I've never ridden up The Tumble. It is on the Cambrian 10A but I took a lane that goes up the side of The Tumble with a gradient of about 33%. It was a long walk on fixed with about 600 hilly miles in my legs and I kept falling asleep after several steps as it was sometime around midnight.
Then when I descended The Tumble, it was dark and very foggy, so it was a slow descent.
The only time I've tried to ride up The Struggle was one Christmas when the road was covered in snow and ice, so I walked most of it. Before then I'd only ever descended it in the dark on the Knotty 600. One year my front light broke, so I had a torch taped to my handlebars then got a front wheel puncture descending The Struggle.