I owned a mountain bike in the mid to late 80's when I was in the Army and I simply don't recall how sizing really works for these bikes. Is it the same as road bikes or is there a different set of rules. I live in the Niagara Region and want a bike I can use in winter.

I currently ride 25 inch road bikes. When I look at ads for used mountain bikes they generally refer only to tires "has 26 inch tires", etc. I've never seen frame sizes named, beyond sometimes seeing "L" or "XL".

I don't want to drive around testing strangers bikes. I could email and ask "how tall are you?" but many sales are by re-sellers who don't fit the bike or don't even reply.