The Brecon to Cardiff Xtreme is the mountain-running edition of our classic ultra.  This 47.5-mile linear race takes on 11 summits and high points between Brecon and Cardiff, with around 2,680m of ascent.  A true winter ultra marathon, it demands strong mountain running skills, solid navigation and excellent fitness. This event sold out in 2024 and 2025 and with limited places available, early entry is essential.

The Taff Xtreme Marathon covers the second half of the Xtreme ultra route, running from Merthyr to Cardiff.  At 26.2 miles with 1,300m of ascent, it’s a challenging winter marathon but one that is ideal for runners ready for a new trail challenge or a stepping stone into the world of ultra running.

The Xtreme begins at the canal basin in Brecon, winding through the old town before climbing straight onto the mountains and the summit of Pen y Fan – the highest peak in South Britain. From there, runners continue with steep ascents of Cribyn and Fan y Big, before a fast, technical descent down the Roman Road leads to Lower Neuadd Reservoir.  A short, sharp climb gains the Twyn Mwyalchod trig point, followed by a long descent towards Pontsticill and Checkpoint 2.

Here the Xtreme briefly converges with the Classic B2C route, enjoying faster forestry trails and rolling hills before reaching the halfway checkpoint at Merthyr College (CP3) – an indoor aid station and the point where Xtreme marathon runners join the course.

While the Classic B2C now trends gently downhill to the finish, the Xtreme still has half its climbing left to conquer. From Merthyr, the course ascends over the saddle of Mynydd Aberdare, skirting the Gethin woodlands, before a fast descent and valley crossing into the Cynon Valley (CP4).

The route then joins the waymarked Glamorgan Way, climbing through the beautiful St Gwynno and Llanwonno Forests. Checkpoint 5 awaits at St Gwynno Church, the resting place of Welsh running legend Guto Nyth Brân. From there, runners descend the long ridgeline of Pen y Foel before rejoining the Classic route near Pontypridd.

At Checkpoint 6 in Pontypridd and the famous Honky Tronk café, runners can refuel with food, Welsh hospitality and maybe even a Tom Jones tune or two.  With the end now within reach, the course climbs over Cefn Eglwysilan before a final, fast drop into the finish at Coleg y Cymoedd, where a warm welcome awaits.

As this is a linear event, competitors park at the finish and are transported by coach to the start in Brecon (or Merthyr for marathon runners).

The event base, registration and race finish is at Coleg Y Cymoedd at the following location: 

Coleg y Cymoedd

Heol Cronchendy

Parc Nantgarw

Nantgarw

CF15 7QX 

The event base provides event parking, café, large indoor area for registration, the finish line, toilets, and changing rooms.  It is easily accessible off the A470 and one junction off the M4. There are many hotels, guest houses, cafes and restaurants in the local area.  In addition there are excellent bus and rail links to and from Cardiff.

Theatr Brycheiniog,

Canal Wharf,

Brecon,

Powys

LD3 7EW

www.brycheiniog.co.uk/en

If you are going direct to Brecon car parking is in one of the many pay and display car parks outside the Theatre and more details are available here.

Marathon
Merthyr Tydfil College

Ynysfach,

Merthyr Tydfil,

CF48 1AR

There is a large pay and display car park alongside the college in Merthyr.

An interactive map and gps file is available at the link at the bottom of the page.

To download the gps click on 'actions', then 'export' and follow the onscreen prompts. 

This is an extreme mountain challenge, and the route is unmarked.  There will be some additional markings provided where the route converges with the classic B2C route, and some additional signs in the dense forest sections, but you must expect to be self-sufficient in terms of navigation throughout. Navigation is using the gps trace and we recommend a primary device such as gps watch or handheld unit and a backup app on the phone such as outdoor gps. 

There are 6 manned checkpoints for the B2C Xtreme and 3 for the Taff Xtreme Marathon.  All of which provide water, energy drinks, squash, sweets, biscuits, oranges, crisps.  The halfway checkpoint (CP3) is indoors at Merthyr College in the town centre and is a great location to meet friends and family and B2C Xtreme runners will have access to your drop bag and some time to get sorted, changed and ready to take on the final half!  Details of where the checkpoints are can be seen on the FAQ page.  The link is at the bottom of this page.  Checkpoints locations can also be seen on the interactive map on map link below.

B2C Xtreme:- As the route is linear you will park your car at Cardiff (Nantgarw) race HQ and catch one of the busses (included in your entry fee) to the start of the event in Brecon. The B2C Xtreme busses leave Nantgarw Race HQ at 0530 on Sunday morning.

Taff Xtreme:- The route is linear and you have a choice of organising drop off at the start or adding coach transport to your entry and parking your car at Cardiff (Nantgarw) race HQ and catching one of the busses to the start in Merthyr. The Taff X marathon busses leave Nantgarw Race HQ at 0830 on Sunday morning.

The time limit for the Xtreme is 15 hours (10pm cut off).  For the Marathon the time limit is 12 hours (10pm cut off).  Only runners finishing WITHIN the time limit will be eligible for a finishers medal. However, there is an option for Xtreme runners of dropping to the classic route at merthyr if you are feeling under the weather or have missed the cut off.

There is a compulsory kit list that must be carried which can be viewed here. 

Saturday

1600-1900 Registration in Nantgarw

Sunday

0530 Bus pick up from Nantgarw and travel to Brecon

0615-0630 Registration in Brecon (only available if pre-booked and not on the bus*)

0620 Bus arrives in Brecon

0650 Race brief at Theatre

0700 Race start from Brecon

2200 Cut off time in Nantgarw

0730-0830 Registration in Nantgarw

0830 Bus pick up from Nantgarw and travel to Merthyr

0900 Bus arrives in Merthyr

0900-0930 Tracker fitting in Merthyr

0940 Race brief on start line in Merthyr

1000 Race starts in Merthyr

2200 Cut off time in Nantgarw

Please note there is no registration on Sunday morning in Nantgarw for Xtreme runners, only for Marathon.
There is also no registration at the race start in Merthyr for the Taff Xtreme marathon runners and you must register in Nantgarw on Saturday evening or Sunday morning.

If you are going straight to the start or being dropped off and would like to register in Brecon you can book this by e-mail. You will receive a pre-race email letting you know when to do this - please don't e-mail before this date as they will need to be re-sent.

B2C Xtreme - Race entry, parking, coach transport and GPS tracking £85
Taff Xtreme Marathon - Race entry, parking at Nantgarw, and GPS tracking £45.

 

Custom unisex tech B2C X race t-shirt (£20)

Custom female fit tech B2C X race t-shirt (£20)

Custom B2C X race hoodie (£40)

RWC race buff (£5)

Taff Xtreme Marathon Coach transport from Nantgarw to Merthyr (£10).

Participation in a classic event

Electronic timing

Live GPS Tracking and map for friends and family to follow from Open Tracking

6 (3 for the Marathon) checkpoints well stocked with refreshments

Half way drop bag transport for B2C xtreme runners (at the Merthyr)

Finishers medal (strictly for finishers only)

Emergency First Aid and First Responder cover

Event photos

Car parking at the finish in Cardiff

Bus transport from Cardiff to Brecon on Sunday morning for the B2C Xtreme runners. 

Optional bus transport for the Taff Xtreme Trail marathon runners (£10)

Welsh weather (hopefully)

Please note: in order to keep entry fees down, support local businesses and inline with what our regular runners prefer there is no meal provided at the finish and instead competitors have a choice of purchasing food and drinks in the onsite cafe at the college or in the numerous local restaurants and fast food outlets next to the finish.

Entries open on the link below.