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| Skatecar (180 Posts)
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Simple aero shell?
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On 1/15/2004 PSR
wrote in from
(24.52.nnn.nnn)
I was going over some old Winter X-Games footage yesterday,when I came across the Shovel Racing events. Lee Dansie was in a Thule Car-Rack Box(with skis fitted on outriggers) meant to carry skis/snowboards and such. The shape on that is classic wedge-nose/high-tail,and does incur some drag,and isn't likely as sleek as say Jack Smith's old Skatecar.Still,it looks like it would fit quite a few luge frames/pans pretty easily.Of course you still have to see outa the thing,so making a clean windscreen would take some creative thinking(Lee had a semi-open cockpit at the rear).Some of the other shapes the shovels used were far,far worse.
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rocket skatecars
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On 1/15/2004 shrox
wrote in from
(165.121.nnn.nnn)
I know rocket luges have been done, but how about a rocket powered skatecar?
shrox
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aero importance
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On 1/14/2004
sean c
wrote in from
(207.5.nnn.nnn)
the only thing that bothers me with aero is that it seems to me that if you have no idea what your doing (like me) you'll end up doing more harm then good. i think my luge as is, would be more aerodynamically better then anything i could make.
sean c
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Importance of aero
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On 1/14/2004 Duane
wrote in from
(68.15.nnn.nnn)
At 50 mph, the drag on a skatecar will be more than 80% from aerodynamic drag.
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Gravity cars
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On 1/14/2004 Duane
wrote in from
(68.15.nnn.nnn)
Those formula one bodies look neat but the aerodynamics are terrible. They would get smoked on any course with high speed runs. Downforce is not needed here, you want to design the body with neutral lift (none), as this gives the lowest COF. Too many people design after supersonic aircraft, where the idea is to keep sonic booms from tearing the plane apart, and cars, where the idea is to increase drag to up to 10 times its minimum value, in order to keep the car glued to the track. Neither of these appraches even comes close to the shape you need. Note that virtually all the Signal Hill cars made these mistakes, even the winner. Also, you cannot keep the air out from under a car, it will come, from the sides if necessary, you'll get vacuum with disastrous results to your drag. Also, open bottom is a loser. Any car trying to keep air out of the bottom, or an open bottom, will have drag coefficients around 0.3 or worse. A competitive skatecar is going to have to be around 0.15. The bottom is more important than the top !!! A good starting shape is the fuselage of a glider plane. The GM Sunraycer had a good form for a wider car. Get up off the ground and you will reap big benefits in coefficient. Y'all can close up a luge, but I'll go head first with much better aero, and see you at the bottom.
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it's all new to me
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On 1/13/2004
sean c
wrote in from
(207.5.nnn.nnn)
my first question is what is the difference between a skatecar and a gravity formula 1 car seen in pictures here http://www.auldovertheroad.com/lugephotos/lugephotopage05/lugephotopage05.htm
next, wouldn't most of these skatecars be allowed to run with street luges because IGSA and GSI(street luge racing organizations) both allow fairings?
would a street luge be allowed to run with skatecars?
sean c
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Skatecar lift
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On 1/13/2004 David Bonnell
wrote in from
(152.163.nnn.nnn)
Regarding the skatecar getting lift ( air getting under the car)The car I have is actually open underneath on the sides around the inner edges of the body and the inner airfiol the board the car sits on has which act like channels for the wind to flow thru and can escape out the back. but since its so close to the road hardly any air gets under it. The faster the car goes the more pressure is added to the nose creating a nice down force that off sets the uplift you would think the back of the car would create. The faster I go the more stable it becomes. I have gone faster than the 62-63 mph that I do without any assist, Now assisting with a car even at speeds over 70, its very stable.Now we all now there are limits to everything but if you design it correctly and trail and error enough it will work. I will take pics this coming week of the underbody of the car and the added weight dispersment (VERY IMPORTANT TO DISTRIBUTE WEIGHT ON THE BOTTOM OF THE CAR IN RELATION TO YOUR OWN BODY WEIGHT) that the inner airfoil surrounds.Thanks David Bonnell.
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Easy shell
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On 1/13/2004 Duane
wrote in from
(165.121.nnn.nnn)
I have made a few aero bodies using foam core material. Sometimes the structure would be done before the shell, so testing was needed in the interim. Foam core is pretty rigid when glued on all edges, the best bodies of this type were made with tapered strips glued up and then taped with packing tape. With the same equipment otherwise, you'd lose abou 1-2 seconds (out of 45) versus a perfect shell. Also not bad is shrink film shrunk over a frame of small aluminum tubing. I'm pretty sure I can't fit in the shells I have, they are for very small people. For those I started with giant blocks of foam, and made full half-molds the old fashoined way. Much time and expense, but the mold lasts years.
