Whatever happened to tyre security bolts?
Discussion
One for the oldies maybe. The changing tyre thread reminded me of a time when bikes had tyre security bolts on the rear wheel, so as well as the valve stem poking through the rim there were security bolts. These were like large metal 'Pringles' shaped things, covered in rubber with a bolt attached. The 'Pringles' thing went inside the tyre beneath the inner tube and clamped the tyre to the rim with a bolt through the rim - just made changing tyres an even bigger pain in the ass.
Of course the bigging-it-up talk down the pub was 'my Commando has TWO security bolts, otherwise with so much torque it would spin the wheel inside the tyre and rip the valve stem off'. ...or at least that's what we thought, as bikes came with them as standard.
In time we moved to tubeless and/or cast wheels, and I kind of assumed that this made more grip between the tyre and the rim. But the Indian has spoked wheels and inner tubes, and is making maybe 3 times the torque and weighs twice as much - but no security bolts. I don't think any of the other modern spoked-wheel bikes run them either now.
So were we all fed some big lie in the 60s/70s that we had to bolt our tyres to the rims, or have tyres and/or rims changed in some way such that they were once necessary but now aren't?
I secretly liked the tale that my bike had so much power (60HP out a Commando IIRC!) that it would rip the tyre off without security bolts.
Of course the bigging-it-up talk down the pub was 'my Commando has TWO security bolts, otherwise with so much torque it would spin the wheel inside the tyre and rip the valve stem off'. ...or at least that's what we thought, as bikes came with them as standard.
In time we moved to tubeless and/or cast wheels, and I kind of assumed that this made more grip between the tyre and the rim. But the Indian has spoked wheels and inner tubes, and is making maybe 3 times the torque and weighs twice as much - but no security bolts. I don't think any of the other modern spoked-wheel bikes run them either now.
So were we all fed some big lie in the 60s/70s that we had to bolt our tyres to the rims, or have tyres and/or rims changed in some way such that they were once necessary but now aren't?
I secretly liked the tale that my bike had so much power (60HP out a Commando IIRC!) that it would rip the tyre off without security bolts.
catso said:
bimsb6 said:
Surely once tyres moved to tubeless they became redundant ?
Indeed, even if your tubeless tyre does move a little on the wheel it's not going to deflate.Last one I saw was on my old KTM MX bike, as mentioned a few posts above running low pressures with a tubed tyre...
and yes, I think my old Z900 had them too, so still felt necessary in '76.Oh yeah, rimlocks. I believe advancements in rubber compounds, and tubeless tyres exerting pressure, made the gum chafer stick to the rim flange so well that rimlocks were made redundant. And you don't have the valve appearing at an odd angle (or ripping itself out) when the tyre slips an inch taking the tube with it, whereas nowadays the (tubeless) tyre could move half way round the rim and all it does is throw the wheel marginally out of balance and you'd only know as the dot has moved....!
Edited by rodericb on Tuesday 24th April 12:39
tvrolet said:
Yea, but there are still quite a few current bikes (mostly retros admittedly) with spoked wheels running tubed tyres. So I've no problem with the tubeless argument for not needing them; that was my thought when I did my first tyre swap years ago on a tubeless tyre/cast wheel. I'm just wondering why the hell we thought we needed them in the 60s/70s when it's pretty clear now we don't on a spoked rim/tubed tyre...unless something else has changed that I'm not aware of.
and yes, I think my old Z900 had them too, so still felt necessary in '76.
What current bikes have tubed tyres ? and yes, I think my old Z900 had them too, so still felt necessary in '76.My old Guzzi has tubes and no rimlocks. Now it's not a very powerful bike but probably at least as powerful as some that were fitted with them back in the day?
That said the rough cast finish on the wheels is an absolute bastid to fit tyres onto as they stick like s
t to a blanket and so I very much doubt they'd slip even if it had an extra 100hp and certainly less so than a smooth chrome plated or alloy spoked wheel...
That said the rough cast finish on the wheels is an absolute bastid to fit tyres onto as they stick like s
t to a blanket and so I very much doubt they'd slip even if it had an extra 100hp and certainly less so than a smooth chrome plated or alloy spoked wheel...bimsb6 said:
What current bikes have tubed tyres ?
My Indian for a start, and I'm going to guess the new Bonnevilles and pretty much anything else running 'conventional' spoked wheels, of which there are still quite a few - although admittedly mostly retros/cruisers. BMW get round it with GSs as the spoke goes through a sort of flange on the rim so the bolts/nipples dont go through the rim itself and thus need lots of wee holes round the centre. But as a consequence I don't think you can re-true a BM wheel by adjusting the spokes?
There are some kits that are meant to seal the holes where the spokes go, but I gather they're none to successful. So if the bike's got spokes and has a 'conventional' rim with the spokes through it, then it'll be tubed.
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