TRP’s four-piston Quadiem has been around since 2013, but after DH legend Aaron Gwin signed with the brand, they collaborated on this new ‘G-Spec’ version. It’s a powerful and solid-feeling brake, but not as polished practically as it is aesthetically.
The Quadiem has always been a big brake, and at 535g for a full front set-up (including one-piece 180mm rotor and brackets) it’s significantly heavier than other flagship stoppers such as Shimano’s Saint (474g) and SRAM’s Code RSC (487g), despite titanium bolts.
That weight includes a sturdily mounted and solid-feeling cold-forged lever with G-Spec grip dimples. The calliper has also been kept closed rather than hollowed out to reduce weight, because Gwin didn’t want to introduce any potential flex.
Cooling grooves have been machined into the calliper though, and the four pistons are ceramic-centred to reduce heat transfer. They’re also compatible with sintered pads, and we’ve had no trouble scrubbing speed off, even on long, brake-dragging alpine descents.
Stainless-steel piston-skins keep retraction smooth, and the system has a clean and free-moving feel even after plenty of mud and loam exposure.
At the lever end, the drilled blade tip helps in wet weather or if you drop your bike in the slop
Bleeding the mineral-oil internals is easy too, after trimming the super-long hose. For a DH/bike park brake, the protruding outside-edge hose attachment point is worryingly exposed to accidental crash/uplift damage.
At the lever end, the drilled blade tip helps in wet weather or if you drop your bike in the slop. The 30 indents on the big reach-adjustment dial mean tons of fine-tuning potential.
There’s a lot of free stroke before the pads contact, though (25mm, compared to 20mm for a Code RSC, with levers set at 80mm from the finger-hook ‘crook’ to the grip), and there’s no independent bite-point adjustment. That means changing the lever-reach moves the bite-point with it, and if you’ve got short digits, the bite-point is going to be right on the grip.
Considering the size and weight of the brake, power levels are adequate rather than amazing, so you’ll want a 200mm rotor for gravity work. The lever feel is extremely solid and totally flex-free structurally, and power is consistently progressive as you pull harder past the initially blunt contact.
It becomes noticeably more grabby if it really heats up though, and it lacks squeezable ‘touchy feely’ fine modulation compared to the most communicative brakes.