"Plus" vs breaker for fairy protection

[UpWrong]

Having suffered an embedded 35mm screw in my 47-559 Greenguard tyre (8.4mm tyre centre tread depth according to BRR), I am wondering if:
1. the tread helped to pick up and guide the screw to impale the tyre (the impalation was between the tread blocks)
2. a breaker belt would have deflected the screw rather than the plus layer capturing it

I replaced said tyre with a 42-559 Pasela Protite I had in my tyre box largely because it reduces the tyre height on the rim from 45mm to 35mm so I can get more foot of the ground but I'm wondering whether to order a 40-559 GG. Would it be more reliable for road use that the Pasela?

[531colin]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

The most amazing I have actually seen in the flesh was a tubular box spanner in the back tyre of a lad at school, and that was long ago. It was at least as thick as your finger.

What I think must happen is the front wheel goes over the object and flips it up, so that it is standing on end as the back tyre runs over it, and your weight drives it through the tyre.
I think this is very different to the usual thorn or bit of glass/flint/etc which is picked up by the tyre and then hammered in by subsequent revolutions.

I think I am saying that the extremely unusual event of an inch and a half screw in your tyre won’t be altered by details of tread pattern and puncture strip.

[UpWrong]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

Yes, the screw put a hole in the rim tape and with the tyre deflated I can believe that iit would quickly have damaged the rim if I hadn't stopped immediately. I wonder if the screw had been there for a few hundred yards, sealing the hole it created and only becoming apparent as the tyre gradually lost pressure with subsequent rotations.

As you say, rather different from the usual piece of flint, glass or a thorn.

[UpWrong]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

Yes, the screw put a hole in the rim tape and with the tyre deflated I can believe that iit would quickly have damaged the rim if I hadn't stopped immediately. I wonder if the screw had been there for a few hundred years, sealing the hole it created and only becoming apparent as the tyre gradually lost pressure with subsequent rotations.

As you say, rather different from the usual piece of flint, glass or a thorn.

Actually, thinking about that, a treaded tyre might be more likely to catch a flipped screw or nail than a slick tyre. Maybe I should have replaced the GG with a Kojak.

[mig]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

Yes, the screw put a hole in the rim tape and with the tyre deflated I can believe that iit would quickly have damaged the rim if I hadn't stopped immediately. I wonder if the screw had been there for a few hundred years, sealing the hole it created and only becoming apparent as the tyre gradually lost pressure with subsequent rotations.

As you say, rather different from the usual piece of flint, glass or a thorn.

that's quite a while for it to be lodged..!

[UpWrong]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

Yes, the screw put a hole in the rim tape and with the tyre deflated I can believe that iit would quickly have damaged the rim if I hadn't stopped immediately. I wonder if the screw had been there for a few hundred years, sealing the hole it created and only becoming apparent as the tyre gradually lost pressure with subsequent rotations.

As you say, rather different from the usual piece of flint, glass or a thorn.

that's quite a while for it to be lodged..!

Oops. I can't even blame autocorrect

[Chris Jeggo]

....

What I think must happen is the front wheel goes over the object and flips it up, so that it is standing on end as the back tyre runs over it, and your weight drives it through the tyre.

....

I have known that to happen and cause a car tyre to deflate in a couple of seconds.

[axel_knutt]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

I had a screw that was well on its way to going through the bed of the rim. It was getting hammered by my bodyweight with every rotation of the wheel so I think it would have gone through if it had been a nail instead of a screw.

The most damage I had was from a 4" nail that went in through the tread, out of the sidewall, and then snagged on the brake block with every revolution, so that by the time I'd stopped it had ripped a slot in the side wall of the tyre.

[drossall]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

This one? I never figured out what happened. I was riding on the Stevenage cycle paths, and there was a bump, followed by a pssst. Took me a while to realise that I had 37 spokes. That was 10 or 15 years ago now.

[531colin]

That’s the one!
That’s maybe a 3 inch nail? Much longer than the height of the tyre, in any case.
So by my reasoning that nail cant have been embedded in the tyre being hammered in each time the wheel went round, I think it went straight in.

Same with my schoolmate; a box spanner, at least 4inches long and as thick as your finger.

[drossall]

Yup. I was only a few hundred yards away from work, which I had just left. And I'd have noticed if that thing were sticking out much for the first few revs. The (back) wheel would have jammed, for a start

[Brucey]

whether its a screw, a nail, or a box spanner, the common factor is arguably that these objects are large enough that some folk would expect to have taken avoiding action instead of running them over. It can be a very good idea to look where you going.

[drossall]

Thank you. I hadn't thought of doing that

[mig]

one thing that i have noticed in the past few years are increasing amounts of screws, drill bits, powered screwdriver fittings, nails etc simply dropped into road side gutters. if walking i often pick up several within a mile. i'm sure that there weren't nearly that many in the past. disposable tools? careless people?

[Cyclothesist]

I don’t think I’m imagining it, I think I have seen ( on here) a photo of a nail not just embedded in a (rear?) tyre, but also piercing the rim. That implies to me a lot of force.

This one? I never figured out what happened. I was riding on the Stevenage cycle paths, and there was a bump, followed by a pssst. Took me a while to realise that I had 37 spokes. That was 10 or 15 years ago now.

Maybe an early victim of
https://road.cc/content/news/cyclist-su ... rap-307187