Mismatched innertube mystery

Poita · Two Stroke Sniffer Joined: 24 Jun 2021 Karma :

I have a bike that is a bit of a Frankenstein, just a knockabout push iron.

About six months ago, I got a flat so checked the info on the tire and bought an innertube replacement online.
When I went to fit it, I found there was overlap as you can see in the photo.
I squished it in, pumped up the tire and within a day I had a flat again.

Fool that I am, I forgot to check the tire for the cause of the flat and found a piece of wire still lodged in and removed it.

I bought a new innertube according to the info on the tire but again it had the same overlap.

It worked ok for six months but now I have a flat again and thought I'd better check here as it seems I'm buying innertubes that are too large for the tire/wheel.

Would be grateful for any insights as to where I'm going wrong.
I have also posted the two innertube purchases that I made which were too large.

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

Looks like the correct tube for the tyre. I think you're fitting it wrong.

One bead on. Insert partially inflated tube (so it's round) into the tyre, valve through hole but NOT fixed down, it's ok to put the nut on the end so it doesn't fall out. Mount the second bead. Then inflate, pushing the valve stem up into the tyre as you do so so it doesn't get trapped under the bead.

I just leave the nut off the valve stem, it serves no useful purpose and can cause the tube to tear round the valve more easily if pressure is low.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

jaffa90 · World Chat Champion Joined: 06 Apr 2016 Karma :

The tyre and the tube size match but what size is the rim?
https://www.youtube.com/watch?v=fNO3o2JVMTo

Nobby the Bastard · Harley Gaydar Joined: 16 Aug 2013 Karma :

Well, as the tyre wwasn''t falling of the rim before the puncture....
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050