Puncture??

@Alun Lambert: thanks Al. They do have my full admiration, for being able to notice anything, while they are negotiating a greasy bend at not inconsiderable speed.

@alex centrella: thanks Alex, yes a cover pic would be very nice

@lisa v: thank you Lisa, that's nice. I'm a computer graphics person, and at the moment I'm between contracts, so I've got loads of spare time to take photos.