The Real Deal on Speedo Accuracy (Should say INaccuracy)

[pro116]

speedo's.

On glare ice I with 192 trail studs and my spedometer was off from the radar by I think 13 mph.The next week I put in 144 ice picks and my speedo was only off by 4 mph.This was on a srx by the way

 

[LazyBastard]

Ok, fine. You're thinking along a different idea of slippage... the *absolute* concept with respect to time. I'm looking at slippage as being relative to forward motion. If your forward motion is 1 inch, and the track spun 2 inch, that is 100% slippage.

 

[Sled Dog]

In other words if for some instance I could gain my speed from 50 mph to 100mph in 18 inch your theory would hold true. But that is not going to happen your going to be spinning out of control which would mean full length scratches.

 

[QCRider]

Realistically if your track is reading 100 mph and your ground speed is 50 mph I would say your scratch is going to be full length.

Nope. If the track is moving twice as fast as the sled, by the time it has slipped 18 inches it is no longer in contact with the ground. You are right that it is constantly slipping, however it is also providing 50% traction, so the sled DOES move forward 1.5 feet while the track moves 3 feet, right? So during that 3 feet of track movement 18 inches of it was slippage and the other 18 inches resulted in the sled moving forward 18 inches.

 

[Sled Dog]

Now lets talk about that other really important subject. Beer spillage over how much you actually drank. My buddy Alexander Keith..... lol.

 

[QCRider]

Ok, fine. You're thinking along a different idea of slippage... the *absolute* concept with respect to time. I'm looking at slippage as being relative to forward motion. If your forward motion is 1 inch, and the track spun 2 inch, that is 100% slippage.

No, that is 50%

 

[LazyBastard]

Spun not= slip. Slip + move = spun. Sorry for the confusion.

1 inch forward + 1 inch scratch = 2 inch.

ie; length of scratch is 100% of forward motion.

 

[QCRider]

1 inch forward + 1 inch scratch = 2 inch.

ie; length of scratch is 100% of forward motion.

That's great, however the slippage is measured relative to TRACK motion. 50% of the track motion resulted in no forward motion of the sled, hence 50% of the track motion was SLIPPAGE.

 

[LazyBastard]

You can look at it that way if you like, just remember to multiply everything by 2.

 

[QCRider]

LB I gotta go, but I love arguing with you. I wanna buy you a beer sometime. Maybe 12.

 

[QCRider]

You can look at it that way if you like, just remember to multiply everything by 2.

For what reason would I do that? Would not 50% slippage mean that the sled is moving 50% as fast as the track? How on earth could you define it any other way?

 

[LazyBastard]

Ok, we continue during daylight hours when I'm not halfway falling asleep.

 

[RedRX1]

Another meaningless argument about a fact... The speedo is off.

If LB changed his name, there would be a new guy to argue with!!!

We can all agree on one thing, that is it isn't difficult to improve the accuracy... or you can do the math as you go.

Yea I would like to see accurate speed but this is not even near the same ballpark as the things on my pissing list.

 

[SoCoRX1]

my speedo is dead even with my friends Vertical Escape RMK. We both have long tracks (my 151, his 159) and 2" lugs. He said his speedo was dead on with a radar. do the 2" deep lugs have anything to do with it?

 

[LazyBastard]

Oh, there is absolutely no question that the speedo does not read anything even close to accurate ground speed.

SoCoRX1: What you say supports my position... it is likely more due to the increased LENGTH than the depth of the lug. When you're running the gun on hardpack, I bet that its not sinking in nearly 2".