You know the ones that are sometimes lifted up at the rear of the cement truck..... sometimes they are down and they can steer left and right.......,they dont really seem to serve a purpose even when they are down.......i have heard it has something to do with the vehicle weight and the number of axles....., if thats the case why dont engineers just design it with functional axles at all times....dont answer that last part........rhetorical question
2006-09-29 12:46:00 · 12 answers · asked by Anonymous in Cars & Transportation ➔ Other - Cars & Transportation
The extra wheels on any truck (that are often off the ground when it is "light") is to absorb the extra weight when it is fully loaded (heavy). If the extra wheels weren't there, the full weight would put so many pounds per square inch on the "regular" wheels that the pavement under them would be damaged. The extra wheels spread the weight over a larger area so the "psi" is reduced to a safe amount, and doesn't damage the road. It also takes the pressure off the regular wheels so they aren't in danger of blowing a tire. Tires are designed to take just so much pressure, just as roads (and parking lots) are designed to take only so much weight. Hope this helps.
2006-09-29 13:02:55 · answer #1 · answered by Pete 4 · 1⤊ 0⤋
These extra wheels are for added weight distribution. Texas isn't really as finicky as some other states about their bridges, but many require that you have more axles to better distribute the weight. If the extra wheels are located between the steer tires and the tandem/drive axles, they are called "tag wheels." They simply drop down with air pressure. If the extra tires are located on the back and swing down on an arm, they are called "pushers." These work in the same way, but are usually used on trucks with shorter frames. But again, since Texas isn't as strict as some other states (YET!) these extra axles are more the exception here than the rule. BTW, my truck which is a 1998 Mack DM mixer, weighs 28,500 pounds empty. Ready-mix cement can weigh as much as 4,000 pounds per cubic yard depending on the mix. So, if I carry 10 cubic yards (standard capacity), I'll weigh roughly 68,500 pounds. That's quite a bit of weight to put on three axles, hence the extra axles. Compare this to tractor-trailer combinations that can have a max gross weight of 80,000 (without an overweight surety bond). Difference is, the tractor-trailer combo has 5 axler to distribute its weight among.
2006-09-29 12:49:18 · answer #2 · answered by Anonymous · 3⤊ 0⤋
Cement Mixer Wheels
2016-12-13 03:30:56 · answer #3 · answered by fiddler 4 · 0⤊ 0⤋
only allowed to carry so much wieght per axle. This lets them have a higher gvw rating when the axle is lowered.
2006-09-29 12:54:18 · answer #4 · answered by ronnny 7 · 0⤊ 0⤋
two reasons when hauling a full load of concrete they use them to more evenly distribute the load. when going of road like on allot of job sites they use them so they wont cut the ground up and get stuck.
2006-09-29 12:50:01 · answer #5 · answered by Anonymous · 0⤊ 0⤋
It allows them to legally carry extra weight when loaded
2006-09-29 12:49:12 · answer #6 · answered by Letsee 4 · 0⤊ 0⤋
to balance the truck out when it is full of cement.
2006-09-29 12:50:57 · answer #7 · answered by goingfasterbmw 3 · 0⤊ 0⤋
replacements probably or for weighting purposes...
or just for "truck-fashion" purposes...i guess people who make those trucks think it looks better with an extra set of wheels
2006-09-29 12:47:04 · answer #8 · answered by skybubbles 2 · 0⤊ 3⤋
it is weight and axles.
2006-09-29 12:49:53 · answer #9 · answered by acefra 3 · 0⤊ 1⤋
weight distrabution when tumble is loaded
2006-09-29 13:11:46 · answer #10 · answered by my4retransport 1 · 0⤊ 1⤋