nFIXED London

EFNEO GTRO 3-speed internal chain-set gearbox

Sale price Price £445.00 Regular price Unit price  per 

perfect for trekking, hybrid, urban, single speed, city and folding bikes, as well as for off-road non-competition bikes, e-bikes and trikes

can shift to first gear from a standstill, like in a car, or under load

immediate gear change, quicker and easier than a front derailleur

no chain-skewing and chain-dropping, even when paired with a rear derailleur

reduced maintenance, no lubrication necessary

heavily tested (on-road, off-road, laboratory and winter tests)

1:1 / 1:1.43: / 1:1.79 ratios

direct-drive 1st gear, second and third are incremental

more on our "TECHNOLOGIES" page

not suitable for competition MTB, downhill or dirt applications

the easiest front gearbox to install

no frame modifications necessary

also available with a standard 5-bolts 130bcd spider

compatible with most bicycle frames, using English threaded BSA bottom bracket shell

shell diameter cannot exceed 45,6 mm

trigger or twist-grip shifter

compatible with any rear transmission  (derailleur, geared hub, single speed hub, rear motor) except fixed wheel. For internal geared hub, please check manufacturer’s specs for the smallest front chainring allowed

"38T conversion kit" includes just chainring and bolts, all you need to convert any standard 28T GTRO and increase all its ratios by 1:1.36

also available for Brompton or other folding bikes


get in touch for more details or to discuss specific requirements