You could change engine cases to an aftermarket FXR case, like one from STD. Just tell STD you want it with the hole for the speedo sensor. No need to got to an FLT case. The other option not mentioned here is a GPS based speedo. I have one on my FXR for the same reason. A side benefit of the GPS speedo is less wires, very clean. Only a 12 VDC power and ground lead. Mine is made by Autometer. It works very well.