Cars without spare wheels

[Michael Chare]

Presumably EVs are more like automatic ICEs? But how easy is it to move just a few inches which can be difficult with an automatic unless you use the brake.

[Roger Mills]

Very easy in the case of an ID.3 A momentary touch on the throttle causes it to creep very slowly, and you brake when you've gone far enough. It's not necessary to use the throttle and brake at the same time.

[jim.gm4dhj]

heaven ! your own sea of sheet metal.....gorgeous three speed auto ....each to their own .....

[jim.gm4dhj]

you could be talking about my mk1 3l Granada estate....

[Rod Speed]

Why is it called a Grenade ?

[Paul]

You can get steel and ally floor jacks (with the wheels). Don't buy the steel one, unless you are the Mighty Hercules (85lb) :-)

If you had one of those overweight modern cars, you need a pretty strong jack. And you need to think about what happens to the jack points, if you use a scissor jack. I don't know if a pinch weld can take that kind of loading.

Even lifting a car via the center of it, is not good. There have been premature failures of cradle assemblies due to rust. I even got to see a wheel fall off a car in the city, due to a failed cradle. But that's Honda for you. They did not used to use cradles, and previous schemes had better wear properties. Cradles suck.

I still find plenty of uses for scissor jacks. When I needed to lift a part of my carport, to reposition a support, I used a post and a scissor jack (because I could not find all the bits to assemble my steel jack post).

Paul

[Paul]

There are EVs that can parallel park themselves. They could not do this, if they were hammering the accelerator all the time.

BEVs do not typically use transmissions. Some of the "peasant-mobiles" do use transmissions, but the cutoff point is around 40HP or so. Above 40HP, the tendency is to use a "reduction gear" to adjust motor shaft speed to axle speed. Some cars have extended-range motors that go at exceptional RPMs.

16,000 RPM in large drive units with 335 – 475kW output 18,000 RPM in small rear and front Drive Units with 220kW output.

That is Dremel speeds, in a significant-sizes assembly.

A conventional compact tranny would be torn apart by monster drive units like that. Alternately, the tranny would be a huge device, and it would make the "GM noise" while you were driving :-)

And sure, you can find exceptions to my description. There is nothing to guide on what "scale" the following is, what the dimensions are. And that is for designs like transit buses.

Usually, the thing stays in one gear, and does not go through the "sequence" while in stop-and-go traffic. Switching to top gear, helps with torque at highway speeds (helps ensure you can pass an ICE). While nominally it is a transmission, in practice the shift points can be quite different, and the number of lifetime shifts is lower.

Paul

[Andy Burns]

Lidaldi occasionally sell trolley jacks much smaller than the typical ones that garages use (2 tonne vs 5 tonne)

[jim.gm4dhj]

it's not rod

[The Natural Philosopher]

Oh yes, I wasnt implying it was the same shit, just that gunk has severe drawbacks,

[Roger Mills]

A 2-ton trolley jack isn't very heavy, and is adequate for lifting one corner of all but the heaviest cars.

You do indeed need to work out in advance where you are going to apply the lifting force so as to avoid any damage. Somewhere on a suspension arm directly below the spring is often best.

[Rod Speed]

My steel one doesnt weigh anything like that and works fine.

[Rod Speed]

I know its not rod, I am rod, stupid.

[Sam Plusnet]

Caravans have a quite limited payload, and the last thing I need is 'the tail wagging the dog' (the towing vehicle needs to be heavier than the thing being towed). Also, that area in the caravan is already filled with all the heavy(er) stuff that must be carried in there.

Incidently, the spare wheel in our old caravan was mounted in the front locker, but I could never get the tow hitch weight down to a safe level unless I removed it. _That_ spare wheel would travel in the 'van, over the axle, and be returned to the locker once we arrived on site.

[The Other John]

The last caravan I had (sold 11 years ago) had the spare wheel in a cradle under the floor behind the axle, so didn't increase the hitch weight.

[Roger Mills]

Mine too. Being behind the axle, it actually *decreased* the hitch load. But it did increase the caravan's payload which seems to be on concern to Mr Plusnet - and it did increase the van's yaw moment of inertia slightly.

[Rod Speed]

But did increase the likelyhood of the van going out of control and ending up on its side and maybe even wrecking the towing vehicle.

[Roger Mills]

Yes, but it only increased it from negligible to minuscule.

[Sam Plusnet]

Payload is almost always a concern for caravans. The quotes max payload for mine is 150kg, but that doesn't include 'extras' like the battery, gas bottles, motor mover, etc. etc. Everything else you want to put in the van, to make it habitable & usable, has to come out of the balance.

The most frequent complaint I hear about the under-floor cradle for the spare wheel is that the cradle has seized up when you need it, or (with a flat tyre) there is no clearance under the van to get the thing out.

Our current van has the spare in the front locker (out of the weather) - and I can get the hitch weight to a suitable value with it in place.

[NY]

I had a very bad experience of a spare wheel on my old Peugeot 306 which was held in a wire cage outside below the boot. I needed to change a wheel, and discovered that I couldn't unscrew the bolt that supported the cage. On the Peugeot, the head of this bolt (inside the boot) is cylindrical (duh!) and has a very broad semi-cylindrical notch cut diammetrically. The thinking is that you insert a flattened end of the wheelbrace into this notch as a primitive screwdriver and unscrew the bolt. Crap design even when the threads (exposed to the road muck that washes onto them) aren't seized up. I found that when I tried to turn the head with this "screwdriver", the sloping (not vertical) sides of the notch made the "screwdriver blade" just climb out of the notch: I tried virtually sitting on the wrench while someone turned it.

It took an RAC man about half an hour, spraying the threads and nut with WD40 and penetrating oil, and directing a blowtorch onto the thread/nut (with the flame carefully shielded from the tyre), before eventually we managed to free the bolt and release the wheel. Aftr that, changing the wheel took a minute or so. Sadly we couldn't even grip the circular head with a Mole wrench, because the floor of the boot was ridged to give it extra rigidity, and the ridges came too close to the bolt head to get any sort of purchase on it.

After that, I got into the habit of loosening the bolt every couple of weeks, and coating the threads with grease. However I don't think I ever had another puncture after that. At least I knew that if I ever did, the spare wheel should be easy to remove.

On another occasion, probably a year or so before the "seized bolt" fiasco, I was driving down a country lane when I suddenly heard a metallic scraping. When I investigated, the cage was dragging on the road and the spare wheel had vanished. I walked about 1/4 mile back up the road, looking in ditches, but there was no sign of it: I had to fork out for a new spare wheel and tyre :-( It was galling to think that the spare could have been just beyond the next bend - but how far do you walk, scanning the road and the ditches like a pillock, before eventually throwing in the towel?

A spare inside the boot (or above the engine on my first Renault 5) is a much safer place for it.