An automatic chain tensioner for motorbikes needs to loosen the axle nut, adjust the wheel, achieve the correct tension, and then re-tighten to the appropriate torque – all without the user needing to use any tools. May One has taken this idea to a first functional prototype, controlled via a mobile device. In chapter 81 of “Toque de Ingenio,” Oriol Santiago explains the origins of the system, the mechanical and safety decisions that underpin it, and what remains to be done to develop it into a production-ready product.
Guest: Oriol Santiago, who was introduced in the episode as the founder of May One. Interview published: June 23, 2026. Episode: 81. Duration: 1 h 15 min.
In this episode:
- Why tightening the chain remains a manual, frequent, and unpleasant task.
- How does the system attach to the motorcycle without welding or drilling, in order to avoid homologation?
- What validation of demand and what funding precede industrialization?
The conversation was recorded at i-mas’ facilities when May One had their first prototype mounted on a motorcycle and had just closed a funding round. It’s a valuable opportunity to observe a hardware project before product engineering.
Tensioning a motorcycle chain: maintenance from the nineteenth century
Oriol describes chain tension as a dual problem – one of safety and one of comfort. A chain that is not properly tensioned wears down the chain’s components faster, causes jerking when opening and closing gas valves, and eventually, can even come loose. Conversely, a chain that is too tight also wears down more quickly and can even break.
According to the report, the adjustment should be made every 1,500 or 2,000 km. With the 10,000 km per year that is cited as an average for the rider, this represents between five and ten interventions per year – significantly more than an oil change. Furthermore, the correct tension also changes depending on the load on the motorcycle.
The operation requires a stand, tools, a torque wrench, and approximately 10 to 15 minutes. Oriol explains that many users postpone it by two or three months, or they leave it until a workshop inspection. As a result, a motorcycle equipped with ABS, traction control, and an electronic display is maintained as it was a century ago.
For Oriol, the chain remains the best option in terms of weight, strength, and the power it can handle. The problem, however, is its maintenance.
To check that it hadn’t been solved before applying for a patent.
The idea arose when Oriol was studying mechanical engineering, following a motorcycle accident in his area. He prepared a presentation and showed it to his professor of systems and transmissions, who responded that the forces involved were too great and that he didn’t have the capacity to carry it out.
Instead of abandoning the task, he sought a mechanism capable of loosening a tightly fastened nut, between 90 and 100 Nm, moving the wheel, and then re-tightening it to the required torque. His calculations indicated a system weighing approximately 1 kg in its prototype phase, a figure he considered reasonable.
Before applying for a patent, Oriol wanted to understand why brands, with significantly higher R&D budgets, hadn’t developed something similar. A preliminary patent search, he explains, didn’t reveal any system that automatically tensioned the springs. The springs used in enduro motorcycles, he explains, only prevent the chain from coming loose as the suspension moves – they don’t actually tension the chain.
“No motorcycle in the world comes with an automatic chain tensioner as standard.”
Oriol Santiago 30:26.
Her hypothesis is that manufacturers have directed their investment to other areas. This early verification provides a foundation upon which to request funding.
How the system works: motor, actuators, and torque.
Oriol describes it as a system that can be easily connected to the motorcycle – a “plug and play” system. A motor loosens the nut on the rear axle. Two actuators, one on each side of the swingarm, move the wheel backwards to tighten it, or forwards to loosen it. Afterwards, the same motor returns to tighten the nut.
The user controls the sequence via an application, specifically an APK for Android. The safety margin is 90 seconds, although this can be reduced. The application is intended to indicate the pressure for each model, according to the manual.
The torque cannot be measured with a torque wrench, but rather by observing the behaviour of the engine when tightening. This observation allows you to differentiate the torque of a 125cc motorcycle from that of a high-cylinder sports bike. Alignment between the two sides is manual in the prototype, and it is planned to automate this process, as one side of the chain offers more resistance.
The position of the actuators provides an additional piece of information: when they reach the end of their lifespan, the chain is worn out, and the system can alert that it needs to be replaced. An IMU records the distance traveled.
