Radyr Weir – Blackweir Bridge and Weir loop from Merthyr Tydfil

Bike touring routes & trails

Radyr Weir – Blackweir Bridge and Weir loop from Merthyr Tydfil

Hard

4.7

(20)

275

riders

Radyr Weir – Blackweir Bridge and Weir loop from Merthyr Tydfil

05:18

85.9km

590m

Cycling

Hard bike ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels. The starting point of the route is accessible with public transport.

Last updated: September 9, 2026

Tips

Includes a segment in which cycling is not permitted

After 43.7 km for 90 m

Waypoints

Start point

Train Station

Get Directions

28.1 km

Coed Caedyrys

Forest

34.4 km

River Taff

Lake

34.8 km

Radyr Weir

Highlight • Structure

A pretty weir of the River Taff, the Radyr Weir runs today as a hydro power scheme and a focal point of Radyr town. Many wild salmon and sea trout …

Tip by

38.5 km

Llandaff Weir on the River Taff was built in the mid 1800s to help control the flow and water levels upstream. It was built in a dangerous rapid part of the river which had previously claimed several lives.

Tip by

40.9 km

Blackweir Woods

Forest

43.7 km

Blackweir Bridge and Weir

Highlight • Structure

Blackweir Bridge crossing the River Taff, was designed and constructed in the 1980s by engineering students at nearby Cardiff University. The students evidently liked the feel of the earth moving under their feet, it can be a bit bouncy!

Tip by

47.9 km

Melingriffith Water Wheel

Highlight • Historical Site

52.3 km

Castell Coch

Highlight • Historical Site

Castell Coch is a 19th-century castle overlooking the village of Tongwynlais. Whilst there has been a castle on the site since the Norman period, architect William Burges transformed the crumbling …

Tip by

53.3 km

The Lewis Arms

Highlight • Pub

Always a good place to stop for refreshments. It’s a popular pub and can be busy at times.

Tip by

55.4 km

Wooded section of the Taff Trail

Highlight (Segment) • Trail

taff trail is lovely . small sections can be industrial, however I found this section through the trees particularly beautiful 🌳

Tip by

58.6 km

View of the Taff Valley

Highlight • Forest

So much gravel to wave a stick at...

Tip by

85.9 km

End point

Train Station

Way Types & Surfaces

Way Types

64.2 km

9.22 km

6.23 km

4.29 km

1.92 km

< 100 m

Surfaces

70.2 km

10.2 km

4.19 km

1.38 km

Elevation

Nothing selected – click and drag below to see the stats for a specific part of the route.

Highest point (180 m)

Lowest point (10 m)

Weather

Tuesday 6 October

14°C

6°C

-- %

Additional weather tips

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Comments

June 12, 2025,Lon Las Cymru. Day 1. Cardiff to Merthyr Tydfil.

I had to finish Day 1 early. It was a horrible day for riding a bike. I was very wet. I needed to find somewhere to get all of my stuff dried.

June 5, 2023,Bicycle Tour

This is a easy ride, but you will need a good level of fitness to complete this ride, plenty of stops to take in all the scenery highly recommended, and don't forget water, food, enjoy.