Does anybody know what the name of this feature is?
This is the back side of a hyperglide hub where the hub body engages the wheel hub. I’m trying to upgrade to 10 speed. Original on the left, new part on the right. There’s 10 teeth on the old one and 15 on the new one.
New one obviously won’t fit due to the difference in the number of teeth, but adding 10 tooth to my searches doesn’t bring up anything helpful
I’ve been working on bikes since the 80s and have never seen one like the 10 tooth thing. But it looks like an early version of the DT Swiss ratchet hub system, but really just a way to attach basically a freewheel vs freehub without screws vs the replaceable double “star ratchets”. I honestly don’t think you’re going to find anything that converts that to what you want without just replacing the hub
More brands are using ratchet hubs now that the patent has expired. Shimano calls their version “direct engagement”.
There are some details in this article, and an animation of Shimano’s version in this youtube animation
From the animation it looks like what DT Swiss called “star ratchets” Shimano calls “hub ratchet” and “outer ratchet”.
I think it’s still a freehub because the ratchet mechanism is at the freehub-wheel hub interface. A freewheel has the ratchet mechanism enclosed within its own body, right? With a static threaded interface to the wheel hub.
I’m still trying to understand how the spline OP is trying to identify fits in. Are we looking at the back of the mated ratchet rings?
So Shimano calls it a freewheel, and the ratchet mechanism is internal. The spline is what transmits force from the cassette to the rest of the hub/wheel, and/or what allows to wheel to spin the ratchet inside the freewheel with not pedaling.
Shimano Fh-c201 was the part I needed.
Edited to say freewheel. Isn’t that just a freewheel and not a freehub body?
No it’s a freehub body, hyperglide. Freewheel threads on, and this has a freehub fixing bolt to lock it down.