Gen II sprocket side wear: running out of ideas

My Gen II tends to wear the sprockets unevenly; the front sprocket gets worn on the side facing the engine but not on the opposite side. Now, I know this is textbook evidence of misaligned sprockets. The question is what type of misalignment and what is causing it. I've thought of 3 options so far:

A) Rear and front sprocket are parallel but slightly offset, i.e. rear sprocket further left compared to the front sprocket
B) Rear wheel is twisted at an angle (counter-clockwise)
C) Rear and front sprocket are offset, i.e. rear sprocket further left AND rear wheel is twisted at an angle (clockwise)


However; no amount of adjustment or fiddling has even remotely solved the problem. I'm using calipers to align the rear wheel when adjusting the chain tension, and both the garages I've been to say the adjustment looks good. The last one I visited used a laser tool to check if the chain line was straight.

I've ben through 2 chain & sprocket sets. The garage replaced my swingarm bearings (these were damaged and thought to cause the issue) and the chain/sprocket set was replaced again (3rd set). This week I discovered that it's starting to wear in the exact same manner. The guy at the garage now says he's run out of ideas since it's difficult to obtain a precise measurement of the misalignment.

I've attached pictures showing each side of the front sprocket (the 2nd chain/sprocket set....). As you can see, it's worn on the inside, but the outside hardly has a scratch. This one has seen about 3000 km.
The chain is only worn on the lower inside of the plates that are facing the engine. This is where it's rubbing against the front sprocket (see picture).





Anyone in here with input or similar experience?

You could try to get a front sprocket that has the rubber insert/padding as that may correct the alignment. My guess is that the front sprocket is smaller in terms of thickness when compared to the OEM sprocket. I could be wrong, but I'd check and see. If not that, back to the drawing board.

superpsu said:

You could try to get a front sprocket that has the rubber insert/padding as that may correct the alignment. My guess is that the front sprocket is smaller in terms of thickness when compared to the OEM sprocket. I could be wrong, but I'd check and see. If not that, back to the drawing board.

Click to expand...

Hi superpsu,
Thanks for your answer. I thought the rubber padding only was there to reduce noise? Judging from photographs of front sprockets with rubber padding the rubber doesn't act as a spacer between engine shaft and sprocket, i.e. there is metal-to-metal contact between shaft and sprocket even though the sprocket is rubber coated on the outer periphery

Just thinking out loud here: Is it even theoretically possible to assemble the rear wheel such that the clutch hub (sprocket carrier) is offset too much away from the wheel? As far as I can see, the collars on each side are not interchangeable as doing so would make it impossible to mount the brake caliper arm. Also when you tighten the wheel axle nut, any play between clutch hub and wheel should be eliminated?

I don't think the rear wheel and clutch hub is the problem. This may be a stupid question, but are you using the correct pitch for your chain and sprockets? Could you make a spacer between the engine shaft and sprocket (in other words to bring the sprocket out a little)? I know there is metal to metal contact with the shaft and sprocket when putting the sprocket on.

One thing you could do to check the alignment of the chain is to find a center spot on the bike and measure from that point to both sides of the chain adjustment guides. If the measurements are the same, then the chain is aligned properly. I had to do this with my Ducati Monster 620i.e. dark. The alignment notches may not be equal on both sides is what I'm trying to say. I will have to think about this issue a little more.

My '09 seems to be doing this as well, but I've only looked at it from the rear sprocket where I see a wear pattern on the chain rollers that is offset to the outside of the chain instead of being centered like on my other rides. Mine has started doing this only recently. And it seems I see this pattern only when I ridden for a while in a "spirited mode". I checked for swingarm play when I installed my Penske shock and there wasn't any that I could detect. I have adjusted on one side of the chain to compensate assuming your option B and that did not help, pattern did not change location or nature.

I need to look at the countershaft sprocket and see if it shows wear on the inside like you mention.

Hello, and thanks to both of you for the input.
superpsu: I agree that the clutch hub is an unlikely culprit. The clutch hub and bearing was replaced last year without this having any effect on the problem. I'll give your alignment method a try. It's a bit difficult to find a proper reference point since the measurement has to be quite accurate, but it's worth a try.
And no questions are stupid. I'm very sure the pitch is correct. I use a 530-chain; more specifically the DID-recommended chain:

530VX-122ZB chain
E579-17 front sprocket
0479-45C rear sprocket

I had a quick look at the bike now and tried using one of those laser pointers used for presentations to look at the chain line. It turned out to be completely useless since it's so difficult to get a proper surface of contact against the rear sprocket to steady the pointer. Also, the laser beam was too narrow.

