emergency tyre repairs

[NY]

"Dave Plowman (News)" wrote in message news: [e-mail]...

I keep meaning to buy a cheap steel wheel and tyre to keep at home as a spare, so at least I can start a journey from home if I have a puncture that has only become apparent after the car has sat on the drive for a day or so. Even if I still have to rely on the idiotic space-saver for a puncture that develops while I'm out and about - and that has only happened to me once in

40 years. I noticed the tyre was flat when I returned to the car after shopping in a supermarket and had to wait for the car next to me to go before I could get sufficient access to remove and replace the wheel. As the car park was very full, I got a lot of abuse for "blocking" a space for the couple of minutes it took me to change the wheel.

I once had a spare wheel go missing! On my Peugeot 306, the spare was in a wire cage below the boot floor, secured by a bolt that was only accessible from inside (to avoid theft). I was on holiday and I set off once morning from the cottage where I was staying. About a mile down the road I heard a strange grating sound: it was the cage scraping on the tarmac. I went back up the lane (typically about 10 cars and a tractor per hour) looking on the road and in the ditches, but there was no sign of it. That required a detour to the local town and a wait of about an hour while a wheel was located and a tyre fitted to it. That cage was a really nuisance. The only time I've ever called out the RAC for a puncture was when I was run off the road by an oncoming car (I had priority) and the tyre wall got ripped by the kerb. When I came to get the spare out, the thread of the bolt had seized to the nut on the cage - and the stupid f*ckers at Peugeot had put a semi-cylindrical notch in a totally round bolt head, rather than a wheelnut-sized hexagonal head. You were supposed to use the flattened end of the wheelbrace as a crude screwdriver in the semi-cylindrical notch. The thread had seized to the point where I couldn't get any purchase on the "screwdriver" because the "blade" kept pulling out of the notch. The idiots had even given it round sides rather that flat vertical ones to make sure that the screwdriver would climb out of the notch ;-) It took the RAC man about an hour, heating the nut with a blowtorch (carefully shielding the tyre!) and applying a lot of WD40, grease etc, before he could get it to shift. He was at the point of contemplating using an angle grinder to grind a couple of flats on the round head so he could grip it with a Mole grip.

[The Natural Philosopher]

I think its a cube law actually. Oh - my bad - the POWER is cubic, the DRAG is square law as you said.

i.e. if you can reach 50mph with 10 bhp, you will need 80bhp to get to

100mph...and 640bhp to get to 200mph, which puts a 2CV, a modern saloon, and a racing car engine in perspective..

So the loss from extra weight due to:

Yes - in cars, weight is crucial for stop start motoring efficiency, although regen braking helps with that a lot.

In the case of e.g. a train, with limited start stop it is far less an issue,and weight helps grip with steel wheels on a steel rail...

If rolling resistance is constant, the power goes up as the speed. So it represents a limit on the mpg you cam get even crawling along at very low speed.

Definitely bicycle style narrow tyres are way better than modern low profiles. But have no traction braking or cornering potential.

[Paul]

Maybe it's when the paddle-tool at the beginning "breaks the bead" and separates the tire from the rim, along the bead ? There are some assumptions about the tire separating easily from the rim.

"Tire Machine: Tire Remove & Install"

Paul

[Peter Johnson]

The last time I changed a wheel was nearly 20 years ago. I imagine that in relation to the number of miles driven punctures are rare. Don't remember the last time I had to change a bulb.

[Kellerman]

My Astra K came with no spare, just a can of gloop. Ah! that'll be why its got 4 odd/different make tyres then .. . . A large sum of money later (about the cost of 2 or 3 tyres) and I have the correct (new, not available 2nd hand in 3 months of looking on Ebay) space-saver spare, tools and the hard foam tray. Dear? yes, but the average punters SOP seems to be...... Dash shows low tyre pressure -- ignore it until the tyre is ruined -- try (and fail or don't bother) to use the can of gloop either due to a RTFM fail or the tyre is split. Drive (on flat tyre) until you remember/payday to get tyre sorted --- get the cheapest tyre available fitted. Don't replace the gloop can (at £30). Next puncture -- rinse and repeat, next puncture -- rinse and repeat .... etc ....

[The Natural Philosopher]

Mmm. I changed several on the last car. Bulbs. haven't changed a tyre on my own vehgicle since some Goth stuck a knife in the sidewall about 7 years ago

Did change someone else's a couple of years back

[Andy Burns]

Three (all repairable) in the first year on the last car, plus another one later on. None so far on this car.

Had to replace rear indicator lamps due to orange paint dip fading for MOT.

[NY]

I last had to change a wheel about 2 years ago (I'd forgotten about it till now) when I was forced to take evasive action once again - in this case when a tractor pulled out to overtake a queue of parked cars on his side of the road and just kept on coming - he didn't even stop to give me time to stop and reverse out of his way which I would gladly have done because it's a damn sight easier to reverse a car than a tractor with a baler on the back, even if he should have waited for me in the first place. I drove on the verge just in time to avoid him and clipped the inside wall of my front tyre against a sharp bit of tarmac on the edge of the road as my wheel went into a rut (I went back to look the following day because it was only down the road from where I was living at the time). I really should have reported the tractor for careless (inconsiderate, bullying) driving.

