Freecoaster Clutch Styles

Essentially, there are two styles of clutches: Axial Clutches and Radial Clutches. The differing characteristic being The direction the clutch moves, along the axle, or radially out.

Axial (KHE Geisha):

Radial (KHE Rollex):

Axial Clutches

The majority of clutches are axial because of the system offers. For the purposes of this analysis, axial clutches can further be broken down into sub catagories:

• Push type clutches push the clutch from driver to hubshell (only stock ones I know of are the Sym Hub and the Stolen/Chosen.

• Pull type clutches pull the clutch toward the hubshell and driver (Geisha, reloader, etc)

An inherent characteristic of the axial mechanism is side load on the bearings. Push systems side load both the driver bearing(s) and one of the hubshell bearings. Which bearing is loaded is dependent on whether the push mechanism is located between the hubshell bearings, or outside the bearings.

Axial-outside-push system (sym-hub)

Welding two clutches together work to convert to a LHD-axial-inside-push system (modified taska)

In Contrast, pull type systems only load the drive-side-hubshell bearing. In all unsealed and some sealed hubs (such as the KHE Reverse ACB), the balls contact the races at an angle, which supports side loads much better.

Axial-inside-pull system (KHE Geisha)

In hubs where the drive-side-hubshell bearing rests on the driver, not the axel, the driver bearings must withstand sideloads from axial wheel loads (i.e. when whipping and the wheel lands at a funny angle). Repeated impacts can cause damage to the drive bearings. Interestingly, unsealed hubs are much less likely to have damage to the bearings. This is due to the angular contact that the cup and cone system provides.

Radial Clutches

Radial clutches are much less comon. The only two I can think of are the KHE Rollex, and the yet to be produced, G-sport Coaster*. The former uses roller bearings and ramps, while the G-coaster uses a cam mechanism and, what can be compared to brake shoes.

The major advantage of radial clutches are they do not interfere with the hubsell bearings, and no sideload is on the driver bearing (unless you are pedaling really hard while landing a tailwhip at a funny angle). These systems avoid the major durrability issues that are all too common in coasters.

We must, of course, note a potential issue of radial clutches: contamination of the freecoaster mechanism. Any hubs that come out with a radial system will have to make sure a good sealing system is in place.

KHE Rollex Explosion

* George from G-sport confirmed that he is still working on the coaster. Seeing how the rollex never quite succeeded, it's probably a good thing he is taking his time.