New tyres, old wheels.

[Mike Stevens]

I've had steels and more recently 'S' alloys on all the Triumphs from 1974 including Mk1s, Mk2s, Stag, Dolomite, GT6 etc, mostly tubeless with no problems at all.

It's the 'company policy' that seems to be the issue. I suspect it's all about avoiding any legal comeback if there is a problem later. What a shame.

I have also on occasion had tubes fitted, sometimes due to a tyre or rim problem and once when I got some tubed tyres 'cheap'! Again no problem.

Cheers,
Mike.

[Addiston]

Can't comment on the design of the wheels, but I've had problems over the years both with and without tubes. A good number of years ago with my first S, the force exterted on the front tyre when manouevring on full lock into my folks' garage caused the caused it to suddenly deflate. I suspect this was because the seal between tyre and rim was broken (and given the then state of the S alloys I suspect it was the paint on the inside of the rim which let go from the rim). So perhaps with dubious alloys, a tube is a good idea, which is what I did till I could afford to refurbish them properly.

More recently returning from a show, one of the back tyres lost pressure very quickly. It was fitted with a tube and was on a set of wheels refurbished in the early 90's for the first 'S', but little used. The air leakage was such that a garage air pump had no effect. Subsequent investigation showed the tube had worn against a small rib inside the tyre, causing in to give way with little warning. What was more annoying was having to break out the never before used spare and jack - and watch the paint flake off the screw of the jack as it was forced into use for the first time in 35 years....

I've now had the tubes removed entirely to avoid a repeat performance.

[Clifford Pope]

A big advantage of tubes is that you can fit them yourself and inflate with an ordinary pump.

There are vintage tyre and tube suppliers on the internet that stock any size.
Don't let a garage use that gloopy soap stuff for lubrication - it dies out and then tubes do indeed rub on the ribs inside tubeless covers. Use copious talcum powder. It has dry lubricating properties and stays effective indefinitely.

Watch the fitter and make sure he really knows how to fit tubes. It is important to partly inflate, then deflate again to let the tube adopt an unstrained position, then fully inflate. Also cleanliness is much more critical than when fitting a tubeless cover. A spec of grit trapped between the tube and cover can rub and create a hole.

Tubes have different valve offsets - you need the right one for the wheel.

[tony]

Wondering why you're trying to re invent the wheel (no pun intended) All of our cars had tubeless tyres when new. I worked for a while years ago doing tyres. We always cleaned the bead area, with a wire brush if necessary and had no sealing problems.
Tubes are surely obsolete in this age
Tony.

[Clifford Pope]

I'm not arguing in favour of tubes, I'm just pointing out there are some basic precautions to be taken if you want them to work. And they do have one or two advantages.

[Charles H]

I carry a couple of tubes in the rally car. I can put a tube into a tyre with basic tools, but not fix a hole!

[David Withers]

I recall similar discussions 50 years ago, when tubeless tyres were becoming popular. The tyre companies' instruction was never to fit tubes to tubeless tyres as the self-sealing properties would then be lost.

With a tube in a tubeless tyre, a puncture from a nail, screw or suchlike is almost certain to let air escape between tube and tyre and to exit via the gap around the tube's valve. This can cause rapid deflation leading to possible loss of control, particularly if it happens when cornering or braking.

A similar puncture in a tubeless tyre will give a much slower deflation, and the partial reduction in pressure can normally be felt or seen in good time.

[Alec]

Hello David,

"This can cause rapid deflation leading to possible loss of control,"

That reminds me of a test that Anthony Crook, the boss of Bristol Car company used to do to demonstrate the inherent stability of his cars. They rigged up a gun that shot into the front tyre, and Mr Crook drove at 100 mph and fired the gun! Do modern manufacturers, or tyre companies do similar tests I wonder?

Alec

[Clifford Pope]

to let air escape between tube and tyre and to exit via the gap around the tube's valve. .

That's a good point, but I don't think there is supposed to be a gap.
Valves and tubes come in different sizes, perhaps hard to find now. I have had quite a few vehicles dating back to 1947 (the vehicles, not me), and I am aware of two different sizes of hole, with corresponding thickness of valve tube. The valve is meant to be a tight fit in the wheel.

I have just restored a 1949 German ex-army trailer. It had it's original tubed tyres, large holes for the valves, and the valves were correspondingly much thicker than common later types, but interestingly used on earlier VWs.
My series LandRover by contrast has tubes with smaller valve diameters corresponding to smaller holes in the wheels. These have to have tubes because they lack the necessary rim bead, and are rivetted not welded so are not necessarily airtight.

I suspect that a lot of specialist knowledge has been lost over the years as tubeless tyres have become standard, so perhaps recorded instances of failure of tubed tyres result as much from ignorant fitting or mismatch of components as fundamental weakness of principle?

I do know from experience that it is inadvisable to use tubeless tyres on a 4-wheel trailer. Once when doing a tight turn a tyre on my boat trailer suddenly deflated. The tyre had momentarilly pulled away from the bead instead of scrubbing on the road. A tube would have stayed inflated.
Similarly I have read it is better to fit tubes on serious off-road vehicles.

However I would only now use a tube in a modern wheel with caution, as a stopgap to do a home-repair.

[David Withers]

Cliff, I'm not an expert... but will carry on pretending I am!

The valve stem on a tube may be a close fit but I doubt if it is always an air-tight fit. The holes in tubeless-type wheels may not even be the same diameter as in tubed-type wheels.

I searched briefly for an answer via Bing and found a prominent notice on the National Tyres website saying: "NEVER FIT AN INNER TUBE WITH A TUBELESS TYRE EXCEPT ON A TUBE TYPE WHEEL". Unfortunately they don't explain why, but it may relate to the valve hole diameter. I'd have no worry about doing this purely as a 'get you home' measure, as you said, but no more than that.

Regarding air escaping between the tube and the tyre, I've noticed on wheelbarrow wheels that when a punctured tyre has been pumped up as a temporary fix, air can be detected exiting past the valve as the tyre goes down again. It would probably be the same with a Triumph wheel, but I've never run one with a tube to find out!