This.
@ditka...mike ditka
Again, I'm nowhere near as fast as most of the guys here. But, what I can offer is coming into this thread almost 3 years ago with no running background whatsoever and learning so much from them here. And, while I've made a few mistakes along the way, I feel like I started out the right way and have come along so much more as a result of it. Here is the gist of it.
1) You're obviously naturally fast. But, if you're having an issue with recurrent injuries, you might want to read a few things on running form to make sure you're at least not doing something major that could be causing problems. Here's a
post of mine from a few months ago with a couple links. There's plenty of articles about running form so might be worth a look before really increasing your running to make sure there aren't any red flags.
2) It's been mentioned here over and over but the key to getting faster is volume. Run more miles and you will get faster. As a personal example, for a while I was in the 25-30 mile per week (mpw) area. I never hit 40 miles in a week but was told if I did that, I'd take the next step in getting faster. From this past December through the end of February I did exactly that. I hit 40 mpw consistently for 3 months straight. I did virtually no speed work. Like, almost no fast running whatsoever. My fast running came as running the last mile or so of a run with some pace. But, everything else was slow, working on keeping my HR ~140 on almost every run. I EASILY PR'd both my 5K and my half-marathon time in back to back weeks in February and beginning of March.
With your background in biking, you almost certainly have a good aerobic base already and probably why you could run that 10K like you just did. But you still haven't adapted your legs and likely have a lot of room to improve, which is crazy. If you really want to, you need to run lots of slow miles and give it a bit of time. The runs should feel ridiculously easy. And even then, you're still probably going faster than you should. But in doing so you're more likely to stay injury free, will enjoy it more (eventually), and ultimately will be faster.
3) To increase your volume, you need to take it slowly. The general rule is 10% increase in mileage each week. At this point, just start at 15-20 mpw and then go up from there. Start with 4-5 runs/week of about 4-5 miles. Run all of them slowly except 1 (of even all of them for now). Within a couple months, you can get up to 30+ mpw and see how things are going. If you can run 5x/week, you can have 4-6 mile runs regularly and then try to do one longer run of 7-10 miles, depending on how things are going for you. Lots of ways to do it and it will depend on how you feel, what you like, what your schedule is, etc. Some guys here do better running more often (I'm one of those). Others do better with a little more rest.
4) 80/20 rule. 80% of your runs should be slow and 20% fast. And, the biggest mistake most make is not running the slow runs slow enough and the fast runs fast enough. See the theme? These guys pounded into me the idea of running more and running slowly. And it really works.
I'll see if I can try and find it but there was an awesome graph I saw about a year ago. It compared elite runners with recreational runners. If you looked at miles per week, the elite runners graph was almost a straight line. They consistently put in miles week after week. Recreational runners, on the other hand, had ups and downs. 35 miles one week. 20 the next. 40 miles. Maybe 18 miles. Little consistency. But then they did the same graph for running pace from day to day and it was the exact opposite. Elite runners had lots of ups and downs. They ran their fast days really fast and their slow days really slowly. The recreational runners were more flat. Their paces didn't change very much because they ran faster than they should on slow days and not fast enough on workout days. A lot of "gray" zone running that results in what some here call junk miles. You'll get some benefit from it, but not nearly as much as you could and eventually plateau. I did that in the beginning without realizing it. I thought I was running slow enough but I wasn't.
If you really enjoy running and want to improve with it, this thread and the guys in here are an amazing resource. I wouldn't be where I am today with my running without them.