/or racing, but sometimes choose to keep it in the truck. I got mine from Richard Landingham in San Clemente, but don't have any current info on him. Good luck. Let me know what you find out there and don't bogart those pictures when you get one!
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Aero Helmets?
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On 6/13/2005
K-Rimes
wrote in from
Canada
(24.87.nnn.nnn)
Hi Chris, I'm an avid speedboarder and love to go as fast as I can. Lately there has been lots of talk about Maryhill and the helmet regulations as well as the aero / non-aero helmets.
I was wondering what the real advantage to an aero helmet is, obviously it's more aerodynamic, but does it really make that large a difference? (I'm considering buying one)
What are some major things that an aero helmet should have? (visibility, light weight, etc)
Also, can you suggest a place to get one and perhaps think of a quote? What should I expect to pay for a well made one?
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Sliding Corners
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On 6/11/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
I think that the Striker in 81a or 84a is what you're looking for. It's radiused edges and narrower contact patch make for a smooth release and hookup when sliding the turns. These are great for the casual rider/slider on hills. The Gumball's profile is designed for traction, and the 84a and 88a versions are meant to hold a line on very smooth asphalt, such a wide open GS course. Softer Gumballs and Strikers are better choices for racing downhill.
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cornering
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On 6/11/2005 isaiah
wrote in from
United States
(24.21.nnn.nnn)
I was wondering which one of your wheels would be better for carve-sliding and cornering at med-hi speeds 25-35mph. would a board with 88a gumballs (more contact harder) or a 81a striker (less contact softer) be better in this kind of situation?
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Pendulum sliding
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On 6/10/2005 Warner
wrote in from
United States
(216.27.nnn.nnn)
Chris
My friends and I have been trying to figure out the pendulum slide, but after a couple of months we still can't get it. Do you have any tips?
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Setups
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On 6/10/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
I recommend starting out with something like my 42" speedboard with the Randal Downhill trucks and wheels that 76mm or taller (Gumballs, Strikers, Flywheels). The slow turning geometry and 34" axle-to-axle wheelbase provide great stability at speed and there's plenty of deck for a wider stance. The 40" version may be better for more technical races (hairpins) and riders who can control a 2" shorter wheelbase.
Comp-IIs won't be any faster as a truck - save your money. I use Biltin Bearings in every wheel that I ride. They eliminate the need for washers and spacers and they take all of the vibration out of the system because you can snug up your locknuts.
You can also try the R-II 180 hangers on the DH baseplates for a wider setup. This works well for centerset wheels like the Flywheels, which otherwise appear to narrow your setup.
As far as speed goes, the 83mm, 90mm and 97mm wheels have a slight edge at top speeds in straight line rolling, and they also run over stuff like a tank. Although they're not as tall, the Gumballs have a smaller core and have a ton of urethane on them to smooth out roads and to stick the turns. They are a very "secure" feeling wheel and are a great choice for most situations.
There are way too many combinations of boards, trucks and wheels to cover here, but you can bomb to your heart's content on any decent board with DH trucks and Gumballs (75a, 78a or 81a) and even win a race!
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Know thy opponent
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On 6/10/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
Michael is a great skater and hindsight is 20/20. There is a risk in every strategy and you have to make critical split-second decisions that can mean the difference between playing it safe, playing it smart (transferring), crashing, or winning. I figured that Michael was young and wouldn't be able to resist the temptation of taking the lead if the opportunity presented itself. Darryl is more laid back and strikes late - always a threat. There is a lot of luck in racing - good and bad. That's what keeps it interesting. There's an opportunity for everyone to shine!
I hate to admit it, but there are also some ulterior motives that can influence your strategy. In the semis I had both Biker and Michael in my heat. I also knew that because of the LIVE television coverage, only the guy who crossed the line in first position in each of the semifinal heats would be interviewed by the lovely Nicole before being shuttled back to the top for the finals. I thought that a good kick at the start could make it a race for second place between Biker and Michael. When Biker slid out on the second hairpin, Michael just cruised for the transfer pot and I got my interview.
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Need for Speed
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On 6/10/2005
M-town boys
wrote in from
United States
(67.174.nnn.nnn)
Hey Chris I was wondering if you could give me some advice. I want to go fast. Really fast. Im outfitting a new board especially for this purpose, and I had some questions about its tech/specs. First off, what wheels? I currently have Abec 11 gumballs at 78a, but would flywheels be a more stable choice? I dont race in organized events so im not really looking to spend more than 30$ on bearings, but what is the best i can get for that price? As far as trucks im looking for something very stable at high speeds(obviously) like the DH or compII. On a board, does wheelbase length make a board noticeably more stable? and if so, what is a good wheelbase? Thanks for your time, and if anyone has any input, id really appreciate it! - Matt
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Epic
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On 6/10/2005 Justin
wrote in from
South Africa
(196.25.nnn.nnn)
Must of been an epic moment to see the inside and take the win just a few feet from the finish.
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right there
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On 6/10/2005 Justin
wrote in from
South Africa
(196.25.nnn.nnn)
I remember that moment. I had basically just arrived and walked up to go watch the races not knowing it was the finals. As I arrived they came round and remember Darryl taking the fall and getting up, looking at the crowd and making the baseball "safe" sign. You can claerly see Mike made a huge mistake by not sticking the inside and could of won.
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Racing Tactics
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On 6/10/2005
MG
wrote in from
United States
(216.52.nnn.nnn)
Wow,
Thanks Chris. Great stuff. This is the kind of thing that used to make NCDSA so great, actual useful racing information from someone who's done it.
Would love to see more of that video footage from DHX.
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1000 words
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On 6/10/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
Here are some nice little video clips (1.3MB mpg) of the finals in that race:
1. The first and second turn
2. Exiting the 2nd turn and the finish
3. Slow motion of Michaels pass
What you may notice is that because I was willing to sacrafice a bit of speed on the entry of the turns, I am able to "finish" my turns a bit earlier than Michael. I get behind him and airbrake again before the second turn and Darryl throws down a quick foot-drag behind me. Now both Darryl and I become heat-seeking missiles with a lock on the rider in front of us. Darryl could have just as easily of won this race, but was stalled in the EXACT same place where I did in the previous year. There's a tricky high speed chicane there that's a scary place for traffic. I made my move just as he was coming on strong and the brief hesitation gave him too little distance to recover before the line.
I hope that they bring back this race. They were epic events at an awesome venue.
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pics
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On 6/10/2005 Justin
wrote in from
South Africa
(196.25.nnn.nnn)
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pics
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On 6/10/2005 Justin
wrote in from
South Africa
(196.25.nnn.nnn)
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corners?
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On 6/10/2005
david
wrote in from
United States
(68.167.nnn.nnn)
chris you said "Rarely do we find nice smooth banked corners in downhill where the track helps you to stay on the road." how true....except for MARYHILL....i love that road!!!!!
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thanks
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On 6/10/2005 Justin
wrote in from
South Africa
(196.25.nnn.nnn)
Thanks for that one really put it down. There is so much involved that there is never one thing that makes it happen which is really cool. So much to learn and I REALLY HOPE that they bring back the DHX, its an amazing hill in a really amazing part of the world and I hope I get the chance to race it not ride it.
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