Tonbridge Triathlon
Tonbridge, United Kingdom · May · Independent (Tonbridge Lions Club)
Course: 0.8 km (0.5 mi) swim, 50 km (31 mi) bike, 10 km (6.2 mi) run. Standard: 800 m (875 yd) pool, 50 km (31 mi) bike, 10 km (6.2 mi) run. Not a true Olympic: 700 m (766 yd) short on the swim and 10 km (6.2 mi) long on the bike.
Why people love it
- Heated 25 m (27 yd) pool with lap counters, no tumble turns and up to three swimmers per lane.
- Reviewers call it the best marshalled event they have raced; Lions volunteers and police cadets cheer the run laps.
- Compact school site with showers, bag drop and a finish on the athletics track.
- Scenic Kent lanes through Shipbourne, Ivy Hatch and Seal.
- Shorter formats run alongside, including a super sprint and a GoTri event for beginners.
Watch out for
- The Standard is not a standard Olympic: 800 m (875 yd) swim, 50 km (31 mi) bike.
- The bike climbs for 10 to 13 km (6 to 8 mi), then drops steeply; a 2017 crash was reported.
- Roads are open with stop-go marshals and no feed stations; later starters met traffic.
- Parking is a good walk from the school. The run is uneven grass with one water table.
- Pool start times are approximate; the pool ran 20 minutes late in 2017. Weather swings from cold rain to heat.
Race
How racers feel about it, how well it is run, and how it treats a first timer. Counts for 30% of the overall score.
Toughness: Very tough
- Racer satisfactionLoved4.0
Racecheck average 4.30/5 from 17 reviews (2025 average 4.75); positive, but a small set. · Medium confidence
- OrganizationWell run4.2
Racecheck logistics 4.59/5 and excellent marshalling; the pool ran 20 minutes late in 2017 and a 2019 age-category error went unanswered. · Medium confidence
- First timer friendlyDoable3.0
800 m (875 yd) pool swim is easy, but a hilly 50 km (31 mi) bike and 10 km (6.2 mi) grass run need prep. · Low confidence
Course traits, not part of the score
- PR potentialAverage2.8
Not a standard Olympic: 800 m (875 yd) swim and 50 km (31 mi) bike, hilly, with four grass laps. Times do not compare. · Low confidence
Swim
Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 16% of the overall score.
- Wetsuit legalRarelyn/a
Pool swim, so wetsuit_legal is not applicable. · High confidence
- Water temperatureComfortable4.3
Heated indoor pool; temperature not published, typically 27 to 29 °C (81 to 84 °F). Racecheck water quality 5.0/5 from 3 ratings. · Low confidence
- Calm waterRoughn/a
Pool swim, so calm_water is not applicable. · High confidence
- Swim easeEasy4.2
800 m (875 yd) in a 25 m (27 yd) pool, 3 per lane; mixed speeds in the same lane noted in 2025. · Medium confidence
- Swim experienceGreat3.9
Heated indoor pool and dedicated lap counters; start order drifted when the pool ran 20 minutes late in 2017. · Medium confidence
- Swim supportAbundant4.6
Pool with lap-counting marshals, no mass start, up to 3 per lane; suits less confident swimmers. · Medium confidence
Bike
Road surface, closures, scenery and wind. Counts for 18% of the overall score.
- Road surfaceMixed3.4
Kent lanes and the A227; surface not criticised in reviews; wet-weather crash on the descent in 2017. · Low confidence
- Road closuresPartly closed2.6
Roads open; stop-go marshals at the exit and one closed lane on the steep descent; buses, horse boxes and an A21 closure disrupted 2019. · Medium confidence
- Bike sceneryBeautiful4.0
Called very scenic and beautiful by several reviewers: Shipbourne, Ivy Hatch, Seal and Hildenborough. · Medium confidence
- WindSome wind3.4
Wind not mentioned in reviews. · Low confidence
Course traits, not part of the score
- Bike speedAverage2.7
50 km (31 mi) over two hilly laps with a steep descent, longer than Olympic; traffic and a long drag back on the main road. · Low confidence
- Bike flatnessHilly2.4
Elevation not published; two laps each with two climbs and a steep descent over 50 km (31 mi); hilly. · Low confidence
- Bike simplicitySome technical parts2.8
Steep descent needing a closed oncoming lane and marshals; stop-go control at the school exit; dismount line right after a turn. · Medium confidence
Run
Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.
