The Aztec HexVent disc brake pads offer great bite and power; quiet and reliable performance whatever the weather; and an unusual honeycomb look. The heatsink section looks a bit cheaper in real life than you might think, but the extra cooling does no harm and I had no issues with brake fade.
Fitting these proved no issue, with everything slotting together and lining up just fine with my Shimano GRX callipers. They come with a new spring for holding them apart – worth using as used ones can fatigue and snap.
The honeycomb vented section doesn’t look as slick in real life as in the pictures, at least to me. Swapping from stock Shimano pads with their fancy forged alloy heatsinks, these just looked a bit Heath Robinson, as if they’d been whipped up out of a curl of chicken wire. Okay, that’s a bit harsh and mostly a first impression while peering closely. Stand next to the bike and they’re quite low key, and after a minute they look just fine.
More importantly, they work really well. The bedding in period (on a very wet ride) was short, and after a few heavy stops the squeal disappeared and never came back.
Their stopping power is impressive, and I particularly like the very positive, crisp and meaningful initial bite. Modulation is as good as ever from my Shimano system, and they give good stopping and feedback whether it’s pouring with rain or hot and dry. Even braking hard from speed on record-breakingly hot days failed to provoke any fade, though Aztec doesn’t supply evidence to show how much the heatsinks actually affect cooling.
> All you need to know about replacing disc brake pads
At the very least, increasing the surface area (and positioning it in a stronger airflow) is right in principle, though whether we’re talking 10 per cent cooler on average or 0.1 per cent is anyone’s guess.
There’s also the question of whether trying to cool the pads is the right approach in the first place, as this interesting article from Kogel Bearings explains. Kogel doesn’t have evidence to back up its own approach either, however – plus it has something else to sell you instead (ceramic backed pads), so this too needs taking with a pinch of salt.
If you’re really having issues with fade, though, logic says bigger discs (greater leverage for lower forces, greater surface area for cooling) are likely to be more help than finned pads.
Whatever the truth of the need for (or efficacy of) cooling fins on brake pads, these Aztec pads work very well, and they’re wearing well too despite the rain, dust and abrasive grit of my gravel riding.
Value
At £24.99 these are slightly cheaper than the equivalent Shimano replacements – Shimano’s sintered L04C pads with cooling fins are £29.99. Those work very well too, as you might expect.
If you don’t care about fins, the Gorilla Sintered Brake Pads to fit GRX are half the price at £12.99. Gorilla says you don’t actually need fins because its pads are ‘specifically engineered for optimal heat dissipation,’ but it offers no more evidence for its claims than anybody else.
Overall
Having swapped some pretty worn Shimano pads for these aftermarket ones, I’m in no rush to get back to stock pads. The Aztecs perform really well, with great initial bite and plenty of power as you squeeze harder. They run quietly, perform reliably whatever the conditions and are lasting well.
Test Report
What does the manufacturer say about this product?:
High performance disc brake pads with patented hollow backplate heat control system.
Tell us some more about the technical aspects of this product:
Heat transfer between the brake pad material and brake piston is reduced significantly, preventing brake fluid vaporisation
Increased surface area and air-cooling-channel dissipates heat efficiently, reducing brake fade during prolonged braking events
How does the price compare to that of similar products in the market, including ones recently tested?:
They’re competitive against other finned pads, though traditional designs are cheaper.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
These deliver crisp, quiet and powerful braking and are slightly cheaper than sintered stock GRX replacements. They have a unique look, too.
About the tester
Age: 48Height: 183cmWeight: 78kg
I usually ride: Temple Adventure Disc gravel bikeMy best bike is:
I’ve been riding for: 10-20 yearsI ride: A few times a weekI would class myself as: Experienced
I regularly do the following types of riding: Fitness riding, Mountain bike XC, Mountain bike Enduro, Mountain bike downhill/freeride
1 thought on “Aztec HexVent disc brake pads for Shimano flat mount Dura Ace / Ultegra / GRX + others”
insert fancy pads, record deceleration video using FLIR camera.
repeat with ‘normal’ pads. post-process video with FLIR tools to exclude imaging under ~35°. compare.
organic/resin pads dump more heat into the rotor, compared to sintered pads which conduct it into the caliper and fluids.