Front is wobbly...They are now saying change stem bearings
They are almost certainly right and its the first thing that ought to have been checked, especially if the wobble you described occurs during decceleration or on a neutral throttle anywhere between 40-80kph.
If, your bike still has its recirculating ball and cup bearings, the top triple clamp is removed and the lower of the 2 castlelated nuts is torqued to 15ft/lbs (imperial measurement), the lock washer and upper castlelated nut returned and the triple clamp returned and torqued to 80ft/lbs. This, Honda reccomends should be a routine occurance.
If, your bike is fitted with tapered roller brgs. (many are, my own included), then the castlelated nut torque should be checked (anywhere from 5-~ft/lbs as this is up rider handling preferance), but only after the lower bearing cup has been inspected for load / usage indenting and if so, replaced.
Both brg types will cause their lower (load), cups to indent, tapered rollers more so than recirculating balls. The advantage of tapered rollers over recirculating ball brgs is improved handling, especially low speed turning for the ST1100 as they are bias to over-steer during low speed manouvers. And high speed stability at higher bank angles are improved considerably without steering damping on the ST1100. But as mentioned, adverse wear or rapid wear at higher torque settings above 5ft/lbs is the trade off for using tapered roller brgs.
Good luck n cheers, the can :-)
