Made from steel, the Genesis Tarn is a dedicated 27.5 Plus bike for riders wanting the spring of steel, the boing of chunky rubber and the confidence and stability a modern geometry offers.
We’re not sure how the bods at Genesis went about developing the Tarn 20 but it’s clear to us that they managed to get their hands on a checklist for someones dream steel hardtail and went to town.
Versatility seems to the name of the game with the Tarn 20. Dual bottle bosses clearly point to a bike that you’re going to spend many many hours on, and with plenty of room on the slender frame to fit luggage, we can picture the Tarn 20 being the perfect choice for a spot of winter bike-packing.
That said, the long, low, sloping top tube does have an aggressive look to it, and with pretty sorted geometry we wouldn’t mind getting a little rowdy on the Tarn 20 too.
The Tarn 20 is built around a two-tone black frame with gold details. The material isn’t just basic steel, but Genesis Mjölnir seamless double-butted cromoly tubing. Those words were actually really satisfying to type and bring back thoughts of classic skinny frames from the early 90’s, not that the Tarn 20 is anything like those bikes of old.
Our medium sized frame comes with a 440mm reach, 638mm stack, and a wheelbase of 1159mm. Genesis offers the Tarn 20 in four frames sizes, S, M, L and XL, all with the same 68° head angle and 74° seat tube, and all with the same length 432mm chainstays. On our bike that makes for quite a balanced and centred ride, we’re not sure how it would feel on the XL with 490mm reach though.
The not too slack head angle has a quality RockShox Pike RC Solo air fork with 120mm of travel plugged in.
As mentioned above, the frame is designed as a 27.5 Plus only bike, but there is a lot of tyre clearance out back, perhaps a 29er wheel could fit?
Plus tyres are provided by Maxxis, with Rekon Dual Compound EXO TR 60TPI 27.5 x 2.8in tyres fitted front and rear. This chunky rubber wraps around a pair of WTB Scraper i40 32h rims built on Shimano centre lock hubs.
Shimano is very well represented on the Tarn 20 and everything from the drivetrain to brakes comes from the Japanese giant. The complete drivetrain comes from the SLX family and is 1×11 only out of the box, although we see no reason why a double couldn’t be installed if you were inclined to do so.
Brakes also come from Shimano this time a set of price-conscious MT500 hydraulic levers and callipers clamping on to a 180mm front disc and 160mm rear rotor.
Genesis covers a lot of the build kit with its own brand range of parts. The handlebar is a Genesis alloy number measuring 760mm wide with a 5mm rise. The stem is another Genesis item. The custom design has a 0° rise, but measures in at a lengthy 60mm.
Genesis has also raided its own parts bin for the Genesis branded MTB saddle, pedals and Genesis Loc on grips.
An X-fusion cable operated dropper posts ensure you can get your saddle out of the way for the fun bits, and if the 150mm drop isn’t enough, then there’s a QR installed for further adjustment too.
While the dropper is a stealth model, it’s only this short section of cable that is routed inside the Tarn 20 frame. All other gear cables and brake hoses are all externally routed for ease of maintenance.
If this all steel, chubby wonder, does it for you then you can pick up the Genesis Tarn 20 as for £2199.99. Share your thoughts on the Genesis Tarn 20 in the comments section below.