Summer gave up horses when she was twelve years old.
The eventing season had just started, and she and her horse - an Arabian/Thoroughbred cross from the finest bloodlines - were both ready, fresh and eager to perform. The first two days went beautifully; her parents were proud of her, delaying their trip out of the country to stay for day three.
Her horse stumbled and took down a bar on the first jump, refused the second, and her parents didn't even stay long enough to tell her how disappointed they were.
After that, she was done with horses; they were too unpredictable, they failed even if you did everything right. She finished the season, of course - it would be beneath a Landsdown to quit in disgrace - but the ribbons and trophies meant nothing to her. She handed her reins to her trainer at the end of her last show, and didn't bother to see her horse again before it was sold.
She spent the next year missing freedom and the rush of wind, before she discovered motorcycles.
Motorcycles couldn't be temperamental, couldn't spook or have a bad day. If you took care of them properly - and she learned, as soon as she started riding - they wouldn't fail you. Her motorcycle was like an extension of herself.
And as long as she was good enough, she could keep things perfect.