Technical Tubeless / Tube tire question.

[jjacob]

The standard steel wheels on 500's came with tube type tires (or tyres for you "English" types ). Is it the wheel that requires tube tires, or is it the tire?
Could tubeless tires be installed on the standard steel wheels (with the proper tubeless valve), or do you have to get wheels that are tubeless.

My gut tells me that it is the tire not the wheel that determines the need for a tube, and that tubeless tires can be mounted on the original steel wheels.

Thanks,
John

 

[Bambino]

John,
This is my understanding of the wheels/ty(i)res stuff, and, as usual, I'm willing to be corrected if wrong -

In the old days of spoked wheels pneumatic tyres needed tubes because the wheels (and tyres) were not air proof. However because of the double layer of rubber, tubed tyres were not very efficient at transferring the heat generated within the tyre out through the sidewall. This was not much of a problem at low speed but as road speeds rose there was a need for tyres to transmit more heat much more efficiently. Along came tubeless tyres and with them better rims boasting a complete air seal and good heat transfer.

Unfortunately, when partially or completely deflated, tubeless tyres had a tendency to peel off the rim under cornering forces as the bead separated from the inside of the metal rim.

So better beads and the concept of safety rims came along. Safety rims have either a circumferential hump or groove on each side of the inner part of the rim to help retain the bead when the tyre is partially inflated- couple of photos attached.

Today's tyres are very well made and as long as they are kept optimally inflated, will be safe up to their designated speed maxima on any undamaged rim. If you feel as though you must fit a tube to a tubeless tyre for reasons of 'safety', be aware that you will significantly lower the maximum speed at which the tyre can be run for reasons of heat generation and transfer. Personally, I would never tube a tubeless tyre as it may invalidate the manufacturers warranty.

My car has standard steel 126 rims and is fitted with tubeless 145R12 radial tyres. They are inflated to the correct pressures. The tyre fitter is happy, the insurance company is happy, I'm happy and all is good. However, you should check with your local authorities and tyre fitters as life may be different where you live.

Hope this helps,
Chris

PS: Rim profiles (eg: J, JJ, B, D etc.) are a black art for me and I have no comprehension of the meaning or significance of the letters stamped on the inside of the wheels.

 

[jjacob]

Thanks Chris for the usual good informaton. Am I correct in assuming that the standard 125SR12 tire that origninally came on the 500, and is the same tire you can still buy today, must have a tube? Or did they tube them because the wheels did not have the safety rims?
I am not too concerned about heat transferance at high speed as my car will most likely never be driven faster than 70 mph (after engine mods of course!).
John

 

[Bambino]

John,

I'm not sure. I'm away from home at present and can't get access to any of my reference material so will have to find out for you when I get home on Saturday.

When I bought my 500 it was fitted with standard 500 wheels shod with very old and badly worn 125R12 tyres. I had the tyres professionally removed but wasn't present to see if they were tubed or not. I gave away the 'round' wheels/rims, threw away the 'elliptical' ones and ultimately converted my car to standard steel 126 wheels fitted with tubeless 145R12 tyres. Because I couldn't fit a 145 profile tyre in my spare wheel bay, I had a tubeless 125R12 tyre fitted to that rim so I know that tubeless 125s are available, or at least they were in Oz about 2 years ago when I did this.

Ultimately I guess, factory branding of the tyre as either 'tube' or 'tubeless' will direct your decision.

Let us know how you get on as I think this will be of interest to a lot of the list members, particularly as 125s get rarer and we are forced into using wider tyres on our standard rims.

