Rear wheel won't stay in place & my chain chipped the teeth off sprocket

[brad black]

one day we'll have teleportation so when the thread gets posted we can all teleport over and stand around, nod knowingly and say things like "dude, it's rooted."

get a laser aligner too to make sure the chain is aligned properly.

[Howie]

You need the sprockets and chain anyway, and, unless the bearings are really bad, that wheel ain't moving.  If that sprocket is aluminum, once the anodizing wears sprocket wear is rapid.  On any sprocket, loose one tooth and the rest will follow shortly.  After reassembly check sprocket alignment and wheel alignment just to be sure.

[Michael]

one day we'll have teleportation so when the thread gets posted we can all teleport over and stand around, nod knowingly and say things like "dude, it's rooted."

get a laser aligner too to make sure the chain is aligned properly.

Struth!

Brad, you gotta be Australian. Am I right?

Well, I like your teleportation idea (but hopefully it's not rooted).

And I love the thought of owning a laser alignment tool, but I'll probably have to just make due with my ruler.

[The Mad King Pepe']

I suspect that IF your wheel wasn't straight the bolts that hold the sprocket in place would be digging into the swingarm either behind or in front of the axle.

As you mentioned the chain has been on a while, so that's the most likely cause for the frequent adjustments it requires, and the teeth rear sprocket might be breaking because of the skipping chain hitting them.

Good luck and keep us posted!

[brad black]

yes, australian.

the laser tools are only $90 or so on ebay.

[Nomad]

I have the exact same bike as you, 96 m900.  If you really think the back wheel might be moving a little, check both sides of the axle to make sure they are torqued to spec.  I had one nut on there that was so tight I couldn't budge it.  But it didn't necessarily spin the axle when tightening, so I could "tighten" that side to spec and the nut on the other side would still be loose.  Last time I took the wheel off I made sure to take both nuts off, took some serious force to get the stuck one.
     Just a possibility, but just because one side is tight doesn't mean the other is, good luck.

[brad black]

the centre bearing part of the axle is larger than the od of the threaded end parts where the nuts screw on, which is why the nuts can jam as xarlo says.  it's a good point and something to be aware of.

[Michael]

I have the exact same bike as you, 96 m900.  If you really think the back wheel might be moving a little, check both sides of the axle to make sure they are torqued to spec.  I had one nut on there that was so tight I couldn't budge it.  But it didn't necessarily spin the axle when tightening, so I could "tighten" that side to spec and the nut on the other side would still be loose.  Last time I took the wheel off I made sure to take both nuts off, took some serious force to get the stuck one.
     Just a possibility, but just because one side is tight doesn't mean the other is, good luck.

That is a really good hypothesis.

If (hypothetically) I only tightened the left nut and failed to torque the right nut properly, then the right side might shift back a little twisting the wheel/sprocket enough to run into the chain.

I have adjusted the chain before while the bike was leaning on the kickstand (I was out of town, in a parking lot, with about an hour of riding ahead of me) and it could be plausible that I loosened the right nut and then forgot about it and only tightened the left. Maybe.



And I still think more than one thing is going on here --

1) There's the maybe-loose-right-nut theory to explain the chipped sprocket

2) Then there's also the age of the chain and the age of the sprocket

3) Also, I didn't realize the sag in the chain changed as the wheel rotated, so I might have adjusted the chain once, gone back to discover a looser chain and thought the wheel moved when it didn't.

So, it might be that I was assuming that two different symptoms were pointing to one problems, when in fact there were two separate problems.

*** UPDATE ***

I put on a new sprocket yesterday and went on a good, long (fairly rigorous) ride this morning. The chain has the exact same sag as when I set it and the wheel is in the exact same place.

I spent a lot of time getting the alignment, torque, and sag perfect yesterday.

However, I still have the old chain -- which I intend to replace ASAP -- but it makes me think that a warn-out sprocket and my own bad wheel tightening practices are to blame.

SOLUTION:
- New sprocket
- New chain
- Correct wheel/chain tightening technique


(This isn't me -- I don't wheelie)

[stopintime]