T47 - TREK for Shimano

The frame type describes the bottom bracket shell standard. This standard is often listed in the manufacturer's bike specifications, but it can also be determined by measuring several dimensions of the bottom bracket shell, such as the width and inner diameter.

The values at a glance:

• BSA — the cups are screwed directly into the frame with a 1.37″ × 24 thread. The bottom bracket shell is 68 mm (road) or 73 mm (MTB) wide.
• ITA — the cups are screwed directly into the frame with a 36 × 24 thread. The bottom bracket shell is 70 mm wide.
• T45 — the cups are screwed directly into the frame with an M45 × 1 thread. The bottom bracket shell is 82.5 mm wide.
• T47 Outboard — T47 standard in which the bearings sit in cups outside the frame. The bottom bracket shell is 68 mm (road) or 73 mm (MTB) wide. The cups are screwed directly into the frame with an M47 × 1 thread.
• T47A — asymmetric T47 variant with a bottom bracket shell width of 77 mm. The cups are screwed directly into the frame with an M47 × 1 thread.
• T47 TREK / Inboard — T47 standard in which the bearings sit in cups inside the frame. The bottom bracket shell is 85.5 mm wide. The cups are screwed directly into the frame with an M47 × 1 thread.
• BB30 — press-fit standard in which the bearings are fitted directly into the frame. The bottom bracket shell is 68 mm (road) or 73 mm (MTB) wide. Our Interlock bottom brackets also allow other crank types to be fitted.
• BB30A — asymmetric variant of BB30 for road frames, used by Cannondale. On the non-drive side the bottom bracket shell is 5 mm wider than with BB30.
• BB86/BB92 — widely used press-fit standard with a bottom bracket shell width of 86.5 mm (road) and 92 mm (MTB) respectively. Also called PF86.5 or PF92. The bearings sit in cups. This standard is used by Giant, Canyon, BMC, Cube and other brands.
• BB89 — variant of BB86/BB92 with a bottom bracket shell width of 89.5 mm.
• BB386 — press-fit standard with a bottom bracket shell width of 86.5 mm and an inner diameter of 46 mm. The large inner diameter of the shell makes the standard suitable for various crank axle diameters.
• BB90 / BB95 — Trek-specific press-fit standard in which the bearings are fitted directly into the frame, without separate cups. The bottom bracket shell is 90.5 mm (road) or 95.5 mm (MTB) wide.
• PF30 — press-fit standard with an inner diameter of 46 mm. The bottom bracket shell is 68 mm (road) or 73 mm (MTB) wide. The bearings sit in cups that are pressed into the frame.
• PF30A — asymmetric variant of PF30 for road frames, used among others by Cannondale. On the non-drive side the bottom bracket shell is 5 mm wider than with PF30.
• OSBB — Specialized Over-Sized Bottom Bracket; a former Specialized standard with a narrow 61 mm bottom bracket shell.
• BBright42 — asymmetric press-fit standard by Cervélo with a bottom bracket shell inner diameter of 42 mm. The shell is widened by 11 mm towards the non-drive side relative to the centreline.
• BBright46 — asymmetric press-fit standard by Cervélo with a bottom bracket shell inner diameter of 46 mm. The shell is widened by 11 mm towards the non-drive side relative to the centreline.

The crank type indicates which type of bottom bracket axle (spindle) your crankset uses. Different brands and systems use different diameters and designs. Choosing the right crank type ensures a correct fit and proper functioning of your bottom bracket.

The values at a glance:

• Shimano — 24 mm axle; also suitable for other cranksets with a 24 mm axle.
• SRAM GXP — 24 mm axle that steps down to 22 mm (stepped spindle) on the non-drive side.
• SRAM DUB — 28.99 mm axle; also suitable for DUB WIDE and SL and other cranksets with a 28.99 mm axle.
• FSA386/Rotor 30mm — all modern cranks with a 30 mm axle.
• CAMPA UT — Campagnolo Ultra-Torque: two-piece 25 mm axle with a Hirth joint in the middle.
• PRAXIS M30 — 30 mm axle that steps down to 28 mm (stepped spindle) on the non-drive side.
• BB30/PF30 — older standard with a short 30 mm axle. Only suitable for BB30 and PF30 frames.

The frame width is the width of the bottom bracket shell of your bike frame. Measure the width of the bottom bracket shell, without any cups fitted, and then select the matching size. Together with the frame inner diameter, this is an important parameter for determining the exact type of bottom bracket shell.

The frame attribute describes the type of bottom bracket shell of your bike frame. It indicates how the bottom bracket is mounted in the bottom bracket shell of the frame.

The values at a glance:

• Threaded — in a threaded frame, the bottom bracket shell has an internal thread into which the bottom bracket is screwed.
• Pressfit — in a press-fit frame, the bottom bracket shell has a smooth inner surface into which the bottom bracket is pressed.

The frame inner diameter is the internal diameter of the bottom bracket shell of your bike frame. Measure the internal diameter of the bottom bracket shell and then select the matching size. Together with the frame width, this is an important parameter for determining the exact type of bottom bracket shell.