Pedal Wrencher: How Many Bikes Is Enough?

A few months ago I posted an update on a side project of mine, pedal wrencher. It’s a really simple little app that just polls the Strava API and then uses Twilio to send users a text message when it’s time to replace a chain, cassette or any other consumable part on a bike.

There’s a lot of technical debt floating around the codebase, but it’s still cranking along, almost totally on it’s own, but tonight I checked in to see where the project is at. The app is set up to create a handful of rules by default to get users started. For every bike they have registered in Strava, they’ll get by default notifications for:

1. chain
2. bar tape
3. brake pads
4. cables

Any of these can of course be turned off, or edited, and any new notification can be added. So I wondered, how popular is that customization feature really? I suspected that the vast majority of users stuck with the defaults, but hadn’t ever checked. Currently there are a little under 500 users (growing just a little bit each month these days) with a little under 1500 bikes between them. On a normal month, pedal wrencher sends out between 1-200 text messages to that group. That gives us a pretty decent sample of data to play with.

First let’s look at the number of bikes per user. As the old adage goes, the number of bikes you need is N+1, where N is the number you currently have. Looks like for most users, N is less than 4.

(Original chart from this post is no longer preserved in the Internet Archive.)

The default bike, as mentioned, gets 4 notifications enabled by default. As expected, the vast majority of the bikes stick with just those 4 (or some other combination of 4). A small cohort of power users will add one or two, and one awesome individual has made 10 rules for 1 bike. Whoever you are, strong work.

(Original chart from this post is no longer preserved in the Internet Archive.)

Finally, combining those two, we can look at the total number of notifications attributed to each user. You can see clear spikes at multiples of 4, because again, most users just use the default 4 notifications for each bike. In total, most users are between 4-16 notifications, with a few users having configured massive numbers (someone has 152?).

(Original chart from this post is no longer preserved in the Internet Archive.)

So there you have it, a few fun charts for a little project, I’ll update these maybe in 6 months or a year to see if in fact the users are getting one more bike each.