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| Q&A: McKendry on Speed (1810 Posts)
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Strong and Straight
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On 9/7/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
David, I didn't have problems with bending axles, and the next generation of axles that I use will be even stronger. Here's why:
The middle of the axle is 1/2" chromoly, and there is a filleted shoulder which steps the ends down to about .314". The four inner races of the Biltin Bearings are really precise steel tubes with an 8mm bore and a 12mm OD. There is a really nice slip fit and when the locknuts are tightened down, the whole system is like a solid 12mm to 12.7mm steel rod. Not only that, but the wheels and trucks want to stay nice and flat on the ground because each wheel is so wide that it doesn't deform as much as a more flexible lipped wheel would. The outside edges are also wide set, so the system as a whole is less likely to tip up on two wheels.
The result is that there is a not only a wider contact patch, but that it wants to stay flatter on the ground than with narrower wheels/setups, and/or more flexible wheels that deform in a turn.
My guess is that someone trying to do what I'm doing with regular bearings is more likely to bend axles because they can't tighten the locknuts and there are just a bunch of non-precision parts (washers, races, spacers) rattling around on the axle. Being able to compress the system adds considerable strength. I'm not trying to pat myself on the back, but Biltin Bearings solve so many problems that I doubt that I would have bothered to try this with regular bearings, washers, spacers, axles, etc.
In addition to the Downhill board, I ran a 6 wheeled streetluge with Doublewides and had no problems there either.
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axles
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On 9/7/2005 david
wrote in from
United States
(68.164.nnn.nnn)
chris you did'nt have any problems bending axles. i'd imagine having 2" of exsposed axles and that huge wheel would bend axles pretty easy? or were you using the same 1/2" Ti that you had at maryhill?
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Axles Anyone?
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On 9/6/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
BTW, You're not going to be able to do anything with these wheels unless and until you get some axles that are extended at least an extra inch of each side (2" overall).
I think that it's time to get Geezer-X involved on a joint mission...
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Making DoubleWides
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On 9/6/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
I'm getting a nice little lathe that will make "mass producing" wheels like this a simple task. I'm going to suggest a few things however.
1. Try them without the glue. I only glued them to comply with the "4 wheels per board" rule at Top Challenge. This means that you won't have to semi-permanantly trap your bearings inside.
2. Try them without the grooves. This can always be done later, like in the rainy season.
3. Try the same concept with 76mm, 90mm, and 97mm Flywheels, Gumballs, Grippins, Flashbacks, NO SkoolZ, and Strikers of various duros.
4. Try making them a little narrow on the inside, so that a small gap between the two wheels will allow the wheels to spin independently of one another. This makes more sense for Slalom wheels, or when you need to make tight radius turns, so that the inside and outside edges won't fight over the different arc lengths they are forced to travel.
The basic "kit", if you will, would consist of eight 3/4 cut wheels, and sixteen Biltin Bearings per board. Don't forget to get yourself some big green cushions (coming soon). The greener the better, if you know what I mean.
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Beautiful wheels
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On 9/6/2005
Patrick
wrote in from
United States
(68.85.nnn.nnn)
Chris, your wheels seem pratical. Any chance you can part with a pair? Do you think double-wides would work with Grippins or any other wheels?
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DoubleWides
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On 9/5/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
It takes a lot of green to make a lot of green...
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DoubleWides
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On 9/5/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
Cut the Flywheels to perfectly match the "washer" face of the Biltin Bearings (each 3/4 wheel becomes approximately 39mm wide). You will seal the fate of the 2 innermost bearings when you glue them up. I did 4 wheels at a time using a couple of 9" x 9" boards and threaded 5/16" bolts. If you mate two wheels together where either (or both) halves were cut a bit too narrow, the bearings in the middle will be pinched and never roll right. If the wheels are cut too wide, you can't tighten the locknut all the way or the outermost bearings will pinch the system.
