Château de Chantilly Bastion Course Guide ENG 2025
CHÂTEAU
SUNDAY 8 JUNE 2025
‘Superb triathlon to do. Beautiful scenery. Very well organised’ .
Audrey M, 2024
Half Iron
Triathlon Château de Chantillly
‘
Nothing to complain about, it was perfect! Beautiful setting, lovely course, well done to the teams!’
Loïc C, 2024 Olympic Triathlon Château de Chantilly
Dear participant,
Have you signed up or are you thinking of signing up for this huge challenge? This guide will provide you with all the information you need for the Bastion at the Château de Chantilly.
Known as ‘The Bastion’ , this extraordinary triathlon will put the toughest athletes to the test. The Bastion features a 3.8km swim, a demanding 180km bike course and a magnificent 42.2km run through the grounds of the magnificent château.
A ‘bastion’ is a fort, a place where soldiers gather and prepare for the next battle. This resilience and will to fight will undoubtedly be needed to conquer this endurance race that will mark your life. This Full Iron distance race will test even the bravest warriors!
Our aim is to ensure that you have the best possible experience, that your loved ones have a great time cheering you on along the route, and celebrating with you in the events village. We want you to soak up the atmosphere, see the sights that make up Château de Chantilly, and the beautiful surrounding countryside that will be your playground for the day.
Please consult our 2025 Competitor Guide for information you need for your welcome and arrival on site, including parking facilities, registration information, the events village and offers from our partners.
If you are yet to book the Bastion and want to sign up, please click here.
We wish you all the best with your training and pre-race preparations and look forward to seeing you at the start line for a race to remember.
Brian Adcock Race Director
1 CE MATION
REGISTRATION
Registration for all Bastion competitors will take place on Saturday 7th June It is compulsory that competitors register and collect your race pack by the specified deadline
Your race pack will contain :
- 2 race numbers (with your name)
- 1 label sheet (with instructions)
- 2 participant wristband
- 1 spectator wristband
- 1 swim cap
- 3 transition bags
- 1 ankle timing chip
- 1 label strip
- 1 temporary tattoo
SWIM PRACTICE
There will be a practice swim on the Saturday for all Bastion competitors.
Check in on arrival, then head to the lake for a safety briefing by the Race Director.
STORAGE AT NIGHT
Bikes must be racked on Saturday afternoon and will be held there securely overnight.
SCHEDULES
These times for Saturday 7 June are approximate and will be confirmed as race day approaches.
Registration - 15:00 - 17:00
Bike racking - 15:00 - 17:00
Practice swim - 16:00
Race Briefing - 17:00 - 18:00
Pasta Party - 18:00 - 19:00
The Race Briefing and Pasta Party will take place in the Tipi Tents at the lower lever of the terrace.
BRIEFING OF COURSE
All competitors are required to attend the race briefing given by the race director.
This briefing will cover the important aspects of safety and the course that all participants should be aware of, and will give you the opportunity to ask any questions you may have.
The briefing will take at 17:00 place on Saturday 7 June at the Château.
The Pasta Party wil take place following the briefing and is included in the race entry fee. Supporters are very welcome to join, and this will be charged at €15 per person.
To book/purchase your ticket, please click here
SUNDAY 8 JUNE
YOUR RAC INFORMAT
2 CE TION
TRANSITION
RACKING
Bastion competitors will have a designated area in transition. Bikes are to be racked on Saturday afternoon and will be held there securely overnight.
COLOURED BAGS
During registration you will be given 3 bags coloured blue, white and red. You will also be provided with stickers with your race number on them to put on these bags.
The Blue Bag is for your cycle gear, the Red for your run gear and the White for when you have finished the race.
CHANGING AREAS
There will be access to a female and male changing areas which you can use during the race should you wish
BLUE BIKE BAG
This should contain everything you need for the bike , including your cycle helmet and race number
Once you have exited the swim and readied yourself for the bike, place your discarded swim gear in this bag
RUN BAG
This should contain the kit you will need for the run After you have readied yourself for the run, use this bag to pack your discarded bike gear in, including your helmet RED
WHITE POST RACE BAG
This is for after your race Put any additional clothing you will wear before the race, and anything you should require after the race in this bag
THE COURSE
The course consists of two laps of a 1.9km loop, for a total of 3.8km of swimming. The start and finish will be at the entrance to the Grand Canal, in front of the Château.
Race Director, Brian Adcock, will record an online briefing prior to race day, which will be shared on the event information page on our website. This short online video will detail the course and safety instructions If you are part of a relay team, please ensure that all members of your team have viewed it.
You will exit via the ramp in the centre of the Grand Canal. The cut-off time for swimming is 2 hours 20 minutes.
