I got a third challenge ride in today, and it was a big 'un. 2,245 m. Almost double my challenge target of 1,200.
I started out thinking I would ride the route of the Kent Grimpeur Audax, but on examination there was one hill I didn't like (River Hill - too much fast traffic, I'm not riding up that). So I made one tiny edit, and then another and eventually my route looked nothing like the original.

But both started and finished in Otford, were 100k and had a ton of hills. And as it happened I played fast and loose with my planned route anyway so my ride itself was even more different.
Beautiful day, with lots of cyclists out. But still a chilly in the shade and a brisk wind. I wasn't sorry to still be wearing longs.
Went very well. I had lots of contingency bail out points in case I flaked out, but I kept going well almost to the end. The last two hills (Hubbards Hill and Mote Rd) were quite tough but I never got into the miserable survival zone. I still had a bit of spring in my legs.
Having said that I went well, that was referring to my legs, not my speed. If it had been an audax I would have been Outside Time Limit. But it waasn't so I didn't need to worry about finding out the colour of the sheds or the numbers on lampposts, only to find it had been a waste of time as I was OTL.
I think I've earned my steak, chips and mushrooms tonight.