I went through a phase of having to change headlight bulbs - about 1 every few months. My local garage recommended using more expensive branded bulbs (Osram etc) rather than Halfords own make. And I've not had to do one since. Odd how it only affected my present car and not my previous one, even though I used Halfords bulbs in both and was driving on the same roads (same potholes and bumps). I do wonder whether there is an intermittent voltage surge, even though the voltage regulator has been checked to see that the voltage remains within limits at all engine speeds, or whether the suspension is a bit firmer, transmitting bumps through to the filaments more than on the old car.

[Dave W]

My Seat Ibiza is like that. I threw away the evil goop and bought a apare tyre instead. Only trouble was that the buggers had only provided a big enough space for a 'space-saver' tyre.

[NY]

That is the problem: no-one seems to think that people want a fully-functional spare wheel which can be used as far and as fast as you like, so you can take the flat tyre to a garage when it's convenient for you, and not as a dire emergency before you can continue your journey - assuming your journey is more than the distance limit that is recommended for the space-saver. It comes under the heading of "not making a drama out of a crisis".

The idea of supplying goop to fill a punctured tyre is utterly idiotic because it means that every puncture you get, you need to buy a new tyre. Nice little earner for the tyre makers, though :-(

On three occasions when I travelled up to stay with my girlfriend (several hours' journey away) I came to set off on Sunday night and found I had a puncture which was not apparent when I last drove the car - in one case it had been fine only a few hours earlier. Because I had a spacesaver, and had to travel a couple of hundred miles, I had to abandon my plans to return home on the Sunday night, and instead had to wait until the morning so I could take the tyre to be repaired - and on each occasion, it *was* repaired, not replaced. With a full-size spare, as on all my previous cars, I'd have been on my way after the minor inconvenience of changing the wheel which only takes a couple of minutes.

[Vir Campestris]

I've got a skinny spare. It'll get me somewhere I can buy the correct replacement for the front or rear that's flat.

(The fronts are narrower than the rears.)

Andy

[Vir Campestris]

How's that work then? You take a weight up against gravity, then you'll get the same back on the way down.

Of course in practice there will be occasions when the extra 1% weight will make you drop a gear.

And other occasions where on the way down it'll be the difference between a tickle of throttle burning fuel very inefficiently, and throttle shut burning none at all.

Andy

[Vir Campestris]

WTF do they think you are going to do with the flat tyre you took off?

Andy

[NY]

That's fine as long as you don't discover the puncture out of hours when tyre repair places are closed. And almost every time I've had a puncture, that's when I've discovered it, often as I was about to begin a long journey. It is a myth the punctures only happen when tyre-repair places are open, that the repair place is on the route that you were planning to take anyway, that they have your tyre in stock and that they can fit it as soon as you turn up. With a full-size (ie fully-interchangable) spare, it doesn't matter if the tyre takes a day or so to be delivered: you leave it with them, get on with your life and pick it up when it's ready - and you have full use of your car in the meantime.

For the record, most of the punctures I've had have been nails/screws through the tread. I must spend a lot of time driving on roads where people have lost a van-load of screws ;-)

Why do manufacturers make cars with tyres which are not interchangeable - at least front/back, if not side/side because of the opposite rotation problem. It means you can't swap the tyres to even the wear.

[T i m]

Except the thing pushing that weight up the hill isn't likely to be working so inefficiently as it might on the way down?

Quite.

Yes, but ignoring any of that, it will still take an additional energy 'input' to get that extra weight up the hill that's unlikely to be recouped 100% on the way down.

The only way it wouldn't would be if you used a 100% efficient machine?

And I'm guessing that's why they often don't fit spare wheels, to save the weight (also) because of such differentials?

Cheers, T i m

[Jethro_uk]

But that isn't "spare-wheel-for-safety" so much as "spare-wheel-for- convenience".

And if you are at home, why not keep a spare in the garage ?

[Dave Plowman (News)]

Different sizes back and front are usually done to give better handling. But not on shopping trolleys, I'd guess.

That hasn't been recommended for many a year. Front and rear tyres develop a different wear pattern. Swap them over when part worn and you could get less than ideal handling until they scrub themselves in. Unless you did it frequently. And it means buying 4 new tyres all at once.

[The Natural Philosopher]

you put it in the boot, loose

[Dave Plowman (News)]

Surely an expert on everything like you knows that just how the rear tyres wear depends on the type of suspension? And the same applies to the fronts too? But perhaps in Glasgow you're more used to cart springs all round.

[Tim+]

If you have room in the boot. If not, beware...

Obviously this isn?t going to happen with a flat tyre but if the car had had a full size spare (and room to store it) it wouldn?t have happened.

Tim