Why Do Some Vehicles Have their Wheels Like This (read for full question)?
The Blind Eternities forum
Posted on Sept. 20, 2020, 8:53 p.m. by DemonDragonJ
Anyone who has pushed a shopping cart will likely have noticed that the front wheels freely rotate, whereas the rear wheels usually do not. Having pushed carts in which all four wheels freely rotate, I can say with complete certainty that the latter design is superior in every possible way to the former design, so I fail to comprehend why anyone would ever design a vehicle in which all the wheels did not freely rotate, since such a design provides unrivaled maneuverability, which is especially useful for heavy tools chests or similar objects.
What does everyone else say about this? Why do some objects or vehicles have wheels that do not freely rotate?
Omniscience_is_life says... #3
Why doesn't WotC errata Cacophodon to be a mythic rare legendary creature? Some questions we will just never know the answers to...
September 20, 2020 9:17 p.m.
DemonDragonJ: The wheels in question that you're describing are called jockey wheels.
As for the use case, it comes down to what the application is. For a tool chest being wheeled around a workshop or garage, they're great because you're probably only moving on a smooth, flat surface at low speeds.
But for a shopping trolley, while the inside of the grocery store might be flat, the parking lot outside wont be. And the trade-off of less maneuverability does mean more control of the trolley, as while the front of the trolley can turn, the trolley itself can't just start drifing sideways. And from experience, the average shop goer struggles to control a shopping trolley without having to worry about them drifting sideways.
At the end of the day, it all comes down to the requirements. Tight workshoop versus relatively open shop with aisles intended for trolleys. And at the end of the day, you could stick omni wheels on the trolley instead which are better than joeckey wheels (for a number of reasons around maneuverability). However again, it comes down to the use case.
September 20, 2020 9:44 p.m.
demongaurd65 says... #5
like several have pointed out maintenance and use case are 2 big factors. trolleys or tool boxes with all omni wheels are great for low weight applications and offer great maneuverability. I'm sure you have met the grocery cart with the broken wheel that wont go straight this is multiplied when you add more weight and time of neglect something with all omni wheels will go everywhere but where you want it to go.
when you get in to things like mechanics toolbox's that can reach several thousand pounds when loaded with tools or something like a pallet jack. jokey wheels are proffered you lose maneuverability but you also don"t have to fight drifting in a random direction
now there are plenty of vehicles with 4 wheel steering lawnmowers,monster trucks, plenty of sports cars but each system is built for its use case. sports cars the rear wheels will turn a few degrees to aid in low speed maneuverability but most systems return to jockey wheels at speed so you don't change lanes into a barrier on the highway.
September 21, 2020 1:32 a.m.
DragonSliver9001 says... #6
demongaurd65 i think you mean preferred instead of proffered.
September 21, 2020 1:01 p.m.
Oh my god. No one cares. Stop with this pointless pedantic correcting. The intended meaning was communicated and all you do is look like a git. It does not add anything to the discussion besides you getting to slap yourself on the back.
September 22, 2020 11:05 a.m.
Also, speed is an important factor. When the rear wheels are fixed and cannot turn freely, then the rear of the "vehicle" has predictable and reliable behavior.
It also helps with centering or tracking. If the rear wheels could move freely you are adding more fail points that can destabilize the vehicle or impact it's direction of travel.
If you have ever been on a skateboard and experienced "speed wobbles", just imagine how much worse it would be if all 4 wheels could turn independently of each other.
September 22, 2020 12:46 p.m.
DemonDragonJ says... #9
MagicMarc, I understand that, but, if I ever need to move a heavy tool chest, I would like to have that additional maneuverability.
An example of that was when I purchase a new grill; on my previous grill, two wheels freely rotated, while the other two did not, but, on my new grill, all four wheels freely rotate, which was one of the factors that helped me to choose it, and that additional freedom of movement makes a huge difference.
On that subject, the small tool chests at the hardware store had all four wheels freely rotating, but the large chests had only two wheels freely rotating, which is unfortunate, because the large tool chests are the ones that could have used that extra maneuverability.
September 22, 2020 4:41 p.m.
I am with you about grilles and things like furniture dollies. During a move, I bought a furniture dolly, (the small, carpeted rectangles with 4 wheels), and one side's wheels were fixed and not free-rotating. Very annoying for that application.
September 22, 2020 4:49 p.m.
The only thing I could think of is that its potentially safer for the consumer and others to limit a given cart to six degrees of freedom (cardinal directions & left/right) compared to 360. This would only apply if you had a destination to go to (A -> B) and not so much for tool chests which only have to move small amounts in a given space. This also only applies for heavy loads.
Maybe I'm wrong. Probably, but that's the only thing that makes sense to me.
September 22, 2020 5:08 p.m.
DemonDragonJ: But again, look at your use case here. Big, heavy (well, heavy-ish) objects moving slowly and typically short distances on relatively flat surfaces. And in addition to this, I'm guessing these items are the jockey wheels with the built-in locking mechanism?
As MagicMarc stated, you can get furniture dollies with 4 jockey wheels. If you get yourself one of those (they are very useful) and then try riding it like a skateboard and build up some speed. You'll very quickly understand the reason you don't want 4 jockey wheels on a shopping trolley.
September 22, 2020 7:38 p.m.
DragonSliver9001 says... #13
LeaPlath you talking to yourself? using the correct word matters and literally changes the whole meaning of the sentence.
September 23, 2020 12:14 a.m.
DragonSliver9001 says... #14
enpc: as someone who has worked several combined years at both UPS and Fedex, i can 100% guarantee that letting all 4 wheels turn freely is better, despite moving heavy objects short distances on flat surfaces. the push carts we had to use to move packages around only had 2 rotating wheels as opposed to 4, and pretty much everyone agreed they were a nightmare to try and maneuver without smashing into pillars or trucks. i would absolutely want 4 rotating wheels on a shopping cart.
September 23, 2020 12:21 a.m.
DragonSliver9001: You're talking about something like a platform trolley right? I know that one is only rated to 150kg, I'm guessing you had bigger ones. But were you using these trolleys between the warehouse and the truck (in a loading bay) or were you using them between the truck and a house as well? Also, did you have any kind of manual handling training/assessment?
Don't get me wrong, as a 100kg, 6'2" person who could actually wield a shopping trolley with 4 jockey wheels I think it would make getting around a supermarket much easier. But the amount of numpties I see who can't even control a regular trolley makes me glad that most shopping trolleys only have 2 jockey wheels. And that's where the tradeoff is. A lot of designs for everyday folk have to take into account the people who are barely functional at the best of times. But for things like toolboxes or platform trolleys, there is an assumed level of "you're using something somewhat technical so we hope you're not a drop-kick".
September 23, 2020 12:51 a.m.
DragonSliver9001 says... #16
enpc: the carts we had were similar but bigger. we used them inside the warehouse, which at ups is where the big brown package trucks are kept when not in use. no need for a manual to know how to push a cart. i think the logic of making the cart easier to control for weaker people is severely flawed. the strength of a person just has never been relevant in my experience. if a person can't control a regular cart, then locking 2 of the wheels is only going to hurt them, not help them.
we were constantly told we had to be "pushing" them for safety reasons, but we would all pull them instead because it just made handling them so much easier.
RNR_Gaming says... #2
Less costly maintenance.
September 20, 2020 8:59 p.m.