They roll as fast as "normal" wheels, the traction is awesome, and they handle beautifully. The track width is cross between having 6" hangers on the inside, and 8" hangers on the outside.
The wheels are exactly twice as much money to make, not including all of the time and/or mistakes. They require twice as many bearings. They become 78mm wide, which is 50% wider than stock. The trucks require banging a stock Downhill axle out, and slipping a Luge axle in. The wheels are super heavy. They want to keep rolling fast (the flywheel effect). They last a long time. They don't cone. They are definite show-stoppers. Everyone does a double-take on the double-wides!
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proto flywheels
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On 9/5/2005
david
wrote in from
United States
(68.164.nnn.nnn)
so chris, whats the low-down on those crazy wheels you rode at TOP? do you think the extra mass made for a wheel with more roll speed or was it to much weight to control? how did they handle the corners?
sounds like you took a beatings, heal those old bones up and i look forward to seeing you again on a starting line... somewhere, sometime...
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Juicy Flywheels
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On 9/5/2005
K-Rimes
wrote in from
Canada
(24.87.nnn.nnn)
How'd you glue them up? I think My 83 could do with some chopping.
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Grippins
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On 9/1/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
Grippins will help quite a bit over Flashbacks, and you can use a harder duro (for slalom) like 81a or 84a. The slower turning rear truck is also a good thing...
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mods
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On 9/1/2005
David
wrote in from
United Kingdom
(80.3.nnn.nnn)
Ok, thankyou for the advice, The picture link is not my actual board its the one from the bozi website, i am using seismics and 75a flashbacks. The rear is wedged to lessen the steering as much as possible, but what i was trying to say is that when the board is weighted it bends lower than flat and the angle of the rear truck goes back to the angle as if there was no wedge, if you see what i mean. basically the end of the board flexes alot during turns and makes the steering at the back too much. i guess i will have to buy one stable turn seismic for the back and wedge it furthermore. There are drilled holes at the rear to make the wheelbase shorter but they are old pattern. I dont use the board for tight slalom and its definatly a longboard and a great carver. maybe a set of grippins will help too. Anyway thanks for the help, i will ask Jeff Yarrington for some advice on the matter as well. Thanks, David
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Mods
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On 9/1/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
The board is cambered, which lessens the steering front and in back. You've added steering in the front, but not in the back. The back however, is narrower and will flex as much or more than the front. The flex will add rear-steer which could result in over-steering the rear. That's probably the fishtailing that you're talking about.
The other issues could include the MASSIVE wheelbase that you have for a Slalom board - even for GS. On a hard pumping turn, a wheelbase that size will tend to induce a slide. A shorter wheelbase and narrow/precision trucks can help. If those are Avilas, you may also consider trimming the edges of the wheels. If a wheel is super wide and you make make tight turns, the inside edge and outside edge of the same wheel will "fight" with each other because they are travelling along arcs of different lengths (the outside edge wants to spin faster than the inside edge).
Before you try changing any trucks, I'd try:
1. Wedging steering OUT of the rear
2. Shortening the wheelbase
3. Trimming the edges of the wheels
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Flex altering the truck angle
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On 9/1/2005
David
wrote in from
United Kingdom
(80.3.nnn.nnn)
Hi, now i know this is not a question about speed, but i need some help from someone who knows alot about geometry and angles and thier effects on trucks, I hope Chris offer some of his expertise.
I ride a Bozi GS36 deck with seismic quick turn trucks, If you see the( http://boziboards.com/GSsidecomplete.JPG ) picture of the deck you will notice that the camber has been put at the front of the deck giving it a ''loaded'' feel, the rear is flat and narrow so when i stand on the deck the rear dips down putting the angle of the truck slightly flatter which increases the turning. I have put a steep angled riser pad to compensate for the angle change when the deck is weighted, making the baseplate almost parrallel to the ground.
BUT when pumping the board it would flex even more when i carve deep into a turn, now theoretically the harder i push the board into a turn the more weight is on the deck therefore the angle of the rear truck is put flatter making it turn more, giving me a 'forklift effect' where the back is turning so much it is fishtailing and sliding out.
