[elinchrome]

Except that the team get sponsored by a manufacturer, and it's not picked by the riders.

[someone_welsh]

To an extent, and seemingly always with frames. But pro riders often use parts that aren't "sponsership approved" - they just make them all black or similar (rather than have another manfacturer's logo on them)

[dagw]

And the manufacturer then works with the team/riders to make sure they get a bike that works for them.