What's a "running gear "

[Biased turkey]

I'm just reading an article about weathering rolling stock.
The author mentions weathering the running gears.I did some googling but couldn't find any drawing or picture about the damn thing.
Could anyone please be kind enough to post a link, a picture or a drawing that answers my question ?
tia

 

[jim currie]

the trucks ,drivers and so forth are the running gear refers in general to the underside of a model.