Tyres

[Iansmi1972]

Looking for a set of new tyres to fit my fiat 126 - 4-98 13 inch alloys. Don't know if it is best to get 165/55/r13 or smaller?

Helppppp anyone

[Bambino126]

How wide are the wheels you're running?

[Iansmi1972]

It has the old steel 12 inch rims just now but have bought a set of 13inch alloys for it but unsure whT tyres are best to get as I have read the 175 size I
Rubs the inner wing

[Pete126]

http://club126uk.co.uk/forum/index.php?topic=3287.0

[drcdb15]

How wide are the wheels you're running?

As Bambino asks, how wide are the new 13-inch rims? Any given width of rim will accept a fairly wide range of tyres of different widths, but the width of the tyre will to some extent determine the depth of the sidewall, and hence the rolling radius. If the rolling radius of the tyre-plus-rim varies by more than 2% from the original specified for the car you will need to think about recalibration of your speedometer in order to keep within MoT requirements.

As well as the practicalities of avoiding fouling of the bodywork by wider or taller tyres, there is also the issue of the hardness of the ride and changes to the steering geometry of the car, so what cosmetically looks quite cool might give handling that is anything but!

Few folks appreciate that the sidewall of the tyre is an integral part of the suspension system of the car, and you mess around with it at your peril.

If you reduce the height of the sidewall by fitting larger rims with skinny tyres, the shock loading of the wheel that was formerly absorbed by the flexing of the sidewall will instead be transmitted to some other part of the vehicle - bushes in the wishbones, bodywork where the shocks are mounted, and so on.

Generally the ride will get harder, and on a light car like the 126 it will get bouncier with poorer roadholding. And those parts now exposed to greater shock loadings will wear out faster.

Having said all that, there is of course scope for changes that will be cosmetically attractive whilst still being within acceptable engineering and legality limits. But before you can say what is possible, you need to know where you are starting from.

So we need to know what is the width rating of your new wheels?

[Bambino126]

The width will be written on the wheel somewhere followed by the letter J

I think you are confusing "width" with "diameter"....... We already know that they are 13 inch.

[drcdb15]

You may well not find a "J" marking, but if they're obviously car wheels I wouldn't worry too much about that. I *would* worry if you find some letter *other* than "J":

Here's why:

http://www.oponeo.co.uk/tyre-article/how-to-read-the-wheel-markings-the-size-collar-profile-and-cross-sectional-profile-of-the-wheel

Changing wheels, eh? I mean, how hard can it be? It's only 4 little nuts, and they're bound to be all the same standard size, aren't they....

You know, I can remember a time, many years ago, when I thought that. How wrong can you be ? !! 

[Iansmi1972]

My car is in Poland at my partners parents house. Trying to upload a pic from my phone but saying it is too large

[Iansmi1972]

The wheel width rim to rim is 16.5 cm any ideas on best tyre size? I need to buy locking wheel nuts aswell, anyone recommend any suppliers

[drcdb15]

Don't worry about wheel nuts until you've sorted out the wheels and tyres. You may need spacers on the hubs to get the tyres clear of the bodywork etc, and wheel nuts will have to be long enough to go through the spacers and still get enough thread into the hub. You also need to consider if you want wheel BOLTS or wheel STUDS. If you get bolts, you will need careful measuring and set up to be sure enough thread is going into the hub to secure the wheel. Bolts also make it more difficult to mount the wheel on the hub. Studs are screwed in first to the hub, so you are sure they are deep enough o be secure. They also aid wheel fitting as you can 'hang' the wheel on the studs and hold it in place with one hand while with the other you fiddle around trying to reach the nuts you left on the other side of the workshop... You can get locking versions of either from loads of places - Halfrauds, eBay, Amazon, Demon Tweeks is good but pricey.... You need to search around, but before you buy you'll need to know the thread size used on the Fiat hub. I can't recall off hand what the size is, but I know it's been posted on here somewhere. There at least two variants used by Fiat iirc, so you'll need to sort that out. And don't expect the supplier to know if you just cite your car model, they won't have a clue, you will need to spec the studs by diameter, length and thread pitch. Separate post for tyre size.

