Bottom of chain, top of exhaust clearance

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Someone pointed out to me the other day that the chain is set really close to the RH exhaust pipe.
It was, which would account for the tinka, tinka, noise I heard the other day when I took a corner.
There appears to be only about 1/2" clearance between them and there is rub marks on the top of the pipe.
The chain is adjusted correctly, I haven't touched the shocks since delivery, its got less than 200 miles, and my fear is that after a few bumps in the road eventually
I'll wear a hole in the muffler, or worse the chain gives in, at 70.
Any one else encounter this issue?
2014 961 sport.
 

BritTwit

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Your report is the first that I have heard of for a stock exhaust system.
I replaced my stock exhaust with the SouthBay Norton exhaust and crossover pipe. I have had a chain/pipe contact issue from day one with this aftermarket exhaust. However, I can’t remember anyone complaining of a similar problem with the OEM exhaust.
Are you certain that your chain slack is between the 35-40mm slack recommended in the owners manual? To check it fully, you may have to remove the right side silencer?

The contact typically occurs on hard braking or after hitting a hard bump and rebounding. That is when the rear shock will reach full extention, and the rear wheel will pull the chain down to its closest position in relation to the exhaust pipe. Upon acceleration, the rear end will squat down and the chain will move away from the pipe.
Also, your chain is made of case hardened steel links, the pipe is made of milder stainless steel. The chain will cut a nice slot through the pipe well before there will be any chain issues.
In which case you will certainly hear the leaking exhaust.

This is something you definitely need to keep an eye on. I would take the bike back to the dealer so he can make sure that the exhaust is installed properly. This should not be appening.

Regards.
 
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Thanks for the response BT. Having just gone to the garage and put my weight on the bike, I realize that , duh, the pipe moves away from the chain not towards it.
There is only about 15mm slack in my chain and more like 25mm if I push down and push up on it.
My Dad always told me if I had a brain I would be dangerous. So with that being said, I'm going to put the dual seat on the back and take the missus out for a spin.
Safe rides.
 
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If you find you do have insufficient clearance anyone with a tubing bender can set you up in 5 minutes. Any muffler shop or any plumber or electrician will have one!
 
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On my bike , If I keep the chain tension near the tight side of the spec. 33-35 mm I do not rub. The chain needs to be adjusted with no weight on the bike , on the paddock stand . To have the exhaust pipe re-bent would be a great permanent solution . Also I have noticed a crack on the cat X pipe bracket , where it bolts to the frame underneath . I must really be revving this thing a lot . I don't know if it is worth trying to repair under warranty . I thought I would just bring it to a welding shop that can handle stainless and remake the bracket thicker like the plates that hold up the rear mufflers. Or add an additional bracket on both sides of the frame boss underneath . Then it wont crack again I hope.
 

BritTwit

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Be very careful not to reduce chain play below 35mm. I was told by my mechanic that this was discussed with Norton when the clearance problem was discovered on my bike. 35mm is the absolute tightest you want to go. Any tighter and there is the danger of an oil seal problem on the countershaft, behind the engine sprocket.

Regards
 
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I agree to that . I just think that the pipe routing should have been done better so that we can actually adjust the chain properly ! Here I go complaining again ! It seems then that a rebend of the pipe IS THE ONLY OPTION.
 

BritTwit

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Exactly.
The engineering done on the pipe routing was not adequate to the task.
Ditto for my SouthBay aftermarket X-pipe and silencers.

But don't get depressed, focus on what the bike does well, deal with the rest.
Out on the road it never fails to put a smile on my face.
 
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Have you seen the NRP Exhaust system made by NRP England ? Look at their website the have a sport there and show the pipes. Really takes care of any chain clearance issues. The problem are that they only hand fit the exhaust ! You have to give them the bike....
 
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BritTwit said:
Exactly.
The engineering done on the pipe routing was not adequate to the task.
Ditto for my SouthBay aftermarket X-pipe and silencers.

But don't get depressed, focus on what the bike does well, deal with the rest.
Out on the road it never fails to put a smile on my face.

Amen to that , at 6000 and up it really gets a move on ! Vibration is high though....
 

