Self Supported Rides

Dorset 300

June 18, 2023

300 km
3,854 m
1 Day
June 18, 2023
Sherborne, Dorset
200 riders
300 km

Previous events

Solstice 300 (2020)

Circumnavigate the 300 km county boundary of Dorset between sun up and sundown on the longest day of the year. Start and Finish from Sherborne. Start any time after ‘Sun Up’ and cross the finish line before ‘Sun Down’.

Dorset is noted for its stunning sea views, castles and climbs. Participants may start any time from Sunrise at 04:53 - with all participants needing to be over the finish line by sunset at 21:29. Riders using the Earth Sports Event App can be ‘live tracked’ by friends and family and will appear on the list of finishers.

While the Dorset 300 is a reliability ride anyone aiming for the Solo or Team (two up) course record may contact Earth Sports expressing their intent to challenge for the leader board at least 7 days prior to the start. Standard Self Supported ITT Ultra Cycling Union rules apply.


The Solstice 300 is a ‘Reliability Ride’ whereby participants demonstrate that they are a ‘reliable rider’, by completing a ride within a specified time. The route follows the county border of Dorset which is 300 km and should be completed between sunrise (04:43) and Sunset (21:21) on Saturday closest to the Summer Solstice. Groups of cyclists work together to ensure that they get around the course safely and in time. All riders are required to be self-sufficient. They need to fix their own bikes and take any food or personal medication with them on the ride. For those that wish to stop for a coffee stop(s) on route we recommend the following:

Convenience Stores

1. @78 km, Co-op Alderholt (07:00 - 22:00)

2. @116 km, Tesco Express, Sandbanks (07:00 - 22:00)

3. @124 km, Studland Village Shop, (08:00 - 16:00)

4. @157 km, Lulworth Stores, (08:00 – 20:00)

5. @201 km, Co-op Weston, (06:00 – 21:00)

6. @224 km, Abbotsbury Stores, (07:00 – 18:00)

7. @240 km, Waitrose Bridport, (10:00 – 16:00)

8. @269 km, Spa Mosterton, (08:00 – 16:00)

Cafe Stops

1. @197 km, The Lobster Pot, Portland Lighthouse (11:00-17:00)

2. @237 km, Watch House Cafe, West Bay (10:00-17:00)

This event takes place on the open roads and rules of the Highway Code must be obeyed at all times. While they do not have the full event support of Sportives they are just as enjoyable, if not more so as they tend to me more sociable with riders working together to get around.
The ferry leaves Sandbanks/Poole on the hour, twenty past and twenty to the hour. Crossing time is normally around 4 minutes.


Cost - £1 for the crossing including your bike (remember to bring change)
Downloadable route maps in the following formats: GPX, TCX & FIT


Live tracking

Timed Segments for key climbs and sectors

Finish Time

All time leader board

For added peace of mind we suggest ETA cycle rescue cover. Cover is for 12 months and costs just £24.


There is no official photographer but please share your own photos on social media #earthsports

Check out the accommodation information for camping and links to local hotels and B&B’s.

The event is open to individuals between ages 18 and 80. And under 18’s if accompanied by an adult. Those over the age of 16 may participate if they provide a completed parental consent which can be obtained by emailing .(JavaScript must be enabled to view this email address)

A standard road bike is the most suitable bike but a gravel bike with road tyres can also be used. Time trail bikes can be used but only if the rider plans to ride solo as they would in a time trial. Riding a time trial bike in a group is not permitted.

Paid parking is available in the Market Car park adjacent to the HQ start or free parking 500 meters from the start at:

Dancing Hill

Participants can meet at garden entrance of The Circus which is accessible from the Market Car Park. Please bring your own post ride food and drinks which you can enjoy from the private garden of the Circus.

Participants can start any time from Sunrise (04.43) until 07:00. The Earth Sports Group will leave at 06:00 and will aim to be back around 17:00.

Please search for the Earth Sports app on your app store and download to your smartphone, register and login via the app and then add the Map My tracks Endurance App (you also need to create an account with Map my tracks), do not use the Outfront App as this will drain battery of your phone. Press start on the Endurance App before you start riding.

If you have used the the tracking app you results will automatically appear on the results page. If you prefer you may link you Garmin, Wahoo or other bike computer to your Map My Tracks account and your results will appear, similar to how Strava functions.


Camping & Caravan Park - 6 miles




Participants unavailable at this time.


  1. All participants must ride in an orderly manner in accordance with the law relating to road travel, not more than two abreast, and must extend reasonable courtesy to other road users
  2. Group sizes on the road are restricted to a maximum of 12 riders
  3. Groups should start a minimum of 2 minutes apart.
  4. If a group is caught, the slower group must allow the faster one to pull ahead and not attempt to latch on.
  5. Riders should single out when the rider at the front or the rear calls upon the group to do so.
  6. The safest way to change pace makers is to have one line moving up the and one dropping back. Changes can then be effected without ever being more than two abreast.
  7. All riders must ride with caution, particularly through Towns and Villages and must be aware that livestock and large farm machinery will be encountered from time to time.
  8. All riders are responsible for ensuring that they have third party insurance, Earth Sports will not be held liable for any injury sustained during the ride.
  9. We encourage participants to consider Cycle Rescue Cover available from ETA for £24 a year.