Chris

 

[Toshi 975]

Tire , that is something us old fellers do after a good lunch and a couple of beers
Like Chris I am no expert but I did work as a tyre fitter way back when I was a student. With tubed tyres the bead of the tyre would act as a location on the rim, rather than a seal, to ensure concentricity. Tubeless locate & seal , kind of "lock & load". There was no need for a very tight fit , tyre to rim , on tubed tyres because of the "seal" of the tube but I well remember ripping tubless tyres off Morris Minor rims (should be tubed) on fast corners. Best thing is to either go with the original or find a tyre/tire man who knows what he is talking about. I took some Cromadora 13 x 5J wheels to have new tyres fitted recently . 4 had tubless tyres that were inflated & 1 had a tube. When they stripped the old tyres the guys told me that the rims were for tubed tyres. One other point is that tubed tyres were relativley smooth on the inner face and most tubless tyres have ridges which may cause excess wear on the inner tube leading to a blow out

 

[lilgreencar]

When I got my 500, it was in need of new tyres and rims. I ordered 5 new stock 500 rims and 5 new 135 tyres (tubeless type). The tyre man at the shop I took it to tried mounting the new tyres to the new rims but the combination would not hold air. He said the rims are not sealed and we needed to add tubes to get the whole setup to stay inflated.

As Toshi mentioned, the inside of the tubeless type tyres have ridges and imperfections that kept tearing the tubes, causing me to have to limp back to the tyre store. Eventually the very understanding chap at the tyre shop was able grind all of the imperfections and ridges down from the inside of the tyres and I've been driving around flat-free for a couple of years now...

Hope that helps!
lgc

 

[JumpJet]

Resurrecting a long-dead thread, but I was wondering if anyone was aware of original-style wheels made to support modern, tubeless radials. I'm planning out my restoration in the near future and I'm thinking of keeping the wheels original looking, but debating some tire updates.

Anyone? Thanks in advance.

 

[the hobbler]

having been in the motor-trade since the start of my apprenticeship, I have always been taught that "for tubed tyres" rims are different from "for tubeless tyres" rims. When I did my apprenticeship (on M/benz cars) all the apprentices had to spend 6 weeks in all the different departments, which included the break-down/tyre fitting section---and in 2-1/2 years ( I had to change branches due to my parents house move) I spent my 'time in the breakdown/tyre section 3 times---I learnt quite a lot regarding fitting & balancing tyres and wheels. The photos from Chris (Bambino) clearly illustrate the difference in the 2 styles of wheel. The "tubed" rim does not have the beading-retaining 'hump' that the "tubeless" rim has. There is a chance that a 'tubeless' tyre when on a 'tubed' wheel could roll off when cornering, not a scenario one wants to experience. If you fit a tube into a tyre that has been fitted onto a 'tubeless' rim, there is a danger that the bead-holding 'hump' will damage the tube. My advice is:-- if you fit an original style "tubed-tyre" wheel, fit a tubed tyre

 

[fiat500]

Resurrecting a long-dead thread, but I was wondering if anyone was aware of original-style wheels made to support modern, tubeless radials. I'm planning out my restoration in the near future and I'm thinking of keeping the wheels original looking, but debating some tire updates.

Anyone? Thanks in advance.

I doubt that you'll get exactly what you describe. You've probably seen the sorts of wheel available which are suited to tubeless tyre and although I love the originals I could bear the style of these ones which are designed for tubeless.

https://webshop.fiat500126.com/en/t...m-cd30-45-x-12-_pitch-circle-190_-offset-27mm

I have original wheels in which the tyres on all but one of them have tubes fitted inside them. I think the Cinturatos will be suited to tubes but I'm not so sure that is ideal in the case of the more recent 135/12 tyre I fitted. But as tyre factors are usually stumped by requests to supply the original sized tyres I have found it easier to simply obtain and fit them myself. This necessitates the use of tubes in any case.

But most pertinent to your question, when I had a serious puncture on a tour which took me hundreds of miles from home, I was unable to find any tyre fitting company that was prepared to fit my tubed tyre even when the tube was supplied as a brand-new item from me. Eventually I found a very helpful bunch of guys at a national chain of tyre-fitting specialists who suggested that they repair the tyre as a tubeless. they did this and with no official charge to me because the computer had no input code to cover the repair. (Some shiny loose-change was transferred )

As a spare I thought this did no harm but within a few weeks, another puncture rendered this spare as an operational wheel.