The new rear sprocket has no obvious wear yet. Looking more closely at the new chain, I can see no wear except for the location shown in my original post.This baffles me a bit as it would indicate the very unlikely Scenario C described earlier. See the very exaggerated figure (I'm going a bit anal here...). The red circles indicate wear points, and in this scenario, both sprockets will will most likely wear the chain on the same side, i.e. the one indicated in the figure of my original post.



If i push the chain against both sprockets and then rotate the wheel a few times, the chain will invariably start wandering back towards the outer side of the rear sprocket, i.e. away from the wheel. This observation doesn't really fit in with Scenario C. Do any of you have a theory which can explain both observations?

Mind you, it's almost impossible to get a proper look on the inside of the chain without using a mirror and spotlight. Unfortunately I don't have access to proper tools during the next few days. But before I start taking things apart (splitting the chain) I would like to have a plan of action.

I tried measuring from center of the SA pivot to the center of the rear axle on both sides to see if they were the same. This is easier said than done since there are no common reference points. What you are basing the measurement on changes from one side to the other. As near as I could tell mine appeared different implying the SA marks were not true. You'd need to machine some pieces that would fit in the various holes (since they are all different) that would come to a point (like a lathe center) so you would have a chance to make an accurate measurement. I have not done that. I do have a Motion Proc chain alignment tool,but its a PIA to use since it requires removing the chain guard. The 8" alignment rod to way to short to be of any practical use. I have chased a longer rod so far with no luck, 5/32" rod that's perfectly straight has been hard to come by.

In my case, I was thinking of option B above, but based on the rear wheel view, it looked like the wheel would be twisted CW to produce that wear pattern on the outside edge of the chain rollers - wheel cocked to the throttle side. I backed off the chain adjuster on the right to shift the wheel CCW hoping to see that wear pattern on the chain rollers shift more toward center,telling me I was going the right way. Unfortunately, no change.

I have recently noticed this chain is a PIA to adjust correctly. When you are measuring travel, the correct range is that range that does not move the upper portion of the chain. If you push the lower part of the chain at all in measuring the travel such that you move the upper portion of the chain, you'll wind up with it too tight. My '09 has only got 2300 miles and I wonder if I've been adjusting the chain wrong all along based on measuring the travel incorrectly. Its looser now but measures correctly. I need some kerosene to give it a good cleaning and a re-lube, then I'll check the chain roller wear pattern again.

This is not like adj the chain on my CBR600 or any of the bikes I've owned before.

I'd be looking at the rear wheel alignment to make sure it all lines up true. Sometimes the measurements on the swingarm aren't right and putting the bike in a jig to test front to rear wheel alignment is necessary.

Do you notice the bike turns/dips quicker into a turn on one side more than the other? If your tires aren't cupped, it may indicate the rear wheel is pointing one way or the other. I had this problem and thought it was geometry - turned out the rear wheel was pointing slightly to the right making the bike dive into left hand corners more than right handers.

Thanks to Duster_360 and Dicko,
I've also come to the conclusion that the MotionPro tool is overrated. Yes, it's way too short and the working principle assumes that your chain is perfectly aligned with the sprockets at each end. And this just isn't true, there's a lot of play from side to side.
I might have misunderstood the whole principle of the string method, but to me it seems completely unrealistic to obtain an accurate measurement when it involves "keeping the front wheel pointing straight ahead" when the bike is just placed on the center stand. But using a jig might solve this problem.

Like Duster says, my plan is to dig around for a couple of very straight rods or pieces of piping that fit into the rear axle, drive shaft and SA pivot respectively. Once inserted, measuring the distance between these at different places should at least tell me if the wheel is mounted at an angle or if my swingarm/subframe is bent (dear God, I hope not...). If the rods/pipes are long enough and not bent, this should give me reasonable accuracy. This method will however not detect any offset.

