BH G6 Review

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The G6 is the next iteration of BH’s aero road bike design, updating the G5 to improve its weight, stiffness and aerodynamics – says BH. As CTech Editor Matt Wikstrom writes, the result is a finely honed race bike that loves to be ridden aggressively.

BH has a long history in bicycle manufacturing, though it started with pistols and rifles. The company was founded in 1909 by Domingo, Juan, and Cosme Beistegui — three Basque brothers, Beistegui Hermanos — hence the initials, BH. The First World War encouraged the company’s growth, but as demand for armaments fell during the early 1920s, the company found a new application for barrel-shaped tubing.

BH supplied bikes to half the riders taking part in the first edition of the Vuelta a Espana in 1935 — Orbea attended to the other half — and the title went to Gustaaf Deloor on a BH. More titles followed as the company grew and expanded, first into motorcycles, and then gym bikes, while continuing with its bicycle production.

In recent years, BH has been renowned for introducing integrated seatposts to road bikes, and manufacturing lightweight carbon frames. The company also has a strong interest in electric bikes and offers a massive catalogue of powered bikes.

Wade took BH’s Ultralight for a ride last year, a 5.6kg affair that proved to be all business with a race-oriented focus. The G6 is the latest version of BH’s aerodynamic road bike platform, previously known as the G5, which was used to great effect by Ag2R’s Rinaldo Nocentini in the 2009 edition of the Tour de France. The new design promises to improve the weight, rigidity and aerodynamics of the monocoque frameset.


Before the ride

The G6 frameset is “built from the inside out” using BH’s Hollow Core Internal Molding Technology. There isn’t much detail on this process, so it’s unclear how it differs from other approaches, but the company says it prevents bubbles and imperfections to improve strength and weight. The G6 is constructed with the company’s highest-grade carbon fibre — designated F1 — to further reduce the weight of the frameset.

In redesigning the G5, BH introduced more aerodynamic features. The integrated seatpost now has a Kamm tail to keep the frame UCI legal and manage the overall weight. The fork is tucked part of the way into the headtube, while a broad aero downtube continues to dominate the frame. In contrast, the seat stays are diminutive, designed to reduce road chatter.

Elsewhere, the forks have a tapered steerer supported by a 1.5-inch lower bearing. The cables are internally routed with options for both mechanical and electronic groupsets and the vast bottom bracket junction utilises the new BB386EVO standard that was developed in partnership with FSA.

The 2014 frameset is finished in matte black with red highlights and some white pin striping. Bold logos announce the brand name and they fit comfortably on the massive aero tubing. The overall presentation is clean and sharp with some pleasing lines.

Frame geometry


The geometry is characterised by a relatively short head tube and a relaxed seat tube angle for all but the smallest frame size. Prospective buyers are advised to pay attention to the seat tube length when deciding on a frame size, since it cannot be cut. The G6 is supplied with 140mm seatpost that has 20mm setback, but there is a zero setback option and longer posts will be available shortly.

To calculate the minimum saddle height relative to the centre of the bottom bracket, add at least 80mm to the seat tube length (to allow for the saddle clamp and the height of the saddle).

The G6 is available in Australia as a frameset for $3,299 or a complete build with Shimano’s Ultegra, Ultegra Di2, Dura Ace, or Dura Ace Di2 groupsets at a starting price of $4,999. The bike supplied for review was a medium frameset with a mechanical Dura Ace groupset (52/36 cranks and 11-28 cassette), Shimano C35 composite clinchers with Vittoria Diamante Pro Radiale tyres, FSA OS99 stem and SLK carbon bars, and a Prologo Zero II saddle. Total weight: 6.79kg sans pedals and cages. Recommended retail: $7,999.

For more information, visit BH Bikes Australia and the company’s Facebook page.

After the ride

The G6 was a difficult bike to get to know. I had a variety of complaints after my early rides — nervous handling, twitchy steering, and an unbalanced feel — but with a little more time, and some experimentation, I found its sweet spot.

In short, the G6 is a bike that must be raced — it rides beautifully once you get in the drops, flatten your back and go to work. Sit up and relax to take in the surroundings and you’ll get a nasty surprise; the G6 does not like to dawdle.

A size medium G6 has a head angle of 73 degrees, which is not unusually steep, so an explanation for the bike’s twitchiness must lie with the rake of the fork and its trail and/or a high bottom bracket. While the former are difficult to measure accurately, I found that the bottom bracket was high with a drop ~65mm. Thus, I dropped my stem and spent more time in the drops to lower my centre of gravity and the G6 calmed down immediately.

Provided I stayed low, the G6 was unflappable and sure-footed through any corner. Every time I sat up, it would oversteer or the rear end would start to skip. Similarly, strong crosswinds could trouble the steadiness of the bike while I was holding on to the tops of the bars, but once I lowered myself to the drops the bike was easy to control.


After a week of riding, I became accustomed to the bike’s twitchiness and started to think of it as eagerness and excitement. There was little I could do to avoid the twitchiness while I was out of the saddle on a climb though, so I found myself spending more time on the seat.

All of the fat aero tubing — plus a measure of BH’s engineering, I’m sure — made for a stiff and efficient bike. It was easy to ride this bike fast and it responded nicely to any acceleration, in or out of the saddle. There was a downside though; all of that stiffness worked against me on rough surfaces as a lot of road chatter was transferred to my body (despite the spindly seat stays).

In this regard, the 22mm Vittoria Diamante Pro tyres were a poor match for the G6; switching to 23mm Continental GP4000s improved the quality of the ride by reducing the road chatter to a soft murmur (and a set of 25mm tyres would probably eliminate it altogether).

The Dura Ace 11-speed groupset was flawless, the shifting was light and precise, the braking equally light and powerful, as noted in my previous review. The mid-compact 52/36 crankset coupled with the 11-28 cassette makes for a generous spread of ratios, though I found it was too broad for a race-oriented bike. Wade reviewed the Shimano C35 clinchers last year and I echo his impressions: a solid wheel that is both easy to ride and suited to racing.

The rest of the build performed as expected. The tops of the FSA SLK handlebars are flattened at an angle to soften the bend of the wrists while the drops have a compact bend that is easy to reach. The Prologo Zero II saddle is flat with plenty of length and should suit any rider that prefers a narrow saddle. All told, there is value in the build save for the tyres that are too narrow and a cassette that is best set aside for long rides in the mountains.

Final thoughts and summary

The price and specifications of the G6 places it squarely in the performance end of the market. Add to this aggressive race-oriented geometry and twitchy handling, and you have a bike that is best suited to experienced racers.

I can’t tell you if this bike goes any faster because of the aerodynamic design, but feels stiff, light and fast. It also responds eagerly to hard, aggressive riding, and is the first bike I’ve ever ridden that was easier (and a lot more fun) to ride when I was putting in more effort.

For those that have arrived at this point questioning the appeal of a bike that is demanding to ride, there is no saving grace for the G6. There are plenty of other bikes that bring high-end engineering and carbon construction to a wider audience; BH has made the G6 for racers.

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