From One Drop:
The late aughts called and suggested it was time for the matador spike and 16mm axles to come back. We embraced the spike on the Thorn by making it big and sharp and beautiful. Do you dare try a spin start or air grab?
The Thorn is smooth and agile. The slightly concave catch zone gives you plenty of room to work with. At 64.6 grams it's right in the sweet spot with much of the weight being towards the rim to balance out the spikes.
We love flat hub yoyos just as much as the next person, but they come with one downside: small axle. In the Giant Book of Machining (Machinery's Handbook) there is a formula for how many threads of engagement are needed. This formula doesn't take into account the use case, but going strictly by the book, 16mm length is the minimum length for correct engagement with a 4mm diameter axle. 12mm length is borderline. Of course, in the yo-yo use case, there really isn't any load so it comes down to being careful when you take the yo-yo apart. 16mm is more secure and less likely to have issues. You can just feel when you screw the yo-yo together how solid it feels. The spike makes this possible.
The box art was generously donated by Nik Struble.
Specs:
Weight: 64.6g/2.28oz
Width: 42.55mm/1.68in
Diameter: 56.77mm/2.24in
Gap Width: 4.45mm/0.18in
Stock Response: One Drop Flow Groove
Bearing Size: Large (C) stainless steel (One Drop 10 Ball Bearing)
Alloy: 6061 Aluminum
Finish: Pyramatte (tm)
Axle System: Tapped, 16mm