I haven't paid special attention to hov the bike turns, but I will definitely do so on my way home from work

Quick update,
It seems I'm guilty of some seriously wishful thinking here. The drive shaft is not hollow. The small hole in the centre does not extend more than perhaps 5mm into the shaft and it's much more narrow than i imagined. I did however manage to find two rods with a reasonable fit to the SA pivot and rear axle. They were about 60 cm long. I measured about 2mm deviation from root to tip, probably less, and I verified this by rotating both rods and repeating the measurement. Some quick and dirty math says this corresponds to about 0.2 degrees twist. Not much at all. Correcting this would require only 1/15th of a turn on one of the adjustment screws. That's probably below obtainable accuracy...

So, I'm back to finding a way to compare front and rear sprocket, or drive axle and SA pivot. A 60-80cmpiece of steel pipe with an internal M22 thread could do the trick. Just take off the front sprocket and screw on the pipe. To hard to find, though.

P.S.:
Put the bike in neutral and let go of the handlebars around 40 km/h this morning, and the bike started veering to the left. Not badly, but it happened each time i let go of the handlebars. Now this could indicate that the rear wheel is twisted CW, but I guess it would also happen if my body was not perfectly centered on the bike?

EISTO said:

P.S.: Put the bike in neutral and let go of the handlebars around 40 km/h this morning, and the bike started veering to the left. Not badly, but it happened each time i let go of the handlebars. Now this could indicate that the rear wheel is twisted CW, but I guess it would also happen if my body was not perfectly centered on the bike?

Click to expand...

The balance of the bike from the factory is spot on. I noticed when I got mine it was perfect. Without touching the wheels and merely putting on the aftermarket exhaust, the bike began veering left when I let go as well. This makes sense as the weight reduction from removing the OEM exhaust is on the right, thus making the right lighter forces the bike to lose it's natural balance.

I have not checked the wear of the sides of the sprockets on the new bike but I will. I have, however, swapped out the OEM tires with the PR4 set when it was new and also moved up to the 55 from the 50. MY wife's bike got the new OEM set.

Found this last night on youtube - https://www.youtube.com/watch?v=4m9tdTN2OKo

Something similar to what you've prob done. Don't discount the accuracy and sensitivity. This guy corrected a 1.5mm alignment problem IIRC and felt that was important even at that magnitude, but provided no post adjustment feedback. I used to use a 1/8' x 1" piece of alum stock when doing chain adjustment on my dirt bike. I had to room to c clamp that piece of alum to the face of the rear sprocket and then adj chain adjusters until piece of alum just touched face of the countershaft sprocket. Not sure there's room withe the FZ1 the way its laid out.

Search around on youtube, I saw a laser setup to check the alignment. You could use it to check for sprocket alignment.

Or your riding on the left side of the road and the bike will automatically start to steer downhill. I wouldn't worry about that.

No one has mentioned the rear wheel. being perfectly vertical compared to the rest of the bike? Just thinking. Bent swing arm?

maybe i missed it but are you using steel or aluminum sprockets?

Hello everyone, and sorry for the late feedback. I've been away on vacation for a while.

Current status is:
Using a dial gauge I've measured a total of 0.6mm wobble on the rear sprocket. This annoys me no end since I was extremely careful when tightening the rear sprocket nuts, systematically cross-tightening them while gradually increasing the torque to the specified value. NO idea how this happened, and unfortunately, I didn't check if the sprocket was warped before mounting it.
As before, the rollers and side plates wear on the bike side, and theres an unpleasant low rattling sound when I ride the bike. This is most noticeable at low speeds in intersections and such. The noise is NOT the pleasant whirr of a chain, but rather the noise you get when pulling a dry chain out of a metal can.


FZ1inTX/Dicko: Interesting point. I've got an Akrapovic-exhaust, and it's very light compared to the (incredibly heavy) original muffler. My guess is a couple of kgs. Also, as Dicko says, the furrows and slope present in any road would affect which way the bike veers.

Duster360: That's good input, I'll search a bit more on Youtube. Still, 1.5mm misalignment so close to the wheel centre is probably more than 5 times what I measured on mine. But it's worth checking the same way this guy did.

Blanchy: Very good point, a twisted swingarm is perhaps more likely than one bent sideways. I've yet to measure the offset from vertical and I'm not sure how this can be done with sufficient accuracy. Perhaps I could use the rods mentioned earlier and see if they point up/down relative to each other.

jared p: The sprockets are the standard steel versions.

It can happen with mismatched sprockets and chain, 520 and 530. also, the writing on the sprocket goes outward