What type of vehicle was once called a Boneshaker?

Bicycle.

http://www.hullcc.gov.uk/museumcollections/collections/subtheme.php?irn=467

...the seat was mounted on a separate wooden or metal spring. This made the seat more comfortable but the wooden wheels and iron rims still caused the handlebars to shake, hence the name 'boneshaker.'

[Text added from provided link -- Zb]

Boneshaker is a name used from about 1869 up to the present time, to refer to the first type of true bicycle with pedals, which was called "velocipede" (from the Latin for "fast foot") by its manufacturers. "Boneshaker" refers to the extremely uncomfortable ride, which was caused by the stiff wrought-iron frame and wooden wheels surrounded by tires made of iron.

https://en.wikipedia.org/wiki/Boneshaker