[drcdb15]

OK, tyres. Wheel sizes are invariably quoted in inches, so your 16.5cm is 6 1/2 inches, making your rims 13 x 6.5.

If we now go to

http://www.tyresizecalculator.com/tyre-wheel-calculators/tyre-size-for-rim-size-width-calculator

and feed in this size, we get a range of tyres you *could* in theory fit to this rim:

Tyre widths you can fit
to the rim width: 6.5"
Minimum
tyre width   185
Ideal
tyre width   195,
205
Maximum
tyre width   215
 
Tyres with
minimum tyre width
for wheel: 6.5x13
185/55R13
185/60R13
185/65R13
185/70R13
185/80R13
Tyres with
ideal tyre width
for wheel: 6.5x13
195/45R13
195/55R13
195/60R13
195/70R13
205/50R13
205/60R13
Tyres with
maximum tyre width
for wheel: 6.5x13
215/50R13

Now you need to see which of those possible tyre sizes is compatible with your original tyre size.

Information on OE Fiat tyres was always a bit hazy in my view. The standard usually quoted was "135 x 12" but this didn't tell you very much as the height of the sidewall is missing. However, I am going to assume that Axel Gerstl know what they're talking about and say that the "usual" standard 12" tyre sizes for Fiat are 135/80 x 12; 145/70 x 12 and 165/60 x 12. Of these, the 135/80 x 12 seems to be the most original "original" so we'll use that.

So now we go to the tyre comparison calculator

http://www.willtheyfit.com/

and feed in the original tyre size and the proposed new tyre size. Now the first calculator showed several different options, and you need to look at each one in turn. For convenience, I'm going to take the mid-range of the "ideal" recommendations, 195/60 x 13. I will also use 4" as the original wheel width and 6.5" as the proposed width.

If we do that, we get this (obviously it's best if you do this yourself and see the diagrams on that web site):

Compared to your existing wheel, this new wheel will have an inner rim which is 11.8mm closer to the suspension strut. The outer rim will poke out 51.8mm more than before.

and

Diameter    520.8mm    564.2mm
Circumference    1636.1mm    1772.5mm
Poke    10.8mm    62.6mm
Inset    90.8mm    102.6mm
Speedo error    0%    -7.69%
Reading at 30mph    30mph    27.69mph
Reading at 60mph    60mph    55.38mph
Ride height gain    0mm    21.7mm
Arch gap loss    0mm    21.7mm

among other helpful information. In the table above, the first column is the existing wheel, the second column is the proposed wheel.

As you can see, using this proposed wheel/tyre combination gives all sorts of headaches as regards the speedometer reading (now illegal) and clearance of the wheel arches and suspension parts.

You need to do this exercise for all of the possible tyre sizes that could be used on your new rims until you find a combination that is acceptable to you, taking into account any spacers you might be prepared to use and any bodywork mods you might be prepared to undertake.

I've used here two particular sizing calculators that I happen to like and am familiar with, but there are lots of others of a similar nature on the web, if you want to hunt around.

I hope you can see now why earlier in this thread we were asking to know the width of your new wheels. If as you said at the start a 175 wide (that is, 175 MILLIMETRES) tyre rubs the bodywork, then a wider tyre will be even more of a problem.

Just a note on dimensions - I said earlier that wheels sizes are quoted in INCHES. That is, radius and width are. The OFFSET of a wheel (or "ET" from the German) is in millimetres. For TYRES, it's even worse: the width of the tyre (eg "135") is in millimetres, the radius (eg "12") is in inches, and the "80" figure is a RATIO - it means (in this case) that the height of the sidewall is 80% of the width - so in this case 80% of 135mm is 108mm.

A 6 1/2 inch rim is pretty wide for a relatively small diameter wheel (having said that, I've got that for my CC Zero, but being a kit car the wheel arch/bodywork limitations are radically different)  and is more usually associated with 14" and 15" wheels unless you go to flared arches.

