Technical Wheel rubbing, 500L, Fergat rims, 145 tyres

[Ant Knox]

Hi eveyone,
I'm new to the forum, and new to classic 500 ownership.
My 500L is fitted with Fergat 'Nuovi' rims and 145 tyres, but i'm getting quite bad rubbing on the rear arch lip on compression and speed bumps with only driver and one passenger.
Do I have a compatibility issue with this tyre/rim combo? Or is there any other things I should check and consider (like springs)?

 

[the hobbler]

145 tyres might be a little bit on the wide side, but a lot also depends on the 'off-set' of your wheels. It would worth while finding out what that measurement is before you do anything drastic. Is the car lowered? Do you have spacers between the drums and the wheels fitted?

 

[Ant Knox]

Thanks, I will check the offset. I'm not sure if there are spacers on the hubs, but they do appear to sit wider in the arches than the standard wheel setup. The suspension, as far as I can tell is standard, there aren't any markings on the springs that would suggest they are aftermarket.

 

[Toshi 975]

Now strangely enough I discovered that I have a set of these wheels in my garage that I never knew I had. They are also fitted with 145 tyres so it is not unknown although I have not tried them on a car but the rims were made for the 500. I have seen a few cars sporting these rims but don’t know what size tyres they had.

 

[the hobbler]

Or, David, were they made for a Mk1 '126' which might, being that the '126' fits larger tyres than the 500, have a bit more tyre/body clearance?

 

[Toshi 975]

Can’t remember for sure bu I think they were from a 500 collection. Yes they will fit the early 126 but I have never seen any fitted to 126 and they would have been an expensive accessory back in the day.

 

[Ant Knox]

I've only seen them on 500's, but they don't seem to be a common accessory.
Apparently mine were purchased for €1000 by the previous owner in Italy, though the arches suggest they were a problem from the very start! I was also told (though it wasn't verified, that they were an official (alledged) 'Abarth' accessory, but I am starting to doubt this. I was wondering whether the 126 (longer) bumpstops might help this issue?

 

[the hobbler]

The reason that I suggested that the wheels might be for a Mk1 '126' is that the 500 has 12in x 3-1/2in wheels with 125 section tyres---1 size up to a 135 section tyre seems to bring no problems.
The Mk1 '126' (same 190pcd wheel-bolt pattern) had, as original specifications, 4in x 12in wheels and 135 section tyres---1 size up on them is---145. That is my thinking behind wondering if the wheels/tyre combination was for a 126.
One last detail---are your 'Fergat' wheels aluminium or magnesium-alloy wheels? If they are 'mag-alloy' check their manufacture date. Mag-alloy wheels must NOT be used on track or road when they are over 50 years old--they can ONLY be used for display purposes. I have only got 9 more years on the Cromadora-Fergat wheels on my 695 replica (they were new in 1980).

 

[Ant Knox]

Thanks, this is all valuable information. The wheels are steel, and in very good condition. I suspect you are right in them being a 126 fitment, though i'd be keen to find out whether a 135 would also fit the rim, it would be a shame to loose them as they really suit the car.

 

[Ant Knox]

I've tried to attach an image, not sure it has worked!

 

[Ant Knox]

The car in the current setup!

 

[Bigvtwin996]

Big question......

Has anyone ever encountered a Fiat 500 where the rear end has been narrowed to accommodate sightly wider wheels.....

This may sound like a bit of over kill...
but I know it happens on a lot of other marques (particularly VWs) so as to retain the original body profile...

some tubular wishbones and shortened drive shafts!!

 

[the hobbler]

Far easier, and cheaper, to measure carefully and have wheels with more INSET.
Before any specific answer can be given as to whether 135 section tyres can be used safely, one needs to know the width of the wheel. When you have ascertained the wheel width (it should be stamped on it), I would suggest that you have a word with Dougal Cawley at "Longstone Tyres" and ask his advice. If the tryes on your wheels are brand new, and 135 tyres can be safely used, might be worth trying to come to "an arrangement"---any cost that you can save would be worthwhile.

