Mk3 Rear wheel, chain, rear sproket - solved - thank you

I have been working on my first rebuild and tried my best to have it street ready for Father's day (all the best to the dads here today!) but the rear sprocket or wheel or something isn't right

There is a clicking at the wheel end of things as the wheel gets up to 5mph. Sounds like it is the chain but I don't know why. Here is a video (clicking starts at about 13 seconds in:

[video]http://www.youtube.com/watch?v=8VFYF0f2UAs&feature=youtu.be[/video]

I purposely loosened the chain because the looser the chain the more prominent the kicking/clicking is, but it still kicks and clicks with the chain tighter (at the correct .75-1 inch movement range on the ground whilst I am sitting on it.

Chain is completely straight from the drive sprocket and is brand new with plenty of lube. (old chain was 98 links + 1 master - NEW chain is 99 links + 1 master)



The spacing on the left side is per the manual illustration, not the parts catalog illustration



The spacing between the rear sprocket and the cush drive is standard:



The sound is coming from the rear wheel/rear sprocket area, not from grinding on the cases:




The right side seems aligned - see the brake and the correct mounting on the right side:




What have I done wrong? Thank you all in advance for your helpful input.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Put slight pressure on the binders (brakes) and see if it goes away. My front wheel was doing it and I came so close to tearing it down until I noticed the pad grabbing ever so slightly at the same point in the wheel rotation. just enough to make a little click against the caliper. Drove me nuts for a minute. Now i know what it is, I can live with it.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

How is the speedometer working. I would possibly suspect the gearbox. try disconnecting the gauge end and check operation with the rear wheel running. Just an option.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

bwolfie said:

How is the speedometer working. I would possibly suspect the gearbox. try disconnecting the gauge end and check operation with the rear wheel running. Just an option.

Click to expand...

The drive spins fine (the speedo, itself, has been at Foreign Speedo in San Diego for 7 weeks now)

The snapping/kicking is coming from the rear sprocket area, NOT the gearbox end.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

pvisseriii said:

Put slight pressure on the binders (brakes) and see if it goes away. My front wheel was doing it and I came so close to tearing it down until I noticed the pad grabbing ever so slightly at the same point in the wheel rotation. just enough to make a little click against the caliper. Drove me nuts for a minute. Now i know what it is, I can live with it.

Click to expand...

Not the brakes binding either - it is making the chain jump! Look at approx second 25 in the video

Re: Mk3 Rear wheel, chain, rear sproket - help please!

thatnameisal said:

bwolfie said:

How is the speedometer working. I would possibly suspect the gearbox. try disconnecting the gauge end and check operation with the rear wheel running. Just an option.

Click to expand...

The drive spins fine (the speedo, itself, has been at Foreign Speedo in San Diego for 7 weeks now)

The snapping/kicking is coming from the rear sprocket area, NOT the gearbox end.

Click to expand...

He's talking about the speedo gearbox.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Sounds like backlash between the sprocket vanes and the slots of the 06-6232 "Drive centre".

With the engine switched off, if you grip the sprocket firmly, and rotate it sharply in both directions can you replicate the clicking sound?

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Does it happen in neutral when spinning by hand and/or in other gears other then first?

Check primary chain also if this is happening only when in gear. Even though the issue maybe forward, the noise may transmit out back.

I am admittedly not a MKIII person. LAB?

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Hi could be the pads rattling in the caliper the front ones on my 72 roadster make a similar noise , also are you using a metric size drive chain as this can sometimes cause these symptoms and i assume the chain is new and does not have any tight spots or siezed links, other than that check the wheel bearings and the gearbox mainshaft bearing, hope this helps regards Tom

Re: Mk3 Rear wheel, chain, rear sproket - help please!

pvisseriii said:

Does it happen in neutral when spinning by hand and/or in other gears other then first?

Check primary chain also if this is happening only when in gear. Even though the issue maybe forward, the noise may transmit out back.

I am admittedly not a MKIII person. LAB?

Click to expand...

Does NOT happen when spinning by hand/slow - only starts at about 5mph

Re: Mk3 Rear wheel, chain, rear sproket - help please!

L.A.B. said:

Sounds like backlash between the sprocket vanes and the slots of the 06-6232 "Drive centre".

With the engine switched off, if you grip the sprocket firmly and rotate it sharply in both directions can you replicate the clicking sound?

Click to expand...

Yes -

In neutral:

[video]http://www.youtube.com/watch?v=ihNLp_PLuvE&feature=youtu.be[/video]

In gear:

[video]http://www.youtube.com/watch?v=Vc5H0YGLvIA&feature=youtu.be[/video]

What do I do?

L.A.B. - "you are my only hope"

Re: Mk3 Rear wheel, chain, rear sproket - help please!

thatnameisal said:

What do I do?

Click to expand...

I think most MkIII sprockets do that to a certain extent (mine does), however yours seems a bit excessive, it could be because the drive vanes are slightly thinner than they should be? I think we have heard of this problem before (I will try and find the thread).

Is it a genuine Andover Norton rear sprocket?

[Edit: The slots in the drive centre could also be worn? Are you sure all 10 cush drive rubbers are intact and fitted correctly ]

Re: Mk3 Rear wheel, chain, rear sproket - help please!

My guess is the speedo gearbox.
Maybe without the cable attached it affects how it reacts to turning.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Is the rear wheel sprocket new, is the chain tension set correctly? If the chain is new and the sprocket is worn the chain may be kinking and slipping on the worn sprocket teeth. Some things to check and confirm.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

To my untrained ears, it sounds like my bicycle about to change gears. There appears to be some vibration in the chain whilst it's happening on the vid. Are you sure everything is aligned?

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Chain maybe hitting the front stay on the swing arm that holds the chain guard?

Re: Mk3 Rear wheel, chain, rear sproket - help please!

whatever happened here? what did you find?

Re: Mk3 Rear wheel, chain, rear sproket - help please!

I noticed that there appears to be too much of a gap between the hub and sprocket. That usually indicates the cush rubbers are not seated all the way, or the bearing is not all the way home. The speedo drive is a piece of crap that will give you ulcers if not put back together in exactly the right way. The clicking may be from the guts of the drive unit moving around if that little plate is not seated in the indents properly. Don't like that gap between sprocket and hub.

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Where is the master link when the noise is heard? Possible wrong master link on the chain?

Re: Mk3 Rear wheel, chain, rear sproket - help please!

Where is the master link when the noise is heard? Possible wrong master link on the chain?

Click to expand...

good questions

check to see if master link is on the ouside of the chain, it can often make contact and the noise can be eliminated
by taking it off and moving it to the inside of the chain