Can I run tubes in a tubeless tyre?

In theory yes you can.

However there are clear cases when you shouldn’t.

Anything Z rated we would never run a tube. That means 120/70 ZR17 fronts or 180/55 ZR17 rears for example – the sort of stuff you see on the average road bike. The reason being that while a tube could fit, the power of the bike coupled with the rim that isn’t designed for a tube is asking for the tube to get pulled around on the rim and fail. On a typical Japanese bike the valves are 11.3mm and a tube’s valve is 8.3mm so immediately you’ll have play around the valve which could also cause it to slip and fail.

When you can run a tube

The only reason to put a tube in a tubeless tyre is to get you out of a hole, for example if you have a puncture but no way of repairing it or you can’t fit a new tyre because the shop doesn’t have one, then a tube will solve the problem. Albeit temporarily.

If you get a puncture on a tubed wheel, 99% of the time it will go down immediately and so while a tube will solve the immediate issue, if it gets a puncture you’re properly stuck and possibly at great risk.

The risk vs reward

The ZX-10R puncture in France scenario

Let’s say you’re on a ZX-10R in the middle of France, you have a puncture you can’t fix it and the only thing the local mechanic has is a 17″ tube then yes, that would get you out of a hole but you would have to ride the bike so slowly and gently as to not cause the tube to fail. Anything over 40mph and you’re putting yourself at risk as if the tube fails the tyre will deflate immediately as in BANG and all pressure lost.

Whereas with a normal puncture on a tyre you’ll get a bit of time to feel and deal with the issue.

The SH300 in the city scenario

If you’re running a smaller bike like a Honda SH300 where power isn’t excessive, fitting a tube to get you out of a hole is less of risk as the bike probably won’t have the power to tear the tube on the rim. However all the same cautions mentioned above still apply.

The KTM 1290 Adventure trail scenario

We read a thread on a forum where a road rider wanted to ride on the trails with low pressures in his tyres. The tyres weren’t designed to run low pressures, so the forum suggested he fit tubes to compensate, with the logic being that when the tyre ran low pressures it was susceptible to popping off the rim and then losing all pressure, which the tube would insure against.

This has some merit, however if you are running a tyre below the recommended pressures the chances are that tyre could fail as the sidewall will be generating a lot of heat, plus the chances are this super low pressure (say, 18psi) will just make you liable to getting a pinch flat in your tube. Double disaster.

The better option would be to run a tyre mousse which although not road legal, would do the job better than running a tube and low pressures.

In summary

So it’s a rare scenario where fitting a tube to a tubeless rim makes sense. Exercise caution.