[utopia]

I picked up a 2cm length of broken round needle file in my rear tyre last night.
A neat hole, about 3mm dia , fairly square to the tyre surface and about 2cm off the tyre's centreline.
The tyre is a Michelin PR2 which has served me pretty well for nearly 7000 miles, but it still retains a decent profile and looks to me like it might have another two or three thousand miles in it.
But if I was going to shell out for a professional repair, I almost might as well fit a new tyre instead. ....and I'd rather not do that just now as I might (unusualy) be doing a few motorway miles in the not too distant, and I might as well square the old tyre off, rather than a new one.
So, I was wondering how folks might rate the "temporary" type plug repairs as a longer term proposition.
As I said, its a neat, clean hole, in a good position and nicely square to the surface, so it seems to me that it should stand half a chance of going the distance.
The bike's a 750 and I do use it, but I don't cane it.

Or alternatively, how common is it for a tyre supplier to offer a free lifetime repair ?
The tyre came from a local specialist bike tyre fitter, who I get all my tyres from.