GTRO Gearbox

Are you like most people that really don’t like all the hassles and problems associated with a front derailleur? Now you have an alternative.

Efneo’s GTRO 3-speed front gearbox is perfect for trekking, hybrid, urban, single speed, city and folding bikes as well as for off road non-competition bikes and e-bikes.

Efneo's 3-speed front gearbox GTRO from efneo on Vimeo.

Product Gallery

Advantages for you

Easy to start from the first gear With Efneo you can reduce to the first gear in a standstill – like in a car – and start easily in 1st gear.

Immediate gear change Much quicker and easier than with a front derailleur. Change gear when pedalling and in a standstill.

No chain-skewing No chain-skewing and chain-dropping when paired with a rear derailleur.

Reduced maintenance No need for tiresome, tricky adjustments.

How it works?

Efneo Gearbox - How It Works? from efneo on Vimeo.

How to oput it on a bike - step by step

Efneo's GTRO Gearbox - How to install? from efneo on Vimeo.


Technische Daten

Gearbox type

It is a planetary gearbox.


It will add about 200 grams to the weight of your bike if you remove a three-chainring crankset of good quality (with aluminum cranks) and put the Efneo gearbox on your bike.

Gear ratio

Overall gear ratio is 179%.
2nd to 1st is -30%, 2nd to 3rd is+25%.
Efneo’s gearbox is equivalent to a front crankset with 28T/40T/50T chainring.

Frame compatibility

You can put Efneo gearbox on any frame designed for a tapered square axle bottom bracket.

Gear shifting

You can change gears when you are not pedaling.
You can change gears under load when upshifting a gear. You have to loosen your leg a bit when downshifting a gear (like in most bicycle gearboxes on the market).

Shifter and cable

We will be using a one-cable paddle shifter, like the one shown in this video. We plan to provide a grip-shifter, too.


Gearbox installed on:
- 68mm long BB Shell: 43.0 mm
- 73mm long BB Shell: 45.5 mm


Gearbox installed on:
- 68mm long BB Shell: 177 mm
- 73mm long BB Shell: 182 mm

Crank length

170 mm
175 mm

Rear transmission compatibility

Can be paired with a rear derailleur, rear gearbox or single-speed hub. For a rear gearbox check the minimum front chainring suggested by the gearbox manufacturer (they often require minimum 34T, and the Efneo gearbox has 28T); this condition does not apply to bikes with much smaller wheels, then standard 26″-28″, for example folding bikes.

Chain / belt compatibility

We will offer a chainring for 1/8 and 3/32 inch chains. Soon we’ll offer a sprocket for a carbon belt (Gates Carbon Drive®).

Installing gearbox on your bike

Installation is presented shortly on this video.

The gearbox package includes:
- a rigth crank, with a gearbox inside,
- a left crank,
- a square tapered axle bottom bracket,
- a shifter, with a cable,
- a complete installation manual.

Maximum torque

We guarantee the Efneo gearbox works perfectly in all conditions except for extreme off-road applications like downhill or professional MTB.

Coating and colors

Crank will be painted. Black and silver versions will be available.
No embossed / engraved logo will be put on the crank, so you can also repaint the gearbox, if you wish.


Aluminium Cranks

Aluminium cranks in oversize length of 190 mm, 200 mm and 210mm available! 3 Colours!!

Preis, 190 mm Länge: 190,00 €

Preis, 200 mm Länge: 200,00 €

Preis, 210 mm Länge: 210,00 €

Gewicht für den Kurbelsatz komplett: 720 g


Rack for recumbents

The highlight of this rack is the versatile adaptation options to your special bike:

The width can be varied by using tubes of shorter (or larger) lengths. Standard width: 115

Inclination: the attached fasteners can be easily shortened and the inclination can be set exactly horizontally or as required.

Weight approx. 800 gr.

Price: 87,30 €/St.



Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.

Version für linke Seite und für rechte Seite.




Fastening elements

Fastening elements for our and similar seats. In the picture the lower attachment with 3 longitudinal bores is shown for the seat, which allows for different seat heights. The matching mechanism enables continuous adjustment of the seat angle.
You can attach these mounts on your seat tube, order an inner width of 80, 70, 60 50 or 40 mm.

Material in natural aluminum, 4 mm, price for the set: 28,50 €

Material in black powder coated, 4 mm, price for the set: 38,50 €


Trommelbremsnaben für Trikes

Einseitig aufgehängte Nabe mit Trommelbremse 90 mm Durchmesser,

Version für linke Seite und für rechte Seite.

Preis komplett mit Schnellspannachse: 87,30 €/St.




Other accessories and parts

(ohne Abb.)

Aluminium rims, no drills, silver anodized

Width outside: 23 mm/26"

€ 25,00 / each

Width outside: 23 mm/28"
€ 25,00 / each



The bike dealer is your partner when it comes to choosing the right parts for you.
Here you find the next dealer for you.



We are sorry that our online-shop is working for German customers only.

Foreign customers are kindly requested to order via email  or



Novosport is also a stockist and partner of

"Radical Design"

Ihr E-Mail