With limited time I cycle to complement some running and short sessions in the gym before work. However, I've increasingly got the bug over the last 2 years and am starting to think about doing some longer rides next year and possibly something like London-Paris. Anyhow, on a recent holiday in France I got to do more cycling that normal and managed 200 miles in early morning rides before time with the family and that got me thinking about possibly needing to improve my speed if I want to develop further and ride with others and/or do some organised rides etc.
After doing a few rides of 20-40 miles, I went with some other cyclists on a 55 mile ride. Monitoring my ave speed on my computer I've been pretty steady at around 15 mph for the last year or so (but thus far haven't been overly bothered with speed as too much clock watching was my downfall in running when I'd push too hard and pick up injuries). From discussions beforehand, it was likely the others were a fair bit faster than me but I managed to hang on the back of them for the first few miles but then decided to let them go on ahead after around 15 miles (in fact I plodded on and completed the route whereas 2 out of the other 4 did not finish after burning out trying to maintain the faster pace which was 17-18 mph on a hot and sunny day). I finished the 55 miles with my usual average of 15 mph and, on reflection, was pretty pleased with that. While that may be pretty modest for some, I was pleased that I managed to maintain that average over longer distances than I normally get to cycle.
Anyway, finally getting to the point, so far my cycling has developed by going over further distances, time permitting, maintaining the same speed. I'm not sure whether there is a right or wrong answer, but given that I seem to be stuck at 15 mph I'm reflecting whether next year I just need to carry on increasing the distances or start to focus on getting faster or both? I guess as someone who cycles alone (again, owing to limited time where I can only get out early mornings) I'm conscious of not being fast enough if I decided to join in something more organised. I consider myself as reasonably fit and in okay shape for a 42 y.o. (other than an aching knee which I think may be a symptom of doing more cycling than normal on hols).
After doing a few rides of 20-40 miles, I went with some other cyclists on a 55 mile ride. Monitoring my ave speed on my computer I've been pretty steady at around 15 mph for the last year or so (but thus far haven't been overly bothered with speed as too much clock watching was my downfall in running when I'd push too hard and pick up injuries). From discussions beforehand, it was likely the others were a fair bit faster than me but I managed to hang on the back of them for the first few miles but then decided to let them go on ahead after around 15 miles (in fact I plodded on and completed the route whereas 2 out of the other 4 did not finish after burning out trying to maintain the faster pace which was 17-18 mph on a hot and sunny day). I finished the 55 miles with my usual average of 15 mph and, on reflection, was pretty pleased with that. While that may be pretty modest for some, I was pleased that I managed to maintain that average over longer distances than I normally get to cycle.
Anyway, finally getting to the point, so far my cycling has developed by going over further distances, time permitting, maintaining the same speed. I'm not sure whether there is a right or wrong answer, but given that I seem to be stuck at 15 mph I'm reflecting whether next year I just need to carry on increasing the distances or start to focus on getting faster or both? I guess as someone who cycles alone (again, owing to limited time where I can only get out early mornings) I'm conscious of not being fast enough if I decided to join in something more organised. I consider myself as reasonably fit and in okay shape for a 42 y.o. (other than an aching knee which I think may be a symptom of doing more cycling than normal on hols).
Sounds like you have got your mind-set right because a few ppl would have wanted to try and keep up with the pack,you resisted and managed to finish while two didn't. 
