Fit issues due to out-of-spec drivers
The XD™️ Freehub body standard was developed by SRAM™️ for wide-range cassette applications. All manufacturing making XD™️ freehubs must license the standard from SRAM™️ and agree to follow their design specification.
We design our cassettes specifically to the XD™️ standard, and an in-spec XD™️ driver is critical for proper installation and clamp force to retain the cassette on the driver.
We have found some cases of undersized and out-of-spec XD™️ drivers on the market. Undersize drivers can reduce the critical clamping function of alloy cassette sections and result in looser than ideal fit. Other out-of-spec features can prevent the alloy section from fully seating on the driver. This can result in poor shifting performance and a slight side-to-side movement of the entire cassette assembly, which is seen at the largest cog when backpedaling.
Some out-of-spec drivers are obvious (Hope Technologies™️), while others require digital calipers to identify the issue. TRS, XCX and Helix cassettes come with three different thickness shims in the box, which can be used for properly fitting e*thirteen cassettes to undersized drivers. If missing, please contact your local distributor or e*thirteen directly, and we will supply one free of charge.
Hope XD drivers are undersized at the clamp location and don't technically meet the XD standard spec.
Due to this irregularity, a shim is required to ensure the cassette clamp functions properly. Please see the cassette section of our support site for installation instructions.
Other out-of-spec drivers
Other out-of-spec drivers are not as obvious and require measurement to identify the issue. Critical dimensions are shown below, and measurement #1 is the most common culprit. In some cases, the thinnest shim can be used to address the undersized driver and cassette fit, however, in some cases, the only option is to replace it with an XD™️ driver which is within the specifications of theo standard.
Other hub compatibility considerations
- Chris King™️ needle bearing freehub bodies: Chris King does not recommend pinch clamp style cassettes to be used on their freehub bodies which use needle bearings in the freehub body/axle interface.
- Industry 9 1/1 Hubs: The Industry Nine 1/1 freehub bodies have splines that are at the very largest end of the range of the XD standard. Our cassettes rely on tightly fitting to this diamter and are designed to be right at the high end of the cassette spline range. The net result is that there may be fitment issues with the 1/1 hubs when used with e*thirteen cassettes, which could result in a VERY tight fit or possible incompatibility.