Bike tech explained

Your quickfire guide to bike jargon

Shimano GRX

● Shimano launched its first gravel- and adventure-specific groupset, GRX, in 2019, which featured new ergonomically shaped hoods and levers, disc brakes and wide-range gearing. This was later than its main industry rival SRAM released theirs, but Shimano GRX is now a very popular groupset. The latest 12-speed incarnation of GRX includes super-wide-ranging 10-45t and 10-51t cassettes.

BSA bottom bracket

● In spite of the myriad standards of bottom bracket these days, the most common BB is still probably the oldschool BSA – named after Birmingham Small Arms, which shows just how old the standard is. To make matters worse, it also goes by the name BS threaded, BSC, ISO, British, Euro and possibly other monikers. Simples. The shell’s inner diameter is 1.37in with a 24 TPI thread. The standard road width is 68mm, with 73mm for mountain bikes, and it comes with threaded internal bearings or external cups. If you’re replacing your bottom bracket, well, just make sure you buy the right one!

TPI

● This stands for threads per inch. This usually refers to the number of threads that cross through one square inch of a single ply of a tyre’s casing (though also applies to a component’s internal thread as with the BB below). Lower TPI gives better puncture, cut and abrasion resistance but is heavier. Higher TPI conforms better to the terrain, offering a smoother, more comfortable ride with less weight.

Bento box

● In its original form, a ‘bento box’ is an Asian packed lunch, but the term has come to be used for bags that attach to the top-tube of gravel, adventure and even triathlon bikes as you can tuck the bags in behind the stem without affecting aerodynamics. These can be strapped around your bike’s top-tube using Velcro straps and loops, but some gravel bikes – and one of our test trio – come with bento box bosses for a more secure connection with dedicated bolt-on bags from the likes of Apidura and Craft Cadence.