One alternative is to use VOX. However, there may be too much wind noise for that. The units are available from several sources.
Remoting a PTT isn't much more complicated than grounding the PTT. The hard part is bringing out the PTT, as most handhelds don't offer an easy way to do it.
I knew a guy in Denver, who road bikes all of the time, and he fashioned a PTT that clipped around his thumb. PTT was just a matter of a thumb-fore finger pinch. This eliminated any wiring attached to the bicycle; a good point in case you fell off. Hopefully you won't fall off the glider.