After about a 6 month hiatus from riding due to circumstances, I finally got back onto the road this week. New battery, fresh air in the tires to proper pressure, and I'm off. However, during deceleration, I can feel a wobble in the front end, usually when coasting and around 30-35 mph. If I take my hands off the bars, it is instantly noticeable.

Any ideas as to what could be causing this?

 

What bike? Usually fall away adjustment. On a Roadglide, they changed the spec to 1.5 turns to try to cope with it...I had a Roadking that I couldn't get to stop...

 

Steering Head Bearing adjustment is possibly to loose. Do a fall away test.

 

as above.
I had the same feeling from rear tire cupping

 

Flat spot on the tire,old,stiff tires...........

 

Vibration or wobble in a motorcycle front end can originate from a couple of causes. The most common problem is usually the tires. You said that you put fresh air in the tires. If you left any old air in it could cause an unbalance (just kidding). Honestly the most common problem is the tire being out of balance. If the tires are fine the problem is likely the steering head bearings. Loose bearings will usually cause the front end to 'wander.' Tight will cause the bike to resist entering turns. I'd check the tires first, then move to the steering head.

 

Check your spokes if you have them.

 

Sorry, 01 Ultra Classic with cast wheels.

 

Swing arm bushings? Hold the bike upright with the left grip and shake it to look for rear end wobble.

 

How many miles on the front tire?

Sometimes the front tire will wear down unevenly -- the result is wobble. I was getting a lot of it on my Road Glide, UNTIL I changed the front tire. Wobble is now gone (but I expect that it will slowly return as the tire ages).

Could your front brake rotors have a little warping? I've seen this, too (on my previous Road Glide as the mileage built up). It doesn't take much "out of true" for the rotors to induce some wobble in the forks.

With the Road Glide, in both cases the wobble would become -very- pronounced as the bike slowed down from around 45 to just under 40 (when you took your hands off the bars). I've always believed front-end "head shake" was inherent to the Road Glide/Tour Glide because of the design geometry (frame mounted fairing has something to do with it), but seems like the batwing models can get it, too.