Since I did the suspension on my '96 dyna, she's been very twitchy at highway speeds. A good bump just about sends the bars into a tank slapper. I think it has to do with running 13" shocks on the rear and the fact that the FXDS (dyna glide convertible) has a steeper head angle 28 vs 32 of the low rider. Any ideas? I was thinking about raked bearing cups? I read that just going with raked triple trees shorten the trail and will be it even more unstable. Or slap a dampener on it.

 

A buddy of mine lower and raked out a Yamaha Roadstar. It developed what he described as some pretty unsafe handling characteristics. He was told to lose the stock front wheel and install a 21 inch front wheel. He says that the handling issues cleared up. Not saying that will fix yours but, it's food for thought. My wife's sporty trike has a dampener on it and it helps a lot with wobbles and such.

 

The only thing that can pull you out of a speed wobble is more power and speed! My dad told me that long ago. Didn't help in my Pinto, had no more power!!

 

Until you have to come back through the head shake.

 

Well right now it's just a wobble that gets induced with a big bump. It settles out if I relax and put even pressure on both grips. But if I'm on the highway and just bump on the bars, it'll wag a few times, then steady out. I'm too scared to try and get it to really wobble. That's why I think it has to do with the 28 degree rake.

 

What did you do to the suspension?

 

JRI 13" rear shocks. Front has racetech 1.0 straight rate springs and gold valves. So the forks ride a lot higher than then did, but also the rear is jacked up. I think that contributes to the steering. On sport bikes, raising the rear or lowering the forks just 10mm makes the steering sharpen up considerably.

 

Wasn't there a difference in the fxd models that had a +2" fork tube?

If your not already there maybe the front can be raised 2" to compensate for the raised rear. That way you don't loose the ground clearence/cornering you were looking for with the 13" shocks.

 

Try your original shocks and see if it's better.

There's a fine line between "more responsive" and "twitchy." Maybe you crossed it.

 

Experiment with your tyre pressures and make sure your neck bearings are adjusted correctly and check your tyres are compatible with each other.