I had a 2010 triglide and some wobble. I actually fixed it with a new front tire. Old one was cupping . This cured it for me. I'm not technical, so not sure why it capped

 

you are rite. Since I started digging into this I have found out a fix. Number one I spoke to legends air which is the rear shocks I have and they said that most definitely the rear shocks could cause a wobble. I have taken off their shocks and put back on the stock OEM shocks and I still have the 9° rake in the front with 21 inch wheel. With the rear shocks being OEM now the wobble is gone with or without wife.

 

Wow. Don't see how the rear shocks could have caused wobbling, since they don't do anything side to side, but I don't dispute you're seeing the results you're seeing. Glad you got it corrected.

 

I found a leaky air shock can allow wobble to occur. Specially when the air starts bleeding out after the oils left. Not OP's issue, but was mine. Cure with new shocks.

 

Well, then it would seem a lot of the wobble is actually bobble. Not a side to side wiggling, but a bouncing on the shocks while leaned over in the turn.

which gets us back to the remarkable under damping Harley has been determined to maintain in their touring bike suspensions.

 

I have no experience with Legends, but shocks can indeed contribute to a wobble. The swingarm on the Touring bikes up to and including 2008 is not very stiff in torsion, unlike later bikes which have far stiffer swingarms. If our shocks have poor damping or a failure such as Trumpet experienced, then they are not going to work in unison and the swingarm is more likely to twist under duress.

 

Good point, that third axis. Wasn't even considering that.

 

I had the same experience after installing, Legends Revo-A, 13 inch shocks on my 2019 Sportster 1200NS. Front-end wobble occurred between 80-90 mph. NO wobble at all with the wife in the back. Stock OEM shocks are 11.25 inches.
Converting the 13 to a 12 inch shocks to try and get rid of the wobble. Hopefully that does the trick. Changing height in the rear sure changes the rake-trail of the motorcycle.

 

Hi from the UK and welcome to HDF.

I fitted taller shocks to my Superlow, to improve ride quality, but also discovered that front fork sag was over half total fork travel. So I also rectified that, which raised the front end over an inch, so the front and rear are pretty level, much as the bike was when new. I haven't had any handling problems, so suggest you investigate your forks first, before changing your shocks. If your forks are sagging too much all you need is a length of thick-walled plastic water pipe and a pipe cutter, from your local friendly IDY store!