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Trailer reverse

Posted: Sat Nov 21, 2009 3:41 am
by Sir Knight
When Michael reversed from the moving trailer in the orig Knight Rider would he momentarily need to shift in to neutral as KITTS tyres hit the road :?:

Re: Trailer reverse

Posted: Sat Nov 21, 2009 11:00 am
by KITT 3000

Re: Trailer reverse

Posted: Tue Nov 24, 2009 7:19 am
by Knight Racer
The only thing I want to know about that video is how far in did they get into the semi before they could stop?Would they have ripped right through the lounge area and stopped an inch from the end of the cab?

Re: Trailer reverse

Posted: Tue Nov 24, 2009 12:45 pm
by neilp9
The You Tube video focuses on KITT entering the Semi and skipped over the reversing out bit.

I too always wondered about when KITT left the Semi that his wheels when reversing down the ramp would be going backward and then when his wheels touched the road they'd be going forward and there'd be a brief point when the wheel would both half touch the ramp (going back) and half touch the road (going forward). Would this then stretch the tyre rubber forward and backward at the same time??

I guess KITT would have to come out at some speed to compensate for this and thats why there's always that skidding noise when KITT leaves the trailer.

Neil

Re: Trailer reverse

Posted: Tue Nov 24, 2009 6:53 pm
by Sir Knight
yes the video on you tube is fascinating but it was more the reversing side of things that always puzzled me. Guess you would soon wear out a normal set of tyres. Luckily KITT has special ones to compensate for this. I wonder if there is some scientific explanation for travelling in reverse from an object moving forward !!

Re: Trailer reverse

Posted: Tue Nov 24, 2009 9:19 pm
by lunchmeat
neilp9 wrote:I too always wondered about when KITT left the Semi that his wheels when reversing down the ramp would be going backward and then when his wheels touched the road they'd be going forward and there'd be a brief point when the wheel would both half touch the ramp (going back) and half touch the road (going forward). Would this then stretch the tyre rubber forward and backward at the same time??


Uh, no. Maybe briefly, but it wouldn't really cause damage to the tire, per se. The car is moving down a slope as well, so there's that to consider, but the main thing here is that the car is already moving out of the semi - once the tires hit the road, any grip from the road will simply serve to pull the car out quicker. The stress transmitted to the tires will actually be applied to the car.

As for the reverse thing....it looks like these guys had a manual transmission on the car they used. I would imagine that this might be possible with a manual - you could simply clutch in, or shift to neutral, if you needed to. (I would do it while rolling down the ramp, using the brakes to control descent; put the transmission in the highest gear so that when I'm on the road, I can rev and let out the clutch without much bucking.) With an automatic, I would imagine that there would be some problems. I suppose that you could shift into neutral from reverse, but I'm not so sure about shifting into Drive while the car is actually moving. You might not kill the car, but I doubt it'd be rough on the car and the driver.

Edit: Typo.

Re: Trailer reverse

Posted: Fri Dec 18, 2009 5:02 am
by ShadowRider
Interesting.

I always presumed they eased down the car in neutral, since it would break the transmission if the gear is on reverse and the wheels suddenly start rolling forward at 40 mph, no? I recall a car with an automatic transmission cannot be towed above a certain limit, due to the drive shaft still rotating the transmission, and withbout turned on engines no oil-flow happens inside the transmission (my Trans Am, being "towed" twice, was lifted on the truck bed each time and not towed with rear tires on the road). But in this case the engine was on, so there'd be no harm, right?

Didn't Jack Gill say in season 1 extras that he sometimes chopped off the Trans Am's side-mirror accidentally while driving in or out the semi? It's not that they had CGI back then to make it with a computer so they had to drive the car in and out, and I doubt they would willingly wreck a transmission just for the scene. Though I do recall they got brand new cars with some minor defects at a really cheap price for the filming.

Re: Trailer reverse

Posted: Fri Dec 18, 2009 9:15 am
by Matthew
The thing to remember is that the car’s backward motion doesn’t suddenly change to match the forward motion of the truck when coming into contact with the road. In fact, the opposite happens, and the backward motion literally hauls the car off of the ramp and onto the road.

You’ll note that more often than not, the car will then come to a virtual standstill before shifting to the forward motion, and this is what allows it to perform the iconic 180° turn in one seamless motion after exiting the semi.

Matt