It's the only road that goes anywhere, until you get up to Peet/Soldiers. Mount St used to be the back way into Clifton Hills if you were coming down from Roley, but....I can't think of any reason to actually go to Clifton Hills.
According to this
Mount St is the start of the Roelystone (sic) to Beverley ride. Looks like your sort of caper.
Thanks, at least the sign I found in Kelmscott is kind of near (and points to) Mount St. The one near my house seems totally out of place. I don't know why you'd be riding through the back streets of Huntingdale to get there. Plus I've yet to see any other signs directing you there so you get to the end of Balfour St and then say 'Now what?'
Further to Juffy's comment, Mount St is a bit of a rat run into the back of the Kelmscott shops at Gilwell Ave, popular for those who don't like that section of Albany Hwy (and the bottom end of Brookton Hwy). I can understand cyclists using it in reverse as a preferred way to get to Brookton Hwy and the start of the long slog up to Karragullen.
At least this sign
at the end of my street should come in useful. It'll point Tash in the direction of her orienteering event this weekend (in case she forgets).
I remember dodging the kangaroos on the descent into the gully on Urch... that was a fun adrenaline ride with frozen arms! I think Peet was the next road (on the way to / from) Canning Dam loop and the Thomson girls' place.