Bombtrack bikes is an offshoot of the highly regarded German BMX manufacturer Wethepeople. The Bombtrack Audax, with its big-clearance steel frame, 650b wheels and huge (47mm) road tyres, seems at odds with its roots.
For most roadies, this Bombtrack model’s ‘Audax’ name will bring up thoughts of fastidious long-distance events, where it’s not about being ’fast’ but instead hitting the pre-determined time window. Success in such events is all about completion, not ‘winning’.
At first glance, you’d think this Audax was a bikepacker or gravel rider’s companion. However, I’ve found a bike that lives up to its road bike roots, but comes at it from a very different perspective.
Bombtrack Audax specification
The Audax is a fine-looking machine, with the heart of the bike a tidy TIG-welded Columbus Cromor double-butted steel frame. The welds do look a little workmanlike compared to the best steel frames, but they are uniform in their execution.
The full-carbon fork features twin mounts and a mudguard mount on the fork leg. It tapers down nicely from the chimney-shaped tapered head tube.
The skinny steel tubes route cables and hoses externally, and the frame has both top-tube mounts and twin down-tube bottle placement, as you’d expect of a bikepacking bike.
It also, however, has a ‘proper’ bridge for rear mudguards and rack mounts. I like the machined and signed chainstay yoke welded to the bottom bracket shell, and the rear thru-axle dropouts are neatly cowled too. It adds up to a very well put-together frame.
It’s completed rather well with a great mix of well-chosen parts. Up front, the Comp-level Ritchey 4-Axis stem and Streem II bar is a smart combination.
The bar is particularly well shaped for endurance riders, with its ergo-shaped compact drop and nicely flattened top section that has a defined rearward sweep, putting your wrists in a comfortable position. These bars are perfectly shaped for big mile munchers.
The drivetrain is a well thought-out mix of Shimano 105 for the brakes, front derailleur and shifters, and a rarely seen and clutch-equipped Ultegra RX rear derailleur sliding up and down a broad 11-34 cassette.
It’s driven by Bombtrack’s own and very well finished direct-mounting chainrings crankset with an ‘adventure’-sized pairing of 48/32.
The biggest difference between the Audax and an endurance bike is the wheels. They’re based around WTB’s broad St i25 rims in 650b size and built onto Bombtrack’s own cartridge-bearing hubs. These are then shod with a front- and rear-specific pairing from WTB’s Road Plus range.
Up front, it’s the lightly treaded Byway in a massive 47c, and at the rear a similarly large but almost slick Horizon, again in a big 47mm-wide sizing.
Bombtrack Audax geometry
For a bike with 47mm-wide tyres, not to mention the smaller wheels, I’d have expected a very relaxed geometry. The Audax, though, isn’t a round-town hybrid disguised with a drop bar. It is, in fact, a rather sporty ride.
The 590mm stack in the size large (between a 56cm and 58cm frame), combined with a 396mm reach, is somewhat more slammed than a classic endurance road bike.
The 72-degree head angle is slightly more relaxed, but the 74-degree seat angle is steeper. It’s an intriguing combination and one that I found quite compelling once I got out on the road.
By mixing speed and stability with a large dose of security from the epic-sized tyres, Bombtrack has created something unique.
|Seat angle (degrees)||74.5||74.5||74||74||73.5|
|Head angle (degrees)||71.5||71.5||72||72||72|
|Seat tube (mm)||470||490||520||550||580|
|Top tube (mm)||504||519||544||566||593|
|Head tube (mm)||105||125||145||170||195|
|Fork offset (mm)||53||53||53||53||53|
|Bottom bracket drop (mm)||68||68||68||65||65|
Bombtrack Audax ride impressions
The Audax absolutely isn’t what I expected. At first glance, those big balloon tyres on smaller wheels and skinny steel tubes had me thinking it might be a commuter-cum-pseudo-gravel machine. Not exactly exciting, but perhaps quite worthy in practical terms.
Maybe the Audax is practical, with its wealth of fittings, comfortable yet tough tyres and buoyant steel frame.
It is, however, an absolute blast to ride; I was truly surprised by how rapid it feels on tarmac.
The big-volume tyres make mincemeat of poor surfaces and the 650b wheels accelerate quickly in combination with the compact gearing.
