Riding your age in "Miles"
Since turning 62 half way through last year, I have only manged two, 66 last sept and a 68 yesterday.
At some point we will all fail this challenge, but at what age does it happen
I've done it and more this year several times.
However, what makes it harder as you get older is the amount of climbing. I did an 87 miler in Mallorca this year with nigh on 7000ft of climbing and I found it tough going. Heat of course made it harder.
A flat ride comparitively so much easier. Obvious I know but worth stating.
How hard a flat ride is depends on the wind. When I was at my daughters in Fife last week, I did 39.5 mph down a slight incline and 9 mph coming back the other way. Windy doesn’t begin to describe it.
Oh for sure. I'd rather ride uphill than into a mega headwind. Same applies I'd say though regards riding age. However for sake of this if we assume neutral or little wind then a flat ride way easier than hilly was my point.
I need to move to where you live if you get neutral or little wind.😉
I've managed it a few times this year, and on July 1st I did my longest ride since Covid (104miles). As a friend stated 'that's a long ride for fish and chips' ; IMHO they are the best in Norfolk (Norfolk Lavender at heacham) , and worth the ride.
Maybe a better 'indicator' or 'target' could be something like 120miles minus the age? I guess it's not a 'straight -line' relationship, but could be more useful? so a 20-year old 100 miles, 80 year- old 40 miles would seem reasonable.
I've managed it a few times this year,
Very good - but without stating your age, it's hard to know whether it was a challenge.
Regarding your other point, I'm 73 and a 47-mile ride is still a doddle.
Yes, it's very much a sliding scale - but I do know some 80+ year-olds who would still find a 40-mile ride fairly easy. I know an 83-year old who still blasts out a 60km ride most days of the year.
We're all different ... but I really don't think 'cycling your age in miles' has much significance for anyone under the age of 70.
How hard a flat ride is depends on the wind. When I was at my daughters in Fife last week, I did 39.5 mph down a slight incline and 9 mph coming back the other way. Windy doesn’t begin to describe it.

I suggested something similar upthread, namely that your effective age should be considered to be 100 minus the distance you can cycle.Maybe a better 'indicator' or 'target' could be something like 120miles minus the age? I guess it's not a 'straight -line' relationship, but could be more useful? so a 20-year old 100 miles, 80 year- old 40 miles would seem reasonable.