Thunderbird Questions

Are you certain you're not hearing the drive belt chirping under load?

 

You could rub the edges of the belt with a wax candle this should eliminate the belt noise for a time, allowing you to verify where it's coming from.
As for riders backrest there like rocky horses shite to get and everybody knows that, I sold my last one complete with touring seat, it took me forever to replace both, don't use it but wrapped up and I intend keeping it, just like the sissy bar and pillion backrest.

 

What I do if it occasionally chirps is to clean the belt with ordinary soap and water...let it dry then spray it with dry silicone spray... that'll take care of it for quite a while.
It's worthwhile getting the tension and alignment checked out...that's the real cure.

 

Yep silicone polish spray is what I used on my thunderbird LT... done the job.

 

My Bird was my 1st bike with a belt also. Had the same problem in the beginning. Used to drive me crazy.
I've found the only fix is proper alignment/tension. Its a bitch to get it dead on. But once you figure it out, its not so bad. I get my belt to where there is 10 thousandths clearance between the right side of the pulley and the belt. That seems to take care of mine. Everyone has their own way of doing it. I dont run my belt quite as tight as recomended since it tightens up when the bike heats up.
Best of luck to Ya!

 

@Greg J.
One on fleabay if your desperate but being sold as a complete touring kit,
Double seat, on/off sissy bar and riders back rest on at a price of 750 quid won't separate items as they know seat and pillion backrest and rack is still easy to find unlike riders backrest. Mine is only 749.99

 

Bear with this as it's quite painful but just found this and looks like it might work.