Blackspire Downhill chainring

[Anthony]

I've found a 32t ring in a box, 104 bcd, 90mm ID, 4 bolt, alloy, 40g.
Didn't know I had it, and don't know what it is.
I believe 90mm ID middle rings are quite rare these days, and later ones don't fit FC-M752 / previous. So I was quite pleased, especially as it looks unused - certainly not by me.
But, would I be right in thinking that the point of the 'Downhill' type was that it was designed to be reluctant to part company from the chain?
And therefore it's useless as a middle ring?
Any information or advice would be much appreciated.

 

[ishaw]

I don't think it's quite the same as narrow wide. I think dh usually equated to burly and no ramps or pins for shifting as designed for single ring use.

 

[Anthony]

I don't think it's quite the same as narrow wide. I think dh usually equated to burly and no ramps or pins for shifting as designed for single ring use.

Thanks
Yes, I should have said it's quite plain, silver alloy, no ramps or pins (not that I know what they do!)
Not burly or heavy either, but maybe a bit tougher than some?
It says Blackspire, Made in Canada and Downhill, and it's a reputable brand, so I guess they can be taken at their word.
Do you have any idea of its vintage? I guess it must comfortably pre-date the narrow wide designs