Does this make any sense?? when you pump a board with camber, would the change in angle of trucks be significant enough to alter the turning radius? how can i prevent the rear of my board sliding out on a hard push into a turn? I cannot put any more angled risers on the rear truck as it is getting too high.
Can anyone shed any light on this matter? its been on my mind for a while, Any help would be much appreciatied.
Thankyou David..
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RE: big gummies
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On 8/30/2005
dennis
wrote in from
United States
(216.9.nnn.nnn)
Thats wht Im talking about. I wish I was going to Montreal but new job and work calls. I can wait, those sound like there gonna be hoot of fun.
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Big Gummy Wheels
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On 8/29/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
Dennis, Wait until you see what I'm bringing to Montreal! It's not anything that you would guess, but I'll post some pictures after the race, regardless of how well I do.
I think that an 83mm centerset Gumball on a medium sized "low-lock" core would be an awesome wheel. If you look at the Gumball hub as being a 25mm "high-lock" core, a 35mm "low-lock" core would give you give you much depth of urethane, without too much deformation in a turn. Centersets would provide even more traction, and the increase in size would give them a higher top end and let them roll over everything in their path.
I'll make some renderings in a bit...
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big gummi's
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On 8/25/2005
dennis
wrote in from
United States
(216.9.nnn.nnn)
Hi Chris,
I was wonderin if a little larger mm gumball wheel was ever discused as a possibily when you were designing the current Gummi that you have out? Do you think it would be to soft for speed, or to heavy? or maybe harder duro's could be used for hard cornering with a big hunk urathane. Just wonderin...
d
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To No A Vail
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On 8/22/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
I didn't go to Vail this year. If I'm going to hurt my back again, I don't want it to be on a bunny slope.
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chris/rob
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On 8/21/2005
mike p
wrote in from
United States
(69.107.nnn.nnn)
so... did u and rob meet at vail? obviously jimmy and rob raced...
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non-leathers
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On 8/16/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
the abrasion resistance of kevlar and kevlar blends is inferior to leather. Further, there is no way to determine whether a weave fabric is indeed kevlar, nylon, polyester, or some other junkier material when you are standing on the hill. leather is easy to verify
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drop through deck truck placement
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On 8/16/2005
patrick
wrote in from
United States
(207.69.nnn.nnn)
To anyone who can answer this--Can i drop a set of Randall 180 trucks through the top of my big red x speedboard? I saw on Chris's website this can be done by snipping the tabs but i think they were Randall DH trucks. If I can I feel stupid for running a less than ideal setup for the past six months. Thanks
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leather substitute
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On 8/16/2005
panda
wrote in from
France
(82.225.nnn.nnn)
there was a time where chris had kevlar leathers that seemed nice and strong.
kevlar has the reputation to be stronger than leather and more wear-resistant
maybe chris can enlighten us on that subject.
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leathers substitute
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On 8/15/2005
brad
wrote in from
United States
(216.233.nnn.nnn)
looking for a substitute for leathers for downhill
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semantics
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On 8/12/2005
david Price
wrote in from
United States
(67.101.nnn.nnn)
i beat chris in vail last year and i lead robmc down the course in the consi @ maryhill, so that means i'm better than both of you right? anybody is better than anybody on any given day. now if i can just stop trippin on my own wheels....
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vs.
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On 8/12/2005
Jimmy Flindt.
wrote in from
United States
(207.200.nnn.nnn)
WAX, it's more like FLINDt vs. ROB!
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WHAT?
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On 8/12/2005
Jimmy Flindt.
wrote in from
United States
(207.200.nnn.nnn)
Rob, you never ever beat Chris, you got lucky I didn't know where the finish line was, just wanted to clear you big head of false memory, don't take me wrong because I am smiling right now having fun on this subject, you raced well last year but watch what you say about how you advanced, see ya in a few days!
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