Some time ago I asked a question about women riding sidesaddle as opposed to astride but I can't find that now.  I've been doing some very basic reading about a woman rodeo rider, Fannie Sperry Steel, (1887-1983). I'd like to read something more detailed about her. Born on a ranch in the mountains of Montana, she was competing in rodeo competitions by the time she was a teenager.  Her husband was a rodeo rider and clown.  She devised a skirt that could be fastened two ways to be either worn as a pair of trousers or a convetional skirt.

Thinking of medieval times, there is a picture of Chaucer's Wife of Bath on another thread - she definitely seems to be sitting astride her horse.  I found a blog written by a lady who also writes fantasy novels though I've not read any of her books.  The post was to me quite an interesting read.  Women and Riding in the Middle Ages - Anne H CampbellAnne H Campbell  

Pat Smythe, the show jumper was a well-known person in my early childhood.  I've been trying to think of famous female riders of an earlier time. I wish I could find my earlier posting but maybe it went where old threads go to expire.

I think the old thread that you are referring to would probably be this one (in the Pub's Tumbleweed Suite), riding side-saddle vs riding astride. The Wife of Bath was indeed mentioned there ... and of her Chaucer said:

Upon an amblere esily she sat,
Y-wympled wel, and on hir heed an hat
As brood as is a bokeler or a targe,
A foot-mantel aboute hir hipes large,
And on hir feet a peyre of spores sharpe.

'Upon an amblere esily she sat' (she sits comfortably on an ambling horse) and has 'a peyre of spores sharpe' (a pair, ie two, of sharp spurs), and so she must have been riding with her legs astride her mount. She also wore a large 'foot-mantel' which was presumably a sort of all-encompassing weather-proof covering extending from her waist down to her feet and serving to preserve her modesty (especially if she was riding astride in an ordinary dress) but more especially to protect her clothes from all the spattered mud. Contemporary illustrators picked up on these cues:

Thanks MM.  I did study some Chaucer at school but not (officially anyway) the story of the Wife of Bath though I did some background reading - and read the Coghill modern English version. I've had lots of years to forget of course.