Croozer App - Digital Product Passport for Bicycle Trailers
Sector: Secondary sector · Industry: Mechanical and plant engineering · Organisation: Croozer · Maturity level: Concept
The Croozer App uses blockchain technology to create a digital product passport for bicycle trailers. Through QR codes on the trailers, users can securely document and verify all maintenance, repairs, modifications and resales via smart contracts. The system enables buyers to transparently view the complete maintenance history and number of previous owners.
Documentation status
- Project status: Concept
- Evidence: Evidence medium
- Editorial review: Ufuk Avci, 15 April 2026
Description
The Blockchain Reallabor Huerth cooperated with Croozer GmbH (Cologne), one of the leading European manufacturers of bicycle trailers and jogging strollers. The jointly developed blockchain app records product usage data immutably: every trip, mileage, and load situations.
Croozer bicycle trailers are used intensively over many years. The problem for manufacturers: how long and under what conditions a product was actually used is unknown — this complicates product improvements, warranty assessments, and sustainability statements. The blockchain app solves this: users voluntarily track their trips via GPS; the aggregated usage data (mileage, terrain type, average speed, weight load) are blockchain-documented. For users: proof of use as a basis for extended warranty claims or as sustainability evidence. For Croozer: anonymised aggregate data help to prioritise product improvements based on data. The IFAA (Institute for Applied Labour Science) presented the Croozer blockchain cooperation at the 2025 colloquium as an industry example of usage-based product documentation. Fraunhofer FIT published the use case in the Blockchain Reallabor portfolio.
Perspectives
B2B — organisations perspective
Product manufacturers can use blockchain-secured usage data apps to design warranty conditions fairly and based on data, prioritise product improvements, and substantiate sustainability claims about product lifespans with real usage data.
B2C — consumers perspective
Consumers can document their product usage secured by blockchain — as proof for warranty claims, as evidence of sustainable use, or as a data basis for individual service offers.
Employees perspective
Service technicians and sales staff must integrate new digital documentation processes into their workflows. However, the app can also make their work easier, as all relevant product information is centrally and constantly available.
Benefits
General
- The blockchain-based documentation creates immutable and transparent product histories.
- Buyers receive complete insight into maintenance history and ownership for the first time.
- The system can extend the lifespan of products through better maintenance documentation.
B2B — organisations
- Manufacturers receive valuable data about the actual use of their products for product development.
B2C — consumers
- Consumers can make informed decisions when buying used products based on complete maintenance histories.
Employees
- Service technicians can digitally document their work and thereby demonstrate their professionalism.
Challenges
General
- Acceptance and consistent use by all parties in the service chain must be ensured.
- Integration into existing business processes of manufacturers and service partners requires adjustments.
B2B — organisations
- Companies must digitise their service processes and train employees accordingly.
Employees
- Service technicians must learn new digital documentation processes and integrate them into their existing workflows.
Technology foundation
The application is based on blockchain technology with smart contracts that enable immutable and transparent storage of all product-related data. The combination of QR codes as a physical interface and the blockchain as a data store creates a secure link between the physical product and its digital information.
Implementation examples
Croozer app demonstration project
The company wanted to create a solution for the lack of transparency in the secondhand market while simultaneously strengthening customer loyalty. Additionally, valuable data on the actual use of the products was to be obtained for product development.
Croozer developed a blockchain-based app in collaboration with Fraunhofer FIT to document bicycle trailer maintenance via QR codes.
The company Croozer implemented a demonstration application for digital product passports together with the Blockchain-Reallabor of the Fraunhofer Institute for Applied Information Technology FIT. The solution integrates QR codes into bicycle trailers, which act as an interface to smart contracts. Through the mobile app, all maintenance, repairs, modifications and resales can be immutably documented. The project is led by Wolfgang Prinz and Diana Dabboussi-Gürman and demonstrates the potential for transparent product documentation in the vehicle industry.
The solution addresses the problem of missing maintenance documentation and lack of transparency in secondhand purchases. Blockchain-based documentation creates trust between buyers and sellers.
Tags
Digital product passport, Smart contracts, QR code, Maintenance documentation, Secondhand market