Bryn Du leaves from the village (town?) of Aberdare and is kind of a funny one - you are in a little place with shops and schools and suddenly you are riding up this steep slope. Of course, it being a Welsh climb, it is a 7/10 climb (just like the previous 2 I had done!) and you ride over a cattle grid...
Cattle grid riding on a road bike with skinny tyres is a bit of a leap of faith - you just point the wheels at the grid, perpendicular to the bars and cross your fingers that they won't twist! Generally I think that taking them at speed kind of makes you "skip" across them quicker - 2 problems are that going up hill, speed is rarely an option and the faster you go, the more it will hurt if you fall off!
Again, there was a distinct lack of traffic - one of the massive upsides about cycling round out here!
Garmin data here: http://connect.garmin.com/activity/81723384 - I was a lot slower than Simon anticipates - taking 17 minutes when his approx climb time is 13.5 minutes. I'm blaming the lack of lunch.....
This is one of those hills that you ride up, worried that you haven't reached the finish so keep going for a little while longer than you should do - just to make sure! I think that there ought to be some sort of campaign to put up little signposts so you know exactly where they start and finish! All this energy is precious stuff you know, not to be wasted!
Photos here: http://www.flickr.com/photos/100hillsforgeorge/sets/72157626733319544/
No video I'm afraid - sorry, need to work my video cameras out better!