Commonly Asked Questions

The Tragfläche® transforms a conventional bicycle into a cargo bike. It offers a cost-effective, simple and adaptable way to modify the bike to fit individual transport needs.

The mechanism of the Kronfeld Tragfläche® allows you to adjust the length of the carrier as required using four quick-release clamps. Simply pull until the desired or maximum length is reached and lock in place.

You can put up to 4 standard sized bike bags.

• It has been tested (DIN EN ISO 11243 test conditions) to hold up to 40kg of cargo.

We recommend you to put on no more than 8kg on the telescopic section to avoid instability when riding.
Overloading can cause the bike to tip over and pose a danger on the road. The riding behavior should therefore be adjusted according to the bike, the load, the body weight and the size and strength of the rider.

• The bike can tip backwards.

• The riding dynamics change, which is also noticeable on the handlebars.

• The bike may break away.

• There is a risk of the bike tipping over as it can no longer be held in a controlled manner.

• The kickstand can bend or even break.

We use powder coating. Though we recommend the raw stainless steel for over the years and extensive use the powder coating will also show defects and wear off.

Yes, the Tragfläche® is stable enough to carry a suitable and approved child seat as well as luggage, provided that the total weight does not exceed the maximum load capacity.

You can still attach up to 4 bags, but we recommend you only use 2 and do not exceed 40 kg of cargo.

You can order the Tragfläche® over our Crowdfunding-Campaign on Startnext → HERE:

https://www.startnext.com/HDY

You need the two standard mounting points on your bike frame. These are located near the rear axle and the seat post (usually M5 inserts). We also recommend using bikes with a system weight of approx. 130 kg. You can usually find the system weight on the manufacturer's website. We also recommend the use of reinforced wheels, such as Ryde Andra 40.

If you are still unsure whether the rack will fit because you have a fat bike with a wide rear axle, for example, then please measure the distance between the mounting points inside and to the rear axle as well as the tire width. Then simply send us this information in a message. Together we will find the best solution for you.

The Tragfläche is made of high quality stainless steel 1.4301.

Yes, we offer different color options that you can select when ordering. There are currently four color options for the powder coating, as well as a raw glass bead blasted stainless steel option available on our crowdfunding page.

Due to its material composition being made of stainless steel, the Tragfläche will not rust in the rain. However, we recommend that you avoid exposure to saltwater or salty rain, as V2A stainless steel can show signs of rusting over time.

The Tragfläche® is supplied together with the mounting struts, the screws required for installation and the integrated rear light cable. Operating instructions and assembly instructions are also included.

Please check out our YouTube video as to how to install the Tragfläche®.

Please check out our YouTube video as to how to uninstall the Tragfläche®.

You do not need to buy a new rear light. In addition, the integrated cable and connector system is specially designed so that no tools are required for installation. There is a standardized Shimano dynamo plug and two insulated wires that can simply be pushed through the holes provided and connected to the inner cables. 

Our flexible connector is made from 100% recyclable and compostable 3D printed material (Willowflex). The rear light can be mounted at a distance of 50mm to 80mm, so that it can be optimally adapted to the needs of different bike models.

Take a look at our installation video on YouTube on how to install the Tragfläche®.

Yes, the Tragfläche® is made of stainless steel, which is 100% recyclable.

First, you must check whether the metal spring that prevents the We recommend that you first check if you pressed in the metal spring that prevents the telescopic part from being pulled out completely. Also check to make sure there is no dirt or debris clogging up the guiding tubes, if so, gently clean out. If the telescoping portion is bent or damaged, try to realign again to ensure smooth insertion. If nothing helps, please feel free to contact us with a photo so we can help you to the best of our ability.

If sand or dirt is causing the mechanism to become stuck,it is best to take the extendable piece out and carefully clean the pipes with towels and rinse out with clear fresh water. Allow to dry and reinsert the piece. Be careful with the cable guiding tube to ensure you don't jam the electric spiral wire.

For this reason, it is best to remove any dirt and possible interference from the telescopic mechanism before inserting it. Simply wipe with a handkerchief or similar, moistened if necessary, against the direction of travel to prevent dirt from being pushed into the guide tubes.

Yes, but they might tear or wear off during use. We do not recommend tampering with the extendable piece, as it could cause issues with extending the product.

We not only evaluated these approaches, but also calculated them in terms of durability and costs. We decided on the simplest possible design to avoid maintenance intervals and high acquisition costs. Rubber seals and plastic guide systems can be useful for frequent use, but as the carrier is a commodity that is not always treated with care, such components could easily be damaged by a dent in the telescopic tube. Our motto was therefore: as simple as possible - no predetermined breaking points, no planned obsolescence, no unnecessary bells and whistles.

Only if your name is Herculine or Hercules and you have superhero powers.

If the bike is fully loaded, the safest way to park it is to carefully lean it against a stable, immovable object. This could be a lamppost, a mature tree (no bonsai) or a wall, for example - they don't usually give way. Alternatively, you can also carefully place the bike on the ground, as it should not be able to fall any lower. Just make sure it doesn't become a tripping hazard for someone like Johnny Head-in-Air (with or without a smartphone).

The loaded bike will be extremely rear-heavy on a staircase and therefore much more difficult to handle. We recommend partially unloading the bike and using several gears to make transportation safer and easier. This point is very important, as our Karl has already made this mistake too often.

No, it is forbidden to use the escalator with a bicycle, which is also indicated by signs on the escalators. However, if you try to use the escalator with a loaded bike, you should be aware that there is a high risk of tipping over. You not only endanger yourself, your bike and possibly your little passenger on the child seat, but also other escalator users.

Technical mechanics 101 - the law of leverage. Make sure that the load is evenly distributed. Ideally, you should also use a front carrier. Otherwise, your bike could do a wheelie or even tip over. We therefore recommend that you either partially unload the bike or simply push the bike on extreme inclines.