"And don't worry about the studs damaging your inner tubes. They won't. The tires are carefully designed to prevent the studs from puncturing the tube... As tires age, the casing deteriorates, and then the studs can push through the casing..."
Had to swap to my winter tyres this weekend. Weather doesn't merit it yet, but my rear summer tyre was so worn it was bulging out in about eight different places. So I thought I might as well just put the winter ones on.
I hadn't bought new winter tyres as they still looked in reasonable nick from last year (they were new then). But lo and behold I get a puncture on the way to work. It turns out the casing is failing on the rear and the studs are coming through.
One fucking season! I cycle far too many miles!
I can't afford a new one yet, so I'm just going to try lining it with the old summer tyre I've just taken off and see how that goes.
[EDIT: 2014-11-27] Forgot to update this post way back when (although did mention it recently), but lining with a tyre (beads removed) was too stiff and didn't work well. I think basically because the outer diameter of the skinny summer tyre was small compared to the inner diameter of the studded tyre and so pumping up the inner tube didn't result in the inside of the actual winter tyre being adequately supported. Nevertheless, as far as I can recall, it got me through some (or all) of that winter. The better approach was lining with two layers of old inner tube - I can't remember if I did that at some point during the same winter or whether it was a following year.