Trelock's range topping BS510 U-lock was a top performer in earlier BikeRadar tests, and the 1.5kg weight tells you this is made from some tough stuff. So it wasn’t a surprise that no amount of levering, hammering and chiselling could make the BS510 budge.
When we brought out the power tools we were able to cut through one side of the shackle in 30 seconds, allowing us to rotate the cut part enough to remove the bike. In all, though, it’s a tough lock and a sensible buy for £40. Top marks for the neat web strap mount bracket too.