The BH G7 Disc: A Versatile Pro-Level Aero Road Bike
The BH G7 Disc was introduced back leading into Eurobike 2015 and offered the promise of a pro-level aero road bike with a bit more versatility.
As one of the first companies to commit to going disc brake-only for their top road bike redesign, BH put their neck on the line as their French Pro Continental team Direct Énergie was preparing to race the bike in the 2016 Spring Classics.
That didn’t pan out, but nonetheless the vast majority of us don’t race under the UCI (although rounded rotors are coming back soon), so the thought of a pro-level aero bike built with tire clearance and disc brakes for the Classics certainly sounded like something we wanted to try.
So we spent more than half a year testing the G7 from the pavé & bergs of Flanders to our own home cobblestones and back roads. We even did some non-UCI racing on it too, and were quite pleased with its fast ride…
The Flagship Aero Road Bike from BH
The G7 Disc is the flagship aero road bike from Spanish bikemaker BH. It was a big improvement on the old school aero optimizations of the previous rim brake G6 with a new narrower profile, dropped seatstays, and partial seat mast.
It has been available for just under a year now, and is about to be joined at the top of the BH road line by the new disc brake-only Ultralight Evo, which shares some similar tech in a less aero, lightweight climbing machine.
As our home roads around our European HQ tend towards the rough and tumble with all manner of broken asphalt, cobblestones & dirt, the idea of a fast rolling premium road bike up to that challenge was more than appealing.
We almost exclusively ride disc brakes on the road here and try to spend as little time as possible on any tire smaller than 27mm, so until recently the possibility for an aero carbon bike was quite limited.
The BH G7 Disc gave us the excuse to put on an aero helmet and pound the pavé, but it also made a good Review sled for some other goodies, like aero disc brake Zipp 404 Disc clinchers, fast-rolling Vittoria Corsa Speed tires, and all-surface friendly wide Challenge clinchers, to name a few.
Testing the G7 Disc
After riding the G7 Disc around Flanders last Spring on the iconic hellingen in the days before and then day-of chasing the peloton during the Ronde van Vlaanderen, we brought the BH back to ride around Central Europe.
The bulk of the kilometers we then put in on the bike were on the rolling roads surrounding our Prague base, doing mid to long distance road rides where most every ride ended up on some dirt or gravel roads at least once.
While the bike came to us with a set of 25mm Michelin tires, with plenty of extra room we mostly stuck with a larger than advertised set of Challenge Paris-Roubaixs that offered 29mm of float to tackle dry, loose, and wet road surfaces.
To take on a couple of amateur road races, a local hilly time trial, and for a few rides on smoother asphalt we did swap in a set of 23mm clinchers to push the aero side of this disc brake bike.
Tech Details & Actual Weight
Internationally the G7 Disc is available in just three builds with either Dura-Ace Di2, Ultegra Di2, or Ultegra mechanical, all with the same non-series R785 hydraulic levers.
Our complete bike was sporting the middle 6500€/$4800 setup and paired a FSA SLK compact crankset and BH’s house Evo 50 disc brake carbon clincher wheels.
(As an aside, in the US the complete bike mostly as we tested it is on a pretty massive sale, although sizing availability isn’t clear.)
In some markets a frame kit is also available.
The bike has plenty of clearance around the fork, stays, and cutout seattube for the 29.2mm actual width tires that we usually rode, and only once when a dirt road dead ended into a field did we ever have any issue with dirt, mud or grime build-up hitting either frame or fork.
The G7 gets internal cable routing inside the fork leg and from either side of the downtube. Since we were rocking the Di2 bike, a single non-driveside wire used the one modular cable port just below the hole for the rear brake line.
The bike gets a full carbon 1.125-1.5″ tapered fork inside of a headtube that is rather wide for an aero bike. There are several other aero tricks on the bike, but it does keep a fairly broad front end to ensure steering precision.
Moving toward the back you can see more of the aero focus. The downtube gets a tall aero foil shape with a squared-off top edge à la Kamm tail, and at the tall bottom bracket it joins a narrow and again aero shaped seattube.
That seattube has a small wheel cutout that keeps chainstay length down to just 402mm across all three sizes of the G7, while maintaining clearance for 30mm tires.
Like most road bikes with short stays and electronic front derailleurs, it was relatively tight between the tire and the body of the Di2 derailleur. Even with our wide tires there was still ~3-5mm left, but it was certainly the closest spot between the tire and the bike.
The G7’s toptube also has an aerodynamically optimized shape, transitioning smoothly from the head tube back to the more narrow seat cluster with its triangular shape.
The rear triangle gets more optimized shaping, with dropped aero-shaped seatstays that are slim enough to damp vibrations and a set of tall squared-off chainstays for excellent power transfer.
The G7 uses a Press Fit 386 bottom bracket, and we had no issues quickly swapping out another identical (except for decal color) set of SLK 386 cranks on which we were testing an early prototype of the Watteam Powerbeat power meter.
The G7 uses the recent flat mount disc brake standard front & rear with 140mm Shimano IceTech Freeza rotors, as well as 12mm thru-axles at both ends.
In a bid to save weight but maintain ease of use, BH includes a pair of house-branded light QR thru-axles. They use a similar external cam design with a tiny carbon lever like we’ve seen from Tune, but don’t seem to offer enough leverage to feel all that secure.
But with that being said never faltered in our use.
Those thru-axle dropouts also include some fairly nicely designed slots for the axles. It might seem to be a minor concern, but many thru-axle road and cross bikes still use a smooth inner surface at the dropout, where you have to align the wheel by eye as you slide the axle in place.
The reasoning is that the internal diameter of the hub/outer of the axle (12mm here) is defined, but the outer diameter of the hub’s endcaps where it rests against the dropout can vary.
It is less of a concern on the fork, but on the rear wheel with the chain pulling on the driveside not having a slot will almost always slow down wheel changes, and if it pulls too much can actually tweak the rotor that is already in place on the non-driveside where the axle has already been slid in a ways.
In any case, the slots on this BH worked well for us with a few wheelsets (BH, Zipp & DT), and we appreciated it.
The G7 sits your saddle atop an abbreviated aero seatpost that slides inside the extended seattube/mast. It lets BH keep the tubing shapes and seat cluster smooth while still offering decent seat height adjustability.
The layout of the set-back seatpost head’s two bolts meant some of our regular P & T-handled wrenches wouldn’t fit making it a bit slower to adjust the saddle.
The proprietary shape post is held in place by a small integrated seatpost clamp that presses two 3mm set screws against a small piece of metal inside the mast that in turn presses the seatpost against the inside of the mast.
While we were a bit skeptical of the setup, tightened down to the correct torque, it never slipped or made any noise.
The bike puts the Di2 battery inside of the…