NEW.GTRO 3:SPEED INTERNAL GEARBOX CHAIN.SET

Compact, front-mounted gearbox that replaces a traditional triple chainring with a cleaner, tougher drivetrain. Built in the UK. Direct-drive first gear plus two step-up ratios (1:1, 1:1.43, 1:1.79). Gearing at the crank keeps a straight chainline, so no front derailleur, less chain rub and drops, and less maintenance. Shifts cleanly under load or from a standstill. Works with a normal rear drivetrain on city, hybrid, folding, e-bike and light touring builds.

Updated version, made in the UK

Gloss black as standard

Suited to trekking, hybrid, urban, single-speed, city and folding bikes, plus light off-road, e-bikes and trikes

Can shift into first from a standstill, or under load

Faster, simpler shifts than a front derailleur

No chain rub or chain drop, even with a rear derailleur

Low maintenance, no lubrication needed

Tested on-road, off-road, in the lab and in winter

Ratios 1:1 / 1:1.43 / 1:1.79

Direct-drive 1st; 2nd and 3rd are step-ups

5-bolt spider for 130 BCD chainrings

Not for race MTB, downhill or dirt jump

Easiest front gearbox to fit, no harder than a normal chainset

No frame mods needed

Fits most frames with English BSA bottom bracket

Shell outer diameter must not exceed 45.6 mm

Trigger or twist shifter

Works with most rear systems (derailleur, gear hub, single-speed hub, rear motor) except fixed-gear wheels. For internal gear hubs, check the maker’s smallest allowed front chainring

Also fits most popular folding bikes

Get in touch for details or special requirements

Follow us on socials for recurring promo codes

Sales outside the UK will incur local duties.

nFIXED London #L35515M0R3

1/2 weeks lead times from purchase