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Definition of vehicle track
carcentric - 10/12/03 at 01:17 AM

I've always understood the term "track" to mean the distance between the centerline of one wheel rim (or tire, assuming they're symmetrical tires) and the centerline of the other wheel rim on the same axle (measured at the axle to eliminate the effect of camber and any toe in/out).

But, lo and behold, the Merriam Webster dictionary says, "(5a) the width of a wheeled vehicle from wheel to wheel and usually from the outside of the rims."
With a pair of 6" wide rims, that measurement would be 6" greater than the way I measure track.

So here's a poll.

I'd also appreciate any authoratative URL's that endeavor to define term. Thanks,

pbura - 10/12/03 at 05:58 AM

SAE Vehicle Dynamics Glossary

6.3.,3 WHEEL TRACK (WHEEL TREAD) : The lateral distance between the center of tire contact of a pair of wheels. For vehicles with dual wheels, it is the distance between the points centrally located between the centers of tire contact of the inner and outer wheels. (See S A E J693.)

There's an ISO Standard 612-1978 that defines track (term number 6.6, in fact), but I'll be hanged if I'll pay for it to find out what it says! Anybody got a copy?

Pete

[Edited on 10/12/03 by pbura]

carcentric - 10/12/03 at 06:07 AM

Looks like I was closer than the dictionary, but not right about the effect of camber (the more camber a car has, the wider it's track - I thought the car's track would not change as camber is increased).

Thanks for the reference, Pete!

Spyderman - 10/12/03 at 02:00 PM

quote:
Originally posted by carcentric
Looks like I was closer than the dictionary, but not right about the effect of camber (the more camber a car has, the wider it's track - I thought the car's track would not change as camber is increased).


Almost!
The more negative camber would increase track!

Terry

carcentric - 10/12/03 at 05:02 PM

That's what I was thinking (but didn't write). As a former competition driver, negative camber is "the only camber" (worth having).

Which brings me to another curiosity, though. In old photos and paintings of 1930s and older race cars, it's obvious they have POSITIVE camber on the front. Why did they do that? Was it for ease of steering or something?

Mix - 11/12/03 at 09:49 AM

Nah!!

It's the metal flexy bit around the wheels of a tank or digger

Mick