Why do power drills have R and L?

[NY]

The exact science of how you make a bicycle or motorbike turn is more complicated that you'd imagine. It's why a bike will stay upright if you are riding it, but not if you push it without anyone riding. It used to be through that the gyroscopic force of a spinning wheel helped keep the bike from toppling sideways, but this has been found to be very small and not the complete explanation. Apparently a bicycle with a central disc inside the wheel that spins in the opposite direction, but with the same moment of inertia so as to cancel out the gyroscopic forces on the wheel, is no more difficult to ride.

The handlebars do a bit more than act as something to stop you falling over. If you simply tilted the bike, the way the steering is set up would make the front fork rotate in the opposite direction - eg if you tilt the bike to the right, the fork will rotate to the left. You have to apply a force to counteract this.

As to whether you initially apply a force in the opposite direction before applying one in the correct direction (*) - well maybe you do, subconsciously. You'd need strain gauges on the handlebar grips to prove it!

(*) Eg if you want to turn right, you initially push the left handle bar slightly and then turn the fork by pushing the right handlebar.

[NY]

Ah, does Australia have a suffix number beside the P symbol to indicate the maximum time you can park? That's a useful addition to the P. I too would have interpreted a solitary P as meaning unlimited, and would have expected

1-hour parking to be P1, if P3 means 3-hour parking.

[NY]

I tend to leave my car's trip computer on the miles-remaining setting and cross-correlate this with the trip meter in miles since I last filled up, as a check against the fuel gauge. If my gauge says I've got 1/4 tank left but my trip meter says I've done 700 miles and my miles-remaining says 50 miles, I fill up anyway: fuel gauge floats can occasionally stick, but I know how far I can travel on a tank of diesel (within a range that depends on type of driving).

I got into that habit after running out of fuel in a previous car when the float must have stuck and the gauge implied I still have plenty of fuel left.

It's been very weird the last couple of months not having to fill up my car because of the Coronavirus lockdown. The other day was the first time I had driven - or even gone outside my garden gate - for a month, and that was just to drive into town to get my monthly supply of tablets from the doctor.

[The Natural Philosopher]

My sodding nephew capsized the dinghy getting that wrong...

[The Natural Philosopher]

you might have to do that on a heavy motorcycle, but on a bike you simply lean into the turn and your reflexes then rotate the handlebars slightly into the turn to stop you falling over...

[FromTheRafters]

on 4/20/2020, NY supposed :

Asthetic balance. VIII is 'chunkier' than IV so they use IIII instead.

[Bob Eager]

Only partially the case. The Romans used IIII a lot anyway. Allegedly because IV was an abbreviation for IVPITER, one of the gods.

[FromTheRafters]

On a bicycle going along you 'punch' the right handlebar and fall over, on a normal motorcycle on the highway it is an emergency lane change maneuver to the right. I had to do it once, it works but it is scary.

[Tim Lamb]

In message <r7jqh3$n68$ [e-mail], NY [e-mail] writes

Ah! Mentally you have to consider what you would need to do if the ball hitch was in your hands. Translating that thought into what steering wheel movement will have the same effect is then much simpler.

Consider the same job but with a twin axle turntable trailer!

[Dave Plowman (News]

Perhaps you need to import them from the EU in future. ;-)

[Dave Plowman (News]

Rolls did too. At least up to the 60s. Not sure about the Shadow.

It made sense with a centre lock fixing. Not sure it ever did with studs or bolts.

[The Natural Philosopher]

Yes. the question on motorbike is how to initiate the lean when you probably weigh less than the bike. I can see how that technique would work, in the same way that rally drivers used to steer out of the turn first in order to rapidly go into the turn and break the tail out.

[NY]

What was the main reason that all manufacturers changed over from studs on the hub and wheel nuts, to threaded holes on the hub and wheel bolts? I've always wondered. It seemed to happen some time in the late 70s or early 80s. I think my first car, a 1981 Renault 5 (Mark 1), had bolts, and all subsequent cars have had them, and yet my dad's cars (an Austin Cambridge, a Ford Corsair and several Hillman Hunters) in the 60s and 70s all had wheel nuts, as had Mum's Morris Minor. I'm trying to remember whether her Renault

6s had bolts.

I much prefer bolts, because you can "hang" the wheel on the protrusion on the hub and rotate it easily (with the weight being taken by the hub protrusion) until the wheel holes line up with the hub holes, and then insert a bolt to locate it permanently. With nuts, you have to locate two holes over two adjacent studs while taking the full weight of the wheel.

Either way, I always squat down at right angles to the car (facing the hub) with my legs apart and my arms resting on the inside of my thighs at about 4 and 8 o'clock taking the weight of the wheel as I offer it up to the hub. I've seen people trying to do it while bending down (ie with knees straight) and it's a lot more difficult to get the fine control to position the wheel onto the hub protrusion or the wheel holes onto the studs.

After I'd passed my test I went on a car maintenance night school course and that was one of the tips I learned. The other is always to loosen the wheel nuts/bolts 1/2 turn with the flat tyre still on the ground. Many people raise the flat wheel and then try to loosen the bolts - and of course the wheel rotates freely if it's the front wheel of a rear-wheel drive car, unless you've got a helper to apply the footbrake... or unless you've got a Citroen where the handbrake acts on the front rather than rear wheels. Even if it's the rear wheel of a front-wheel drive car, the handbrake isn't always enough to prevent the wheel rotating when you apply serious force (eg standing on the crank of the wheelbrace) to loosen the nuts. And always apply handbrake and put the car in 1st to provide extra braking to prevent the car rolling or skipping when you jack up one of the handbraked wheels if you've hand to stop on a gradient.

[rbowman]

She's good. Backing the dolly up can be interesting. As far as backing up the entire set I could make it about ten feet before everything went to hell. Some people who always pulled double were much better.

[rbowman]

One of the programmers brought in a wall clock that have Roman numerals. It hung on the wall for six months before anybody noticed it had two XI's.

Our bug tracing system has numbers like CE-29543 that I can remember for about 2 seconds. I'd worry but the people in their 30's and 40's don't do any better.

[rbowman]

I've seen a gimmick at fairs which is a bicycle with the handlebars geared to reverse the relationship. You get a prize if you can ride it

25 feet. They don't give out many prizes even after the carnie demonstrates how easy it is.

[rbowman]

Even on a fairly heavy bike it seems like you're shifting your weight at anything above parking lot speeds. As I said initially it's better to not overthink exactly what you're doing.

[rbowman]

I have one bike that has a fuel gauge but all the others I've owned didn't. You get used to filling up based on the odometer reading and that carries across to cars.

The method failed me once. I had been running 90-95 against a head wind so the fuel consumption was high. I knew I needed to fuel but figured I'd do it in the morning. Bikes have a petcock that you turn to get another half gallon of fuel. I got a mile away and the bike started to stutter. I reached down to turn the petcock and found I was already on reserve. Luckily it only weighed a little over 350 pounds so I could walk it home.

[rbowman]

Until recently cars were massively over-engineered and many things were done because it always was done that way going back to horse drawn wagons.

[rbowman]

I vaguely remember one car that had bolts, all the rest had studs and nuts, including the new Toyota I bought a few weeks ago. I wish I could remember which had bolts, maybe the Audi?