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A curious thing.
My SouthBay X-Pipe dispenses with the under frame support that the stock cat pipe uses.
This leaves a rather long, unsupported section of exhaust, from the header to the rear silencer bracket.
I wonder why?
 
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I've just been out to the garage and had a look at my 2013 Sport, and the chain is alarmingly close to the right hand exhaust. In fact there are rub marks on the top of the exhaust where the chain has clearly been rubbing.
At first service last year, which was carried out back at the factory, I had the louder silencers fitted (at no little cost I might add!). I must say that my concern is that the chain will eventually wear through the silencer.
This is clearly appears to be another bit of poor design, marring what should be, a marvelous machine.
Not too sure what to do about it now. warranty claim?
What do you all think?
 

BritTwit

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:lol: First, check the free play in the chain if it is greater than 35mm, then you should tighten it to 35mm, but no tighter. This will alleviate the problem for now. Considering your proximity to the factory, I would make the folks at Norton aware of the issue, in person.

My short term solution was to purchase stainless clamps, and position one precisely where my chain was contacting the exhaust. As my chain loosens it leaves a witness mark on the clamp where the contact occurs and I know I have to tighten the chain. It’s a PIA but it works for me right now. I have already gone through 1 clamp. The drive chain has case hardened steel end plates, they it will cut through the mild stainless steel clamp, or pipe easily. I check the clamp before every ride.

As BPHORSEGUY suggested in a previous posting, I intend to take my bike to a shop that builds custom exhausts, and ask them to bend/cut/weld/modify the pipes for proper clearance. I can only image the price I’ll be charged.

One way to look at this is that it’s just another undocumented feature for the 961. :lol:
 
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Can anyone who has installed a South Bay Norton Torque muffler and retained the stock cat x-pipe let us know what the clearance is between the chain and the muffler/exhaust pipe. And also how loud are they and are they worth the money ? Tony.
 
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BritTwit said:
A curious thing.
My SouthBay X-Pipe dispenses with the under frame support that the stock cat pipe uses.
This leaves a rather long, unsupported section of exhaust, from the header to the rear silencer bracket.
I wonder why?
Almost sounds like a 750 or 850 Commando ....
 

BritTwit

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True,

But the 750/850 Commando had an extreme vibration issue that the factory "solved" by rubber mounting the mufflers at the rear of the bike. Those rubber mounts eventually disintergrate and have to replaced. By the way the under frame pipe mount on the 961 - the bolt has a rubber isolation tube/pipe around it too. Funny, the old saying is true, what's old is new again.

I do think that the under frame mount should be utilized by any after market exhaust. Otherwise, that unsupported length of pipe is a potential issue.
 
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TonyA said:
Have you seen the NRP Exhaust system made by NRP England ? Look at their website the have a sport there and show the pipes. Really takes care of any chain clearance issues. The problem are that they only hand fit the exhaust ! You have to give them the bike....
Here it is.




Now that's a good looking set of Pipes !! I cant tell if it has a middle support or not . I like the way the diameter is carried all the back to the muffler full size. These are stainless and they look like they ride higher , no chain issues and the route looks good to me. Also the pipe diameter looks larger ? Also it has optional db killer plugs so you can quiet it down if needed. Tony.
 

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Interesting,

Changes the whole like of the standard 961 exhaust, but completely removes the right side pipe/chain clearance issue for sure.
Do you know if there is a crossover tube between the pipes under the bike? Without the crossover there will be an impact on midrange performance. I wonder if the headers are ceramic coated.
 
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All good questions , We need to email them and ask. Doesn't look like a crossover and no middle support either. They also look a little UJM , but at least it may resolve some issues. I still like the look . They certainly look like they will flow great. The Domiracer has no crossover on the open pipes. Also Triumph Arrow two into two has no crossover .
 
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TonyA said:
Can anyone who has installed a South Bay Norton Torque muffler and retained the stock cat x-pipe let us know what the clearance is between the chain and the muffler/exhaust pipe. And also how loud are they and are they worth the money ? Tony.
The SBT Torque exhaust have the same issue with clearance, but supposedly SBT is redesigning the pipe to address this issue as we speak. The sound and performance of these pipes are impressive.
 

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