Her trike doesn't have handlebars, it's a direct drive tadpole trike that steers with control arms. She had a Sigma BC-509 wired computer on her EZ-3 (this one has handlebars over the front wheel), which she still has. Sigma makes a recumbent harness for around $10.00 for that model. This is what I wanted to put on the bike in the first place, but she bought the wireless when she bought her cycling shoes. Since the bike shop she bought it at is so far away, I didn't want to have to drive 40 miles to return it, so I decided to mount it and ran into the issues above.

On one of my other forums BicycleTutor.Com one of the bent riders posted a photo on how he mounted his wireless on the caliper mount for the disk brakes by using a metal bar. I looked at my wife's disk brakes and they are a different make/model than his and they have no way that I can see to mount the sensor where the rotor isn't in the way. I'll check out that adaptor from Greenspeed and see if it looks like it will work.