Power, control, adjustability and eye-catching heritage are combined in Brembo's return to the mountain bike brakes market.
While at the Bike Connection Winter event, I was able to jump on what might be the most hotly anticipated MTB brakes to be released in years – the Brembo GR-PROs.
These eye-catching brakes have been in the works for a few years, with the Specialized Gravity team – Loïc Bruni’s outfit – having raced them for the past couple of seasons during their development.
The brakes bring 50 years of motorsport heritage, a little Italian flare, buckets of power and market-leading adjustability to mountain biking, but they come at a price (€750 for the kit) that’s going to be tricky to justify.
Brembo GR-PRO details
The GR Pro brakes feature what is possibly the bulkiest lever in the performance MTB space, with a large master cylinder held onto the bar with a split-clamp design.
Brembo’s experience with motorbike brakes is a tell-tale design cue, while larger fluid volumes are good for brake consistency.
The aluminium lever blade is long. This, according to Brembo, is to increase the leverage of the lever, when pushing on the small master piston, improving the brakes' efficiency.
The long blade has a very fine texture, a straight main section of the blade and a short but effective hook at the end to lock your finger in place.
With the combined size of the lever body and blade, I had to run the clamp fairly far inboard of the grips. Fortunately, Brembo’s shifter and dropper lever adaptors, meaning you only need one clamp on the bar, are long enough to compensate.
The most notable feature of the GR-PRO is the range of adjustment on offer.
There’s 30mm of lever-reach adjustment, with a knurled wheel giving 40 distinct clicks as you turn it, while there’s also a broad range of bite-point adjustment – accessed via a 3mm Allen key. While one influences the other, there’s ample adjustability to get the lever and bite point just where you want them.
In addition, there’s the ability to adjust the ratio of lever pull and piston push.
By adjusting this between Soft, Medium and Hard (S, M, H on the dial), you can move from a lighter-feeling lever pull with a less dramatic bite to a stiffer lever feel with a very definite bite.
Think moving from a Magura brake to a Shimano brake, but on steroids at either extreme.
Brembo says that, in combination, the three adjustments mean you can set the GR-PRO brakes up to feel like any other MTB brakes on the market.
Within the steel braided hoses, a low-viscosity mineral fluid flows. This is Brembo’s own in-house formulation that has taken it time to develop (its motorsport brakes run on DOT fluid, but the MTB space mostly uses mineral).
The brand claims its fluid is more consistent in its behaviour across the temperature ranges experienced in mountain biking, and thus gives a more consistent performance. Its low viscosity also helps it flow through the hoses and piston assemblies with less friction, improving feel.
The two-piece alloy caliper, with its design inspired by Brembo’s four-wheeled vehicle brakes, is much more svelte than the lever.
It features four 18mm pistons, whose aluminium outers are filled with a fibre-polymer insulating material that extends past the edge of the alloy piston.
This polymer is in contact with the pads, and thanks to its heat-insulating properties, is designed to transmit less heat to the caliper and fluid.
The pads are the result of plenty of testing with the Specialized Gravity team.
Of 30 compounds, three were shortlisted and tested at World Cups, with the semi-metallic compound that came out on top being the same that’s offered in customers’ brakes.
A choice of 2.3mm-thick 200mm or 220mm rotors is offered, with their spokes’ design following Brembo’s motorbike rotors – they’re not mounted the wrong way!
The bleed kit is specific to the brakes.
Brembo GR-PRO performance
I tested the GR-PRO at the Bike Connection event in Massima Maritima in Italy, over the course of a couple of days. The brakes were fitted to a Mondraker Level eMTB, with a total rider plus bike weight of over 100kg.
The trails were fast and fun, but with plenty of tight corners and steep chutes, ideal for testing power and control. The hills weren’t big enough to get serious heat into the brakes, though.
The lever’s adjustments are some of the most effective I’ve used. Pairing the lever-reach and bite-point adjust made getting the pull and bite of the brakes just where I wanted them an easy job.
Most impressive, though, was just how effective changing the lever-pull to piston-push ratio is.
In the Soft setting, the brakes’ bite point is still very much there, but it’s less harsh or digital. There's a fair amount of lever travel while the pad is in contact with the rotor, giving tons of soft modulation and feel.
This gives you so much control of the brakes' power.
A gentle squeeze feathers your speed, while power is added progressively and predictably, all the way up to incredible levels.
To test how good the control was, I dropped into a loose, loamy slope and rolled down as slowly as possible using only the front brake.
There was no slipping, no sliding, just predictable control.
Shift to the Hard (H) setting and the feel changes. The lever blade requires more force to pull it, and when the pad hits the rotor, the power is instant – think Shimano rather than Magura.
Despite this, once you’re used to the instant application of power, it's still controllable, but the in-contact lever stroke is a little shorter, ramping up to full eye-popping power much quicker.
Predictably, the M setting, between the two, balances both.
When it comes to power levels, I was impressed. There is a lot – certainly as much, if not more than the likes of Hayes’ Dominion, Shimano's XTR or Hope’s Tech 4 V4 brakes I’ve ridden recently.
This should be no surprise, given they’ve been built for a multiple world champion.
As such, DH racers, heavier enduro racers and eMTB riders shouldn’t worry about any lack of power.
There were a few negatives, though.
They’re not silent – an occasional hum was emitted during comfort braking, and there was the odd squeal when they got warmer.
I also felt the lever blade could do with more texturing to help give the finger a more secure feel – something Shimano does well.
The price is high, too. While I don't have UK or US pricing yet (with July shipping, I expect to receive this in a couple of months), the European pricing is certainly punchy.
Brembo GR-PRO pricing
- Bike Brake Kit (pair of calipers, levers, hoses, 2 sets pads): €750
- Brake rotor adaptor (+20 or +40): €21
- Shifter adaptor: €29.83
- Pads: €32.70
- Discs (200mm or 220mm): €59.95
- Bleed kit: TBC
- N.B. Pricing excludes VAT
Brembo GR-PRO bottom line
Brembo has clearly used its vast experience of building motorsport championship-winning brakes – the GR-PRO brakes are genuinely some of the most impressive stoppers I’ve used.
There's tons of power, precise control, and some of the most effective and useful lever-feel adjustment on any brakes.
Brembo says you can make its brakes feel like any others on the market – and I don’t doubt that. But the question remains, if you like the feel of a Shimano, SRAM or Magura brake, why not just buy another Shimano, SRAM or Magura brake and save yourself a packet?
