Good looking mule, out of a Belgian(sp) mare by any chance.
No, she is out of a halflinger,which is sort of like a minature belgium pony.Here is her mama.She was 13hds, the mule is now 15hds, out of a std jack.
"I doubt it is the bike itself that spooks the mule. Most likely it is the silent way a bike makes a quick approach, like a cat/predator would."
She certainly spooked at those bikes coming up from the rear, but when I first started this, she would not even get close to a bicycle.Having it set right outside her stall gate,she would stand out side and snort at it. It took her several days to come into the stall.I even had a bike tied up in her stall all one winter and that did not help.
Three things that have really spooked her in her life have been bicycles, baby strollers and sheep.Other things,not so much.
Setting out in the arena, it took a week to get her to within touching distance of it. If the bike fell lover, it backed me up a day.
I got to the point where she did not mind it as long as it was not moving,but it took me anothe rweek to get her close to it while I rode it.
We are now working on me riding her,while my wife pushes the bike around the arena.
Then I will start getting someone to ride the bike while I am riding the mule.