Another licence question

I did a quick search and didn't see this topic, so I apologize if it has been discussed already. 

I know that you can drive on a US license for 1 year before you must have a UK license, or permit.  Does this only apply to autos, or does it also apply for US motorcycle licenses?

You're covered for motorcycles as well. 

You may drive vehicles up to 3.5 tonnes and with up to eight passenger seats, provided your full licence or driving permit remains valid for up to 12 months from the date of coming to GB.

http://www.direct.gov.uk/en/Motoring/DriverLicensing/DrivingInGbOnAForeignLicence/DG_4022561

Driving licences issued in any other country

* you can drive any small vehicle eg cars and or motorcycles, shown on your driving licence, for a period of 12 months from the date that you last entered the country, as long as it remains full and valid

http://www.direct.gov.uk/en/Diol1/MotoringDecisionTrees/ExchangeaTestPassorForeignLicence/can_you_drive_in_gb.dsb?DPF0=&DPF1=1&vgsubmit=%C2%A0+Next%C2%A0+