This architecture, with mechanics and control. electronic and an application that decides and summarizes a large number of projects product development: The value lies in how the different elements are coordinated.
Safety and secure attachment without altering the motorcycle.
The first question the project receives is: what happens if something goes wrong. Oriol explains that the system only operates during the adjustment phase – once the wheel is in place, the actuators stop working, and it’s the nut that maintains the position, just like in a motorcycle.
“The system isn’t working when you’re riding your motorcycle”.
Oriol Santiago 38:52.
Furthermore, the tightening mechanism is irreversible: the nut cannot come loose due to vibrations, even if the battery fails or the motor malfunctions. According to their report, the team has analyzed potential failure modes using an AMFE to ensure that, in any of these cases, the wheel remains securely fixed.
The attachment replaces the moving parts within the bearing with its own components, complete with the necessary holes and threads to attach a plate using two or three screws. Removing this plate allows access to the spindle nut, and the wheel can be disassembled in the same way as a conventional motorcycle.
The reason for this is to avoid any welding or drilling, as any structural modification would require the system to be certified. Oriol recommends that it be installed by a mechanic, although a user can do it, and he anticipates selling it to workshops, distributors, and the end consumer.
Verify the demand before investing in industrialization.
Oriol was concerned about the reaction people would have when they saw the system for the first time. Before taking further steps, the team released four videos on Instagram, which went viral, and opened a waiting list, receiving over 800 emails.
Using that signal, they recorded a video for a YouTube channel and launched a small crowdfunding campaign of around €300, which was enough to cover a basic stand at the Valencia motorcycle fair. Oriol recalls the audience’s reaction when they saw how the chain was tightened with a touch on the screen.
The team studied Kickstarter and decided to rule it out for the time being. They were concerned that the motorcyclist might be buying a product through that platform that raises safety concerns, so they focused their resources on a pre-sale supported by social media, which was working well at the time of the interview.
The anticipated price is €295. Edgar warns that this price is only achievable with large volumes, and that molds, matrices, plates, and initial units could cost more than the entire preceding development.
From the first prototype to product engineering.
The prototype that existed at the time of the interview was the first one built and functioned perfectly from the outset – something Oriol describes as exceptional. It took approximately nine months to complete, with three or four of those months involving intense work, alongside his employment in the automotive industry.
This prototype works, but it’s not aesthetically pleasing and isn’t optimized for distance, thickness, or manufacturing cost. The next step, with the roadmap clearly defined, is to hire engineering expertise to transform it into a product suitable for mass production. This is the phase where prototyping Stop responding to “Does it work?” and instead, start responding to “Can it be manufactured and sold at this cost?”
To finance it, May One was closing a €250,000 round, with €150,000 in equity and the rest in public-sector loans, to cover around 18 months. They then planned a second round of half a million euros to reach the market; overall, Oriol describes around €750,000 across two phases. The target date was mid-2027.
Motor manufacturers are cautious and are waiting to see the finished product. The plan is to demonstrate demand in the retail channel so that brands can integrate the system for mass production.
What can another development team learn?
The May One case offers four lessons applicable to other hardware products:
- Check the space before investing. A driving test and a review of existing solutions differentiate an appealing idea from a genuine opportunity.
- Design security with the worst-case scenario in mind. “The ‘rest while turning’ and ‘irreversible tightening’ responses indicate faults that will occur, rather than those that are anticipated.”
- Avoid modifications that would necessitate standardization. A fastening method that doesn’t require soldering or drilling alters the cost, installation process, and sales channel.
- Measuring demand with minimal resources. Videos, a waiting list, a fair, and an advance sale – these all provide signals before committing money to molds and matrices.
At the time of the interview, May One was in the process of securing funding, with pre-sales open and a planned launch in mid-2027.
In i-mas, we support projects that move from a functional prototype to a manufacturable product, integrating mechanics, electronics, and production. If your team is at that stage Tell us about your project..
To continue reading: How to plan the transition from prototype to manufacturing..
Source of article: Interview with Edgar Guerrero on Toque de Ingenio with Oriol Santiago. The excerpts cited link to the minute of the conversation. The recommendations for other projects are an editorial summary from i-mas.
