Originally Posted by Edd
As for noises apparrently this varies between models and components and there have been posts to deal with these, although it may just be part of this bikes design and magnified by the aluminium main tube resonating.
Honestly, I don't know why this is. I've also heard some have the squeak, and some don't.
I sold my Birdy in January after about 5 years of storage. The last time I rode it, it squeaked. When I went to clean it up and check it out before I sold it, I rode it around for a few miles, and to my surprise, it didn't squeak anymore, despite my jumping up and down on it and cranking it hard. I almost ended up not selling it, but I still had the fit problems (reach was too long), so I bit the bullet and shipped it.
I guess they're like wine, getting better with age.
(BTW, the original tires were horrendous so I put on some 18" Schwalbe Marathons before I sent it.)