Back in the day, with BackTrack 5, setting the bit rate of a wifi adapter was as simple as:

iwconfig wlan0 rate 2M auto

and it worked! The bitrate would be limited to 2M which is VERY useful when you're trying to maintain a long link which breaks whenever the device tries to use more sophisticated modulations which I don't need since the WAN speed is limited.

However, this has never ever worked for me in Kali. Even if the command doesn't error (which seems to happen purely by chance), it will NOT limit the bitrate. I have tried updating the firmware files. I have tried various kernels. It never ever works. The only solution I have is to go back to the ANCIENT BackTrack 5.

This is for an Atheros AR9271