To avoid bodywork problems you will need to run a very narrow tyre, but on a very wide rim you will be at the limit of what is safe to use on that rim. You'll notice that for your new wheels, the narrowest "safe" tyre is 185mm. That's 10mm wider than a size you already know rubs on the body. So, it seems to me you are faced with either getting rid of the new wheels and buying something narrower (5 inches would be the obvious choice, I don't know if 4.5" are available) or making some fairly major changes to bodywork and/or suspension.

You can see now why I say to get the tyres sorted out before you worry about which wheel nuts to buy.

Good luck in finding a way forward, and sorry if my conclusion is not what you were hoping to hear.

[drcdb15]

Correction: in my previous post I used "radius" when of course I meant "diameter".

[drcdb15]

I see in reading through the thread that Pete126 linked to above a number of folks are using 5" wide 13" wheels, and even at that they report having to use spacers and or wide/modified arches to avoid the tyre rubbing on the bodywork. Really sorry, Ian, but I think your 6 1/2 inchers just aren't going to fly 

[Iansmi1972]

Many thanks guys absol gutted as the wheels I have bought in Poland state they fit the 126. Haven't tried any tyres and not sure if to try to get tyres at the 185 size or not

[drcdb15]

A quick Google shows a new budget 185/70 x 13 tyre will cost about £35, so a set of 4 will cost around £140.

When you get to a point like this, it's oh, SO tempting to think "if only I spend £X more on item Y everything will work out fine..." but sadly all that does is put you even more out of pocket, and even further from resolving your problems.

There's a lot of wisdom in the old saying, when you're in a hole, stop digging. So let's stop and assess where you are:

You have spent some money on a set of wheels. The wheels are fine, good condition, usable, saleable (I presume). The wheels don't suit your purpose, which (again I am assuming) is to fit wide alloys to unmodified Fiat 126 bodywork.
OK, that's where you are.

Now, where can you go from here? You have two basic options: you can either stop. Or you can go on. The question is: which of those two will get you nearer to achieving your objective?

If you go on, and buy 185 wide tyres, you will have spent a further £140, you will have four wheels which STILL don't suit your purpose, and you will have made the wheels LESS saleable. Why LESS saleable? As bare wheels, a buyer could fit whatever tyres he wants; as wheels fitted with tyres, the shipping costs will be higher, the price you ask will be higher (because you want to recoup the £140) and the buyer will be faced with either having YOUR choice of tyre on his wheels, or paying for perfectly good new tyres and then scrapping them so he can fit HIS choice of tyre to his new wheels.

If you stop, you can sell the wheels. You may not recover all what you spent on them, but even if you sell them all for only ONE PENNY you will have one penny more than you have now, plus you will have disposed of wheels that are no good to you. I suspect that you will easily sell a set of four perfectly good alloys for significantly more than one penny. And remember, by selling, you are gaining cash and losing a problem. So whatEVER you sell them for, you come out ahead. Don't get trapped by saying 'but I won't get back what I paid for them'. You won't get that money back whatever you do. That money is gone, sunk cost. Put it down to experience. And of course there is always the possibility that you may get back MORE than you paid. Unlikely, but you never know.

So, there's your choice - spend even more money, keep hold of your problem, and make what you have less saleable, or cut your losses, sell what you have for whatever you can get, and start again armed with more knowledge and more experience. Here's the question again: which of those two options will take you closer to achieving your objective?

When the seller said the wheels will fit a 126, he doubtless meant that a wheel drilling of 4 x 98 is the 126 size. But it's also a size used by much larger Fiats, as well as by many other Italian cars, like Lancia, Alfa Romeo, Seat and of course Lada. If you advertise as suitable for some of these models you will increase the chances of finding a buyer, and if you further promote that the use of PCD variation bolts (commonly known as wobble bolts) will allow safe fitting to 4x100 hubs (which it will) then you open up your market to all the 'north European' marques which use this size, which includes Ford, the French brands, Rover and many more - have a look at this page for more information:

http://www.carlsalter.com/all-wheel-fitments.html