H&H 5 speed cassette for C-line

Upgrading a Brompton C-line 2-speed to a 5-speed using the H&H cassette is a complex modification that requires several additional third-party components beyond just the cassette itself. It is not a simple swap and often requires some technical expertise for proper installation and tuning

• H&H 5-speed unibody cassette: This replaces your existing two sprockets. The common gearing is 11T-13T-17T-22T-25T.
• Compatible rear wheel/hub: The H&H 5-speed cassette is designed to fit on the stock Brompton 2/6-speed rear wheel (which has a specific type of freehub body that uses a circlip). You do not necessarily need a new wheelset, but you might need to re-dish the wheel in some cases.
• 5-speed shifter: The original 2-speed shifter is not compatible with the 5-speed indexing. You will need an aftermarket 5-speed thumb shifter (e.g., an H&H SQT shifter) or a compatible 10/11-speed MTB shifter (like a SRAM 10-speed shifter).
• Third-party derailleur/tensioner system: The stock chain tensioner on older models is designed for only two sprockets and cannot handle the range or sideways movement needed for five. You need a specialized aftermarket parallelogram-style derailleur/tensioner (e.g., from H&H, MiniMODs, etc.) that can accommodate up to a 25T cog.
• 11-speed or higher chain: A narrower chain is necessary to fit the tighter spacing of the 5-speed cassette.
• New gear cable and housing: The new shifter and routing may require a new, longer cable and housing.
• Chain pusher modification (optional but recommended): Some kits include modification parts or a chain catcher to reduce the chance of chain drops, which are more common with multi-sprocket systems