What a long couple days it's been! I endeavored to pull both wheels off so I could bring them in for a tire swap and to swap all the brake pads out as well. The front axle really liked being attached to the forks, all the brake caliper pins were a bit seized, and most annoyingly, the speedometer cable was seized onto the speedo drive. I had pliers on the knurled cable end, trying to loosen the threads that way, but quickly noticed that the whole cable was just spinning.

This last point seemed no big deal. I just left the cable attached and pulled the wheel anyway. Upon reassembly, I had no speedometer. Thinking I'd misaligned the speedo hub or something, I pulled the wheel and checked everything, put it back together and repeated this process at least three times.
Well, at one point I managed to snap the little guide pin that's supposed to hold the speedo hub in place. In fact, the whole speedo hub body looked cracked:

Anyway, I realized with the cable seized to the drive hub, there was no way to ensure it was spinning correctly. I unhooked the cable at the speedometer, gave the wheel a spin, and watched the cable end spinning just fine.

So there's something wrong with the speedometer itself now?

What could I possibly have done to break it?! Is there anything else I'm missing? If the cable is spinning at the speedometer end, it has to be the speedometer, right? But it worked fine before!!
Thanks for any pointers,
Crestfallen Ducati owner

Most likely, it is the drive hub. It will spin the cable when unloaded, but is fooked when you install the axle and torque it. I wore out two of these over the years. Sucks, but replacing is the only cure. Get both the hub and cable.

If you really want to, you can test the speed by putting the end of the cable in a drill and giving it a rip. I think it only registers to about 10mph at drill speeds?

Have a good one.

 

If you really want to, you can test the speed by putting the end of the cable in a drill and giving it a rip. I think it only registers to about 10mph at drill speeds?

Have a good one.

I will try that, thank you!

I had a similar experience. First time I removed and replaced the front wheel, the speedo quit working. The cable was the culprit. But if your gear is cracked, may as well replace it as well. The hub/gear is ~$70 and cable is ~$40. Not too outrageous as far as Duc prices go.

Yup, I ordered a brand new speedo drive gear. The cable was unavailable, backorder with no expected date. I'll see if I can salvage mine for now. I'm thankful and sort of impressed the drive hub was available though!

 

I had a similar experience. First time I removed and replaced the front wheel, the speedo quit working. The cable was the culprit. But if your gear is cracked, may as well replace it as well. The hub/gear is ~$70 and cable is ~$40. Not too outrageous as far as Duc prices go.

 

Quick update, I was able to liberate the original speedo cable from the hub. Those threads were rather seized, but since I'm trashing the hub anyway, I had no problem clamping some vice grips to the hub side of the threads and slowly unthreading the cable.
I then inserted the cable end into a drill and spun the cable. The odo turned slowly but the speedo did nothing. So I turned on the key and did it again, speedo works fine!
So, as soon as my speedo hub gets here from wherever, (the old country I guess?) I should be good to go. Will update at that time.

 

That's strange? The speedo should work regardless of the key being on or off. Isn't it a mechanical link and not electrical. That's why its a cable?

 

Okay folks, my new speedo hub arrived yesterday and I am putting the front wheel back on this morning, but am having more problems. First, when I assemble everything loosely, I spin the wheel and see no movement on the speedo needle at all.
With the speedo cable detached, I held the speedo hub in place and spun the wheel, and could see the little square recess turning, so I know the tangs in the wheel are contacting the speedo hub gear.
As mentioned before, I put the speedo cable in a drill and was able to spin it and see the speedo move.

When I try to torque the front axle nut, things aren't lining up and the speedo hub is rubbing against the screw heads that hold the front disc.

There is no spacer that I'm missing?
I can't for the life of me see what I'm doing wrong. Any clues? This bike is causing me to lose hair (I don't have children so that hasn't been a problem )

 

The speedo hub looks like is not seated square in the wheel, seems to a gap in front. But the problem looks like the hub is not seated/aligned with the fork. There is a notch in the hub which should be at 12 o’clock to fit the fork.

 

Sometimes if you do not have the tangs on the drive ring misaligned you can squash them which may cause the hub to sit like the photo. I did that with mine once. Also don't be fooled by the wheel not driving the speedo. You will be unable to rotate it fast enough by hand to see the speedo move. It fooled me for a while and made me think I hadn't repaired it until I took it for a ride. See the attached pictures. I damaged the drive ring and had to straighten it. The last picture is how it should be. This was the result of not having the drive hub aligned with the drive ring.

 

Thank you, I will check that ring. How does it come out of the wheel? Is it necessary to pull the seal out first? I did get a new seal.
And just how does the hub mate up to the tabs on that ring? I assumed the nylon tangs in the speedo hub go opposite the metal tangs, right? So I would just make sure the speedo hub gear was 90 degrees off from the metal tangs in the wheel?
I don't know why this is so confusing for me, I'm sure I'm missing something stupid!

 

Update: Got it working!

Firstly, thank you all for your guidance! This forum has been a tremendous help.
I gave it a couple days and took another look today. I removed the wheel and speedo hub from the bike, and the speedo hub mates up perfectly to the wheel. The metal ring in the wheel was fine so I left it in. And I was able to rotate the speedo hub and watch watch the little insert rotate, so that was all good.

I then held the speedo hub up to the fork. The spacer surface of the speedo hub was not contacting the fork correctly. Bingo!

Why this is, I do not know. I thought maybe my fender had shifted in a recent minor accident, but I loosened the fender screws, wiggled it around, made no difference. So I rotated the whole speedo hub back and it mates up perfectly. For some reason, this is actually how it was installed when I first removed the wheel, because I remember the speedo cable right behind the caliper.

Anyway, I just let the speedo hub rotate back enough so the axle and everything lined up, and it works! So my ST2 is [temporarily] no longer for sale

I took a test drive and everything was good to go. And I gave it a wash (which I intended to do when I first tackled this). Here it is in my father's garage, which has become kind of a United Nations of vehicles. Not pictured is my Swedish Saab, Japanese Honda CB, and dad's Toyota

 

Excellent! Glad you managed to get sorted