Safety is at the heart of the event - we have safety boats and kayaks manned by fully trained safety representatives to look after your swim. If you feel you're in trouble, just lie on your back and raise your arm - someone will come and help you immediately. Resting on the boat or kayak at any time during the race is acceptable with no implication on your race timings. Floats or any other swimming aids are not permitted during the swim.
Swimmers will be manually and electronically counted into and out of the water for additional safety. Regular water quality and temperature tests are taken in the upcoming months, weeks and during the event. . This information will be posted on the Château de Chantilly competitor information page.
WETSUITS
Depending on the water temperature, you may need a wetsuit. Between 12°C – 16°C: Wetsuits are compulsory. Between 16°C – 24.5°C: Wetsuit is permitted but not compulsory Between 24.5°C – 32°C: Wetsuit is prohibited.
Find out more here.
TIPS
You must wear your chip on your left ankle. It is recommended to wear it underneath the leg of your wetsuit to prevent it from being lost. As for your watch/GPS, losing it in the water can be very frustrating! Wear it underneath the sleeve of your wetsuit.
CYCLE COURSE
The route consists of two laps starting from the Château. Cyclists will pass through some of the most beautiful tourist sites and towns in the Oise region.
JUNCTIONS
All key junctions will be guarded by marshals, but remember that you will be riding on public roads that are not closed to traffic. It is your responsibility to ride in accordance with the Highway Code, and FFTri referees will apply penalties to those who do not.
FEED STATIONS
There will be fully - stocked feed stations along the cycling route. We'll let you know in our pre-race communications what food will be available on the course.
BIKES
Don't forget that all athletes are recommended to use road or triathlon bikes. If you are an experienced cyclist, a TT bike is allowed.
RELAY TEAMS
Relay teams must ensure that the timing chip is passed between team members during the transition. This must be done next to the position of your bike on the bike rack.
WASTE
Competitors must not litter the course. If they are caught littering, they will be disqualified.
OTHER COMPETITORS
Please note that you will be sharing the cycling course with competitors of other race distances. Please respect the signs and the marshals' instructions when you are on the course.
RESPECT FOR ALL
Respect other competitors, event staff and members of the public during the race.
NON DRAFTING
This is a non-drafting race. You will be expected to maintain a distance of at least 12 meters between your wheel and the back wheel of the rider in front of you. Should you wish to overtake you will have 25 seconds to complete the manoeuvre.
CYCLE COURSE OVERVIEW
The route consists of 2 laps of a 90km course around the stunning Oise countryside. Passing through Forêt de Chantilly and Forêt d'Ermenonville, before skirting the edge of Bois du Roi this beautiful route will truly put you through your paces.
THE ROUTE
Heading south from the château the route takes cyclists through the stunning Forêt de Chantilly and past the entrance to Parc Astérix. Passing the beautiful man-made reservoir of Étang de Vallière and the quintessential town of Mortefontaine, cyclists will then head east through the villages of Montaby and Loisy. After passing through the town of Ermenonville, cyclists continue east passing the Château d”Ermenonville and the famous JeanJacques Rousseau Park After the towns of Montagny-Sainte-Félicité and Nanteuil-leHaudouin, athletes then head north-west towards Versigny and Baron. The route then heads north-east to Rosière and then northwards to Le Luat Here, cyclists turn left and head east through Ducy, before then heading north through Rully. Competitors head north-west again towards Néry before finally turning
ELEVATION
homewards through Raray and Brasseuse Upon reaching Senlis and passing its famous Cathedral the route heads past Chantilly Polo Club before returning to Château de Chantilly. The route will be on open public roads and not closed to traffic. The course has a total of 504m ascent. The majority of the route is flat, with one steep climb in the first middle part of the course
THIERS-SUR-THÈVE TO MONRTEFONTAINE
Having passed through the village of ThiersSur-Thève, again taking care of traffic calming measures and parked cars, continue on the D607 to Mortefontaine Just after the 15km marker take a right hand turn at a junction in th e road and then listen to the marshal on the top of a small humpback bridge Take two lefts in the village and then pass the first Feed Station on a slight incline tucked in a school layby on your right hand side.Exit the village on the D922 following signs for Loisy and Ermenonville.
