Nerg Nail and Theo Thorn.... how do they find my tyres?


Legendary Member
Older readers of Bike magazine will remember Paul Sample's Ogri biker cartoon which sometimes featured Nerg Nail, who lies in the road waiting for hapless motorcyclists then jumps up and punctures their tyres. Well Nerg Nail has a brother called Theo Thorn, who punctured my tyre today.

My question is this: when I'm riding a bike with a contact area, say 20mm wide along a road, say 5000mm wide, how do Nerg and Theo manage to get me exactly in the middle of my tyre? And Theo Thorn, who has been lying in the road since Farmer Giles flayed the hedge last Autumn, manages to lever himself upright and penetrate the tread at exactly 90 degrees and just far enough to puncture my inner tube? Can anybody explain this self-levitating phenomenon?

Anyway I'm pleased to report that old-style butyl inner tubes intended for tyres 20-26mm wide do stretch to fill a new-style 30mm tyre... there was always a question mark in my mind. My lovely latex inner tube now has six holes in it, which is a bit too holey even for me so it's gone in the bin.


Ming the Merciless

There is no mercy
Inside my skull
Front tyre flicks it, and rear tyre embraces it


Sunny Radcliffe
My local car tyre chap says the most common car puncture is a screw from the front mud flap in the rear tyre. When I change from summer to winter wheels and back again I always check these screws. More often than not I get a little turn on them. On bike tyres I suspect the thorn or glass is embedded in the tyre and constant riding pushes it deeper until it finally enters the tube. When doing checks in the work stand I always deflate the tyres, this makes it easier this dig out the little b******s.
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