Punctures.

[DP]

Tyre on my wife's car had two nails in it. Took it to Kwick Fit. They repaired the puncture, balanced the weel and it was filled with nitrogen (have no clue why nitrogen is better than good old air). I got stung for 20 quid.

Today decided to go to another tyre place (independent) who charged me £5 but would not balance the wheel saying tyre was not new (cannot see how Kwickfit can do it and he cannot)

Can you learned guys say what is what?

 

[Diyisfun]

Any age of wheel tyre can be balanced.
My puncture last month at an independant £16.50 inc vat

 

[Burnerman]

Nitrogen may be used as it remains at a steady pressure irrespective of temperature - but thats not really necessary on a car.
Any tyre can be balanced, old or new. However, if the tyre is removed from the rim but its position is marked before that and replaced, balancing isn't necessary!
Neither is automatic valve replacements that the big outlets insist upon. Just another way of extracting the dosh.
John

 

[Peter.N.]

Puncture repairs around here are about £10-15.00 but the last one I had was on holiday in the north of Scotland and that only cost me a fiver - and he did it while I waited

Peter

 

[FriedFreddy]

Nitrogen may be used as it remains at a steady pressure irrespective of temperature - but thats not really necessary on a car.


Any tyre can be balanced, old or new. However, if the tyre is removed from the rim but its position is marked before that and replaced, balancing isn't necessary!


Neither is automatic valve replacements that the big outlets insist upon. Just another way of extracting the dosh.
John

Nitrogen also has a larger molecule thus does not permeate through the butyl liner of the tyre as fast as regular air thus holding pressure longer, it's also a dry gas (whereas compressed air is moisture laden which can rust rims and degrade the tyres inner liner) but is however not cost effective on smaller car tyres unlike larger car tyres and motorcycle tyres where exact pressure makes a big difference to grip, mileage and handling, all said & done though the tyre firstly need evacuating of any air before adding the nitro or fill/empty/re-fill several times to remove as much O2 as poss.

Not correct - there's the plug/patch to consider and also the previous wear of the tyre could already have thrown the tyre/wheel assembly out of balance, not to mention the odd kerb contact that can move/remove a knock-on balance weight.


Again not correct - at 30+ mph a tubeless valve will bend under centrifugal force, at high speed on an unsupported valve the valve cap can actually touch the wheel rim (this will not happen on a TR412 valve but a regular TR413/4 valve will degrade at the base through all the flexing, a TR418 valve will generally fail before a tyre is worn out if not supported (hence they are usually only fitted to steel rims with wheel trims where the hole in the trim supports the valve stem) - hence racing and high performance rims are usually fitted with bolt-in valves.

 

[Burnerman]

Fair enough, but I can see there will be a bit of disagreement here!
I get my tyres from a local independant guy - I'm not saying he is absolutely correct of course, but he has shown me some interesting stuff.
I took a punctured steel wheel in. He marked the tyre and rim position, took the tyre off and plugged it. Back on the rim, all balancing was the same. On the car - perfect.
Another wheel - balanced perfectly, showed 00 - 00.
Off the balancing machine, rotated 90 deg - showed 00 - 15. Rotated another 90 deg, showed 00 -00 again! Back on the car - alls perfect.
Puncture in almost new Pilot Premacy (500 miles). Hi Q insisted a new valve was fitted. Ok - I'm not bothered about a few quid. Did it really need one? I doubt it.
Fitted new Bridgestone 020 to a 168 bhp motorbike by a nationwide supplier / fitter. 2 year old tyre, worn out in 2500 miles. New valve? No. Nitrogen? Yes.
Costco Michelin outlet? Will only fit 2 new tyres to rear rims, because 'the car will definitely spin in the wet' FWD car? Thats debateable.
I'm not saying who's right and who's wrong at all here - just in the real world, everyone's out for what they can charge you for. i'm not interested in saving a few quid either - if the tyres are worn, then put new ones on.
Interesting discussion, I think?
John

 

[stuartturbo]

I believe balancing of tyres is recommended at 6000 miles to extend life. as is rotation ( think how many pot holes and curbs get clumped these all effect it)
I tend to (FWD) when the front are worn put the part worn rears on the front and the new ones on the rear.
The part worn from the rear are barley touched and ensure the rear dont't end up on the car for 10 years and barley worn.


The fwd spinning out with worn on the front is a valid point

• You enter a corner with the best grip on the front.
  You reach a point where the car understeers.
  Panic and lift off the throttle or just lift off the throttle to much or brake
  Rear goes light
  As the rear has less grip from the more wore tyres it steps out ( Lift-off oversteer)

the other benefit of NO2 fill is they stay the same pressure better standard air set before a 20min drive set to a low 36psi after they where 50psi ( on Donnigton track) using NO2 virtually no change ie set to 38psi

 

[Avocet]

I'm puzzled by the notion that "nitrogen maintains its pressure better than air"? For a start, "air" is about 70% nitrogen anyway! (and that's before you take into account whatever was in the empty tyre prior to inflation)! Secondly, Nitrogen is a gas, and like any other gas, is subject to the gas laws. If you heat it up, it will expand. If that takes place in a closed chamber, the pressure will increase. Whether it does so less than other gases, I'm not sure, but given that 70% of what's in any tyre is already nitrogen, I'm surprised at any differences claimed.

I think the main benefit of using nitrogen is that
(a) as has been said, it's quite a big molecule, so won't leak through the rubber as readily as the smaller molecules in the remaining 30% of the air;
(b) its pretty inert, so is less likely to react with the rubber of the tyre, improving its life very slightly
(c) because its an industrial gas from a bottle, as has been said, it's likely to be drier than air straight from a compressor.

