Review: Hammerhead Thumper / Switchback Unveil

I didn’t really plan to buy a full-suspension 29er, it just sort of happened.

I’d been riding my Trek Stache hardtail for a good few months and it had really opened my eyes to the possibilities of big wheels on my new local trails – which basically consist of long moorland drags between technical rocky bits, combined with the odd bit of singletrack in the woods.

But while the hardtail rolled over all those little bumps, it still came unstuck on more rugged terrain – leading me to ponder just how good a 29er with similar angles and a reasonable amount of rear travel could be.

Hammerhead Thumper
The Thumper might look a bit generic but I don’t think it looks cheap.

Then I became aware of the Hammerhead Thumper – a US direct-sales bike which was being offloaded at a bargain price following a re-branding exercise.

I checked out the geometry, which looked promising, smiled when I saw that it had a conventional bottom bracket rather than a press fit one, and emailed Scott Robinson at Switchback Bikes (as the company has been renamed) in the US to ask a few questions.

An hour or two later I’d put an order in – and then a week or so after that the frame turned up.

Pulling it out of the box, the black cherry paintjob looked much nicer than it had on the internet and I immediately cancelled my vague mental plans to get it resprayed. The build quality was equally impressive and the frame seemed reassuringly solid without being porky.

Modification time

The bike came with a nice Fox CTD Factory shock, but I replaced that with the just-released Cane Creek Double Barrel Inline before I even built it up. As well as the shock upgrade, I also had a Works Components minus-one-degree angle-adjust headset installed, taking the head angle to a nicely slack (for a 29er) 67 degrees.

Any lowering effect on the BB was counteracted by fitting a Rock Shox Pike RC 150mm fork, which is a tad longer than the bike was designed for.

This resulted in a slightly longer and slacker version of the bike – which I was hoping would make it capable of riding the kind of rugged mountain trails I like to frequent in the Lake District and elsewhere.

Spec-wise I went with a Shimano 2×10 transmission, mixing SLX, XT and XTR bits – teamed up with SLX brakes, a Funn 45mm stem and a 785mm Race Face Sixc handlebar.

I started with a set of Superstar Tactic wheels, but quickly upgraded to a secondhand pair of Mavic Crossmax ST after finding the Superstar wheels disconcertingly flexible when pushed hard through rocks.

These later moved over to a more fitting home on my hardtail and were replaced by a bargain pair of Superstar Tech 4 hoops.

Dropping at Gisburn Forest
Dropping at Gisburn Forest – is turquoise an appropriate colour for enduro?

In the saddle

So how does it ride, you ask?

Well, I certainly felt instantly at home on it. The geometry’s not a million miles away from that of my Stache and the suspension action feels a lot like the Lapierre Zesty which it has replaced.

It pedals very well, with the four-bar suspension feeling neutral and efficient enough. Flicking the “climbing switch” on the shock firms the rear end up further though – and the CCDB Inline provides sublime damping over rough terrain so the bike always feels composed in situations where I expect the bike to buck about.

The RockShox Pike RC fork matches up reasonably well – offering good support and the ability to soak up repeated hits without choking.

The bike’s geometry feels reasonably neutral too – with a longish effective top tube of 600mm on my medium and mid-length rather than super-short chainstays keeping it feeling stable but still allowing the front wheel to be lifted easily if required.

The neutral and stable geometry combine with the big wheels to create a very capable bike on rough trails – the handling can feel slightly lazy and it’s not easy to hop between lines, but the flipside of this is a runaway train feeling and the ability to keep your momentum across lumps and holes that might stall a smaller-wheeled bike.

I’ve ridden the Thumper on some pretty challenging trails, in the Lakes, the Peak District and Scotland and only once or twice has it really felt out of it depth.

The bike feels stable at speed (which of course is easy to maintain with the wagon wheels) but was still comfortably capable of threading its way down the golf course trails at Innerleithen – which are steep, densely wooded and twisty if you’ve not had the pleasure.

On the tour of Great Gable
Taking a breather on the tour of Great Gable

Comparisons and qualifications

Generally I’m finding the bike more capable in almost every way than the 140mm Zesty (with a 160mm fork) that it replaced. There might only be 130mm of travel at the rear but the magic rollover power of the big wheels means that unless you’ve hitting big square edges you can ride it more like a 160/160mm 26in bike.

In fact I managed to nab a couple of Strava KOMs in the Lakes on it, including one down Helvellyn to my surprise (now lost sadly).

Going full tilt into one of the most rugged sections of the Garburn Pass caused me to back off a bit when the rear end bottomed out hard and the wheels flexed a little too much for comfort.

But one lesson this bike has taught me about 29ers is that they need stiff wheels if you’re going to be riding gnarly trails. After fitting the solid-as-a-rock Superstar wheels the bike felt as though I’d added the final piece of a jigsaw and I no longer found myself holding back from hitting boulder fields or slamming turns.

I’ve been trying to think of negatives, but I’m a bit stumped to be honest. It’s just a really well-sorted frame which rides very nicely and comes at an absolute bargain price.

I’ve had a bit of contact with Blue Flow Bikes the UK dealer, and Stuart has been very helpful with info and advice. He might have sold all the Thumpers now but the Switchback Unveil is basically the same bike with a different graphic treatment and possibly a better shock.

Stop press: I have now remembered a minor negative – I bought a lovely MRP chainguide and taco for it but couldn’t fit it because it fouled the chainstay.

My favourite photo spot for Rivington Pike

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