Boulder Group Rides

An interactive map showing cycling group rides in Boulder, Colorado. It aggregates Strava and Ride with GPS club events and displays upcoming rides by day. It also lists nearby races and events sourced from BikeReg.

Live version

• Primary site: https://boulderrides.cc
• GitHub Pages: https://rbergua.github.io/boulderrides/

Features

• 7-day calendar — Quickly see which days have scheduled rides; the first day with rides loads automatically
• Interactive map — Routes are drawn as color-coded polylines using MapLibre GL JS with MapTiler vector tiles and an automatic fallback to Stadia Maps
• Metric/Imperial units — Bottom-left "Metric" button switches between miles/feet ↔ km/meters; updates tooltips and mobile sheets instantly (imperial by default)
• Paved vs unpaved surfaces — Routes are drawn as solid lines on paved surfaces and dashed lines on unpaved surfaces
• Start pin markers — A colored pin marks the starting location of each ride
• Desktop — Hover over a route or its start pin to highlight it and dim the others to gray, showing the club name, ride title, start time, and whether the ride is women-only; click to open the Strava or Ride with GPS event in a new tab
• Mobile — Tap a route or its start pin to see its details in a bottom sheet; tap "View on..." to open the event; swipe the panel down (or tap the map background) to dismiss it and restore all routes
• Auto-fit bounds — The map zooms to fit all routes for the selected day
• Races & Events — Dedicated page listing upcoming races and events
• Progressive Web App (PWA) — Installable on Android and iOS home screens for a full-screen, app-like experience with custom splash screens for all device sizes

Getting Started

Prerequisites

No build tools required — this is a plain HTML/JS app. You just need a local HTTP server.

Run Locally

# Using Python
python -m http.server 8000

Then open http://localhost:8000 in your browser.

Tip: Hard refresh (Ctrl+Shift+R on Windows/Linux, Cmd+Shift+R on Mac) forces the browser to re-download all files instead of using cached versions.

Tip: To emulate a mobile device, open browser DevTools (F12) and toggle the device toolbar.

Ride Data Format

Ride data is automatically fetched from the Strava and Ride with GPS API by a backend process that runs twice a day (12 PM & 1 AM) and keeps club_rides.json up to date. Each entry in the array represents one ride:

[
  {
    "source": "Strava",
    "club_id": 575042,
    "club_name": "Rapha Boulder",
    "title": "Social Ride",
    "date": "2026-03-08 10:00",
    "url": "https://example.com/ride",
    "starting_location": [
      40.016888,
      -105.285529
    ],
    "women_only": false,
    "route_id": 3471700207861648642,
    "distance": 24.8,
    "elevation_gain": 1247,
    "route": [
      [
        40.01962,
        -105.27153,
        "paved"
      ],
      [
        40.0195,
        -105.27212,
        "unpaved"
      ],
      ...
    ]
  }
]

Field	Type	Description
source	string	Data source: "Strava", "Ride with GPS", or "Site"
club_id	number	Strava or Ride with GPS club ID
club_name	string	Name of the organizing club
title	string	Ride name
date	string	"YYYY-MM-DD HH:MM" in 24-hour format; displayed as 12-hour (AM/PM) in the frontend
url	string	Link to the Strava or Ride with GPS ride event
starting_location	[lat, lng]	Start marker position (optional; if not available, it uses the first point in route)
women_only	boolean	If true, indicates the event is women-only. Since Ride with GPS does not support this flag, the value defaults to false.
route_id	number	Strava or Ride with GPS route ID
distance	number	Route distance in miles (1 decimal); null if unavailable
elevation_gain	number	Total elevation gain in feet (integer); null if unavailable
route	[[lat, lng, surface], ...]	Array of latitude and longitude coordinates defining the route; each point includes a surface tag ("paved" or "unpaved"), or null if the OpenStreetMap surface classification failed

Race and Events Data Format

Race and event data is stored in races.json. Data is refreshed weekly from the BikeReg API (Mondays at 3 AM). Some major events not listed on BikeReg (e.g., Triple Bypass, Mt. Blue Sky Hill Climb) are hardcoded in the backend. Each entry in the array represents one race or event:

[
  {
    "name": "Koppenberg Road Race",
    "url": "http://www.withoutlimits.co",
    "reg_link": "http://www.BikeReg.com/73713",
    "location": "Superior",
    "latitude": 39.9527634,
    "longitude": -105.1685977,
    "type": ["Road Race", "American Cycling Association"],
    "date": "2026-05-03"
  },
  {
    "name": "Superville Stage Race",
    "url": "http://www.withoutlimits.co",
    "reg_link": "http://www.BikeReg.com/74224",
    "location": "Superior",
    "latitude": 39.9083424,
    "longitude": -105.1699298,
    "type": ["Road Race"],
    "date": ["2026-05-16", "2026-05-17"]
  }
]

Field	Type	Description
name	string	Display name of the race or event
url	string	Event website URL
reg_link	string	Registration link (typically a BikeReg URL)
location	string	City or town where the event takes place
latitude	number	Latitude of the event location
longitude	number	Longitude of the event location
type	array of strings	One or more event type tags (e.g. "Road Race", "Criterium", "Time Trial", "Mountain Bike", "Special Event") and/or sanctioning body (e.g. "American Cycling Association", "Colorado Bicycle Racing Association (CBRA)")
date	string or array of strings	Event date in YYYY-MM-DD format; use a plain string for single-day events, or an array of strings for multi-day events (e.g. a stage race)

Project Structure

├── index.html        # Main app (map + calendar)
└── club_rides.json   # Ride data, auto-updated by the backend process (Strava and Ride with GPS API). The file is only committed when its contents change
└── races.json        # Race and event data, auto-updated by the backend process (BikeReg API). Major events not on BikeReg are hardcoded

Customization

• Days shown — Change the 7 in generateCalendar() to show more or fewer days. Note that a longer window of time could be misleading. Recurring weekly rides on Strava only appear once their previous occurrence has passed, so looking further ahead would result in missing entries
• Default map center — Update defaultCenter in index.html (currently set to downtown Boulder)
• Default zoom — Update defaultZoom (currently 12)
• Route colors — Edit the colors palette array in index.html to change the cycle of colors assigned to routes
• Map tiles — The app loads Stadia Maps immediately (no key required) so the map is instantly visible, then silently upgrades to MapTiler (outdoor/terrain) if the key is valid and quota is available. The MapTiler API key is locked to requests from boulderrides.cc

Built With

• MapLibre GL JS — Interactive maps with vector tile rendering
• MapTiler — Outdoor/terrain map tiles (primary)
• Stadia Maps — Outdoor/terrain vector map tiles (fallback if MapTiler quota is exceeded or unavailable). Free, no API key required
• Service Worker — Extends MapTiler tile cache from the deault 8 hours to 120 days, saving API requests and making the map load faster for returning visitors (tiles served from disk instead of the network)
• OpenStreetMap — Road surface data source used for paved/unpaved classification, queried via the Overpass API by the backend
• Strava API — Source of group ride data, fetched by the backend
• Ride with GPS API — Source of group ride data, fetched by the backend
• BikeReg API — Source of race and event data, fetched by the backend
• GoatCounter — Privacy-friendly analytics

Support

If you find this project useful, you can also buy me a coffee (donate a small amount) with the link below: