On my 98EV, the hex top is 36mm. However, the 98 has adjustable damping and that might not be the case with your model. Also, by visual inspection, I seriously doubt there is adequate room to fit the socket wall around the hex with the handlebar in place. Take a chance and buy the 36. Just be sure you can take it back and exchange it if you find your size is different.
Patrick Hayes
Fremont CA