run then bike

It's not on many published plans, but I do this quite often on weekends when I'm in a run focus. I've never had any problems with it, even after long runs up to 2:15, unless the run was a really intense one, or maybe I didn't hydrate adequately. If anything, I feel better biking after running. It seems to take me forever (as in 60-90 minutes!) to really "hit my stride" on the bike. Doing an easy run firsts shortens that time considerably. That being said, if the 16 km run was hard or the distance was a push for you, maybe do the bike more as a recovery effort if you're just maintaining or base building. If the focus is intensity, I'd pick one workout (run or ride) to focus on and use the other more as warmup or recovery.