There have been gay motorcycle clubs in New York since the early 60s. Don’t know if they show up in Sturgis though.
The Gay Bikers from my old neck of the woods all but own the Russian River area. So, they zoom up north across the Golden Gate bridge for weekends.
Sturgis is truly a far more rigorous ride; and the event of Sturgis is the climactic celebration of the ride.
But then heck, the reality is... Why would Dykes on Bykes wanna go to Sturgis when they can bogey on down through the streets of SF, as they own 'em, in a manner of speaking. ;>