I have just discovered and pulled out a small M2.5 bolt stuck in the tyre, about 12mm long. No sign yet of the tyre deflating. Is this going to pose a danger ie is the tyre wall now dangerously weakened, do I have to replace it ?

- (#6828) Bill Jones, 17 Jan 03

Bill,
If you take it to a tyre depot they will, obviously, try to sell you a new tyre. If the 12 mm long bolt went completely into the sidewall, I should think that it was very near to penetrating into the compressed air and, yes, the structure of the wall is likely to be damaged and escape of air is not far off
If the tyre is on the front, I would not risk it. Why not change it for the spare, mark the damage/hole, and keep your eye on it over the next few weeks.
Small damage to the tread can be repaired (I believe) but, sidewall damge repair is not allowed or practised (I believe)

- (#6829) John Davis, 18 Jan 03