From monstercross to rim brake conversions, here are five weird and wonderful gravel bikes from Grinduro Wales

Sep 07, 2023

A suspension-equipped monstercross bike, a rim brake cyclocross conversion and more

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By Jack Luke

Published: July 13, 2023 at 5:00 pm

Grinduro’s popular blend of festival atmosphere, chilled riding and timed stages has seen the series grow massively in popularity and scope, with events now in Germany, California, Pennsylvania, Wales, Italy and Japan.

Over 280 riders tackled fast fireroads, chunky chutes and snaking singletrack at the Welsh edition of the event.

Despite encouragement to ride at a party pace, there was no shortage of go-fast riders and spicy bikes on the hills surrounding Machynlleth.

Here’s a selection of five weird and wonderful gravel bikes from the sharp end of the day’s racing.

If you’re not familiar with Grinduro, be sure to check out our video from the 2021 edition of the race – it really is a fun event and the video is well worth a watch.

Cervélo-sponsored ultra-endurance rider Chris Hall built this ZHT-5 hardtail as a 120mm-travel suspension-equipped gravel bike after two broken wrists left him unable to ride a regular gravel bike.

Hall initially tried riding a bike with a short travel gravel bike suspension fork and Redshift Shockstop suspension stem but this didn’t provide enough comfort for his recovering wrists.

A conversation with Cervélo’s engineers revealed Hall could replicate the fit of his Caledonia – the brand’s all-road endurance bike – on the ZHT-5 frameset with a 120mm fork and carefully selected finishing kit.

Hall describes the resulting creation as the most fun bike he’s ridden, offering greater control on descents than a gravel bike with little perceptible difference in overall speed.

The bike is built with Shimano GRX Di2 shifters paired with an XTR Di2 rear derailleur.

Hall says this setup is fine for most riding but admits that the 42t chainring sometimes leaves him wanting, particularly on fast descents.

It would be possible to fit a slightly larger chainring, but he’s limited by the official 10-42t cassette capacity of the XTR Di2 rear derailleur.

The derailleur was released in 2014 when a 10-42t cassette was considered large. It pales in comparison to the 10-51t cassette used on modern-day mechanical XTR groupsets (not to mention the 10-52t cassette used on SRAM mountain bike groupsets).

He begs Shimano to “get a move on” with releasing its new electronic mountain bike groupsets so he can create a modern mullet drivetrain.

Tom Ryan was flying the #savetherimbrake flag at Grinduro, riding this 2013 Cannondale CAAD-X cyclocross-to-gravel conversion.

Ryan has converted his Shimano RS-100 wheels to tubeless using “tonnes of Gorilla tape and sealant to ‘glue’ the tyre to the rim.” A pair of 38mm-wide Hutchinson Touareg gravel tyres are fitted to these.

Though fiddly, Ryan said this setup is fine for lower gravel bike tyre pressures.

Ryan’s bike uses Shimano Tiagra 4700 shifters paired with a GRX RD-RX400 rear derailleur.

Though these are both 10-speed components, they actually use the same cable pull ratio as the Shimano’s mechanical 11-speed kit. This led to some initial confusion when an older pair of 10-speed shifters wouldn’t work with the GRX derailleur.

The FSA crankset is on its last legs with shoe rub wearing out alarming gouges on the outside face of the cranks.

Ryan swapped the original cantilever brakes for a pair of TRP CX9 mini V-brakes.

These are much easier to set up than traditional cantilever brakes and can provide more braking power (though only if you have any brake pads left – Ryan almost wore through a whole set at Grinduro).

The bike’s cockpit is aggressive, pairing a 130mm stem with 38cm-wide Condor Strada standard compact handlebars and aggressively inward-facing shifters.

The zero setback seatpost provides Ryan with a punchy over-the-cranks pedalling stance. The top tube-mounted frame pump completes the roadie-inspired aesthetic.

Ribble-sponsored rider Metheven Bond rode this custom-painted Gravel SL to the win in the pro men’s category.

The bike is built with a 1x drivetrain Shimano GRX Di2 groupset. Bond opted for a 42t chainring for Grinduro but often uses a 46t oval chainring depending on the course.

He backs up the narrow-wide ring with a neat MT Zoom chain guide for improved security on rough terrain.

Bond usually runs Specialized Pathfinder tyres but opted for more aggressive 44mm-wide Vittoria Mezcal tyres paired with Tubolight tyre inserts for Grinduro.

A neat integrated cockpit finishes this fast build.

It was impossible to ignore Sam Andrews’ custom marble-finish Titici Relli, which he piloted to second place in the pro men’s category.

The Relli is Titici’s all-out gravel race bike and features the brand’s signature Flexy top tube.

This radically-shaped top tube starts out with a boxy shape and tapers down to a plate-like profile.

The bike rolls on a pair of Hunt Limitless gravel wheels.

Andrews started out with a pair of Goodyear County tyres for the morning loop, swapping to the brand’s slightly more aggressive Peak tyres for the wetter afternoon conditions.

A custom X-Pac top tube bag from Cordel sits just behind the stem and attaches to the bike using the integrated bento box mounts.

Andrew’s teammate Tom Hardie also had a tasty custom bike in the form of this Vitus Venon Evo (our 2023 Bike of the Year-winning bike).

The bike was painted by Elite Refinish in a lovely off-white tone with smoke-like blue details on the inside of the fork.

The one-piece cockpit has been sanded back to a raw carbon finish and sealed with a gloss coating for a neat look up front.

Hardie often rides the bike in longer gravel events, where he prefers road bike gearing. He opts for a Shimano Ultegra Di2 R8170 groupset with 54/30 chainrings and an 11-34 cassette.

Hardie admits the Specialized Women’s Romin Evo Pro Mimic saddle was originally bought because it was available for a good price but it’s since become his favourite perch.

Hardie says the Hutchinson Tundra tyres are the hardest-wearing gravel tyres he’s used yet.

These plump out nicely on the bike’s 56mm-deep Prime wheelset. Hardie deemed these “overkill for Grinduro… but they look cool.”

Deputy editor

Jack Luke is the deputy editor at BikeRadar and has been fettling with bikes for his whole life. Always in search of the hippest new niche in cycling, Jack is a self-confessed gravel dork, fixie-botherer, tandem-evangelist and hill climb try hard. Jack thinks nothing of bikepacking after work to sleep in a ditch or taking on a daft challenge for the BikeRadar YouTube channel. He is also a regular contributor to the BikeRadar podcast. With a near encyclopaedic knowledge of cycling tech, ranging from the most esoteric retro niche to the most cutting-edge modern kit, Jack takes pride in his ability to seek out stories that would otherwise go unreported. He is also particularly fond of tan-wall tyres, dynamo lights, cup and cone bearings, and skids. Jack has been writing about and testing bikes for more than six years now, has a background working in bike shops for years before that, and is regularly found riding a mix of weird and wonderful machines. Jack can also often be seen zooming about with his partner aboard their beloved tandem.

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