Koyote

Okay, so you just eyeball it? Seems rather imprecise, but a starting point. Thanks for the response.

Andrew R Stewart 

Yes, seeing equal gaps on both sides of a rim, to the corresponding blade, is fairly easy if you have a somewhat practiced eye for these visual line ups. But when doing an "in my shop" alignment measurement tools are at hand and used as needed. (Added Edit) I use my fingers too. Slip a finger on both sides of the rim to feel the gaps to the blades.

While I have not established a form that I use for fork alignment steps I have done so for the frame. Here's an example of that for a frame I built my wife last year. Note that some of the dimensions are in thousandth's of an inch. No eye balling here! Andy.

Luc_D

In the end, I've swapped both wheels and the handling is acceptable, but still a bit squirrely.

I am under the impression that my handlebar have excessive swetpback and are putting too much weight on the back, So I will try a different one and report back if handling improves further.

ljsense

I thought I recalled you mentioning, at some point in this thread, that you had a recent issue with your back. It's possible that if you're riding with a tight back or your body in a different position to compensate, that might be having more effect than anything on the bike. The rider is the most significant force and weight in the whole system, so it's worth thinking about that possibility as you deal with the difficulties of pinpointing speed wobble.

Luc_D

Thanks for chiming in, but I was saying that on the contrary, I am much more flexible and my backpain no longer bothers me.

Anyhow, the speed wobble is still present, albeit at a lesser degree...

TiHabanero

I mentioned the frame at BB joint because that is exactly where this same problem originated on one of my bikes. The down tube had broken at the BB. Not all the way off, but half way around the weld.

Had a customer with a Specialized Secteur that had a speed wobble that would not go away. Replaced both wheels with known good wheels, replaced handlebar, fork, stem and headset to no avail. Replaced the bike and the problem was solved. Something in that frame was causing the problem, but we were unable to determine what it was.

Luc_D

In the very end, I've managed to find the culprit: the saddle had slided back, pointing up — imagine 78 vs 90 degrees.

base2 

While everyone was figuring mechanical problems, doom & gloom of mystery goblins.

Post 23 had it right all along.
That guy is a genius.

Anyhow, it's good to see you got it sorted & are on your way to a summer full of miles.
Cheers