Inner tubes have been used inside pneumatic tyres since the dawn of motoring, and decades later when radial ply tyres got invented, radials were also fitted with inner tubes. By the early 1950's there was a marketing drive to find ways to fit tyres without inner tubes, but realistically nothing much happened. This tubeless idea had become a possibility with the invention of the material Butyl by scientists at Standard Oil in the USA, towards the end of the war in 1943. Dunlop for example claimed they were working on this from the late 1940's and I am aware that for 1957 Dunlop did market a (cross ply) tubeless car tyre which they claimed had just "a slow rate of air loss", for fitting to normal car rims of up to 16 inch diameter, and they dedicated 8 pages in a pamphlet to the extra care needed, the difficulty in fitting and the different methods of doing this, finally with the whole tyre assembly needing to be placed in a bath of water to check for leaks at the bead area, and so on.

Observing original wheels that come into Blockley Tyre Co. for fitting and balancing, we have deduced that by around 1966 some wheel rim makers had started to modify their rims with the addition of safety ridges to the rim, enabling tubeless tyres to be fitted safely i.e. a tubeless compatible wheel rim. The ridges are for the tyre bead to pop over and be rigidly held in place, designed specifically for radial ply tubeless tyres, as we can see with the original Mercedes and Porsche wheels that come in. But this isn't across the board - even Alfa Romeos from the early 1970's we have fitted tyres to were still using the tube type rims. And unlike the Europeans, the Brits were a bit more conservative and car manufacturers kept going with cross ply (and therefore tube type tyres) well into the 1970's even though they often offered as an extra a radial tyre option, so the British motor industry lagged behind in adopting the wheel rims with safety ridges that allow for tubeless tyres to be fitted without having inner tubes in them.

So when should inner tubes be used? Unfortunately to answer this we have a bit more of a history lesson!

All cross ply type tyres need to be fitted with inner tubes, and in any case all cross ply tyres made today are tube type anyway, that have to be fitted with inner tubes irrespective of what wheels they are being fitted to. If you don't fit tubes, the air inside will gradually leak out through the sidewalls and after a few days (or a week at most) you will have a flat tyre. The same applies to the earlier radial ply tyres which were made at a time when all tyres were fitted with inner tubes, which is why for example the Blockley 165HR400 radial tyre needs to be fitted with inner tubes which we made as per original specification. Then there are a few Classic car radial tyres such as the Michelin X range which all need to be fitted with tubes (the tyre will have "tube type" written on the sidewall presumably). Then there are also some radial off road tyres that are tube type for reasons we can go into later. Other than that all radial tyres made today are tubeless type which means they will hold air without an inner tube fitted inside. Which means you do not have to fit an inner tube in a radial tubeless type tyre PROVIDING THAT they are being fitted to tubeless compatible rims! So as an example, if you fitted tubeless type tyres to an original wire wheel, the air would leak past the spoke heads so of course you have to fit an inner tube to keep the pressure in - irrespective of whether the tyre is tube type or tubeless type! Often the problem with a modern tyre fitting shop is that if a tyre has "Tubeless Type" written on the side they vehemently insist it has to be fitted without tubes," Tubeless tyres damage the tube, mate" and all the rest of it - and although well meaning, they are wrong. Also you might be surprised at how many tyre shops don’t know how to fit a tube in a tyre.

So it is fairly obvious that you have to fit an inner tube when fitting any tyre to an original wire wheel, but what about the ordinary steel (or sometimes alloy) wheels that are original equipment on a classic car? As a rule of thumb, you would fit an inner tube when fitting to a conventional wheel rim (that's anything pre 1966 at best, but could be pre mid 1970's is some cases), and not fit a tube if the wheel rim is the later type i.e. which has the safety ridges. Note that some examples of rims only had one safety ridge which makes these tubeless type too. The reason is that with the earlier tube type rim if you curbed a tyre this would push the tyre inward, so if you didn’t have a tube there would be an instant deflation, whereas if you had a tube fitted the deflation wouldn’t happen. That is the only reason for having the tube in the tube type rim when fitting a radial ply tubeless tyre. Hopefully that all seems fairly straightforward and sensible, but there is just a bit more to think about.

Another factor to consider is that as time has moved on the inner tubes available for Classic cars has become particularly garbage like in quality, really quite shocking in some cases, so relying on this dross to hold air while in use is just guaranteeing a miserable outcome, especially for those that like to give their cars some use - understand a fact which is that inner tubes for "Classic cars" (and tyres as well for that matter) are made for the benefit of the classic tyre wholesalers selling them, rather than for the benefit of the people paying for them! So on that basis although you should be using inner tubes in the situation they should be used in, you are actually better off running without them, and many quite sensibly don't, after having gone through the misery themselves! And that is why we make our own Blockley Superior inner tubes that are sized correctly (the size they fit is written on the tyre, no some code), super thick as they should be and made from the best material butyl, and so on, which means if you want to use inner tubes in a correct inner tube situation, you can use the Blockley tubes we make with full confidence. We use our tyres and tubes ourselves, and make tubes to supply with the tyres we make, so our customers (many of whom we know) can have a trouble free experience. And finally something to note is that there is no rule or law that we are aware of stating that you must use inner tubes with a tube type wheel rim when using a radial tubeless type tyre for safety, because when tubeless tyres were first introduced in the 1950's the rims were these same "tube type" design, so there is precedent. 

So to recap, Blockley recommends that you ought to fit Blockley tubes when fitting radial tubeless tyres to tube type rims (i.e. rims without the safety ridges) and no need to use them if the rims have the safety ridges. Sometimes you'll find some older alloy wheels on Maseratis or Alfas etc. have a tendency to be porous, and in these situations you can fit inner tubes, and many do. But when wanting to fit tubes to more modern tyres with leaky rims, remember that you cannot fit a tube in a tyre size less than seventy  (/70) profile, one reason being that no tubes exist with dimensions for these lower profile tyres.

Mention should now be made of the vast range of wire wheels supplied by MWS (Motor Wheel Services) for Classic car owners. Over a period of time they converted many of their wire wheels to be tubeless compatible, which was done with the addition of the safety ridges and covering the wheel well (and thus the spoke heads) with an air tight material. So these MWS wire wheels can be fitted with radial ply tubeless tyres without needing inner tubes, as stated by the manufacturer. The MWS website details all of their wheels and at what date they became tubeless type, but if unsure we can tell you if they are tube or tubeless type if you send in a picture of your wheel. It may be possible that after a number of tyre fittings that the rubber bead covering the spokes could get damaged and leak, but this would be a rare event if fittings are done by a competent fitter. In the rare occasion that this might happen a tube can be used. We have fitted many thousands of these wheels over the years at Blockley and never came across a problem. One of the larger classic tyre wholesalers is insistent that all wire wheels, including the MWS tubeless wheels, must all be fitted with inner tubes, but then their reason for existence is to sell stuff, which includes inner tubes, whether the customer needs them or not.