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Show HN: I Built an Indoor Cycling Web App to Get in Shape Through Gaming (startona.com)

13 points by olivier-k ↗ HN
I spent the past three years developing an exercise game for indoor smart trainers called Startona. The game is built from scratch in TypeScript and only uses a couple of small libraries. The result is a PWA that showcases the capabilities of a modern web browser through technologies like Web-Bluetooth and WebGL.

Developed to turn turbo-trainer workouts into intense gaming sessions, Startona combines structured workouts with exercise games that boost specific aspects of the player's fitness, such as speed, power, and endurance. Although Startona is built for fun by providing new and unique indoor cycling experiences, the game also contains all the features you would expect from a modern indoor cycling app: single-player workouts, multiplayer challenges, personalized structured workouts, detailed activity logs, built-in Strava support, regular content updates, and various fitness tracking systems to help players stay motivated.

All that is needed to try Startona is a smart trainer and a web browser with Bluetooth support (Chrome, Edge, Arc...). Sorry, no iOS support yet.

15 comments

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graylien
that's so cool - I don't cycle but I just love the website and the language used like "Welcome , intergalactic athlete" haha the video does a good job of showing the app too, good luck with it!
matteason
This looks great. Sadly I've got a non-smart exercise bike so I can't try it out but the design of the game looks great and I love that it's browser-based

The only feedback I'd have is that it might be nice if the website pulled through the aesthetic of the game a bit more? Though on the other hand maybe the darker look helps the screenshots stand out more

olivier-k
Thanks, I see your point. The original design sketches were more similar to the minimalistic UI of the game. However, the main feedback there was that people felt the website did not portray the colorful contents of the game. As you said, the color also helps lift the screenshots, though I will probably add a little more animation to the page in the future since it feels a little bit static at the moment.
openair18
Is your bike bluetooth enabled at all? Might be working checking out if it’s compatible with this app: https://www.qzfitness.com/ which could then send the metrics to Startona
matteason
It's not, no - it has a rinky-dink little computer with a simple 7-segment LCD, which is connected to whatever in the bike is measuring rotations via a 3.5mm jack. I did experiment with seeing if I could read a signal from it via a mic input so I could hack together a more advanced display but didn't have any luck.

I've just had a look for ways to adapt it though, and found BitGym [0] which doesn't require a connection to the bike at all - you just place it on the handlebars and it measures your cadence with the front-facing camera somehow. That would be a neat feature for Startona. Maybe you could even measure it via the accelerometer? FFT the lateral motion of the device to find the frequency of movement? Maybe it wouldn't be strong enough but it would be an interesting experiment

[0] https://www.bitgym.com/

olivier-k
It should be fairly straightforward to measure the cadence in the way you describe, but you would still need a way to measure input speed. Startona uses a physics simulation to calculate the player's speed based on the power input since this gives the most accurate results. In case power is not available, the game uses speed as a fallback. Although, it would be fun to add a way to connect an Arduino-based solution via USB so people can homebrew their own speed measuring systems (with hall sensors or similar). I am open to adding that option if enough people ask for it.

You could try to use a Bluetooth speed sensor like the "Wahoo RPM Speed Sensor" if your home trainer somehow allows you to fasten it to it's flywheel - if not, you would still have the option to put your bike on a cheap roller. That way the game would work, but you would only get a limited experience since only the high-end rollers support erg mode. At that point, you have come full circle and it may be cheaper to opt for an entry-level hub trainer like an Elite Suito.

deskinvestor
The world needs more apps along the lines of this.

Job well done, mate!

stevengraham
This is super cool. Does it connect to all my gear like zwift? (smart trainer, fan, power meter, HRM)
olivier-k
Yes, the game supports most Bluetooth speed, heart rate, cadence, and power sensors, as well as most smart trainers and smart bikes. There is currently no support for fans or grade simulators.
stevengraham
Thanks! Please consider my humble feature requests: -Full support for Wahoo device ecosystem -Apple TV app (this is a deal breaker for me)

My current setup - right now I use zwift on apple TV which connects to a wahoo cadence sensor, rpm sensor, HRM, kickr rollr smart trainer, kickr smart fan. Also have a SRAM power meter connected.

You probably already know this, but Apple TV has some limitations on simultaneous bluetooth connections so you have to use workarounds (for example zwift has a separate smartphone app that bridges the ATV and the devices).

Good luck, and let me know if you'd like any help with product or marketing.

olivier-k
Thank you for your input, Steven. AppleTV is high on the roadmap for future product updates. Regarding your Wahoo sensors, they are all supported (except for the fan). I am not 100% sure about the SRAM power meter since there is some variation in the way different vendors support the Bluetooth sensor specification, so that is something you would need to try out. I would greatly appreciate your feedback if you ever have the chance to try the game.