Now, over twelve months later, the tyre is still in use, has the best air-retention properties of the whole set, and gives no indication of any intention to fail me. The tyre is on the front axle and is consequently inflated to a relatively low pressure.

I'm sure that it is very unwise to run a car with the one wheel without a tube; to run with four of them might be inviting trouble. I would previously have been very firm about the wisdom of this. But if I had the facilities to fit or repair a tyre myself, without the use of a tube, it's definitely what I would do although I regularly drive at 60mph+.

 

[JumpJet]

If you fit a tube into a tyre that has been fitted onto a 'tubeless' rim, there is a danger that the bead-holding 'hump' will damage the tube. My advice is:-- if you fit an original style "tubed-tyre" wheel, fit a tubed tyre

I'm tracking and don't disagree with you. Just looking to see if anyone makes wheels that, from the outside, look identical to the original tube-supporting wheels, but inside, have all the proper grooves/beads to support modern tubeless radials. Granted, that's a very niche demand, so I'm not holding out too much hope, but it never hurts to ask.

 

[Bigvtwin996]

whilst I don't disagree that many "modern" wheels have the "super safety" bead.... none of the steel wheels I have that are tubeless for other cars nor the alloy wheels have this bead...
I always thought it was the shape and height of the edge of the rim that defined if a wheel was for tubeless or tubed tyres....
I the case of my lotus experience where cars were regularly run at over 00 mph.. I have a set of Original Dunlop SP Sports (now only for show use) and they are technically Tubeless but Lots wheels were never 100% leak free due to the riveted construction so were fitted with tubes from the factory....
New replacement wheels are made and are advertised as tubeless and this I believe is because they are welded construction rather than riveted...
Having changed a few tyres by Hand without a machine just using levers I know it is much harder to get a tyre onto a modern rim rather than an older one where a tubed tyre was fitted... so I would suggest that possibly the actual internal diameter of a tubeless tyre may be different to provide a better seal...
or even the rim diameter may be slightly different... this may ony be a few mm but it makes a hell of a difference changing a tyre...
Try breaking the bead of a flat tyre n a modern tubeless steel wheel... it takes some effort, but a tubed tyre it easy...


just my personal experiences...

 

[lazylobster]

I’m no expert and others have posted with far more knowledge than I.

However. All I will say is that I would not take the chance. The tyres, wheels and brakes are the most important aspect of any car. The interface to the road etc.

Like the OP, I really like my original L wheels. If I could find a set that are 4.5 inch and supporting tubeless tyres then happy days. But no rush. I can wait. Others have mentioned steel banding, but I’m not too into that look.

Rob

 

[Bigvtwin996]

Tyres....
Well I had a nice conversation with Tom Homan at Longstone tyres.... they know a bit about Classic wheels and tyres... and some info I found when looking up some Borrani wheels for someone...

this refers to steel wheels:

A modern tubeless wheel will have a safety bump on the inside of the wheels often on both sides, a tube type wheel tends not too. (some very early tubeless wheels didn’t have safety bumps but had a larger bead)

The Fiat 500 any many others have a wheel rim with a centre riveted/welded in there for making them porous as technology then wasn’t what it is now, also running full profile tyres to give better suspension and comfort.

The tube thing has been lost in translation over the years however, you cannot put a tube in a tyre that is lower than 70 profile, for example a 125x12 (full/80 profile) a tube is fine, a 205/55x16 you cannot run an inner tube. A quality inner tube of the right size fitted correctly, will cause no problems and give no reason for any issues. You can run an inner tube in a tubeless tyre as long as it fits the above criteria IE 70 profile or above.

There is no modification needed to a tubed tyre to be fitted with an inner tube

As you can imagine in our classic market that is an awful lot of vehicles from Edwardian to 2CV and everything inbetween, You have to run an inner tube in a wire wheel.

Borrani wheels were obviously fitted with tubes and such cars travelled well in excess of 100mph, and those of more senior years will recall F1 cars with wire wheels...

