Installation & compatibility

Will I be able to install it myself?

If you are not afraid to make your hands a bit dirty – yes, you will be able to. See the installation video and decide.
You can also take your GTRO to the bike shop to have it installed.

How to check compatibility with my bike?

Please take a look here – “check before you buy”. Please read it carefully. If you have any doubts – use a mail form to e-mail us and ask. That’s the easiest option.

Can I use my shifter?

In theory it’s possible, but we do not recommend it. Your GTRO comes with a shifter, either trigger or twist.

What about chainring exchange?

GTRO’s chainring is made of high quality steel (not aluminum), so it should last much longer without the need to replace it than most chainrings on the market. However, if you need to exchange it, the chainring as a replacement part will be available in our online store very soon (with a video how to exchange it).

When will you have a press-fit bottom bracket version?

In 2018.

What is a “chainstay”?

Chainstay is a pipe that goes from the bottom bracket shell (where the cranks are installed) to the rear wheel hub. We use a chainstay as a point of support for the reaction lever.
If your bike has no chainstay, please choose the option “recumbent/trike – yes” when making a purchase. We’ll send you a longer reaction lever that can use any middle plain tube as a point of support.

Is it compatible with 1/8” and 3/32” chains?

GTRO is compatible with any chain of maximum width of 1/8 inch. If you use a rear derailleur, you usually need a thinner one, but it is ok with GTRO.

GTRO parameters

What’s the gearbox drag?

The drag is a loss of efficiency due to internal friction of the gearbox mechanism. All gearboxes have some drag.
The rule is that the higher load the smaller % efficiency loss (drag). At very high load we had around 2% drag. The problem with the drag measurement is that there is no official norm for measuring it and nobody knows how different companies measure it. Are they measuring it at 10Nm? Or 50Nm? Or 80Nm? And it has a huge impact on the result in percent. If you take any bicycle gearbox in hand (front gearbox like ours or an internal gear hub) you would have a feeling of a big drag. That comes from the fact that your fingers are hundreds times weaker than your legs and at this minimum torque the feeling of a drag is high. You would feel it even on a single speed hub or a bottom bracket. That is a bit misleading.
Our construction is only a 3-speed system, so the drag is lower than in multi-speed systems with complex gear sets that have a long kinematic chain for the torque to go through.

What’s the maximum load?

We have tested the GTRO gearbox heavily under maximum 120 kg load (rider plus additional load).

Can I use it on a cargo bike?

It depends on its type. If you use your cargo bike for pizzas or some other light stuff – yes. For anything more than this (e.g. café bike) we do not recommend the GTRO gearbox, as it has not been tested for loads above 120 kg.

What about other colors?

Black color will be available soon.

Are you offering a drop handlebar shifter?

We are now testing the indexed drop handlebar shifter. It will be available soon.

What about beltring version?

Carbon Gates Belt compatible gearbox will be available by the end of 2017.

Will it work with a fixed rear hub?

GTRO has a freewheel inside so when you backpedal it does not transmit any torque. Thus, you cannot brake with your legs like on a traditional fixie.

Will it work with a coaster brake?

No, you cannot brake with your legs.

I have a shifter integrated with a brake lever, can I use it?

No, you have to exchange your brake lever to another one.

How does it behave in low temperatures, salted snow and mud?

We have tested it in temperatures as low as -10 Celsius. It’s difficult to get lower temperatures in Poland, even in winter. We had no problems. GTRO is sealed with four different seals and they keep snow and mud away from the internal mechanism.

What kind of grease is used?

We are using bicycle grease that is used widely for hubs or bottom brackets in the bicycle industry.

Purchase, service & warranty

Is lubing necessary?



We are offering two-year warranty.

What if my GTRO does not function properly?

Please go to our “technical support” section.

Are you shipping to my country?

We are now shipping to the United Stated, Canada, European Union, Switzerland, Japan and Australia.