- Crowd supportStrong3.5
Police cadets and Lions volunteers encourage runners over the laps; supporters at the school track. · Medium confidence
- Aid stationsStandard3.2
Racecheck aid 3.85/5 (13 ratings); no feed on the bike, a single water table on the run with a bin right after it. · Medium confidence
- Run sceneryPleasant2.8
Laps of school playing fields; reviewers said there was not a lot to see. · Medium confidence
- Run conditionsModerate3.0
Four laps of uneven grass (trail shoes if wet) and one water table; mentally long. · Low confidence
Course traits, not part of the score
- Run flatnessMostly flat4.3
Four flat laps of the school fields and track; no climbing reported. · Medium confidence
Conditions
Air temperature, how predictable the weather is, setting, and spectating. Counts for 13% of the overall score.
- Air temperatureWarm or cool3.4
Early May is typically 7 to 16 °C (45 to 61 °F); reviewers report cold, torrential rain and 28 °C (82 °F) heat. · Low confidence
- Weather reliabilityVariable2.8
Bank-holiday Monday weather varied widely: cold, torrential rain in 2017, flooding in 2018, heat in 2018. · Medium confidence
- Venue beautyLovely4.2
Reviewers called the school grounds beautiful and wonderful; historic buildings and playing fields. · Medium confidence
- Spectator friendlyEasy4.0
Compact school site with a track finish and a multi-lap run; pool viewing not described. · Low confidence
Course traits, not part of the score
- Low altitudeSea level4.8
Tonbridge is about 30 m (100 ft) above sea level. · Medium confidence
Stay and travel
Hotels, walkability, getting there, and the town around the race. Counts for 10% of the overall score.
- Hotel availabilityGood4.0
Tonbridge and Tunbridge Wells have a range of hotels; no event-weekend data. · Low confidence
- Hotel valueNormal3.3
No pricing data found. · Low confidence
- WalkabilitySome driving3.3
Parking is a good walk from the school (2019, 2025); registration, transition and pool are in separate places on the grounds. · Medium confidence
- Travel easeEasy4.2
Tonbridge station about 0.8 km (0.5 mi); Gatwick about 50 km (31 mi) by road. · Medium confidence
- LogisticsSimple3.6
All stages on the school site with showers and bag drop; parking is far and swim start times are approximate. · Medium confidence
- Town and foodGood4.0
Tonbridge town centre and castle nearby; burger van and coffee on site. · Low confidence
Key facts
- Location
- Tonbridge, Kent, United Kingdom
- Typical month
- May
- Latest or next date
- 3 May 2027
- Organiser
- Independent (Tonbridge Lions Club)
- Field size
- About 500 athletes
- First held
- 1991
- Distances (non-standard)
- 0.8 km (0.5 mi) swim, 50 km (31 mi) bike, 10 km (6.2 mi) run
- Swim venue
- Tonbridge School heated indoor 25 m pool (pool)
- Wetsuit
- Not applicable (pool)
- Swim start
- pool time-trial: up to 3 swimmers per lane, no tumble turns, lap counters; no mass start
- Bike laps
- 2
- Key climbs
- Long climb in the first 6 to 8 miles (10 to 13 km) via the A227, Shipbourne, Ivy Hatch and Seal
- Run laps
- 4
- Run shade
- open playing fields
- Air temperature
- 7–16 °C (45–61 °F)
- Humidity
- moderate
- Altitude
- 30 m (98 ft)
- Nearest airport
- London Gatwick (LGW), 50 km (31 mi) away
- Where to stay
- Tonbridge town centre
- Booking
- Tonbridge and Tunbridge Wells have a range of hotels; distance to Gatwick is an approximate road estimate, 50 km (31 mi).
What racers and reviewers say
- Racecheck (17 verified reviews)Raced 2025 · aggregator · Positive
Racecheck shows 4.30/5 from 17 reviews (2025 average 4.75). Reviewers agree on excellent marshalling, a friendly Lions-run atmosphere and good school facilities with showers. Recurring points: a hilly bike (long climb first, steep descent), a run of laps on uneven grass, no feed stations on the bike, little water on the run, parking a walk from the venue, and later starters meeting traffic. One 2019 older-athlete review (2.4/5) complained of an age-category error and unanswered emails.
“Best marshalled event ive seen in my decade of UK tri races.”
- CycleChat forum thread (GoTri entrant)Raced 2019 · forum · Mixed
A beginner entered the short GoTri event (200 m (219 yd) swim, 14 km (8.7 mi) bike, 2.5 km (1.6 mi) run planned). A major A21 accident forced the director to cancel the bike leg at the poolside briefing, so the event became a swim and run. She found the change calming, enjoyed the swim and finished with heavy legs. The event reacts to road incidents, but the open-road bike can be lost.
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Sources
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