Review: Genesis Tarn 20

Review of: Genesis Tarn 20
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On 12th January 2018
Last modified:12th January 2018


A brilliant go-anywhere bike with modern geometry and good off the shelf components.

If you’ve been thinking about buying a fat bike but not sure if you want to give up room in your stable for it then the Genesis Tarn 20 may be exactly what you’re looking for. With a steel frame, the ability to run either 29″ wheels or 27.5 plus and brilliant, modern geometry this bike really is a go-anywhere beast that I’ve found to be perfect for hammering around South Wales.

Frankly, I’ve never been one to weigh in on the wheel size debate – personally, it’s each to their own and if 29er or 26er is your flavour then who cares, ride your bike. That said – tyre width is something I’ve recently found myself being really pulled into.

Almost all tyre manufacturers are bringing out wider tyres, either to fit the “plus” category or in the new “wide” category. It isn’t until you actually ride a bike like the Genesis Tarn 20 that you realise why this trend has come about – they’re a ridiculous amount of fun!

Genesis Tarn 20 Review

Genesis Tarn 2017

I initially took out the 2017 model of the Tarn 20, which for all intense and purposes is exactly the same as the 2016 version AND the 2018 version – the only major difference is the fork that’s provided as stock:

  • 2016 featured the Rockshox Reba
  • 2017 was the Rockshox Yari
  • 2018 has the Pike

All of them are the solo air and all of them feature 120mm of travel. The geometry hasn’t changed over the years and they’re all specced with SLX 1×11, Shimano Deore brakes and different variations of tyres.

I ended up buying the 2016 model (largely because it was orange and orange bikes are the best) because there was an epic sale on so I got a mega bargain – the same is happening right now with the 2017 models (depending on when you read this).

I’ve been hammering this bike around for nearly 800km now and I can’t believe how lively, playful and versatile it is. Like everyone, I tend to ride the same trails over and over again but the Tarn makes them feel like they’re new! I recently took it around Cafall at Cwmcarn and got PBs on almost every climbing section and a few DHs – which considering I’ve ridden this trail countless times on my Bird Aeris and the Nukeproof Scout  I’d say that’s a fairly impressive feat!

Roots, breaking bumps, loose terrain all get eaten up by the 3inch wheels and once they get rolling they really bloody go! The amount of speed you can pick up on this thing is incredible – especially around corners, the tyres let you really lean the bike over without ever giving you the impression that they’re going to let go at any point.

You do need to play around with tyre pressures a bit to get the most out of it and I’d recommend going Tubeless straight away – you’ll save nearly a 1kg in weight and won’t have to worry about punctures as much. I tend to run mine around the 20psi mark but have dropped them as low as 15 in some places, which is really weird to see on the dial.

Genesis Tarn 20

If I was to start picking out faults, I’d say that it doesn’t jump well, but that’s arguably because it’s not what it’s built for but everywhere else on the trail it exceeds.

As for components, I immediately swapped out the stock grips with some DMR Deathgrips, changed the pedals out for some Superstar Nano Tech pedals, and swapped out the Shimano Deore brakes for some SRAM Levels. None of these were especially bad components (except the stock pedals), I just like to make sure that I’m comfortable in the cockpit and can run components that I believe will help bring out the best in the bike.

Overview of the Genesis Tarn 20

This bike is brilliant. I’ve yet to run it as a 29er, but I like having the option available to me if I want it. Having boost spacing on the frame and forks really helps to future proof this bike, as does the stealth dropper cabling. It doesn’t have a push fit BB which is a major win in my books, the steel frame gives that touch of compliance on really rough trails making it nice and comfortable on long days out.

It is without a doubt the best bike I’ve ridden in a long time when it comes to climbing! The extra traction on the big wheels practically pulls you up even the steepest of hills. The geometry is also dialled when pointing down, giving you stability and confidence when attacking super fast singletrack or crazy technical off piste.

Genesis Tarn 20

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Genesis Tarn 20
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One thought on “Review: Genesis Tarn 20”

  1. my hardtail is two years old now and was thinking going a little plus sized if I changed it. Sadly I can’t afford to change the bike this year though… Nice review Joe.

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