BMW X1 Big Brake Kit Upgrade / TTSPORT Classic 8657
The second-generation BMW X1's 1.5T engine (140 kW, 220 N·m, 7-speed wet dual-clutch) isn't quick off the line at a claimed 10.5 seconds to 60, but its low-rpm torque peak makes it feel livelier than the spec sheet suggests — and it leaves real room for upgrades elsewhere in the drivetrain, starting with the brakes. This owner skipped the factory M Sport brake package and went with a TTSPORT TT8657 six-piston big brake kit instead, chasing better pedal feel and stopping power without the OEM price tag.
The build swaps the factory front caliper and rotor for a TTSPORT TT8657 six-piston caliper, a 355x32mm high-carbon heat-treated curved rotor, and TTSPORT stainless steel brake lines — all fitted behind the X1's 18-inch factory wheels with no spacers needed.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | BMW X1 (2nd generation), 1.5T engine, 18-inch factory wheels |
| Front caliper | TTSPORT TT8657 two-piece forged six-piston caliper, symmetric layout, 38/34/30mm pistons, 3.9 kg |
| Front rotor | 355x32mm high-carbon heat-treated curved rotor with Dacromet (zinc-chromium) coating |
| Lines | TTSPORT stainless steel brake lines |
The TT8657 caliper is built as a two-piece forged unit, which resists the heat-driven flex a one-piece casting can suffer under hard, repeated braking. Its hollowed-out piston design cuts weight while opening up more surface area for airflow, helping the caliper shed heat faster during sustained use.
Why It Works
- Two-piece forged construction keeps the caliper body rigid under load, which translates to a firmer, more predictable pedal instead of a soft, sponge-like response.
- The 355x32mm rotor adds mass and surface area over the factory disc, giving it more heat capacity before fade sets in, and the curved-vane design helps clear dust while pulling in cooling air.
- The whole assembly was engineered to clear the X1's 18-inch factory wheels with no spacers, so the swap doesn't force a wheel or offset change.
- The larger six-piston clamping area, paired with the three piston diameters (38/34/30mm), evens out pad pressure across the caliper for more consistent bite — TTSPORT cites roughly a 30% gain in braking force over the stock setup.
Installation Gallery
Frequently Asked Questions
What's included in the TTSPORT TT8657 big brake kit for the BMW X1?
Will the TT8657 kit fit behind the BMW X1's factory wheels?
What piston sizes does the TT8657 caliper use?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.