Over more than 100 miles of testing the bike, all on solo endeavours, I averaged a tad over 18mph / 29kph, which I certainly didn’t expect.
I thought the Audax was going to be a lazy Sunday pub ride bike, but it’s a bit of a dark horse.
On the climbs, those big tyres and smaller wheels require more of a steady aerobic effort than an out-of-the-saddle dash.
Stay with me, though, because once you crest the top of a climb and head down the other side, the Audax throws caution to the wind.
The massive-volume tyres and incredible grip afforded by their broad shape makes every descent a test of courage rather than equipment. I found myself pushing on every descent, laughing out loud about what I could get away with.
The Audax performed beautifully. Gear changes are crisp and clean, and the 105 brakes are smoothly progressive with no vocal protestations, even in some truly horrid weather.
I do have a couple of quibbles though. The Bombtrack saddle, with its long, narrow and very firm shape, is completely at odds with the rest of the bike’s character. Saddles are a personal choice, and this is one I wouldn’t swipe right with.
The other niggle was that after 100 miles or so of testing I was getting a grouchy clicking sound from the bottom bracket. This would most certainly be cured with a bit of maintenance (almost half the miles I did on the bike were in very foul wet weather) and a bit of lubrication.
Bombtrack Audax bottom line
If you’re the sort of endurance rider who’s interested in PBs and Strava KOMs, the Audax isn’t for you.
If, however, you’re interested in every ride being fun-filled and in fine comfort, with a bike that simply wafts you over the worst road surfaces and won’t protest if you drift onto proper gravel for extended periods, I’d fully recommend the Audax.
It’s a totally different approach to what an endurance bike should be and one that’s wholly successful in its execution.
If I was riding an epic-distance, time-windowed event, then Bombtrack’s leftfield design approach would put the Audax high up on my list of bikes.
It’s cosseting over horrid surfaces, more than quick enough on rolling terrain and what you lose with its plodding climbing you’ll more than make up on the descents.
In conclusion, would I choose this Audax for long-distance riding? Yes I would.
Endurance Bike of the Year 2022 | How we tested
The best endurance road bikes combine a comfortable ride position with heaps of versatility – including features such as mudguard or pannier rack mounts – and speed, to create a useful platform that will fare well no matter the ride.
Testing for our 2022 Endurance Bike of the Year category began with a high-tempo 2.5-hour ride to get an early impression of a bike’s ride quality and to carry out any adjustments.
For the meat of this year’s testing, each bike was taken on the same 82-mile/132km loop through rural Wiltshire.
After this, we rode the bikes back-to-back, coming to a decision on the best by comparing how well each handled across a variety of terrain and, in a competitive market, how its spec compares with the other bikes on test.
Our 2022 Endurance Bike of the Year contenders are:
- BMC Roadmachine X
- Bombtrack Audax
- Cannondale Synapse Carbon LTD RLE (category winner)
- Cervélo Caledonia Ultegra Di2
- Trek Domane SL 6 eTap
|Price||AUD $4400.00EUR €2850.00GBP £2750.00USD $3415.00|
|Available sizes||XS, S, M, L, XL|
|Handlebar||Ritchey Comp Streem III drop bar|
|Tyres||WTB Byway TCS 650b x 47c, tubeless ready|
|Stem||Ritchey Comp 4-axis 44 forged aluminiu|
|Shifter||Shimano 105 ST-R7020 STI 2x11|
|Seatpost||Ritchey Comp 2-bolt aluminium|
|Rear derailleur||Shimano Ultegra RD-RX800-GS, clutch, medium cage|
|Headset||Sealed external aheadset|
|Grips/Tape||Bombtrack Command bar tape|
|Bottom bracket||Bombtrack T47 internal-sealed BB for 30mm spindle|
|Front derailleur||Shimano 105 FD-R7000|
|Frame||Columbus Cromor double-butted, TA, rack / fender mounts|
|Cranks||Bombtrack Lyer forged aluminium crank, chainring Aluminium, sub-compact, 48 / 32t|
|Chain||KMC X11 EPT Anti Rust|
|Cassette||Shimano 105 CS-R7000 11-speed, 11-34t|
|Brakes||Shimano 105 BR-R7070 flat-mount hydraulic disc brakes with 160mm rotors|
|Wheels||WTB ST i25 double wall, with Bombtrack TAU sealed hubs|