Road · United Kingdom
Lôn Las Cymru (South)
A rolling 112 km road cycling route from Cardiff Bay, Vale of Glamorgan through Butetown, Maindy and Morganstown, with 874 m of climbing. Mixed surface: 80% is mapped as paved and 17% as gravel or unpaved and 3% has no surface data.
At a glance
- Best for
- Rolling day rides for fit, experienced riders
- Distance
- 112 km
- Elevation gain
- 874 m
- Riding time
- 8 h
- Difficulty
- Hard
- Bike
- Road bike with sturdy tyres, or gravel bike
- Surface
- Mixed surface
- Traffic
- Mostly minor roads
- Food & water
- Longest gap 16 km
- Best months
- Jun to Sep
- Navigation
- GPX download
- Start → finish
- Cardiff Bay
Map and elevation profile
Elevation profile
- 874 m
- 112 km
Route description
- Cardiff Bay
- Butetown
- Maindy
- Morganstown
- Pontypridd
- Edwardsville
- Cae-draw
- Trefechan
- Dorganloch
The ride begins at Cardiff Bay and passes through a series of nearby places including Butetown, Grangetown, Cardiff City Centre, Canton, and Llandaff before reaching Coryton at 9.8 km. It continues north-west past Radyr and Tenby towards Merthyr Tydfil at around 44 km. The route includes multiple climbs, such as a 2.8 km climb starting around 13.7 km with an average gradient of 2.2%, and several other moderate climbs between 45 km and 93 km, the steepest being 8.5% maximum gradient over 2.4 km at 86 km. The highest point on route is at 435 m, reached at 62.2 km, and the lowest at 4 m early on at 0.5 km.
Why ride this route?
- Tops out at 435 m, 62.2 km in.
- A 10.3 km descent dropping 281 m.
Highlights
- Cardiff City Centre at 2.8 km
- Merthyr Tydfil at 44.4 km
- Steepest climb 8.5% max gradient at 86 km
- Highest point 435 m at 62.2 km
Along the route
Places passed
Climbs
| Climb | Starts at | On this ride | Top on this ride |
|---|---|---|---|
| Unnamed climb | 13.7 km | 2.8 km · 62 m · 2.2 % · max 4.1 % | 98 m |
| Unnamed climb | 45.4 km | 2.9 km · 69 m · 2.4 % · max 3.8 % | 255 m |
| Unnamed climb | 48.7 km | 2.4 km · 53 m · 2.3 % · max 2.8 % | 309 m |
| Unnamed climb | 52.5 km | 2.5 km · 82 m · 3.4 % · max 5.4 % | 389 m |
| Unnamed climb | 60.5 km | 1.4 km · 53 m · 3.9 % · max 6 % | 417 m |
| Unnamed climb | 86 km | 2.4 km · 93 m · 3.9 % · max 8.5 % | 266 m |
| Unnamed climb | 89.8 km | 2.6 km · 61 m · 2.4 % · max 9.2 % | 290 m |
Traffic, surface and gradient
Mostly minor roads and streets on the map; 5.8 km is on main roads without a cycle lane.
- Roads
- 34% minor road · 28% cycle path · 13% path · 7% track · 18% other roads and tracks
- Main roads
- 5.8 km on main roads without a cycle lane — likely busier
- Fast roads
- 4.6 km on roads with a limit of 80 km/h or more
- Cycle paths
- 34.5 km on cycle paths or roads with a cycle lane
- Main roads used
- Taff Trail (5 km)
- Surface
- Mixed surface: 80% is mapped as paved and 17% as gravel or unpaved and 3% has no surface data.
- Gradient
- 20% climbing · 19% descending · 61% flat
- Steep sections
- 2 km over 5% · steepest 500 m averages 6.8% at 94.8 km
- Longest descent
- 10.3 km from 65 km, dropping 281 m
Food, water and services
The longest stretch without a café, shop or water is 16 km, from km 60 to 76. Along the route: 355 cafés and restaurants, 90 shops, 12 water points, 14 petrol stations, 19 public toilets and 8 bike shops.
Food, water and shops in ride order
- 1.1 kmEsso · petrol station · 60 m off route
- 3.6 kmWater point · 90 m off route
- 3.9 kmHWB Bach Cafe · café · 90 m off route
- 12.5 kmFirst Light Coffee · café · on the route
- 19.2 kmThe Food Warehouse · supermarket · 90 m off route
- 23.8 kmPark View Cafe · café · 40 m off route
- 24.8 kmLondis · convenience store · on the route
- 29.4 kmTexaco · petrol station · 130 m off route
- 43.7 kmAldi · supermarket · 50 m off route
- 45.4 kmTasty Trotters · café · on the route
- 45.4 kmBoots · pharmacy · 120 m off route
- 75.5 kmDrinking water · 40 m off route
- 79.8 kmWater tap · 100 m off route
- 83 kmToilets · on the route
- 83.5 kmBiped Cycles · bike shop · 380 m off route
- 97.6 kmTalgarth Bakery · bakery · 190 m off route
- 97.9 kmTalgarth Medical Centre · clinic · 90 m off route
- 107 kmGulf · petrol station · 60 m off route
Need to bail out?
- 2.5 km — Cardiff Central (station), 220 m off route
- 13.8 km — Taffs Well (station), 50 m off route
- 22 km — Treforest (station), 370 m off route
- 32.6 km — Quakers Yard (station), 90 m off route
- 44.4 km — Merthyr Tydfil (station), 300 m off route
- 53.2 km — Pontsticill (station), 250 m off route
- 61.6 km — Torpantau (station), 110 m off route
Worth a stop
- 3.5 km — Blackfriars Friary (archaeological site)
- 12.8 km — Castell Coch (castle)
- 49.6 km — Pontsarn Viaduct (viewpoint)
Stay after this ride
- Foyles of Glasbury · hotel · 90 m from the finish
- Aberllynfi House B&B · guest house · 500 m from the finish
- Millfield Caravan Park · campsite · 1.5 km from the finish
Start and access
At the start
- Trains and ferries
- Channel View Water Bus Stop (460 m)
- Food and coffee
- Brod (690 m), The Hideout (1000 m)
- Shops
- A&K General Store (510 m), Londis (660 m), Cardiff Food Centre (790 m)
At the finish
- Food and coffee
- Foyles of Glasbury (110 m), The Paddlers Rest (310 m), River Cafe (560 m)
Know before you go
- Longest stretch without café, shop or water: 15.7 km from 59.8 to 75.5 km
- 5.8 km on main roads without cycle lane
- 4.6 km on roads with speed limits 80 km/h or more
- 17% gravel or unpaved surface