 

[Toshi 975]

I guess that when the Fiat 500 was designed tubeless technology did not exist at least on production cars. Also part of the design brief would have been to keep things light and the 500 rims are a fairly light gauge of metal compared to many and can easily get bent out of shape if bashed. If tubeless tyres are fitted to non tubeless rims and the tyre pressure drops they can get dragged off the rims on cornering. The tubeless tyre relies on the rim integrity to square the circle when pressurised with an outward force on the bead where a tube will spread the load between the tyre and inner rim, will run to almost dead flat before the tyre leaves the rim and punctures can be repaired by the roadside just like a bicycle.

 

[JumpJet]

What are you guys using for tire spoons - or whatever they are called across the pond - the tools used to slip the tires over the wheel lip? All the ones I see online look like they'd wreck the paint finish of the wheel, but I doubt plastic ones (like bikes use) would take the forces of a car tire change.

Short of balancing, it looks like this could be a relatively easy roadside repair assuming I have the right tool(s). I already threw a bottle of tire slime in the car, but for larger issues a new tube might be required.

 

[Bigvtwin996]

What are you guys using for tire spoons - or whatever they are called across the pond - ...................................

............................... I already threw a bottle of tire slime in the car, but for larger issues a new tube might be required.

When I have put tubed tyres on rims... I tend to try to do it without any levers...
if you can get the wheel secure then lots of tyre soap... and brut force...
the first side will go on fairly easily... and after a few tries you will learn how to position the tyre bead in the middle of the wheel so as to allow the tyre on more easily..
(you can always practice with an old tyre and wheel and no tube)

only the last little bit you may need a lever, you can protect the rim with a little flap of rubber sheet where you need to use a lever..as you can take it out afterwards....

Always ensure when the tyre is on that the tube is not trapped when you blow it up... checking all the time as a single "pinch" will probably cut the tube...

Slime/foam is if no use in a tubed tyre... the tube is too thin for it to have any effect as will deflate quickly, they only work in tubeless tyres because the structure of the tyre maintains it's shape so the hole is more easily "plugged".

 

[fiat500]

When I have put tubed tyres on rims... I tend to try to do it without any levers...

Heck...you must have strong hands.

I use a couple of long, steel tyre levers and work from the back of the rim to reduce obvious paint damage. But I repaint the weels every couple of years when they start going rusty.....the paint does get slightly damaged.

You describe the knack of changing tyres well; This morning, I've just put two new tyres on the back wheels; thus removing my one and only tubeless tyre which served me well for eighteen months.

 

[JumpJet]

Slime/foam is if no use in a tubed tyre... the tube is too thin for it to have any effect as will deflate quickly, they only work in tubeless tyres because the structure of the tyre maintains it's shape so the hole is more easily "plugged".

They make slime for tubed tires. Here in the states it's available at bike shops and most auto parts stores, heck most of the local bike shops stopped carrying it because so many of the tubes come with it from the factory. There is a different compound for tubeless tires, but plenty of things still use tubes.

Amazon.com: Slime 10003 Tube Sealant, 8 oz.: Sports & Outdoors

While I'd agree that lots of soapy water would be best, I'm just thinking of a more comprehensive roadside repair kit. Throw in some spoons and if the slime isn't enough, a spare tube can be swapped in.

 

[Bigvtwin996]

They make slime for tubed tires......

Amazon.com: Slime 10003 Tube Sealant, 8 oz.: Sports & Outdoors
, ........

That is Slime for Push bike and Motorcycle tyres.... I wouldn't rely on it in a car tyre...

 

[Bigvtwin996]

Heck...you must have strong hands.
....................................

My mates dad was an old school tyre fitter... long before all these machines were about... he would always buy tyres and fit them himself...

I remember him showing us with a piece of string as to why you can fit a tyre with a bead that is smaller than the rim...
He simply took a piece of string and tied it around the rim bead (effectively the same as the bead of the tyre)...... then he simply showed how the sting could be pushed over the actual rim with ease...

his sort of magic trick...