What's your average?

This is a very common question.  Someone inquiring of you about your "average" is looking to know how strong of a rider you are.  They're creating some mental picture of how you compare to them.

Well, maybe.

A cyclist that averages ~17mph for any given ride is usually cruising at 18 to 18.5 mph in order to average 17.  The math just works out that way given your starting, stopping, slowing, etc.  There's nothing wrong with saying your average speed is 17 mph!

So, when another cyclist asks you about your average -- don't inflate the number.  Just say what it is.  A "real" cyclist will know that a person averaging 18mph on rides can ride 19 to 19.5 pretty consistently.  

When you look to go from a "B" group to an "A" group ... do so when you know that your average is capable to increase.  Your solo rides should be at the minimum for the "A" group.  If so, you KNOW you can keep up with them; particularly in a pace line.

If your cycling goal is to reach the "A" group ... then work you way into the "A" group.  Move up the cycling ladder while being true to yourself and your capabilities.

Cycle well my friends.

Sometimes cyclists go down ...

Hard.

When this happens, particularly in a pace line, everyone should review how it happened and what, if anything, could have been done differently to avoid the crash.

Sometimes it is just simple equipment failure.  And sometimes that equipment wasn't maintained sufficiently.

Sometimes the cyclist going down is at fault - nothing anyone else could have done to prevent the mishap.

And sometimes the group, or at least a few others in the group could have made a signal or voiced a warning that may have prevented the crash.

It's well worth the time to think through a crash event and consider all possibilities of how to prevent another one.  We're all out to enjoy our time on the road and helping to keep each other safe is a great way to ensure we have fun doing it.

COVID-19 infection potential

There's another study (European) which delves into the effects of strenuous exercise and the potential to become infected afterwards.  Here's the reference:
https://onlinelibrary.wiley.com/doi/abs/10.1111/pai.13271

One gist of this long document is that extreme exercise, while making the lungs more efficient for that exercise (e.g. marathon running, long-distance cycling), is likely a detriment to the body being able to deflect the virus naturally -- the virus is able to penetrate much more of the lungs.  They state the vulnerable period AFTER the exercise is 3-72 hrs (while your body recovers).

As for the Cyclepaths, we generally do ride longer as the year progresses (we're up to ~52mi on the long routes already) which do take more than a couple of hours.  To me the length of the ride is not so much the issue as is the amount of exertion you're putting on your body; i.e. if you're able to ride long and basically breathe from your nose most of the time, then you're not over-stressing your body.  I'm certain there is some wiggle room in how much your lungs are expanding even though you don't feel over-stressed, but we're not marathoners nor Tour de France atheletes.

As is the usual case, the position you take on this issue is up to you.  If you can tell you're over-stressing your body on a ride, according to this paper, you're likely to be increasing your risk of COVID-19 infection within 3 days after the event.  If you're uncomfortable with this assessment, then you'll need to back off the exercise level and/or isolate yourself for ~3 days after the event.  That's up to you. 

Also keep in mind that pace-line cycling puts you in the "path of exhaust" of cyclists ahead of you; thus, you could be breathing in a sputum, unknowingly, from pace-line cyclists and that "event" could be the trigger within the following 3 days ... you/we just don't know.

As for the group that meets every Saturday, the following guideline still applies:
We ride upon our own personal cognizance, taking all risk upon our individual selves -- this COVID-19 situation is no different than any other Cyclepath ride in this regard; we're all aware of the increased risk in this situation.

Hip Rocking

One "general rule" of road cycling fit is that you're hips don't rock back-n-forth as you pedal; i.e. ensure your saddle is at the appropriate height for your leg length.

From what I've gathered ... there are many opinions about this.  Some say whatever is comfortable for you determines what your saddle height is; others say get the "fit" and leave it alone (unless you have issues, of course).

My position on this is as follows:
1) like all "rules" or "guidelines" they are intended for the average person (is there one?) whereby most people will benefit from adherence. 
2) if you're new to road cycling, you should be "fit" to your bike by your fav LBS and start from there paying attention to how your lower back and knees feel after long rides a few weeks later.
3) if you have not been fit, you'll have to gain experience only by cycling and paying attention to your body ... keeping in the back of your mind the possibility that your saddle is not at it's optimum position for your body and style.
4) if you've been cycling, fit to your bike or not, and you've had no physical issues and are satisfied with your performance (power, etc.) ... then leave your saddle alone; even if I mention that your hips are rocking back-n-forth.

Here's a discussion that meanders back-n-forth on this issue:
https://forums.roadbikereview.com/general-cycling-discussion/hips-rocking-176982.html