Swapfiets’ product service system (PSS) offers bicycles as a service: customers pay a monthly fee to get a Swapfiets bicycle and whenever something is wrong with the bicycle, Swapfiets makes sure the bicycle is repaired or replaced with a working bicycle. Two of Swapfiets’ longer term challenges form the subjects of this research: 1) What can Swapfiets do with the bicycle frames, when they are at the end of their lifetime? And 2) How should the methodology for revision of the material flow be set up? The current material flow of the bicycles leaves room for improvement. The bicycle is not designed from a lifecycle perspective, but it is optimised to increase the maintenance efficiency and prolong its lifetime. Reasons for Swapfiets to revise the material flow are diverse. The current material flow is unsustainable and can directly harm the brand value, on which Swapfiets builds strongly. Furthermore, it is economical unbeneficial, since the depreciated value of the frames are turned into direct costs when thrown away. Closing the material loop can add economic and brand value to the PSS. However, there is no methodology in place at Swapfiets to revise the material flow of the bicycles. The current way of working is not long term focused. Comparing Swapfiets’ PSS to other PSSs described in literature, shows that a closed material loop is a common success factor for PSSs. A PSS with a closed material loop is referred to as a sustainable product service system (SPSS). Optimising the lifecycle to create an economic benefit is one of the main drivers to develop an SPSS. No methodology is yet developed to transform a PSS into an SPSS. However, barriers to overcome and success factors to develop an SPSS are extensively described in literature. To create a successful SPSS, the project vision should be flexible, the network should be reconfigured and managed strategically. A methodology that has the capabilities to fulfil these requirements is co-creation. Co-creation is the joint development of concepts by the firm, its network and other external participants. For co-creation, the network is reconfigured by inviting a mixed set of participants. However, little research is done to link different sets of participants to the quality of the outcome. This research is exploring that gap, by organising two co-creation sessions with two sets of participants. The first set of participants are operating in the same sector as Swapfiets: inter-sector actors. The second set of participants are actors who have similar PSSs, but in different sectors: cross-sector actors. The two sets of participants are posed with the same question: how to keep the bicycle’s frame longer in the loop? The results of the research are separated in two categories: outcome and process. The direct outcomes of the sessions are three concepts for each session. Inter-sector co-creation shows a more technical focus and concepts can be implemented in the mid- or long-term. Cross-sector co-creation shows a customer centric focus and the concepts can be implemented in short-term. Both sessions show how interactions between all actors open windows for collaborations. Inter-sector actors are more interested in possible business partnerships, while cross-sector actors are eager to create in-kind collaborations. The co-creation process causes actors to find common ground. Inter-sector actors are more precautious in sharing information or experience, since they considered Swapfiets as a potential competitor. This was not the case for cross-sector actors, who share very specific information about their own companies.