FAQ

When ordering a Gravaa wheelset you will receive – next to a front wheel and rear wheel:

• Disc brake rotors of your choice (mounted, in the selected size, 140-160-180mm),
• A freehub body of your choice (mounted),
• An ergonomical designed wireless control unit, which must be mounted on your handlebar,
• A GRAVAA wheel bag, and
• A set with small tools and some spare parts.

The GRAVAA wheels have a product lifetime comparable to standard wheels. We provide you with a warranty period of 2 years on non-wear parts. If you experience any degradation or issues with the performance of your wheels, please contact us. We will make sure to get you back on the bike as soon as possible. Read more about warranty conditions here.

Yes, you can. Your smartphone, with the GRAVAA app installed, is an alternative control and display to ride with. Without your phone and your control unit, you have no means to adapt the tire pressure – it will then keep the tire pressure at the last used setpoint.

You will not need it often, but it’s there to give you the option to directly start with the correct pressure (before a ride you can pump it up using your standard bike pump if you want) or in case you have a flat tire. However, in most cases there is no need to use your bike pump anymore – just leave it to the KAPS inside your wheel hubs.

No, this is a one-time setup. After one (full) rotation, your wheels get active. Your control unit wakes up after a button press. Hereafter, the coupling between the wheels and control unit is set automatically.

Don’t worry, we will help you. We will give general advise on which pressure to use. This will be shown to you in the app. As a user, you are free to change these default settings the way you want it.

Read more about optimal tire pressure here.

Further data acquisition on tire pressure data will help to give detailed personalised advise to each GRAVAA rider, such that you can ride with optimal tire pressure settings on your planned tours.

Upon ordering you can select the correct freehub body. We can deliver our wheelset with one of the following freehub bodies which are compatible with the following cassettes:

• Shimano Microspline 12 speed,
• Campagnolo Ekar 13 speed, and
• SRAM XD/XDR.

Yes, you can display the tire pressure (front and rear) on your bike computer using ANT+ or bluetooth.

Our first two wheelsets, the GX-30 and XC-28 sets, are intended for gravel biking and (cross-country) mountain biking respectively and are not specifically designed for e-bikes. However, they may fit in bikes with a middle engine. Bikes with an integrated motor inside the hub will conflict with our wheels.

No, but the good news: we are compatible with a lot of bike frames!

The following requirements apply:

• Either boost (110 mm front / 148 mm rear) or non-boost (100 mm front / 142 mm rear) will work, and
• Disc brake only: with rotor diameters from 140 mm to 180 mm*,
• Thru axles with diameter of 12 or 15 mm front, and 12 mm rear,
• Freehub types for Shimano/SRAM 9-10-11 speed, Shimano Microspline 12 speed, Campagnolo Ekar 13 speed, or SRAM XD/XDR.

*this range will be extended further in future

Yes, you can just use the one from your bike.

No, we have designed dedicated GRAVAA disc brake rotors, to make an optimal integral design and to save weight. Our disc brake rotors are mounted with 7 bolts and are one of the lightest on the market. The disc brake rotors are standard delivered as part of your wheelset.

Yes, you can. There is still a Presta interface mounted, which fits to your bike pump. You will not need it often, but it’s there to give you the option to directly start with the correct pressure (for example, before a ride you can pump it up using your standard bike pump), or in case you have a flat tire.

However, in most of the cases there is no need to use your bike pump anymore. Just take your bike out for a ride as long as your tires are not too low in pressure: the GRAVAA wheels will automatically inflate your tires back to the last used setpoint while riding.

GRAVAA wheels shall be compatible with tire sealants as riding tubeless is widely used. As you can imagine we do not want any of this substance to enter our system. The prototypes are undergoing intensive testing to make it function optimally.

You can install our wheels like any other wheels. There are no wiring or any other requirements. Simply tighten the axle of the wheels, pair the control unit with the wheels, follow the in-app instructions before first use, and go out on a ride.

Watch our instruction video here (available soon), or follow the instructions in our app.

Basically, all internal parts inside the hubs are free of maintenance, except for:

• Standard wear parts in the wheels like wheel bearings – these can be replaced. Instructions will follow in our User’s manual.
• Air filters, which keep the KAPS clean from outside dirt to function properly. The system will recognize when to replace filters automatically and notify you. Replacement can be done easily. Spare filters are delivered with the wheelsets and will also be available via our webshop. Replacement instructions will follow.
• Furthermore, you will need to charge your hubs every now and then, to enable wireless communication and proper/safe usage.

! Please do not open the hubs yourselves, your warranty will then expire (please check our service and warranty conditions). In case you feel uncomfortable about our product and/or in case of issues, please do not hesitate to contact us via our Contact form

The batteries inside the hubs are rechargeable. In normal use, you can ride about 1 to 3 months with full batteries. To prevent issues, we recommend to charge batteries before each use of your wheelset.

Inside the control unit, there is a replaceable coin cell battery (type CR1/3N), which last for about 6-12 months, depending on usage.

You can easily read the battery status of both wheels and the control unit from the GRAVAA app.

The answer is simple: only a little. The exact power consumption with the pump ON depends on many factors, as explained on the Technology page. On average, the power consumption is 4 Watt (per wheel) once switched on. This is easily compensated by the advantages you will get in case of the right tire pressure: by less friction/rolling resistance or improved traction you will beat your friends or competitors!

No energy is required, it’s very fast and free!

This depends again on some factors, like also explained on the Technology page. The volume of your tire, riding speed, and the pressure levels you are switching between, are the main factors that determine the time it takes. On a gravel bike with 1.50″ (40 mm) tires, it takes about one minute to increase the tire pressure with 0.6 bar. With a mountain bike with 2.25″ (57 mm) tires, it takes about three times longer to bridge the same pressure difference.

This depends as well on some factors (alike inflation), but is that fast that you will not notice it. Deflating your tires is a matter of seconds, as it goes with (at least) 0.6 bar/s.

The wheelsets won’t be shipped until the wheelsets are ready to hit the consumer market. The expected delivery date is mentioned during checkout. As soon as it’s possible, orders will be shipped directly. Our customers will be notified about progress and shipping updates regularly via our newsletter.

We aim to be there for all of you and aim to roll out our technology as wide as possible. However, to commit to all regulations and to provide good service, we have chosen now to limit our coverage to the countries listed under Shipping. In future, we aim to extend our coverage, so stay tuned.