Sprocket Alignment

ntst8 · Aug 24, 2018

Giving things the once over and the rear sprocket is a mess, severe wear on the outside face and an impressive amount of shavings gooped up under the alloy front sprocket cover. The rear sprocket has black face out/bright face to the wheel which seems correct and the front sprocket looks correct.Would appreciate any thoughts on what is out of alignment?
One other small query, when removing the clutch slave cylinder the cap screws pass through the slave cylinder then through a washer/spacer, then into the alloy cover. Are the washers normally there?

piper 600 · Aug 25, 2018

Chain tension ???

when adj. chain I like to get someone of similar build to sit on the bike .
I just count the flats on the jacking bolts , never been a problem (dads advice)

contours · Aug 25, 2018

Wow - that is some nasty wear!

My personal experience adjusting the chain has been frustrating primarily due to the brake side adjuster having very little impact. After 3 different attempts I finally did a string alignment to get it more acceptable. But my final adjustment was done by a local shop and I'm sure it required two mechanics to get it right. I hope you have better luck.

TonyA · Aug 25, 2018

That looks way too much wear. Is it possible that the sprocket carrier is walking over. Inspect the carrier and bearings inside. Also send a picture of the slave cylinder , I think i've got the answer for your washers behind the slave. Probably you don't have a Brembo clutch slave .

TonyA · Aug 25, 2018

contours said:
Wow - that is some nasty wear! My personal experience adjusting the chain has been frustrating primarily due to the brake side adjuster having very little impact. After 3 different attempts I finally did a string alignment to get it more acceptable. But my final adjustment was done by a local shop and I'm sure it required two mechanics to get it right. I hope you have better luck.

You are the guy I thought about when I saw that wear ! Clearly something is amiss .

TonyA · Aug 25, 2018

ntst8 said:
Giving things the once over and the rear sprocket is a mess, severe wear on the outside face and an impressive amount of shavings gooped up under the alloy front sprocket cover. The rear sprocket has black face out/bright face to the wheel which seems correct and the front sprocket looks correct.Would appreciate any thoughts on what is out of alignment?
One other small query, when removing the clutch slave cylinder the cap screws pass through the slave cylinder then through a washer/spacer, then into the alloy cover. Are the washers normally there?
View attachment 6294 View attachment 6296 View attachment 6295

Are you saying that the inside face of your sprocket is not black ? Mine is black both sides. Send in pictures of the left and right spacers and measure the widths. Rob Jameson can look and verify if you have the right parts in there. When the sprocket is installed the writing on it should face outward when installed.

TonyA · Aug 25, 2018

Its hard to see it all but check that you have the spacers you need and in the correct order. Also the bearing may be failing and walking over . While you are at it make sure the front sprocket is OK as well. There is a spacer behind the front sprocket too.

TonyA · Aug 25, 2018

It is always possible that your chain alignment/wheel alignment is so far off. I don't like telling people that because i just assume everybody know how to do it . I use the flats but always measure with a ruler too. Just like they suggest in the service manual. You can also supplement this with a long carpenters square place against the sprocket face and sight down it . Should be parallel with the chain run. Check the measurements after you torque up and snug up the adjuster screws after you torque the axle to keep the adjusters from loosening .

Fast Eddie · Aug 25, 2018

Iain, is the the bike you have just bought, with 2,400 miles by the PO?

At 2,400 it should not look like that. Alignment may be a factor, but I think it’s main root cause it that it has been run too tight, and too dry.

Check the alignment, and tension first as explained by previous posters, clean it, adjust it, and keep your eye on it. I wouldn’t panick and replace it all, but it’s something I’d be keeping a close eye on knowing it needs replacing in the not too distant future.

One other thing though... IF it has been run too tight, and looking at the stresses things must have been under to cause such damage, it may have damaged (or even destroyed) the rear wheel shock absorbers. Other posters have discovered that hese are of minimal design and if they wear badly, the wheel hub itself gets damaged. So checking them would be prudent I feel.

Raphi · Aug 25, 2018

Yes, check the backlash of the wheel. The rubber dampers may be scrap.
Regarding the front sprocket cover I had the same and did cut off a bit so that chain doesn’t grind it anymore...

ntst8 · Aug 26, 2018

Thanks for all the feedback,
1 - slave cylinder, has a G on it so not Brembo i presume - not a concern here as long as it works.

2 - sprocket, the talon name is engraved on the external (black) face, the inside face appears to be non coated. Hard to get a picture but it does appear that there is rubber trapped between the hub and the cover the sprocket mounts to (not the right terms i am sure). Will pull all down for a look.

I am on the road for a couple of days so there will be a pause in proceedings.

TonyA · Aug 26, 2018

Ok , Ive got your answer on the washers behind the clutch slave. Yes , That's the same clutch slave I have with a G on it. And mine works well by the way . So Norton must have run out of Brembo's or supply chain issues at some point and were installing these. The washers are fitted to allow the clutch slave to sit flush with the case. If you try to mount the "G Brand " clutch slave you will notice that the sprocket cover casting indentation does not fit this slave properly . It will catch on the corners , place it down and see what I mean . It wont sit flush , because the Brembo is just a touch more radiused. I fixed mine by having a machine shop mill out the tiny bit of metal on the sprocket cover so the "G Brand " slave will fit flush. So now I can run a G , Brembo , or Oberon . Let us know how the sprocket issue works out.

Fast Eddie · Aug 26, 2018

I assume G is for Grimeca ?

Raphi · Aug 26, 2018

The trapped rubber might be what is remaining of the rubber dampers. So quite sure they are scrap though...

TonyA · Aug 27, 2018

Fast Eddie said:
I assume G is for Grimeca ?

I don't know. A good guess though.

ntst8 · Aug 27, 2018

Looks like it is, i know a man who can with the milling so will add that to the list.

TonyA · Aug 27, 2018

Raphi said:
The trapped rubber might be what is remaining of the rubber dampers. So quite sure they are scrap though...

Almost certainly you are correct. ntst8 should order a new set . I have two sets at home I keep hoping Norton will make a new version of cush-rubbers more durable .

ntst8 · Aug 27, 2018

My Y*m*h* also has a reputation for eating cush rubbers and potentially bearings, and that is only 48hp.
Any 961 parts look like they will either be from Australia or direct from the UK so will be doing a full list before ordering, to keep postage down.

Raphi · Aug 27, 2018

The carbon wheels came with much better cush rubbers. They have a metal core on the inside...

Rob Jameson - Norton UK · Aug 28, 2018

I've seen this once before on a rear sprocket, it was a combination of wheel alignment being out and the chain being too tight for the rider weight. The same effect was achieved in about 1500 miles.

With regards the slave cylinder, it appears that sometime (before my time) we were unable to get brembo units so we used Grimeca ones instead, which you have to put a washer behind to get them to sit right.

Sprocket Alignment

Similar threads