OEM Rear Sprocket...

OEM rear sprocket...

I really think that rubber is causing problems. I've had the chain slip after a 500km day. I think this is caused by the rubber on the sprocket not letting the chain sit in the sprocket fully. This is the first time i've had the chain slip on any bike i've owned.
The rubber is just there for noise suppression, and the 09 model doesn't have rubber on te rear sprocket... has anyone seen rubber on a rear sprocket before?

My rear sprocket is really worn now and i've only done 3800kms!

I'm thinking of cutting it off...

Any Thoughts??

Why cut off the rubber ring? Your sprocket is already shot. Just buy a new one.

I've got almost 5,000 miles on my '08 and the sprocket looks nothing like yours. My wear pattern seems fairly normal in my opinion. Either you are riding hard and/or your chain is not adjusted properly.


Chain adjustment procedure

Yeah. i know.. That's not the point. My main questions are:

-Why have people reported slipping chains?
-Why is there has there been an update to the chain adjustment procedure?
-Is the Rubber ring causing chain adjustment woes? ...not just for us, but for the Yamaha engineers as well???
-Has anyone seen rubber on a rear sprocket before?

If i ride the bike for 500km in a day.. why should i have to adjust the chain half way through the day.

My chain is definitely adjusted properly... at the start of a long day. however at the end of the day is slapping around like a bastard.
I've removed the shock (so it's easy to swing the wheel through the entire range and find the tightest point)
and adjusted the chain at the tightest point in the suspension travel, the chain is not lose.

I'm going to get new sprockets and a different brand chain, maybe they'll last a bit longer..


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Also, is the rubber on the rear sprocket in place of (only slightly) a cush-drive hub... or is it just for chain noise suppression?
Don't 250cc thumpers (that are for Road use) usually have cush-drive hub?
If not, is there any power-pulse damping in the motor/clutch/gearbox. (like huskys?)

I know, lots of questions... this issue is really intriguing me :)

Louisbiker wrote:

Any Thoughts??

That picture is worth repeating.

Going by that picture alone, there is not enough clearance between the bottom of the valley and the rubber.

Any signs of wear on the rubber?

EXACTLY!

there isn't much wear on the rubber. None that i can see anyway. the rubber still looks perfect.
Maybe the rubber is too hard. When i first bought the bike it i thought it may let the chain sit in the valleys properly after a couple of hundred kms... i was wrong.

I would have to say that sprocket is toast, but not bad enough to be eating away at your chain.

Might as well change our rear out now and salvage what left of your chain.

Yep it's toast alright. That's not the issue.

I was just thinking too along the lines of that rubber ring. When I ripped out my 13T, that sucker has hard rubber guides on BOTH sides of it. Makes me wonder if that is also part of the problems people are having with the front skipping... It hasn't happened to me, but by looking at that puppy, there isn't much meat there for the chain to have contact with.

In my mind there is something wrong with the stock chain/sprocket combo.
I have about 6700km on my WRX and the chain and sprockets are toast!
I originally put that off as a DSPO thing, but a lot of people have reported only getting 5k+ out of them.
I'm looking forward to seeing how the aftermarket ones last.

SheWolf wrote:

I was just thinking too along the lines of that rubber ring. When I ripped out my 13T, that sucker has hard rubber guides on BOTH sides of it. Makes me wonder if that is also part of the problems people are having with the front skipping... It hasn't happened to me, but by looking at that puppy, there isn't much meat there for the chain to have contact with.

I've had a very close look at my front sprocket and it still looks new. The case saver shows no sign of the chain hitting it...and i definately had the chain slip. I'd love to see a closeup picture of a front sprocket that had the chain slip, there would be some damage to the teeth for sure.

The rubber on the front sprocket doesn't stop the chain sitting in the valleys of the teeth (not like the rear).

I've removed the rubber from the rear sprocket and it seems much better, and there's no more noise that i can tell. That rubber is seriously hard.. pretty much like plastic.. but tough!



I'm going to watch for wear patterns on this sprocket.

WOW! Is your sprocket and chain always that clean, or did I miss something and those are brand new?

No, not usually that clean. But in the process of removing the rubber I cleaned it up a bit. That was taken just after i put it back together...

Louisbiker wrote:

How the hell did you get the sprocket so clean

I have just removed (most of) the rubber from my rear sprocket There are still a bit left eg. the rubber in the holes of the sprocket - how did you remove ALL the rubber?

T

That plastic/rubber is really tough.

I used a blade to cut the main rubber off
I drilled it out of the holes..
then I used a flap-disc (on an angle grinder) on the rest of the rubber/glue
then I used a wire wheel on a bench grinder
then superfine sandpaper
then autosol metal polish...

There is some seriously strong glue holding the rubber onto the sprocket...

Fun

Louisbiker wrote:

I used a blade to cut the main rubber off
I drilled it out of the holes..
then I used a flap-disc (on an angle grinder) on the rest of the rubber/glue
then I used a wire wheel on a bench grinder
then superfine sandpaper
then autosol metal polish...
Fun

I think that I'll just leave the remaining rubber where it is

At 4K miles my chain & sprockets are still in good shape, and never had the skipping problem. I am fairy anal about adjustment/cleaning/lubrication (not too hard since 80% of riding is street). I did have a thought about this: With the factory rear shock adjustment the rear end really jumps badly on washboard dirt. This really pounds the driveline. Maybe those that have re-adjusted the rear suspension have helped to ease the excessive sprocket wear. Just a thought in the ever-deepening and controversial sprocket saga.

could the wear be happening from the wrong chain tension?

I saw someplace (think it was on ADV) that the '09s are coming with
no rubber on the new factory delivered sprockets.

If this is true then it looks like Yamaha has identified it as a problem and
taken steps to correct it.

I think a replacement is needed. Maybe a 46t to make the bike FUNNER !!

I have changed to a 12T front sprocket and removed the rubber on the rear sprocket - after 3 days of really hardcore offroad riding I can report that not ones did the chain skip a tooth eventhough I ride with quite a bit more chain slack than recomended by Yamaha...

Stock mine came with NO rubber on the rear sprocket. I swapped the 13T with a 12T...still no skipping.