Boy oh boy oh boy do I have THOUGHTS on this.
First of all to the post that claimed they rarely see women over 50 going very fast: I ( a woman) earned over 300 QOMs *after* 50. A mix of BOTH road and mtn bike. AND in a pretty competitive area. You just don't know the right women if you don't know fast women over 50. Plus I have several friends who are faster than I am.
As to the MTB question: I have been an MTBer for well over 25 yrs. Agree with everyone who says it is safer for the faster person(s) to go in front on a downhill, I really hate following slow downhillers, and agree it isn't safe either. Most women tend to be more tentative though I have ridden with some who are braver and faster than I, so I go behind. But I also find the best downhillers choose good lines so I like following them too, men or women.
However, climbing is a different story. When I rode with a team the guys would all sprint off ahead at the start of a ride, I was still warming up and followed more slowly up climbs. But by halfway through they had burnt out (& women can often have better stamina)... by the end of the rides I was leading all but the fittest guys up the climbs. (Chuckling all the way... ;-))
I will add, because I agree with the person who said it, that when a man rides off quite far ahead then what's the point of riding "together"? My ex initially rode with me on climbs or went ahead then came back and encouraged me, but after a few years started riding further and further ahead... maybe he didn't want to be seen as the same speed or slower but.. there's a reason he is an ex. 😉 I thought it was pointless being left so far behind I couldn't see him. And - as mentioned - I ain't a slow chick. 🙂
So guys I'd definitely agree if you want to ride "with" your other halves, stick close if you can and certainly not so far ahead you can't see them. I used to grumble that I might as well ride alone or with women friends. Happy trails everyone!