LOISY TO ERMENONVILLE
At 20K you’ll pass through the village of Loisy At 24K, take great joining the roundabout on the outskirts of Ermenonville as you are joining a major French road here called the N330 (which is following a bypass route of the town). Follow the N330 south for 1km before turning left, still on the N330, at a 2 roundabout just after the 25KM sign and head west for 2km On arrival at a 3 roundabout take a further left and leave the N330 by heading north for 1km towards the centre of town on the D922. Before the town take a right and head out into the proper French countryside nd rd
MONTAGNY-SAINTEFÉLICITÉ TO BARON
After the 30KM marker you’ll pass to the south of a village called Montagny-SainteFélicité Continue on the D922 for a further 5km before coming to a t-junction just to the west of a large grain silo and railway line on the outskirts of a town called Nanteuil-leHaudouin. Take care at this junction as you turn left across traffic Follow this road, the D330A, for 8km until you arrive at the village of Baron
BARON TO ROSIÈRES
In the village of Baron take care as this is a confluence of many roads and there could be some traffic.On arrival in the village take a right hand turn onto the D100 and head north for 300m Just as you are exiting the village take a right hand turn signposted to Rosières. Climb steadily uphill for 3km to make the village of Rosières which doubles up as the halfway point and the 2 Feed Station nd
ROSIÈRES TO LE LUAT
In Rosières, take the first left, the Rue de la Muette, which will take you downhill on a single track road that leads to the village of Le Luat Take care on this single track road as there are one or two blind bends ad there may be some farm vehicles operating.
LE LUAT TO DUCY
On entry into Le Luat be aware of the newly laid speed bump on the outskirts of the village! On making th e crossroads at the centre of the village take a left onto the Rue de Dix Arpents signposted to Fresnoy-Le-Luat When you arrive at this village you will have completed 50km Head west towards a village called Ducy crossing over the TGV railway line in the process and remake the D100 Take a right hand turn on the D100 and head north
DUCY TO HULEUX
At 55KM you will be in the village of Rully In the centre of the village take a right hand turn onto the D113 (Rue du Vignet) and head northeast towards Néry for 7km passing through the village of Huleux en route
NÉRY TO BORDÉ
Just after 60KM join the D98 by turning left across traffic. A further 1km will bring cyclists into the village of Néry. On entering the village turn left at a crossroads, again across traffic, onto the D554 also called the Route de Néry.After 3km on the D554 cyciists will pass through the village of Bordé and a further 1km on from there take a left turn, just before the 65KM marker onto the Rue de Monchy
RARAY TO D26
At 67KM cyclists will enter the village of Raray which is dominated by the chateau of the same name Cross over the D100 in the middle of the village and then handrail the chateau wall for half a km before turning right at a T-junction onto the D26.
BRASSEDSE
At 69KM cyclists will cross over the A1 (main French motorway) and then enter the village of Brassedse. Take care as another D-road joins from the right on the outskirts of the village Pass the busy town green with a number of side roads leading onto it with great care but continue on the D26 in the direction of Senlis.
CHAMANT TO SENLIS
At 72 5K cyclists will turn left a a Tjunction across traffic onto the D932A This is a busy road and leads into Chamant and then Senlis. Cyclists needs to take particular care when crossing the double roundabouts in a retail area called Le Poteau Continue on the D1017 into the stunning walled city of Senlis arriving at the Rondpoint du Ser (Roundabout of the Deer – there is a bronze statue on the top of a plinth on the middle of it) at just under 80KM Nearly there!
SENLIS TO AVENUE DE CHANTILLY
At the Rondpoint du Ser take a right hand turn and follow the inner ring road around the edge of the city walls in an anticlockwise direction Take care with the various side roads and mini-roundabouts as you go.After 800m you’ll arrive at the Rondpoint D’Obelisque (as it sounds –there is a great big obelisk on the middle of it) where you’ll need to follow signage and the gendarmes who will direct you onto the Avenue de Chantilly, the D924. Nearly home now…
RUN COURSE
On the run course, the athletes will pass through the magnificent grounds of the Château. This flat and fast run course is perfect for those looking to complete the run section in a quick time.
THE COURSE
The run course is primarily on tracks or paths.
The finish line and event village are located near the castle and the Grand Canal, where there will be plenty of refreshments and drinks on offer.
THE COURSE REMAINS OPEN TO THE PUBLIC
Please exercise caution when running along all sections of the route as there may be walkers, people on horseback and motorists using the same tracks, bridleways, paths and roads.
RESPECT FOR ALL
Respect other competitors, event staff and members of the public during the race.
LITTER
Competitors must not drop litter out on the course. If caught littering you will be disqualified.
THE TERRAIN
This stunning, fast, and flat course features a mix of grass, tracks, and paths. Multi-terrain shoes are recommended for optimal performance.
ELEVATION
The course has a total of 51m ascent per lap The route is largely flat, with a few gentle ascents and descents.
MARSHAL POINT 14 - 19
Having run past transition and then nearly a km down the Grand Pelouse (between marshal points 14 and 15) and having passed the first Feed Station, at marshal point 15 you will pass through some green estate perimeter gates and turn half left onto a shaded forest trail After 500m turn right at marshal point 16 and head south for a further 400m before turning right again to complete the triangle and return to marshal point 15 At marshal point 15 bear half left and run along a pubic footpath, the GR11, until arriving at the Grille D’Honneur at marshal point 19.
