Where does the noise come from?

[TonyA]

Surprised you’re gonna bother… thought you’d have had Ollies shorties on there by now…

There is no stock , I have been waiting for these.

 

[cliffa]

I think this is the appropriate thread to post a video of a new 961 Classic running. To me it sounds remarkably rattle free.

 

[Stu Bodycote]

To me it sounds just the same as many I see. They all vary....occasionally you'll get a noticeably quieter one, which I assume is just a random tolerance build up that fell right.

 

[BritTwit]

The stubby silencers help limit how much of the mechanical clatter that gets through to the ear.
I suspect the clatter would be much more noticeable with old stock long silencers in place.

 

[Fast Eddie]

He needs to point the mic at the primary …

 

[Fast Eddie]

To me it sounds just the same as many I see. They all vary....occasionally you'll get a noticeably quieter one, which I assume is just a random tolerance build up that fell right.

So… occasionally you get a random one that was accidentally right

Mine was way noisier than the one in the pic. And mine sounded the same as any other I came across.

The horrid noise was the main reason the love died…

 

[trident sam]

So… occasionally you get a random one that was accidentally right

Mine was way noisier than the one in the pic. And mine sounded the same as any other I came across.

The horrid noise was the main reason the love died…

Strangely the one I owned was very quiet mechanically, never made any strange noises at all. My mate who bought it from me says the same.

 

[baz]

Strangely the one I owned was very quiet mechanically, never made any strange noises at all. My mate who bought it from me says the same.

My mates one is very quiet
It's one of the very first made

 

[Clive]

Look - will you all quit bleating on about the mechanical noise - it's part of the character of the bike. All you need is a helmet with a bit of padding and you hardly notice the noise at all;

 

[Stu Bodycote]

So… occasionally you get a random one that was accidentally right

Mine was way noisier than the one in the pic. And mine sounded the same as any other I came across.

The horrid noise was the main reason the love died…

Pretty much, yes.
As you know, there's no adjustments we could have made during assembly to combat the primary noise, and I'd assume the gears etc to be pretty much identical. If anywhere, I'd imagine the slight tolerance variations to be in the engine case castings. This was often highlighted by the camshafts, where some would be very tight and require fettling to clear the casing to allow a smooth rotation.

 

[Clive]

At an early visit to the factory I was told they were looking at the noise problem. I did pass on details of the suggestion that the anti-backlash gear was back to front; must get back in touch and see what I can find out it would be most interesting to get a technical low-down.

 

[Fast Eddie]

Why did they make the primary so complex, why not just use a good, strong, chain?

Anyone know ?

 

[cliffa]

I wish my 2011 sounded like the one in the film. I have put in a new complete backlash gear, new bearings in the clutch basket (including a double row one on the inner), drilled out the rivets (which had been welded up before) and replaced with HT bolts and pinned the ring gear. I did find some wear on the centre of the basket and found rotating it 180° from its original position got rid of the play I could feel between the basket and the drive gear plate. (Obviously it will return eventually). That did quieten down some of the rattle at idle that I heard with the clutch out. I had also put in Bel-Ray Sport transmission oil, but the clutch and gear changes didn't seem to like it, so I drained it out. I was alarmed at the amount of silver content in the oil after only a few hundred miles, so I pulled the primary again to see what was going on or if I had screwed up something on reassembly. The original idler gear was replaced as it showed wear on one side of the flange on which the scissor gear rotates (which must be a miniscule amount). During the subsequent inspection of the new one I found witness marks in exactly the same area so there is definitely some big force acting on it. I could not find anything untoward so cleaned it all up with brake cleaner. The amount of metal content that came out from the joint between the ring gear and the backplate was unbelievable. It must act as a centrifuge. I presume the metal content is the new idler gear running in and the stuff behind the ring gear has just accumulated over time. While I had it apart, I drilled out the centre of the drain plug and JB welded a strong magnet to it. After what I had found, I would strongly recommend doing the same or buying one. (Maybe the later bikes already have one fitted?)

I also changed the timing chain and tensioners from the early metal version to the nylon type hoping that would help on the noise front, but it still sounds bloody awful TBH.

On initial start-up it's acceptably quiet but the noise gets progressively worse as it warms. Also Under load it also sounds like a jackhammer, is that normal, or should I be looking somewhere else?

I would really like to get to the bottom of it, as I love the bike, but the noise really gets me down.

On the Facebook 961 page somebody asked what you would call a group of 961's - I suggested "A Clatter"

 

[Stu Bodycote]

If you dont change the primary oil, eventually the metal debris forms a thick paste....which dampens the noise
Ive got motul 300v 15w50 in my engine and primary, along with an old billet clutch. Seems pretty quiet....but Ive not done any long term testing.

