[pigsinspace72]

So I had recently put the front wheel on and I rolled it out of my shed.Then I hear a snap and I look down and the speedometer cable broke. Further investigation, I saw that the whole speedometer assembly that is on the wheel rotates when I spin the front wheel. Im pretty sure that isn't suppose to happen. Looking at the front wheel assembly diagram, all you are supposed to do is put the axle through everything and the speedometer acts as a spacer as well. So Im not sure why the speedometer assembly is rotating about the axle. Did I tighten the wheel axle nut too much?

Also, for the broken speedometer cable, is this something that I can just clean off the dirt and then use some sort of epoxy on it?

 

[Dodsfall]

The assembly shouldn't rotate. Many forks have a stop located on the speedometer side to keep it from rotating with the wheel. It has to be oriented correctly when installed with the wheel.

I highly doubt epoxy will work. A new cable is the only real solution.

 

[pigsinspace72]

The assembly shouldn't rotate. Many forks have a stop located on the speedometer side to keep it from rotating with the wheel. It has to be oriented correctly when installed with the wheel.

I highly doubt epoxy will work. A new cable is the only real solution.

I do not remember there being any notches or anything to keep it to stop rotating on the forks or the speedometer assembly. Looking at the diagram, there is something called a speedometer receiver, is this something that would hold it in place?

 

[jag13]

My guess is that you did not have the stops that Dods mentioned properly aligned when you tightened the axle and possibly broke part of it. I've never seen a bike that didn't have some sort of notch or stop to keep the housing from spinning.
Also replace the cable. They are only about $10 on Ebay. In fact if the 1981 model is the same, you can get the cable and housing used on Ebay now for $7.50

 

[WintrSol]

If there are no stops, then just properly tightening the axle should make it bind to the fork leg - that's how it works on my CB450. The spacers in the wheel and on either side of the wheel have to be arranged correctly, for the axle to torque down properly. It's not clear because of the lens flare, but it does appear that the speedo drive unit has a finger sticking out, above and left of the cable connection, that should reach into the casting on the fork. Maybe it wasn't lined up when you torqued the axle nut?

 

[jag13]

@Wintrsol; As far as I'm aware, even CB450s have stops. On the early years (late 60s-early 70s) they have a tab internally in the housing. Not saying everyone's does, but they did from the factory.

@pigs; After doing some research, your model should definitely have a stop. There should be a small square protruding from the fork that matches up to a slot on the housing.

 

[yahmyxs]

speedometer placement.

All speedometers that are front wheel driven, have a gearset inside them, that is driven by a cog on the wheel. The housing is on a bearing that the axle rides inside of, when the wheel turns. There is a greased bearing spacer, that keeps the speedometer, seperate from the wheel. As the front wheel turns, the cog on the wheel engages with the gearset in the sender, and the cable to the meter, attaches to the sender.
The sender is designed to mount into a notch on the forks, that maintains its position while all this goes on.(some bolt to the forks, others just ride inside a fitting notch in them.

It is a very interesting piece of motorcycle mechanism, and you should pull the wheel, take it all apart, and see how it all works.

otherwise, I would suggest getting a new or used (if it is good) cable, and hope you didn't mount it so wrongly that it broke... Like I said, pull the wheel, and check it out! It's really quite interesting how one system supports another.

 

[pigsinspace72]

If there are no stops, then just properly tightening the axle should make it bind to the fork leg - that's how it works on my CB450. The spacers in the wheel and on either side of the wheel have to be arranged correctly, for the axle to torque down properly. It's not clear because of the lens flare, but it does appear that the speedo drive unit has a finger sticking out, above and left of the cable connection, that should reach into the casting on the fork. Maybe it wasn't lined up when you torqued the axle nut?

Well, I tightened it even more and it seems it stopped spinning

After doing some research, your model should definitely have a stop. There should be a small square protruding from the fork that matches up to a slot on the housing.

I wasn't able to take off the wheel as its a two person job and its just a pain. I had a friend helping me when we where putting the front wheel back on and I could have sworn that there was no obvious orientations to put the wheel in order to prevent it to spinning. This bike was probably owned by many people from 1984 to now so it might have broken off.

Also where did you find the information that it has a stop on it?

 

[jag13]

I looked at close up images of factory forks and speedo housings for an '84 Kawi GPZ550. There are quite a few on Ebay that show the stop (forkd) and matching slot (housing), if you know what you're looking for they are pretty easy to see in the enlarged images.

Myself, I wouldn't trust "binding" against the forks as a reliable fix to your problem. But hey, it's your bike. Be safe!