Compiled and fact-checked by Tommo, Verus founder · Last verified August 2026 · Spot an error?

Triathlon · Olympic

Grafham Triathlon 2026

Race day
Saturday, 26 September 2026
Location
Grafham, Huntingdon, Cambridgeshire, UK
Distance
49.5 km total

1.5km swim 38km bike 10km run

Grafham Triathlon: 26 September 2026 — the reservoir swim and dam-wall run at Grafham Water, a split-time calculator, and real Verus athletes racing it.

16 days to go

Key Race Metrics & Overview

Date
Saturday, 26 September 2026
Venue
Grafham Water Visitor Centre, Marlow Park, Grafham, Huntingdon, Cambridgeshire PE28 0BH
Distance
Olympic — 49.5km total
Start Time
8:00am (Sprint); 8:15am (Standard)
Draft-Legal Bike
No — non-drafting
Cut-Off
Not published for this event — check the official site.

Also this weekend

The same day also offers a Sprint distance (750m/17km/5km), a Standard Aquabike (swim and bike only, no run), and a 2-3 person Standard Relay.

Sprint

0.75km 17km 5km

A single lap of each leg, with the bike turning at Perry rather than St Neots.

Standard Aquabike

1.5km 38km

Same swim/bike as the Standard triathlon, no run — for swim/bike-only athletes.

Leg 1 of 3

Swim — 1.5km

Two laps of 750m each in Grafham Water reservoir.

Venue
Grafham Water reservoir
Elevation gain
No official figure published — see notes above
Surface
Reservoir — still water.

Wetsuit: Determined on the morning of the race by a British Triathlon Technical Official, per BTF rule 4.2 — water temperature isn't published in advance. Zone3 wetsuit hire is available on-site either way.

Leg 2 of 3

Bike — 38km

A flat, out-and-back bike route through nearby villages, turning at St Neots for the Standard distance — a touch shorter than the World Triathlon standard 40km bike leg, worth knowing if pacing off a generic Olympic-distance plan.

Venue
Roads around Grafham, Cambridgeshire
Elevation gain
No official figure published — see notes above
Surface
Road.

Non-drafting

Leg 3 of 3

Run — 10km

Two 5km laps of the reservoir footpath, crossing the dam wall.

Venue
Grafham Water reservoir footpath
Elevation gain
No official figure published — see notes above
Surface
Footpath.

Wetsuit outlook

Will you need a wetsuit at Grafham Triathlon?

Water temperature at reservoir in September has typically been 15.2°C, ranging from 13.7°C to 16.7°C in eight of every ten years. Against British Triathlon's thresholds for this race's 1500m swim, that means:

Wetsuit optional — and recommended

Between 14°C and 22°C the choice is yours. Rule 4.2(b) recommends a wetsuit for all novices and age-groupers up to 22°C.

What would have happened in each of the last 16 years

  • Wetsuit mandatory4 of 16
  • Optional (recommended)12 of 16

What the organiser says

Determined on the morning of the race by a British Triathlon Technical Official, per BTF rule 4.2 — water temperature isn't published in advance. Zone3 wetsuit hire is available on-site either way.

Estimated from air-temperature history — no direct measurement of this water exists, and small, shallow venues tend to run a degree or two warmer than shown. The official temperature is taken an hour before the start, and only that reading decides the rule on the day.

Transitions

Transition is at Grafham Water Visitor Centre.

Grafham Triathlon Split Calculator

Grafham Triathlon Split-Time Calculator

Enter your own swim, bike and run pace to project a real finish time.

Swim /100m
T1
Bike km/h
T2
Run /km

Projected Finish Time

2:45:00

Swim1.5km @ 2:00/100m
30:00(30:00 total)
T1Swim → Bike
2:00(32:00 total)
Bike38km @ 30km/h
1:16:00(1:48:00 total)
T2Bike → Run
2:00(1:50:00 total)
Run10km @ 5:30/km
55:00(2:45:00 total)

Racing a different distance? Try the generic split calculator or the swim pace calculator.

