Twmpa Cycles GR1.0 review

Twmpa Cycles is named after a mountain on the west scarp of Wales’ Black Mountains that stands a few miles from the family-run brand's workshop near Hay-on-Wye.

Twmpa is the brainchild of engineer Andy Dix and his business partner Miguel Ferros, an expert in product management with a background in technology industries.

What unites them, and inspired their unlikely wooden machine the GR1.0, is a shared love of cycling.

It’s fitting, also, that the brand is named after a local landmark, as locality is Twmpa’s touchstone.

The ash wood used in Twmpa's handcrafted frames comes from a sawmill just five miles away. Former furniture maker Dix goes direct to them and chooses particular cuts for each frame build.

“I’ve always believed in using local resources and timbers whatever I’m making," Dix tells me. "It seems like madness to ship materials around the world when we have such great resources here.”

Twmpa Cycles GR1.0 materials

I’ve seen bikes made from natural materials before. These include bamboo, plywoods and flax – remember Johan Museeuw’s flax-carbon Museeuw MF-5 bike in 2008? Yet Andy’s bikes are something else again.

At first glance, the round tubes appear to be made from solid wood, but it’s much more complex than that. The frame itself uses 12 100cmx15cm planks of British ash, as well as nine 2mm-thick veneers for the chainstays.

The front triangle is made of four layers, each following the front triangle shape. These are then bonded together under high pressure to create the form. The individual triangles are all CNC'd into precise sizes at Dix’s second facility in Cardiff, where the computer-controlled side of Twmpa’s operation is based.

When bonded, these create hollow tube-like forms. Wall thicknesses vary from over 6mm at the head tube down to around 5mm at the centre of the tubes. Butted wood? Who’d have thought of that?

Dix’s local approach enables him to provide comprehensive information for buyers. He can tell customers not just in which area of the country the ash grew, but he can usually pinpoint the individual estate it came from and even the specific area of woodland within it.

Some of Twmpa’s prospective customers have even brought their own wood and asked Dix to build a bike.

The frame pieces are interconnected via jigsaw puzzle-like joints, with the four individual slices having interlocking sections opposed to each other to increase the strength. Dix is quick to reassure me about the strength of his frames, which are all tested to current ISO standards.

Twmpa’s current frames weigh around 1,600g-1,700g. This isn’t spectacularly light, but it’s a similar weight to a steel gravel bike frame similar in design to the GR1.0.

So, why does Dix choose ash for his staple material? “For more than a century,” he says, “ash has been the go-to material for making handles for tools, hammers, chisels, axes and more.

"Ash grain is incredibly tough, it’s not heavy and because of the make-up of the wood, it has elements that are strong and stiff, and further elements that act like an elastomer, absorbing shocks and deadening big hits.

"If you imagine hitting rocks with a steel-handled sledgehammer, it’s going to hurt, but do it with an ash-handled sledgehammer and you can keep working.”

“I thought the same should apply to frames and bikes,” adds Andy, “and right from when I made the first prototypes, I knew we had something. To be honest, if it hadn’t worked, we wouldn’t be here now.

"First and foremost, I’m a cyclist who loves riding and I couldn’t bear to make something that didn’t do the job and do it well.”

Twmpa Cycles GR1.0 ride impressions

When testing a bike, I’m always trying to compare the way a frame feels to something I’ve ridden before. Steel has its springiness, titanium can be smooth and forgiving, and aluminium can combine lightness and stiffness when done well.

Carbon fibre can be the lightest, stiffest and least forgiving material or the most compliant depending on how it’s manipulated. But wood? And more specifically British ash?

Well, firstly, while it’s not like any other material I’ve ridden, it has characteristics associated with all of them. It’s impressively solid and its stiff feel is a match for the ENVE Gravel Disc fork our ‘Ultimate’ build came with. But it’s not stiff like aluminium.

It’s resolutely immovable from side to side, but it has a vibration-damping quality unlike anything I’ve ever ridden without suspension.

The flipside of this is when you hit ruts and roots, the frame has a solid ‘thunk’ that genuinely reminded me of hitting a cricket ball in the bat’s sweet spot. There’s a sonic response and a total lack of reverb. It’s an odd felling, but it’s a good one. It seems it’s not only the GR1.0’s looks that are unique.

Twmpa Cycles GR1.0 frame and spec details

The frame is long in reach and on the aggressive side for a gravel bike, though this is tempered with a stack height that is more endurance than full-on race, and a head angle that’s slightly relaxed.

Twmpa is reluctant to specify exact geometry figures because all of its bikes are built to order and are tunable to each prospective customer’s needs.

Tyre clearances on my early GR1.0 frame are pretty tight, with the GR1.0 only taking tyres up to 40mm wide. The rear end has now been reshaped to provide more generous space around the rubber.

This Ultimate build doesn’t come cheap, but it’s very hard to fault.

The Easton EC70 carbon gravel bar is beautifully shaped, and its great blend of stiffness and compliance suits the bike perfectly. The flared design encourages you to ride in the drops, with the extra width adding lots of control.

The ENVE Gravel fork is of the quality you’d expect from Utah’s carbon manufacturing expert, and its solidity and lack of lateral flex add to the snappy, direct feel the GR1.0 is brimming over with.

Fellow UK brand Hope provides the carbon seatpost and the tough, lively Hope 20FIVE aluminium clincher wheels that are built using its Pro 4 hubs. But with a front wheel weighing 855g and the rear adding 970g, they’re not exactly flyweights.

It does, however, make the GR1.0’s overall 9.56kg complete weight even more impressive. Spec a lightweight set of carbon wheels such as the Zipp 303s and you could easily shed around half a kilo from the Twmpa’s weight.

The 20FIVEs have the springy, responsive feel you get from a quality set of alloy rims hand-built with traditional J-bend spokes.

Unless you’re obsessive about weights, I’d stick with the Hopes for their impressive ride quality.

WTB’s 700x40c Nano tyres have a pronounced centre strip, which keeps the GR1.0 decently sharp on tarmac, while their knobbly tread and pronounced shoulders offer plenty of bite when it comes to the dirt.

The result is that the GR1.0 holds its line with impressive ease through corners on loose and potentially hazardous surfaces.

The drivetrain mixes SRAM’s Force AXS and an Eagle XO AXS rear mech with its 10-50 cassette.

These are accompanied by a swish-looking INGRID chainset, which has a direct-mount 7075 alloy chainring with highly machined 2024 aluminium crank arms that are anodised to match the bike’s golden-bronze dropouts, Chris King headset and even the bottle cages.

At 540g, it's light, with chain retention as good as the SRAM unit it replaces. The 73mm BSA threaded bottom bracket shell is bonded into the frame, so it should remain free of creaks and squeaks.

The Brooks Cambium saddle has a natural rubber hull, is forgiving and flexible, and proved a great companion to the GR1.0. That compliant hull does have a bit of bounce to it, however, so it’s certainly one to try before you buy.

Twmpa Cycles GR1.0 bottom line

It’s fair to say the Twmpa isn’t a budget buy at £9,000. But the sustainable nature of the frame, and the fact it’s hand-built in the UK from such an unusual material mean you’ll be getting a unique bike.

These things may be enough for you to consider digging into – necessarily deep – pockets. That its ride is equally eye-catching only cements the justification.

We talk about innovation a lot, but genuine cycling innovations are rare – and ones that work rarer still. Andy Dix and the Twmpa team deserve praise for a new approach to bike building that actually works.