What I want to know is whether people who have had their tyres filled with nitrogen always go back to a nitrogen-vending outlet to get their pressures checked - and if not, how do they top their tyres up?

As for valves, I have re-used ordinary valves in the past and lived to tell the tale, but I do a fair few miles and get through tyres relativey quickly, in terms of time. Whether they hit the rim or not depends, as much as anything, on the design of the rim. I've known various very quick cars to have been fitted with conventional valves with no ill effects. I prefer them to bolt-in valves as they will usually get replaced every time the tyre is changed (thereby also changing the valve core - another potential source of leakage) and it gives a chance to clean the valve seat on the rim. I've seen alloy rims damaged (corroded) and leaking as a result of bolt-in valves being fitted.

 

[Peter.N.]

I would have thought that valves would only be subject to centrifugal force when you were accelerating or decelerating, might be a bit of wind resistance though

Peter

 

[Avocet]

Whenever the wheel is turning, they are getting "flung" outwards (as a kid on a roundabout). The faster, the bigger the force. However, (also like kids on a roundabout) they are very light and don't seem to mind the experience!

 

[Peter.N.]

Hadn't thought about that, was thinking of the wrong force

 

[Burnerman]

I think there's a fair bit of the main tyre outlets guarding their private parts really - Quack Fit say the car owner is recommended to return to have the wheel nuts retorqued, but who does? The last time I used them for an MOT (06 Micra, 11k), they said the shocks were gone (no leaks)
and there was some rust on the inside of the fuel filler neck, but they wouldn't do an advisory this time. Some people must be blessed with x ray eyes.
Anyway - I'll go with keeping good tyres all round and the best on the front, and checking the pressures on a reasonably regular basis - topping up with compressed air.
John

 

[Burnerman]

Hadn't thought about that, was thinking of the wrong force

Would that be centripetal force then Petal? Sorry Peter?
John

 

[PJF220]

Nitrogen doesn't escape as quick so maintains pressure better... maybe so, but My classic car has maintained the same pressure for 6 years now on good old air, the company car gets nitrogen from quickfit as I have to take it there under contract, always seem to have to top up the tyres as I've banged the wheels about so much. Have to say that I just top them up with my own compressor so any 'benefit' is lost.

 

[FriedFreddy]

Fair enough, but I can see there will be a bit of disagreement here!
I get my tyres from a local independant guy - I'm not saying he is absolutely correct of course, but he has shown me some interesting stuff.
I took a punctured steel wheel in. He marked the tyre and rim position, took the tyre off and plugged it. Back on the rim, all balancing was the same. On the car - perfect.
Another wheel - balanced perfectly, showed 00 - 00.
Off the balancing machine, rotated 90 deg - showed 00 - 15. Rotated another 90 deg, showed 00 -00 again! Back on the car - alls perfect.
Puncture in almost new Pilot Premacy (500 miles). Hi Q insisted a new valve was fitted. Ok - I'm not bothered about a few quid. Did it really need one? I doubt it.
Fitted new Bridgestone 020 to a 168 bhp motorbike by a nationwide supplier / fitter. 2 year old tyre, worn out in 2500 miles. New valve? No. Nitrogen? Yes.
Costco Michelin outlet? Will only fit 2 new tyres to rear rims, because 'the car will definitely spin in the wet' FWD car? Thats debateable.
I'm not saying who's right and who's wrong at all here - just in the real world, everyone's out for what they can charge you for. i'm not interested in saving a few quid either - if the tyres are worn, then put new ones on.
Interesting discussion, I think?
John

If the tyre/rim was in perfect balance AFTER the combi plug was fitted it was obviously out of balance before as the combi weighs in @ 12g ! - either that or your fitter has the balancer set to show zero for anything under 20g (most balancers can be manually set to ignore up to a preset weight (we keep ours on 5g for the car machine and 1g for the bike machine))

There's also the obvious, checking the balance takes the same time/effort and use of the balancer as actually doing the balancing, most companies like to get paid for that work ! - I don't hear of many gas fitters coming out to check a customers boiler and saying 'thats allright love, there's nothing wrong with your boiler so no charge !!!!!!!

As for the puncture after 500 miles, how does the fitter/repairer know the valve was changed with the tyre, it's done regardless to cover themselves, if the valve is faulty and the repaired tyre goes down because of it and end up with run-flat damage you as the customer is going to go back and quite rightly jump up & down for a new tyre.

on the bike (@168 horses I assume a B/Bird or Busa or simular) I assume you are running a 180/55 or 190/50 rear (5.5 - 6.0mt rear rim), as a biker you should know the MASSIVE difference 2psi can make to handling, is it really worth risking dumping the machine on the blacktop for the sake of 1 - 2 quid, even at 5mph it will do for some plastic, bar end, peg/s, alloy engine cover etc (with a side panel you are looking at best bit of a grand) - at speed the cost rises dramatically for the bike repairs and then the rider injury's come into play as well.

Again on the bike, the valve should be replaced regardless, just in case someone has slimed/finilec'd the tyre (can easily clog the core up), though centrifugal force is not so important as with the exception of a few Harleys all bike valves come out the centre of the wheel and are fitted with ultra short TR412 valves (unless bolt-in valves (MS525 or Bridgeport Turrets) are fitted, even then the core should be changed just incase).

New tyres on a front wheel drive car should ALWAYS go on the rear, think about it, you have a heavy engine/gearbox up front giving good traction, at the rear you have hardly any weight (a light beam axle at best), making aquaplaning in the wet much more likely causing a rear end spin !