Magura Gustav Pro Brakes
Stated Weight: 348 g per brake, w/o rotor or adapter
MSRP: €299.90 (including VAT); US pricing TBD
Adjustments: Reach (tool-free)
Fluid Type: Mineral oil
Intro
The Gustav M was Magura’s first hydraulic bike disc brake when it launched in 1996, and after a very long hiatus, they’re bringing back the Gustav name (drawn from that of their founder, Gustav Magura) and what they’ve come up with is pretty interesting.
Earlier iterations of the Gustav were known for being hugely powerful, at least by the standards of the day. The biggest, most gravity-oriented mountain bike brakes have gotten massively more powerful in recent years, so what has Magura done to compete in today’s market?
Design
It’s worth noting that Magura describes the new Gustav Pro as being suited for gravity MTB applications, but expressly mentions eMTBs and “SUV” bikes (i.e., cargo bikes) as intended use cases as well — and some of the design details seem clearly tailored to the latter options.
Gustav Pro Caliper
The design of the Gustav caliper is very clearly a Magura design. It’s a four-piston caliper with a forged one-piece design and uses a separate brake pad for each piston (i.e., four per caliper) instead of the usual two. The pads are kept in contact with the pistons by magnets rather than the more common leaf spring, and the hose fitting at the caliper uses a banjo bolt so that the hose orientation can be adjusted. As per usual for Magura, the Gustav Pro uses mineral oil for the brake fluid.
So far that’s all more or less the same as Magura’s longstanding flagship gravity brake, the MT7; the main thing that sets the Gustav caliper apart is that it’s a lot bigger. The Gustav Pro uses four 19mm-diameter pistons (up from 17 mm pistons on the MT7), and while 2 mm of diameter might not sound like that much, it adds up to 25% more total piston area.
The Gustav Pro also gets a new pad shape to go with the bigger caliper. Magura says the Gustav’s pads have 40% more material than the MT7 pads, for better durability and heat management; the Gustav Pro pads also feature cooling fins to help dissipate heat.
Another less visually obvious change is that the Gustav Pro is designed to use Magura’s new 2.5mm-thick MDR-S rotors — up from 2.0 mm on their other brakes. The bigger rotors come with a bit of a weight penalty, but Magura says that the added material improves heat dissipation and overall braking consistency so much that they purposefully don’t offer a 220 mm diameter version because they simply feel it isn’t needed. (For reference, Magura’s stated weights of 219 and 266 grams for the 180 and 203 mm MDR-S rotors, respectively, are about 40-50 grams heavier than the thinner MDR-C options.)
Magura says that 2.0mm-thick rotors are still compatible with the Gustav Pro if you prefer, or you just need to run a non-standard option in a pinch.
Gustav Pro Lever
The Gustav Pro lever design is very identifiably Magura, too, but relative to its caliper, the new lever design is much more visually different from that of the MT7. But let’s start with the commonalities: the Gustav Pro uses a radial master cylinder orientation and a carbon-reinforced plastic body. The lever blade is made from forged aluminum, and its shape is based on the Loic-Bruni-spec HC-W lever option for the MT7. Reach is adjustable tool-free, but there’s no contact-point adjustability to be found. The lever blade also features a designed-in breakaway point to help reduce the chance of damaging the main lever body assembly in a crash, and to hopefully leave you with enough lever blade left to get down the hill should you break off the tip.
Magura also says that their goal for the Gustav Pro was not so much to make a more powerful brake than the MT7, but one that’s more consistent in its performance under heavy use. To that end, the Gustav master cylinder has also been upsized to match the bigger caliper pistons (to 12 mm, from 10.5 mm on the MT7). That’s roughly a 30% increase in area, so the Gustav Pro actually has a slightly lower hydraulic leverage ratio than the MT7.
The idea here is twofold: (1) achieve a similar amount of power with less hydraulic pressure in the line, which Magura says improves consistency and mitigates sponginess in the lever if the brake isn’t bled perfectly, and (2) increase the overall oil volume, both for heat management reasons and to work better with Bosch’s ABS system for eBikes.
So far, we haven’t seen that system popping up on a lot of eMTBs, but Bosch does offer a “Trail” mode on their ABS system with off-road bikes in mind. So far, it seems to be getting more traction (sorry) on commuter and cargo bikes, but it’ll be interesting to see if that changes in the future.
Magura’s brake levers have long used self-tapping screws threaded directly into the composite lever body, but they’ve done away with those on the Gustav lever, which uses a hinged clamp with a single bolt. Shiftmix adapters for various styles of integrated controls are also available.
Easy Link
Magura has also revisited their hose connection design and came up with a new quick-release “Easy Link” system at the Gustav lever. In short, instead of using a typical threaded fitting with a one-time-use compression olive and barb, the Gustav Pro uses a push-in fitting that’s secured by a wire clip inside the lever assembly. The lowest-profile version of the fitting is crimped onto the line; Magura sells the crimping tool in both mechanical and electronic versions for shops or bike companies that are assembling hoses in large volumes, but the tools are on the expensive side for everyday home mechanics.
Magura says that the Easy Link arrangement has a few benefits. First, it’s simply quicker and easier to attach and disconnect the hose from the lever end, and you don’t need to replace the fittings when you do so. That potentially saves time when swapping brakes or assembling bikes, but the bigger advantage for the average consumer is that the crimped-on version of the fitting is small enough to fit through internal routing ports on most frames — including those going through the headset.
That has the potential to make dealing with headset cable routing (or regular internal routing) a lot easier. If you need to take things apart, you can simply unclip the brake hose and, at least in theory, re-route it without needing any replacement fittings or having to re-bleed the brake afterward. The grumpy old man in me still sees that as a solution for a problem that never should have existed in the first place, but it’s not Magura’s fault that headset routing is a thing now, and it’s nice that they’re doing what they can to make the Gustavs easier to live with.
Some Questions / Things We’re Curious About
(1) The big one: how do the Gustav Pros perform, from power to lever feel, consistency, modulation, and so on?
(2) Do the Gustav Pro brakes feel like they’re meant to be a high-performance gravity MTB brake first and foremost, or do the other parts of their design brief — e.g., the ABS compatibility — introduce notable compromises for off-road use?
(3) Is the Easy Link hose connector really as easy to use as Magura claims it is, and can you really disconnect and reconnect it without needing to re-bleed the brake?
Bottom Line (For Now)
The new Magura Gustav Pro is an interesting-looking offering from Magura, and an intriguing throwback to the earlier versions of the Gustav, which had a reputation for truly massive power, at least compared to the other brakes of their day.
We should be getting a set of Gustav Pros in for long-term review when they become more widely available in late 2024, so stay tuned for a Full Review down the line.
These look sturdy. Needing a special crimping tool will limit aftermarket sales (if Magura cares). The olive/barb system may be a bit fiddly, but I can do it in my garage with 100% reliability.
You don’t *need* the crimp tool to install them — as mentioned in the first look, there’s a threaded version of the fitting that works like a standard barb and olive; it’s just bigger diameter and won’t fit through most guided internal routing like the crimped one will. The banjo fitting at the caliper end is also threaded, so you can shorten the line from that end and preserve the factory crimped fitting, too — you’ll just probably need to bleed the line in that case.