Going up onto Great Dodd (boggy bridleway from the Old Coach Road) then south along the Dodds ridge is a good call.
The Dollywagon descent is still rideable for those with the skillz *but* long travel and armour recommended, balls of steel obligatory. I possess none of those things… last time I was there (January this year) I mostly walked down it.
Your other option is to ride out to Dollywagon then backtrack over Helvellyn summit again, and go down Keppel Cove zigzags (fast and furious, but over rather soon) or down the Sticks Pass (some nice techy singletrack).
Watch out for the walkers, will be packed out this weekend…