The most common question we receive before a Bafang kit order: “Will it fit my bike?” The answer depends entirely on your frame’s bottom bracket shell. This guide covers how to check compatibility and which bikes work — and which don’t — with Bafang BBS01B, BBS02B, BBSHD, and M600 mid-drive kits.

The Critical Specification: Bottom Bracket Shell

All Bafang mid-drive kits (BBS01B, BBS02B, BBSHD) thread directly into the bottom bracket shell — the tube at the bottom of the frame where the pedal cranks attach. The shell must meet two requirements to be Bafang-compatible:

Threading: BSA (British Standard) — 1.37″ x 24 TPI, right-hand thread on drive side (most bikes), left-hand thread on non-drive side
Width: 68mm or 73mm for BBS01B/BBS02B. 68mm, 73mm, or 100mm for BBSHD (100mm fat bike only)

How to Check Your Frame

Step 1: Identify Your BB Standard

Look at the bottom bracket cups on your existing bike. BSA cups thread in with a wrench — you can see the threads on the cups and the shell. If the cups appear to be pushed in without threading, your frame uses a press-fit standard — not compatible with Bafang kits without a significant workaround.

Step 2: Measure the Shell Width

Measure between the outer faces of the BB cups (not the inner dimension). 68mm = standard road and most mountain bikes. 73mm = wider mountain bike shells (very common on older hardtails). 100mm = fat bike shells (BBSHD only). You can verify the width from the bike’s original specification sheet, or by measuring with callipers after removing the BB cups.

Step 3: Check Chainstay Clearance

The Bafang motor housing is wider than a standard bottom bracket. Some frame designs — particularly those with very narrow chainstays or tight cable routing through the BB area — do not have enough clearance for the motor. Frames with carbon chainstays may also have different constraints. If your chainstays are narrower than 70mm at the BB junction, contact us before ordering.

Generally Compatible Frames

Most steel and aluminium hardtail mountain bikes built before 2019 with BSA threading are compatible. Popular UK examples:

Carrera Vengeance / Vulcan / Kraken (Halfords) — BSA 68/73mm, broad range compatibility
Trek Marlin 5/6/7 (pre-2019) — BSA 73mm shell, good clearance
Specialized Hardrock (pre-2018) — BSA 68mm compatible
Cube Attention / Aim (BSA models) — confirm BSA before ordering
Giant Talon (older models with BSA shell) — confirm model year
Voodoo Bantu / Zobop (Halfords) — typically BSA 68/73mm
Most steel-framed hybrids and city bikes with threaded BBs

Incompatible Bottom Bracket Standards

Standard	Also known as	Identify by	Bafang compatible?
BSA	English thread, BSC	Threaded cups, 68 or 73mm wide	YES
BB92 / PF30	Press-fit	Cups push in without threading	NO (without adapter)
BB386	386EVO	Wide press-fit, road bikes	NO (without adapter)
BB30	Cannondale standard	30mm spindle, press-fit	NO (without adapter)
T47	Threaded version of PF30	47mm ID threaded shell	NO — wrong threading

Some press-fit frames can be converted using threaded inserts (e.g. Wheels Manufacturing BB30-to-BSA inserts), but this is a workaround — the motor fit and chainstay clearance must still be verified.

Specific Models: Compatible or Not?

Bike	BB standard	BBS02B	BBSHD	Notes
Trek Marlin 5 (2020+)	BB90 press-fit	NO	NO	Changed from BSA in 2020
Trek Marlin 5 (pre-2020)	BSA 73mm	YES	YES	Confirm year before ordering
Carrera Vengeance E	BSA 68mm	YES	YES	Popular conversion donor
Specialized Rockhopper (2020+)	Press-fit	NO	NO	Changed to press-fit
Voodoo Bantu	BSA 73mm	YES	YES	Good Halfords option
Cube Aim (aluminium)	BSA 68mm	YES	YES	Verify specific model year

Still Not Sure?

Contact VOLTARC with your bike make, model, and year. We have helped hundreds of UK riders check compatibility before ordering — it takes 2 minutes and saves a return. We can also advise on the right kit for your intended use and confirm chainstay clearance for less common frames.

Bafang Compatible Bikes UK: What Frames Work? (2026 Guide)