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skatecars for the average guy
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On 1/13/2004 hugh r
wrote in from
(24.48.nnn.nnn)
Geezer... would love to post the pics! Stories too if you can put them into a word.doc!
PSR... I think your on to what most average guys will end up doing... modifying an old streetluge.
I am wondering what kind of a shell I can make too... HR
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Aero Shapes
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On 1/13/2004 PSR
wrote in from
(24.52.nnn.nnn)
Geezer,That's awesome to read about! One of the things I noticed with the skatecars of the 70's was that few of them didn't create the potential for lift and manage to be sleek at the same time.The Silver Streak and White Lightning cars were both very slick,but I'd assume that those shapes create lift(or would If air got underneath them).I think Sam Pugh may have had a wedge-nosed car at Signal Hill in '78? But I didn't see really good airflow management until Hickey made the Formula Cars,which were kinda like mini LeMans Racecar shapes,wedged nosed with a flat + tall tail.Of course by now we've got some amazing vehichle shapes to borrow from.Just look at F-1 cars today,able to push air in order to acheive 3G's in a corner! Not that those are as sleek as they could be,but they don't do the 'instant airwing' trick the Mercedes CLK did at LeMans a few years back. Hmm,now I'm thinking I should yank that old chromoly luge sled back outa storage and see what kind of shell I can make to fit it.I had built it with a panned seat that acts as an inverted wing,and ducted the airflow out the rear.Nah,I can't even fit the dang thing into my apartment...WHAT was I thinking?
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I'll build one
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On 1/13/2004
Geezer-X
wrote in from
(149.2.nnn.nnn)
I need to scan the pics and get them to Hugh R, but briefly, Belair Boards (who Chaput was riding for at the time) in Belair MD had a contest in like '77 or '78 on Racetrack Rd in (I guess) Bowie MD. There was slalom, which was my principle interest, and they were have a downhill race. I called and asked what the rules were for the DH, and they essentially said "push at the top and we'll either have a radar gun or we'll use a stop watch" I inquired as to the presence of any equipment restrictions, and they said there were none. My 17 year old conspiratorial mind went into overdrive.
I was quite an avid cyclist, and was impressed by the Teledyne fully-faired bibycle ridden by Ron Skarin to a (I recall) 57 mph record. I fished a couple refrigerator boxes out of the dumpster behind Sears, and found some scrap plexiglass. I used a hotmelt glue gun and masking tape to tack together a big symetrical airfoil with enough section thickness for me to crouch in the front third. I made some handles out of aluminum tube and mounted them at the bottom on the inside. The "leading edge" had a plexiglass windscreen. It was about 6 feet long and 4 feet high, maybe 20" wide. and the top was also curved in sort of a "science class bernouli effect airfoil" shape.
I painted it with a striking cream and red paint scheme using leftover latex house paint, lettered it with it's name; The "Mt. Borgo Speedy Special" after some weird rubber wheels I thought had an amusing name, and tested it on a local hill.
I made a 48" coffin shaped deck out of 3/4" walnut faced lumber core plywood, and fitted it with Tracker Fulltracks and RSI Surge 4" wheels.
The day of the race, I strapped it to the roof of my '73 Volvo, and dragged it to the venue. I did reasonably well in the slalom, and practiced for the downhill without anyone seeing the MBSS. When it was about time for my run, I came rolling up to the start box wearing the thing, and everybody about crapped themselves.
"You can't use that!!!" "No fair" "etc etc"
I explained that I was specifically told that there were no equipment restrictions, and that I'd be happy to wait for 2 hours for everyone elso to make one, since that was about how long mine had taken to construct.
The muttering stopped, I pushed off, tucked and went rumbing and whooshing down the hill. I ended up with fast speed for the day which I seem to recall was like 42 mph, but pushing the thing was a bastard to do, and I got beat by a heavier guy with a strong push. It was a huge amount of fun, and marked the beginning of a lifetime of carefully scrutinizing rulebooks looking for free speed. (actually I guess that started with Pinewood Derby, but who's keeping track)
My parents gave me copies of the pictures of it, and I'll get them up here somehow. And when, after 25 years I ran in Andy "GBJ" Bittner whe I got back into slalom a few years a go, the first words out of his mouth were "Captain X!!! The Mount Borgo Special!!!" so at least it made an impression on someone...
