Solstice Triathlon – 2023

Pentland Triathletes host their open water, off road sprint distance triathlon event at Threipmuir reservoir, Balerno – in the scenic Pentland Hills just outside Edinburgh.

This is an annual event that takes place on the evening of the summer solstice (or as close as we can make it) and is open to competitors aged 16 or over.

For 2023 the event will take place on the evening of Wednesday the 21st June.

Due to various restrictions the number of individual competitors is limited to 85.

Cash prizes are presented to the first three in the Male and Female categories. Due to the limited number of entrants there are no age group prizes.

The following video provides a good insight into the spirit of the event:


Entry for to the 2023 Solstice triathlon is on a first come, first served basis and is managed via Entry Central.

We operate a waiting list and there are typically a few call-offs as the event date approaches, so it is worthwhile adding your name to the waiting list if the event is full.

Please click on the following link to enter :

Solstice Triathlon Entry


The cost of individual entry is £40 for Triathlon Scotland and British Triathlon Federation members holding a race number, and £45 for non-members. In additional competitors are responsible for paying the Entry Central administration fees.

Cancellations and Refund Policy

If you cancel up to the 7th June 2023 individuals will receive a refund of £28. Unfortunately if you cancel after that date we will be unable to offer a refund.

It is not possible to transfer your entry to someone else as we will be operating a waiting list. 

Getting There

Threipmuir reservoir is located in the Pentland Hills on the south of Balerno, which itself is located to the West of Edinburgh. Follow the signs in Balerno to either Harlaw or Threipmuir car parks- these are a similar distance from the Registration:


Registration is located at the transition area at the North East corner of the reservoir and commences at 6:15 pm on the evening of the event and closes at 7pm. If you are late for registration your place may be re-allocated. A race briefing will be given at 7:20 pm – 10 minutes prior to the start. Bikes must be racked on your numbered slot before the Race Briefing. You will be provided with a race number and swim cap.

This race is held under the rules of TriathlonScotland and the British Triathlon Federation.


Swim start at Threipmuir Reservoir

750 m open water swim in Threipmuir reservoir. Weather is usually reasonable at the time of the race, but wetsuits are compulsory. Please keep an eye on our Facebook page for updates. We encourage all abilities to enter, but participants MUST have some previous experience of open water swimming and be able to complete the course within the 25 minute cut off time.

In the unlikely event that conditions dictate it is not possible to swim in the reservoir we will run the event as a duathlon replacing the swim leg with a 4km run.


The bike ride is a 15km off road anticlockwise cycle that is best done on a mountain bike; however you could get away with a hybrid with the correct tyres. 

NOTE: Bikes with drop handlebars – Cyclo-cross or Road bikes are NOT permitted

On leaving transition you head out on a graded forest track past the Red Moss car park and up the deceptively steep tarmac hill to Bavelaw Castle. You are now onto a nice Pentland Hills single-track path, with styles to negotiate, that takes you down through Green Cleugh to Loganlea reservoir – another opportunity to get wet if you decide to cycle through the stream!

Green Cleugh

You are now back onto a single track tarmac road all the way down to Glencorse reservoir. Look out for fisherman casting from the shore on your right, farm vehicles, walkers, horse riders and grit on the road. Remember you are responsible for the safety of yourself and others who are in the Pentland Hills Regional Park. Often other park users only respond or react to a bicylce bell. This would be advisable for your swift progress. There will be race marshals stationed at gates and other areas of potential hazards; and the fishermen have been made aware of the event.

You leave the road at Glencorse reservoir and climb up the Maiden’s Cleugh single track path, down the gravel track on the other side to Harlaw reservoir and return to the transition area at Threipmuir via the forest track.

NOTE: There is a 9pm cut off time for completion of the bike ride


That’s the hard work over with. All that is left is a nice flat off-road 5.2 km run along the north shore of Threipmuir reservoir followed by an anti-clockwise loop around the picturesque Harlaw reservoir, returning to the finish line at Threipmuir reservoir.

NOTE: There is a cut off time of 9:45pm for completing the event.

Getting There

Traffic can be busy along the Lanark Road so please allow plenty of time.

Parking is limited so cycle/ lift share where possible. There are 2 car parks near Threipmuir reservoir (one at Red Moss (nearest Threipmuir) and one at Harlaw and both are about a 15 minute walk to the start from the car park.

Toilets, Showers and Changing

  •  Due to the remote location the toilet facilities are basic – a minimum of two chemical toilets. The toilets at the Rangers centre close to the Harlaw car park will also be available.
  • There are no showers available, but feel free to throw yourself in the reservoir when you have finished.
  • There will be male and female changing tents available for your use. The amount of space is restrictive so you may want to bring a large towel for changing.


  • Your entry fee includes a voucher for hot food and a drink once you finish the event.
  • There will be medical facilities available at transition. If you are unfortunate enough to have an accident out on the course it may take a bit more time getting to you, but you won’t be anywhere too remote!
  • The Pentland Hills are an area of scenic beauty. Please help look after them by not leaving any rubbish (wrappers etc.) out on the course, or in the transition area.
  • Results for previous years of this event are available on the Results page
  • Follow our Facebook page for race updates: Pentland Triathletes Solstice Triathlon@PTSolsticeTri
  • Any Questions? Please email with ‘Solstice Triathlon’ in the heading and your enquiry will be directed to our race director.