The Ren? Herse Nivex is a brand new rear derailleur from a niche maker that specializes in doing things a little differently, with the focus on mechanical purity.
Compatible with cassettes from 6 to 12-speed, the Nivex is a twin-cable design that operates ‘desmodromically’, i.e. using a positive action for both up- and downshifts rather than relying on cable pull for one direction and spring tension for the other in the way that a conventional mechanical derailleur does.
It’s matched to a dedicated shift lever which is currently down tube only.
Described as ‘NOT for everybody’ by Ren? Herse owner Jan Heine (capitalisation his), the Nivex doesn’t attach to the frame at the rear dropout in the conventional way, instead being located further forward on the drive-side chainstay, out of harm’s way.
As such, it requires a dedicated braze-on mount that’s included with purchase. The Nivex will likely see action primarily on custom builds although Ren? Herse notes that it’s perfectly feasibly to retro-fit the braze-on to an existing steel frame.
The Nivex is priced at $729 for the derailleur while the shift lever is $249. An optional inline cable adjuster adds $39 while the shifter cable itself is a standard extra-long item, as used on tandems.
According to Ren? Herse the first production run of derailleurs sold out almost immediately when they were made available this week, but more are due in early January.
Like a Ducati
Photo: Rugile Kaladyte
The Nivex is inspired by a design patented in 1937 but it’s essentially all-new, the product of over four years of development by Ren? Herse that’s included outings at the 350 mile Unbound XL gravel race and other long-distance events.
The term ‘desmodromic’ is most commonly associated with Ducati motorcycles whose engines for decades employed a unique design wherein the valves were both opened and closed by positive cam action, rather than relying on a spring for the closing movement.
The Nivex is similarly positive in its operation. The twin cable design means that shifting feel and performance should be more or less identical in both directions.
Mechanical involvement is central to the design according to Heine and the Nivex aims to shift as well as a modern electronic derailleur, if not better.
He likens it to choosing a good kitchen knife over a food processor – the latter is arguably more efficient but there’s no direct connection between the user and the action, it’s simply about pressing a button.
The Nivex’s aesthetic is distinctive. It comprises over 50 parts and there’s more than a hint of Paul Components to its angular, machined lines, albeit with a strong retro flavour.
A key selling point of the Nivex is that – unlike many components from the big three groupset makers – it’s designed to be fully rebuildable and Ren? Herse will stock all parts.
The derailleur pivots use durable bronze bushings and the brand says the shifter cable lasts virtually forever thanks to the design, while the pulleys run on standard bearings.
The derailleur is claimed to weigh just 176g while the lever is 54g. By way of comparison, a mechanical Dura-Ace R9100 rear derailleur isn’t much lighter at a claimed 158g.
Photo: Linda Guerrette
The Nivex supports cassette sprockets up to 30-tooth (it’s optimised for 11-30) and at launch only an indexed 11-speed shift lever is available, but 7-, 8-, 10- and 12-speed levers are coming as well as a friction option.
Groupset manufacturing is dominated by just three brands and the vast majority of riders will never look elsewhere when it comes to their drivetrain, but the Nivex is a fascinating piece of design that will delight lovers of mechanical jewellery.
Find out more at Ren? Herse.
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Photos: Ren? Herse except where noted