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skatecar stuff
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On 1/13/2004 hugh r
wrote in from
(68.232.nnn.nnn)
I have some more pics and stories up... HR
Skatecar Pages
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Skatecar (from the Street Luge forum)
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On 1/12/2004 Duane
wrote in from
(68.15.nnn.nnn)
I would advocate an allowed axle width of over 12". It might be fun to watch people wreck, but 12" allows too much weight outboard over the wheels. 15" would make more sense. There should be a braking test, if you pass without a parachute, you don't need one, say, a stopping distance at min. speed. A quick brake test AFTER the heat is a good idea, to discourage brake tampering. Skatecar forum !!!
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Skatecar (from the Street Luge forum)
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On 1/12/2004
Duane
wrote in from
(68.15.nnn.nnn)
drag brake is similar to the 2x4 bolted to the side of the gravity go-carts we made as kids, but those used to light on fire at speed ! no, realy, its a trailing arm that pivots off of a bolt and oilite bushings. To the end is mounted one or more friction pads (the afore-mentioned toe stoppers work good and mount with a single bolt). The actuation is by a pancake pnuematic cylinder, with spring return. A small composite air tank is filled with air from an N2 cylinder. a line is run to the steering arms, and a little button for the right thumb actuates the brake. There is no "strength" modulation available, so you just pulse it, or stomp on it, as needed. The internal cylinder spring returns it to the "up" position when you let off the air, and you glue a piece of the bodywork to the bottom so it disappears when it is "up". Placed just behind the rear wheel or wheels is best, as it will straighten you out if you get sideways. Trust me, this works much better than trying to stop the wheels, which invariably flat-spots them, ruining your hours at the lathe. Not to mention uneven braking (spin, spin, spin) And cobbled-together disk brakes have a nasty way of failing, or worse, rubbing off speed when you don't want. Do you really want brake mechanisms anywhere near your wheels when you are trying to win ? And besides, it makes heating your wheels that much more difficult (hint). A good back-up is to have a way to use your (leathered) hands to stop the front wheels, it'll save your ass if the brakes fail completely (e-brake). Im going to build a car that turns, and turns well, even if the race is straight, it'll be more fun and could be run on many courses. Maybe I'll fit a locker for the rear "truck" to use for straight courses, or variable geometry.
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Skatecar (from the Street Luge forum)
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On 1/11/2004
hugh r
wrote in from
(68.232.nnn.nnn)
PSR... I have a couple of sets of brakeboard trucks... the drums are pretty small and I would think that they would burn through after a couple of stops... they work well on skateboards under light loads, but probably wouldn't hold up to the weight and momentum of a loaded skatecar.
I propose that we keep this gentlemenly and sporting... by not finding the tiniest woman to drive the cars! I'd say that if you don't have a driver/builder that weighs over 200 lbs (which is still skinny in my world), that you need to go find one!
The skatebrake trucks have a small disk on each side of the hanger... they may be able to handle more of a load... but I don't have any of those on hand... HR
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Skatecar (from the Street Luge forum)
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On 1/11/2004 PSR
wrote in from
(24.52.nnn.nnn)
Not to take this page away from 'luging',but man skatecars are something that could be just too much fun!! Duane,I'm in! I've even got a low-drag body shape in mind that allows for lean-steering up to 15* without exposing the wheels by more than 1",and it allows for feet-first(although head-first is likely sleeker/lower overall).Just think of the 'area rule' shape from an F-102,minus wings and missles. Brakes unfortunately are not something I've been too impressed with within the realm of skateboarding so far,and trying to miniaturise Jaguar's inboard discs might be a bit too complex.Maybe Mt. Bike parts? The Brakeboard stuff might work,might overheat,I dunno...And Chutes aren't retractable,are they? Still,it'll be cool even if this only goes as far as conjectural projects,and it'll be even better if the ideas take to the road!
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Skatecar (from the Street Luge forum)
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On 1/11/2004
hugh r
wrote in from
(68.232.nnn.nnn)
Duane... can you supply a pic or drawing of a "drag brake" set up?? If not, maybe a detailed descrition? (because the first image that came to my mind was a sort of an anchor deal... ey maties, anchor ho!) Thanks! HR
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Skatecar (from the Street Luge forum)
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On 1/9/2004 hugh r
wrote in from
(68.232.nnn.nnn)
I have some more pics and a small amount of unofficial info up... HR
Skatecar Pages
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Skatecar (from the Street Luge forum)
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On 1/9/2004
hugh r
wrote in from
(68.232.nnn.nnn)
David... Hugh Regalado here,
I would be very happy to host some of your pictures and stories about skatecars and such on one of my sites!