MARSHAL POINT 20 - 22
Having run past the Grille D’Honneur, continue along the footpath that borders the cobbled road until re-entering the estate grounds via the Grille de Jeu De Paume at marshal point 20 and the 9km marker. 50m in, and having passed the Jeu de Paume court (large building) on your left hand side take a left hand turn at the junction at marshal point 21 and soon after you will arrive at the 2 Feed Station. nd
MARSHAL POINT 23 - 25
At 10km you will arrive at marshal point 24 If you are doing 1 lap (ie 10 5km) only then turn right and follow the avenue of lime trees towards the Chateau and the finishing straight. If you are doing more than 1 lap (ie the demi marathon or the marathon) then continue straight on handrailing the waters edge and then turn right to complete a circumnavigation of La Manche (the Sleeve) which takes you past the swim start, past the run starts and back to marshal point 3 where you will continue out onto the 2 , 3 or 4 lap of the 10.5km route. nd rd th
TIME LIMITS
The cut-off time for the Bastion race is 16 hours.
AFTER SWIMMING
2 hours 20 minutes (+10 minutes for transition)
BIKE
Competitors must complete the first lap of the bike course as well as the swim within 6 hours and 30 minutes in order to be allowed to start the second lap.
The time limit for the swim and bike is 9 hours and 45 minutes (which corresponds to an average speed of 24 km/h).
The cut off time to exit T2 is 10 hours (at the start of the run) AT THE EXIT OF T2
FULL LIMIT (MUST HAVE STARTED THE LAST LAP OF THE RUN )
Competitors must have started their final lap of the run course within 14 hours and 30 minutes (from the start of the race).
If the competitor has not completed the third lap of the run before 21.30 they will not be allowed to continue and will be directed to the finish.
PERSONAL BAGS
You will be able to obtain a personal needs bag at feed station 1 on the bike and run courses. Please hand these bags filled with your nutritional requirements, to the registration team on the morning of race day It will be your responsibility to locate your own bags at the feed stations. Please note that we cannot guarantee that these bags will be returned to you. Please do not place valuables in these bags.
ON THE SWIMMING COURSE
There will be a floating pontoon on the swim course, which will be stocked with a selection of drinks including water, Coca Cola, Pre-mixed cups of Overstims HYDRAXIR (iso which contains electrolytes) as well as Sliced banana, jelly sweet and a savory snack. Drinks will be dispensed in cups. Please return used cups to the pontoon, where officials will ensure that they are disposed of responsibly.
RUBBISH
We suggest disposing of your bottle in the container preceding the bike feed station if you wish to collect a pre-filled water bottle or electrolyte drink at the feed station. On the run water, electrolyte and Coca Cola will be available in cups. Please ensure that all rubbish and bottles are placed in the large containers before and after each feed/water station.
ON THE BIKE
A feed/water station will be placed at 17K / 42K / 60K on the 90K bike route. Therefore you will pass by the feed/water stations a total of six times.
The refreshment points offer:
Bottles of water
Pre-mixed bottles Overstims
HYDRAXIR (ISO which contains electrolytes)
Overstims Gels ENERGIX
Overstims Bars
Half bananas
ON THE RUN
A feed station will be placed at the 1.5K / 3.5K and 7K points on the 10K loop. You will therefore pass these three times on every 10km lap
The refreshment points offer:
Cups of water
Cups of Coca Cola
Pre-mixed cups of Overstims
HYDRAXIR (ISO which contains electrolytes)
Overstims Gels ENERGIX
Overstims Bars
Half bananas
Cakes and savoury options (crisps)
SPECTATORS VIEW
Many of you will be bringing spectators to watch your herculean efforts. This is our recommendation of what to do and where to go at certain times whilst you are racing. This guide is based on a 13-hour completion time.
06:30
Go and have a coffee in the Event Village whilst athletes prepare for the race.
07:00
Make your way to the edge of the Grand Canal to watch the swim start and follow along the spectacular waterway. Watch your swimmer complete the t-shape in the Grand Canal - great viewing spots all the way around and you can literally touch them as they swim down the main canal section.
08:20
Run back to the swim exit ramp so you can watch athletes climb out of the water and run back up the ornamental steps of the Chateau to transition on the Terrace D’Enghien
POST RA INFORMA
3
ACE ATION
AFTER THE RACE
After your race, you'll receive your medal at the finish line, right next to the recovery area where you can get something to eat.
PRIZES
MEDALS, AGE GROUPS AND PRIZE-GIVING CEREMONY
The top 3 finishers will receive a trophy and a gift! There will also be age group trophies for the first places in the 40+, 50+ and 60+ categories, as well as prizes for all places.