Where Grafham Triathlon starts and finishes

Grafham Triathlon starts at Grafham Water Visitor Centre, Marlow Park, Grafham, Huntingdon, Cambridgeshire PE28 0BH and finishes at Grafham Water reservoir. We haven't been able to place those on a map accurately enough to show one — a pin in the wrong place is worse than no pin.

These are the start and finish points, not the route. Verus doesn't hold course files for this race, and drawing a line between two pins would be a guess you might end up training on. The official course map is the one to use: view it on the organiser's site .

Entry & Ballot

Direct entry summary

Sprint £83.74; Standard £104.94; Standard Aquabike £94.34; Standard Relay £127.20 per team — confirm current pricing on the official ATW site, since these tiers can shift closer to race day.

Ballot policy

No ballot — entry is direct via Active Training World (ATW).

Age requirement

Not published for this event — check the official site.

Charity Places

Alzheimer's Research UK is the named charity partner — contact them directly for current fundraising terms.

Race Day Info & Checklist

On the day

  • Organized by Active Training World (ATW) at Grafham Water, a well-known Cambridgeshire reservoir venue.
  • The bike course includes around 384ft of ascent on the Sprint distance and 33ft on the run, per the organizer.
  • Zone3 wetsuit hire is available on-site for the reservoir swim.
  • Race pack: 2 race numbers, a timing chip on the left ankle, and 2 numbered labels for your helmet and bike — you also need to write your race number on the back of your hand.
  • Two mandatory full-stop junctions on the bike course (around the 9km mark, and around 12km for the Sprint at Perry village) — failing to stop risks a penalty and possible disqualification.
  • Registration is at the café, opening 6:30am and closing 8:00am.
  • Only portable toilets on site — no changing facilities. Headphones are banned on every leg, and littering carries a penalty.
  • Aquabike finishers have their time stop on entering T2, then walk or run unofficially to the main finish for their medal. Relay teams pass the timing chip as their baton, with the handover point decided on the day by the BTF Technical Official rather than fixed in advance.

Checklist

  • Wetsuit (own or hired via Zone3) for the reservoir swim, since it isn't mandatory but many athletes choose to wear one
  • Bike checked and race-ready, including a working helmet
  • Race number and any timing chip fitted per your race pack instructions
  • A plan to reach Grafham Water Visitor Centre, Marlow Park, Grafham, Huntingdon PE28 0BH

Transport, Spectating & Where to Stay

Transport

Huntingdon and St Neots railway stations are both in the wider area — exact distance to the venue was not confirmed in sources checked.

Not published in detail for this event — check the official site closer to race day.

The bike course runs on open roads around Grafham and nearby villages rather than a fully closed circuit — check the official site for specifics.

Spectator guide

Grafham Water Visitor Centre covers the swim start/exit, transition and finish, making it the natural spectator hub. The dam-wall crossing on the run is another notable viewing point.

Not published in detail for this event.

Where to stay

Huntingdon

+ The closest town of any size to Grafham Water, with a reasonable range of accommodation.

Still a short drive from the venue itself.

St Neots

+ A similar distance away, with its own range of accommodation.

Requires a drive to the venue on race morning.

Frequently Asked Questions

When is the Grafham Triathlon?

Saturday 26 September 2026 — Sprint starts 8:00am, Standard starts 8:15am.

What distances does the Grafham Triathlon offer?

Sprint (750m/17km/5km) and Standard (1.5km/38km/10km), plus a Standard Aquabike and a Standard Relay.

Do I need a wetsuit for the Grafham Triathlon?

It depends on the water temperature on the day — a British Triathlon official decides mandatory-or-not per BTF rule 4.2. Zone3 hire is available on-site either way.

How much does the Grafham Triathlon cost?

Sprint £83.74, Standard £104.94, Standard Aquabike £94.34, Standard Relay £127.20 per team.

Who organizes the Grafham Triathlon?

Active Training World (ATW), at Grafham Water Visitor Centre.

What charity does the Grafham Triathlon support?

Alzheimer's Research UK.

When were Grafham Triathlon results published?

No results yet — they'll be added here once the race has actually happened, or check the official results source directly.