Shoot me an email at hugh308@yahoo.com
HR
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Skatecar (from the Street Luge forum)
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On 1/9/2004
David Bonnell
wrote in from
(205.188.nnn.nnn)
In Florida there is a 70s skatecar,that hits 62-63 mph very time down a hill in central Fla.Non assist. I can sent pics to you all,just give me the info were to send them to. I also ran into Eric Lee down here were I live in Sarasota Fla and skated a pool park session with him on 1-8-04.I told him about the skatecar and a video of it and also some 55-60 mph standup runs done by me in central Fla non-assist.Wearing no leather,no shirt,nothing but shorts and shoes and some runs in leathers(too damn hot in Fla for leathers)I am very familar with road rashes and busted up body!!!!!.But you all have runs with high speed turns and in Fla we have s#@!. Would someone give me Eric lee email address (I lost it)so I can send him a copy of the video. I know some pics are floating around on the internet of the skatecar but it was not completly put back together this past summer. Now it is and repaintd and with lots off 70s decals.Including a big Kryptonic dealer decal that covers the back of the car. Its 9.1 long and weighs approx 60lbs and 85mm kryps and Gullwing Pro trucks.I am David Bonnell and I built the car and luges here in Fla back in the 70s I Quit downhilling in 1980 and resumed back in May of 2003.(23 years later) Thanks for your time David.
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Skatecar (from the Street Luge forum)
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On 1/9/2004 hugh r
wrote in from
(24.48.nnn.nnn)
Hey PSR,
Jack Smith posted up a couple of the rules he remembered... lean steering, 4" or smaller wheels, brakes, parachute, max 10' long, max 75 lbs...
Hopefully he'll have a complete list of rules up soon! I am planning on doing a hugh308.com entry. Probably built on a modified luge set up... feet first for sure!
Rumor has it that a regular street luge broke 100 mph down the grade south of Mammoth, CA on hwy 395 (and reportedly there is a video out there somewhere, which I would love to see)
So I would think that on a big enough hill, that an enclosed, or faring'd skatecar should be able to go at least that fast!
If it is head to head racing, I would be most comfortable with straight line drag racing, rather than having too many turns.
I would like to discuss braking systems though... I am thinking that using a Randal luge truck with longer axels, and maybe attaching some sort of a bicycle disk brake system... any thoughts?? HR
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Skatecar (from the Street Luge forum)
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On 1/9/2004
Duane
wrote in from
(68.15.nnn.nnn)
PSR, I think its incumbent upon us to defend the Northeast with a serious skatecar entry. I'm getting started as soon as rules are established. As for the issues you raised, the skatecars of mine shown on Hugh's page deal with them with rack & pinion steering, plenty of polycarbonate windshield (you can see 45 degrees off in either direction), and pnuematic drag brakes (stop the wheels with disks and its goodbye tires). Stability is not a problem.As for speeds, these things do just over 40 on a hill that gets me only 18 or so in a stand-up tuck. I've give a good skatecar at least 15-20 mph over a luge on the same hill, the more straight the higher the margin. If there is no racing, it becomes a small driver contest, get the smallest girl you can find, fit the body to her, and ballast up to the weight limit. That's no fun.
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Skatecar (from the Street Luge forum)
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On 1/9/2004 PSR
wrote in from
(24.52.nnn.nnn)
Nice photos,Hugh!! Hmm,Skatecars making a comeback? This could be very interesting indeed! I wonder just what 'category' something like Hickey's old Eagle sled would end up in? 'Open Cockpit Aero' perhaps? As it is the Rogers Bros. pegless + panned sleds are almost Aero,although maybe not as tidy as Hickey's older rigs. The possibilities of using streamlining have intrigued me for a considerable number of years,but obviously rules have kept ideas like that at bay. Still,I'd love to see streamlined sleds make a comeback,at least for bragging rights of 'top speed'.I don't think it'd be wise to consider actual racing however,as there's a few issues with handling,Driver's visibilty,braking,etc. How fast do ya'll think these could get nowadays? I'm betting that 90+mph is feasible.
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Skatecar (from the Street Luge forum)
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On 1/8/2004
hugh r
wrote in from
(68.232.nnn.nnn)
Hey Streetlugers,
There is talk going on now about bringing back Skatecar racing... should be pretty exciting!
I have started a page to share info and pics as they come up... HR
Skatecar Page
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Skatecar (from the Street Luge forum)
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On 1/5/2004
Jack Smith
wrote in from
(207.114.nnn.nnn)
The return of Skate Car racing...2004. More information soon.
The Vetter Streamliner was the Skate Car I drove at Signal Hill and Derby Downs in 1978. I tied for second with Henry Hester at Signal Hill and placed second at Derby Downs. Top Speed was 59.27mph.
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