‘Click – Yank; Click – Yank’.
That 5-second procedure is all it takes to securely mount a tailbag or duffle to your bike. The click of the plastic clips joining; an optional yank on the strap’s loose end to tension it against the elastic.
It ought to be obvious and it’s not ROKet science, but watching some riders faff about mounting or removing tailbags by other means makes me realise how brilliant two-part ROK straps are.

Regular adjustable webbing straps are far less dangerous of course, but fail to account for a loose bag’s tendency to ‘shift & shuffle’ on the back of a bike – something which tensioned elastic reliably compensates for. And you effectively needed double the length of webbing to loop across frame loops and back. Forgotten straps and bungies fell by the wayside or got snagged and shredded in your rear wheel.

Before ROK
Back in the Flintstone era but after the invention of string, bungies were the next best thing; a bunch of cheap elastic strands encased in a jaunty woven nylon sheath tipped by two coiled metal hooks. Bungies were such a hit they spawned the daredevil activity of bungy jumping. B-u-u-u-u-n-g-i-i-i-i-i!
But even back then we knew bungies were a cheap and nasty convenience, and sometimes it was the bungy that was jumping back at you. Because they were way too stretchy you had to tension them to the max to eliminate movement of anything heavier than a copy of MCN, and there was no adjustment other than knotting them [forever]. Add some UV, rain, more UV plus persistent over-stretching, and over the years several unfortunates have suffered nasty eye injuries from a stray hook recoiling into their face at 350mph. It’s said that was the motivation behind the invention of ROKs in Australia back in the 1990s.
Regular adjustable webbing straps are far less dangerous of course, but fail to account for a loose bag’s tendency to ‘shift & shuffle’ on the back of a bike – something which tensioned elastic reliably compensates for. And you effectively needed double the length of webbing to loop across frame loops and back. Forgotten straps and bungies fell by the wayside or got snagged and shredded in your rear wheel.

Stiff elastic + clips + adjustable strap + tethering loops = ROK Strap

ROK Straps come in two parts: a shorter sheathed section of thick, flat rubber producing minimal recoil. It clips to a regular webbing strap with an adjustment buckle and best of all, both chunky sections end with a sewn loop to thread through itself round a subframe or rack tube. Result: all pieces of ROK Strap are always attached to the bike (but remove easily) for lashing down bike loads quickly and reliably.
At the end of a long ride when you can often be weary or forgetful, just click your two straps apart, lift off your bag and stroll into a velvet-lined riad for a poolside aperitif while others are still fumbling with buckles or stumbling around clutching their eye in agony. It can be that simple.
An inch-wide, 1.5 metre long pair of ROKs (left and below) cost about 15 quid, thinner ones go for under a tenner. Rok On.