 

[Ant Knox]

It doesn't appear the hubs have spacers fitted as the rim sits flush to the hub. Visually, it looks like these rims have a fair amount of negative offset though.

 

[Ant Knox]

The rim itself is stamped with 400(b?)x12, which i'm struggling to translate into modern tyre terms, even with the helps of Longstone Tyres very informative website!

 

[Toshi 975]

The rim itself is stamped with 400(b?)x12, which i'm struggling to translate into modern tyre terms, even with the helps of Longstone Tyres very informative website!

Wheel rim sizes are still measured in inches so the 4.00 refers to the rim width and 12 is the rim diameter. More modern tyres use metric measurements for the tyre width , 125, 135, 145 and so on but still use inch sizes for the bead that mates with the rim.
Standard 500 tyres are 125 x 12 on the 3.5” wide rims. Standard 126 tyres are 135 x 12 on the 4” wide rims.

 

[Dougal Cawley]

Hi

Do you have 145R12 tyres fitted?

or are they 145/70R12?

I am under the impression that a 145/70R12 should fit. It is actually a mini tyre, but correct me if i'm wrong but i think a 145/70R12 would fit (assuming the wheels are right) where a full profile 145R12 (or 145/80R12 if you like) would be too big.

Pirelli have now made a few 145/70R12 Pirelli Cinturato CN54.

https://www.longstonetyres.co.uk/classic-car-tyres/fiat/500.html

I list it on here as i beleive it is an option.

a 145/70R12 like a 125R12 can fit inner tubes if your wheel rim determins you should.

400B12 rim means it is 4 inches (101.6mm) wide to fit 12 inch tyres. the B is i think descriptive of the shape of the profile of the rim, proper tyre nerd stuff. width and diameter are what really count when determining what tyre you can fit.

the proper 125R12 tyre has a recomended rim width of 3"-4"

a 145R12 or a 145/70R12 have recomended rim width of 3.5"-5"

However a 145R12 is over 1 1/4" taller than a 125R12 or a 145/70R12.

We are currently out of the black wall 125R12 Pirelli Cinturato CN54 but we are expecting more in soon.

However i beleive Ricambio still have stock https://www.ricambio.co.uk/tyre-pirelli-cinturato-(125sr12)-classic-fiat-500

 

[the hobbler]

Your 'Fergat' wheels are so nice that if they were mine, with the information that Dougal Cawley has just given,I would get a pair of 145/70R12 tyres and see how they work. If all is OK, complete the set and revert to using the 'Fergat' wheels

 

[Ant Knox]

Thanks, this is very useful info! I do like the Fergats a lot, they are listed for sale at the moment, though i'm not desperately keen on selling them if I can find a solution.

 

[Ant Knox]

Hi

Do you have 145R12 tyres fitted?

or are they 145/70R12?

I am under the impression that a 145/70R12 should fit. It is actually a mini tyre, but correct me if i'm wrong but i think a 145/70R12 would fit (assuming the wheels are right) where a full profile 145R12 (or 145/80R12 if you like) would be too big.

Pirelli have now made a few 145/70R12 Pirelli Cinturato CN54.

https://www.longstonetyres.co.uk/classic-car-tyres/fiat/500.html

I list it on here as i beleive it is an option.

a 145/70R12 like a 125R12 can fit inner tubes if your wheel rim determins you should.

400B12 rim means it is 4 inches (101.6mm) wide to fit 12 inch tyres. the B is i think descriptive of the shape of the profile of the rim, proper tyre nerd stuff. width and diameter are what really count when determining what tyre you can fit.

the proper 125R12 tyre has a recomended rim width of 3"-4"

a 145R12 or a 145/70R12 have recomended rim width of 3.5"-5"

However a 145R12 is over 1 1/4" taller than a 125R12 or a 145/70R12.

We are currently out of the black wall 125R12 Pirelli Cinturato CN54 but we are expecting more in soon.

However i beleive Ricambio still have stock https://www.ricambio.co.uk/tyre-pirelli-cinturato-(125sr12)-classic-fiat-500

Unfortunately, I have the 70R12's fitted, it would seem the tyre width is the problem here, rather than the height.