Longer track

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Brian Clark
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Re: Longer track

Post by Brian Clark »

So what your saying is make it a rail rider vs rail running? Hope I said that correctly.
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FatSebastian
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Re: Longer track

Post by FatSebastian »

Brian Clark wrote:...make it a rail rider vs rail running? Hope I said that correctly.
:idk: What is the difference between rail rider and rail runner in the context of this topic / question? (Did you mean straight runner?)
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Re: Longer track

Post by Brian Clark »

I though riding was negative cant and running was positive cant on dfw.
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Re: Longer track

Post by knotthed »

No to this "I though riding was negative cant and running was positive cant on dfw."

Look at the picture at the bottom left with yellow cars and please ignore Caster for PWD. This should help with some terminology.

http://nordoniatireandservice.com/wheel_alignment.htm
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whodathunkit
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Re: Longer track

Post by whodathunkit »

What changes might you guys try for a 63' S-shape track or a constant slope?
What type of automobile can be spelled the same forwards & backwards?
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FatSebastian
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Re: Longer track

Post by FatSebastian »

Brian Clark wrote:I though riding was negative cant and running was positive cant on dfw.
I've heard some confusing terminology in the past, but this is news to me. Regardless, positive camber is recommended on the DFW.

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Stan Pope
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Re: Longer track

Post by Stan Pope »

whodathunkit wrote:What changes might you guys try for a 63' S-shape track or a constant slope?
For a constant slope track, my "intuitive reaction" is to push the CM forward until almost no DFW Toe-in is needed to keep it on the rail.

For an S-shape track, it depends! The answer, I think, is in the details of the vicinity of the starting line. The key issue is the initial slope and the distance until the major downslope change starts. A configuration that I would try is forward weighting, one lifted rear wheel, and slight Toe-in on one front wheel.
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Stan Pope
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Re: Longer track

Post by Stan Pope »

Re "cant" and "camber" ...

"Camber" is a well defined term, but I haven't found a definition for "cant." From usage on this forum, I concluded that they have opposite sign, i.e. "positive cant" is the same as "negative camber." But, I don't use the term "cant" and I will readily accept documented correction!
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LightninBoy
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Re: Longer track

Post by LightninBoy »

Brian Clark wrote:So what your saying is make it a rail rider vs rail running? Hope I said that correctly.
Rail riding and rail running are synonymous in most pine heads minds. However, there are some in the PWD community who distinguish the two as follows:

rail riding = achieving negative cant on the rear wheels by bending the axles
rail running = achieving negative cant on the rear wheels by drilling the axle holes at the desired angle.

I'm not sure why some feel the need to apply (and constantly reinforce) such unintuitive language, but I'm assuming there's some history and grievance involved.

In any event, in either case (rail riding or rail running) positive cant is recommended on the DFW.
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Stan Pope
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Re: Longer track

Post by Stan Pope »

Well, not everyone uses 'cant = - camber"! :)

My understanding of both running and riding is that the critical factor is that the DFW is toed-in to keep the front of the car from drifting away from the rail i.e. to keep the car running straight. Yes, it is advantageous with most wheel styles to apply negative camber to the rear axles, but that is an efficiency consideration independent of the RR definition.
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FatSebastian
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Re: Longer track

Post by FatSebastian »

LightninBoy wrote:there are some in the PWD community who distinguish the two as follows...
Thanks for the education. I suppose that such pedantry might be motivated by the reputed trademarking of the term rail-riding, and that Jay Wiles' original essay (which introduces the term rail-riding) mentions a slight bending of the rear axles?
Stan Pope wrote:that is an efficiency consideration independent of the RR definition
...unless one considers Wiles' essay to encapsulate the definition of "rail-rider". Negative camber migrates the rear wheels away from the rail, which is an important operating feature behind the concept. Regardless, I do not plan to make a terminological distinction between "riding" and "running" so defined (probably by avoiding the term "running").
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Stan Pope
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Re: Longer track

Post by Stan Pope »

FatSebastian wrote:... Regardless, I do not plan to make a terminological distinction between "riding" and "running" so defined (probably by avoiding the term "running").
Good analysis!

Personally, I prefer the term "rail guiding". It is highly descriptive, and it avoids the "concept claim" for an idea that is old but kept "close to the vest" by most of those who "discover the secret'.
Stan
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Re: Longer track

Post by Speedster »

"cant" - Angular deviation from a vertical or horizontal plane.

"Camber" - is the angle made by the wheels of a vehicle; specifically, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when viewed from the front or rear.
I thought the word "cant" was used on Derby Talk because it's shorter to type.
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Stan Pope
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Re: Longer track

Post by Stan Pope »

Speedster wrote:"cant" - Angular deviation from a vertical or horizontal plane.

"Camber" - is the angle made by the wheels of a vehicle; specifically, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when viewed from the front or rear.
I thought the word "cant" was used on Derby Talk because it's shorter to type.
The problem with the dictionary definition is that it is unsigned, i.e. just some distance off vertical. Most usage on DT, when it was clear, showed a sign and it was opposite from camber!
Stan
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Re: Longer track

Post by Speedster »

I know we're way Off Topic here but I don't understand what you just said. Can you say it another way or draw me a picture?
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