 

[TonyA]

I wish my 2011 sounded like the one in the film. I have put in a new complete backlash gear, new bearings in the clutch basket (including a double row one on the inner), drilled out the rivets (which had been welded up before) and replaced with HT bolts and pinned the ring gear. I did find some wear on the centre of the basket and found rotating it 180° from its original position got rid of the play I could feel between the basket and the drive gear plate. (Obviously it will return eventually). That did quieten down some of the rattle at idle that I heard with the clutch out. I had also put in Bel-Ray Sport transmission oil, but the clutch and gear changes didn't seem to like it, so I drained it out. I was alarmed at the amount of silver content in the oil after only a few hundred miles, so I pulled the primary again to see what was going on or if I had screwed up something on reassembly. The original idler gear was replaced as it showed wear on one side of the flange on which the scissor gear rotates (which must be a miniscule amount). During the subsequent inspection of the new one I found witness marks in exactly the same area so there is definitely some big force acting on it. I could not find anything untoward so cleaned it all up with brake cleaner. The amount of metal content that came out from the joint between the ring gear and the backplate was unbelievable. It must act as a centrifuge. I presume the metal content is the new idler gear running in and the stuff behind the ring gear has just accumulated over time. While I had it apart, I drilled out the centre of the drain plug and JB welded a strong magnet to it. After what I had found, I would strongly recommend doing the same or buying one. (Maybe the later bikes already have one fitted?)

I also changed the timing chain and tensioners from the early metal version to the nylon type hoping that would help on the noise front, but it still sounds bloody awful TBH.

On initial start-up it's acceptably quiet but the noise gets progressively worse as it warms. Also Under load it also sounds like a jackhammer, is that normal, or should I be looking somewhere else?

I would really like to get to the bottom of it, as I love the bike, but the noise really gets me down.

On the Facebook 961 page somebody asked what you would call a group of 961's - I suggested "A Clatter"

You have done a lot of work to your primary and clutch. There must be some bedding in going on with the basket and ring gear hence the silver (aluminum) . I have read and seen that some 961 have the silver color in the primary oil when drained . I don't know what else it could be other than aluminum from the clutch basket. Have you considered a new Birmaham Norton 961 clutch assembly ? I have never seen this silver color in my primary oil , but I have the later cast basket not the billet one. There is a drain plug of the correct thread available from a magnetic drain plug maker . It is 12mm long and requires a couple of crush washers to get the correct protrusion into the primary. The head is also larger but its not too noticeable. You could also replace it with a larger more available size.

This is from Dimple brand :

M10x1.0x12 Magnetic Drain Plug​

For early BMWs and many other applications.

$35.95

 

[cliffa]

You have done a lot of work to your primary and clutch. There must be some bedding in going on with the basket and ring gear hence the silver (aluminum) . I have read and seen that some 961 have the silver color in the primary oil when drained . I don't know what else it could be other than aluminum from the clutch basket. Have you considered a new Birmaham Norton 961 clutch assembly ? I have never seen this silver color in my primary oil , but I have the later cast basket not the billet one. There is a drain plug of the correct thread available from a magnetic drain plug maker . It is 12mm long and requires a couple of crush washers to get the correct protrusion into the primary. The head is also larger but its not too noticeable. You could also replace it with a larger more available size.

This is from Dimple brand :

M10x1.0x12 Magnetic Drain Plug​

For early BMWs and many other applications.

$35.95

Thanks Tony, I'll look into it.

Regarding a replacement clutch basket, i'm unclear of the position Norton are taking on spares for the SG bikes. I quote from the email they sent out some time ago..

"Our Parts Department will shortly open, and when this happens, we will sell parts that are fitted to our own Norton Commando Classic 961 only. For the reasons set out above we will not be able to guarantee that they will fit your bike, nor that they are suitable or fit for purpose on your motorcycle. "

So are they saying they will refuse to sell spares unless you can prove you have one of their bikes? Or do they mean they will sell me a clutch basket, but if it doesn't fit or later fails and causes me to have an accident they will accept no liability?

They also informed me that the 'new' Commando will not be available outside the U.K. until they have got their operations running properly there

 

[cliffa]

If you dont change the primary oil, eventually the metal debris forms a thick paste....which dampens the noise
Ive got motul 300v 15w50 in my engine and primary, along with an old billet clutch. Seems pretty quiet....but Ive not done any long term testing.

Perhaps I could fill the primary with grease

 

[Stu Bodycote]

Perhaps I could fill the primary with grease

Sawdust

 

[Stu Bodycote]

TVS built 961's are currently msva'd...they'd never get that through euro 5, especially given that euro 4 kinda had to be blagged to get through five years ago. So as they aint homologated, they cant be sold new overseas.

 

[BritTwit]

TVS built 961's are currently msva'd...they'd never get that through euro 5, especially given that euro 4 kinda had to be blagged to get through five years ago. So as they aint homologated, they cant be sold new overseas.

Stu,

Are you referring to the "40", or the NEW 961s?