Gear change Grrrrrrrrrremlins!!

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Awesome 150 km ride today, until the final half an hour! Pulled out to blast past a couple of cars whilst chasing my mates Ducati, went to change up - nothing! I knew exactly what it was straight away as this was my second such experience.

My gear change actuating rod had snapped at the forward threaded portion! For the second time; the first was inside warranty. Clutch in, freewheeled into a rural driveway, car horns blaring! Yup, snapped in exactly the same place:(.


So, 20km from home, no way to bodge up a repair. It’s RACQ home, or hand select a gear and try riding. The actuating rod snapped in 4th (I think). Although on a slight up hill section, she still pulled away, just; bags of revs and feather that clutch! Made it home easy enough. Felt the clutch physically slip a couple of times and there was some labouring occurring, obviously. In hindsight I should have tried to hand select 3rd.

Has this happened to you? If not, I suspect the likelihood is pretty high that it will. The design is obviously poor, so what’s the answer? Has anyone designed a more robust link bar? Should we all carry a spare and the tools to change it roadside?

Pulled into my garage over 5 hours ago and the engine casings are still warm to the touch. I’m hoping not to have damaged the clutch in any way, guess it’s designed to slip when under excessive load.

Any thoughts my fellow Nortonistas? I can accept one failure, bad batch right? But two?!

View attachment 18854

I would if Norton , keeping the beautiful stainless curved rod ,BUT thread it on the OD (outside) . Go to 8 mm ball joints and finish it for good this way. The rod is very pretty ! The rod should not be narrowed to 6mm but kept at full diameter , and 8mm ball joints.
 

Graeme Mitchell

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I had a cracked gear change linkage. Happened when riding back from second done by a dealer. Setting the position of the linkage is a bit fiddly as the moment can easily clash with the casing. There were signs the linkage had been bent. I can only assume this was done because the service technician might have had trouble refitting it. I wasn't too impressed at the time but Norton sent replacement FOC directly for me to fit. No issues since.
 

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Awesome 150 km ride today, until the final half an hour! Pulled out to blast past a couple of cars whilst chasing my mates Ducati, went to change up - nothing! I knew exactly what it was straight away as this was my second such experience.

My gear change actuating rod had snapped at the forward threaded portion! For the second time; the first was inside warranty. Clutch in, freewheeled into a rural driveway, car horns blaring! Yup, snapped in exactly the same place:(.


So, 20km from home, no way to bodge up a repair. It’s RACQ home, or hand select a gear and try riding. The actuating rod snapped in 4th (I think). Although on a slight up hill section, she still pulled away, just; bags of revs and feather that clutch! Made it home easy enough. Felt the clutch physically slip a couple of times and there was some labouring occurring, obviously. In hindsight I should have tried to hand select 3rd.

Has this happened to you? If not, I suspect the likelihood is pretty high that it will. The design is obviously poor, so what’s the answer? Has anyone designed a more robust link bar? Should we all carry a spare and the tools to change it roadside?

Pulled into my garage over 5 hours ago and the engine casings are still warm to the touch. I’m hoping not to have damaged the clutch in any way, guess it’s designed to slip when under excessive load.

Any thoughts my fellow Nortonistas? I can accept one failure, bad batch right? But two?!

View attachment 18854

Hello Steve , You can get some stainless tubing , slide over the fracture and weld at both ends . Can you find a welding shop that can work on stainless ? Or like FE stated , it can probably just be welded right at the two nuts . The collar will be stronger of course .
 

Clive

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For my final musings on the subject - FYI just to illustrate how strong a high tensile bolt is this is a 4mm bolt carrying my full weight with no deformity. Stainless A2 is obviously the best solution but a bit weaker. So I reckon a new stainless rod, drill it in the lathe, tap it 6mm, bend it how you fancy then A2 S/S stud Loctited in and existing ball joints on. A tad overengineered but easy to make and I guarantee it will not fail.
1601309646779.png
 

Fast Eddie

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Sooo (and this is a serious question, I’m not being facetious), why are some failing currently?
 

Clive

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Sooo (and this is a serious question, I’m not being facetious), why are some failing currently?

Facetiousnness not taken at all my good Sir. Correct me if I'm wrong but the thread at the end of the rod is either die cut or CNC'd and, as implied earlier, a sharp corner with the main rod invites cracks (ref the DH Comet windows). Put it under tension by tightening the lock nuts and you are helping the fracture along. Give a frequent thump with a size 9 plate of meat and Houpla as the French so frequently say. As you imply; to try to make the load more axial by reshaping the rod would help. I am a lousy welder so tend to go for bolt together solutions.
 
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Sooo (and this is a serious question, I’m not being facetious), why are some failing currently?

Its called fatigue strength, a high tensile bolt has a higher tensile strength but keep the thread with the sharp root then it will likely have a low fatigue strength still. Unless you have a jig for applying and unapplying a regular force for a number of cycles you cannot know if a high tensile bolt improves fatigue strength or makes it worse.

Just eliminate the thread and up the rod diameter is a more certain fix.




The skin of Yoke Uncle had undergone 3057 flight cycles (1221 actual and 1836 simulated) before a fatigue crack produced a failure. This occurred at a rivet hole near the forward port escape hatch.

Fatigue is the growth of a crack. This takes place with repeated loading at a level below that which would normally cause the failure of the material. This was little understood at the time.
 
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Fast Eddie

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The plot thickens!

Personally, assuming the rod and rose joint are both stainless, I’m still for welding the sucker together.

Well, I would be if I had one !
 
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I think Tony hit nail on the head... if mine ever breaks then I will simply form an 8mm bar to same shape and thread the ends to take an 8mm rose joint, reducing the ends down to 6mm doesn't make sense.
 
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Happens on the new Triumphs all the time, The shifter and ball ends all need to be moving slick with no binding once adjusted to where you want the lever, everything needs to be oiled regular otherwise they dry up pretty quick, at least mine do
.
Over here in the USA we uses these [get them from Mcmaster Carr]
They tighten everything up on the shifter linkage, Most people that break them are the kind of rider that stamps on the gear lever, good to know whats actually happening in a gearbox and then lighten up on the shifting helps a lot. Cheers Adrian
 

Stephen_Spencer

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All good points/options. I especially like the riding in slippers proposal, unfortunately Norton don’t sell them! Missed a trick there!

This is a problem that definitely needs to be solved and you guys have come up with some great potential solutions. Between my two threads on this site and the Aus FB site there has been a good number of reports of failure. Extrapolate that relatively small number to the entire ownership community! Some have just welded up and cracked on, others obviously ordered a new rod. I’m gonna wander around a few local workshops with the broken bits and look at repair options. I’ll keep all proposed option in mind.

Got an email from Maria at Norton overnight, so they are being very responsive; she‘s looking at cost/availability as we speak (incl a new clutch master cylinder). I’ll let you know the feedback. I may order two rods. May seem excessive but I really don’t need a reason to doubt my bikes reliability as I have just started getting some real ‘mental reliability credits‘, having got over the ‘will she or won’t she’ start feeling - usually whilst surrounded by dozens of local bikers! Thank you Shorai Lithium :) .

Completely relaxed about this, got other bikes to ride. Still love this machine.

Long live Norton.
 
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Stephen_Spencer

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Maria got back to me quite quickly with a price for the gear change rod at GBP 22.00. Quite reasonable I thought. She didn’t however raise an invoice or detail how I could order/pay for the parts. Sent a second (and third) email asking for this detail and got an out of office until next week. Guess I’ll wait ......... patience, virtue and all that! :oops:
 

Fast Eddie

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Cool. Fit the new one and use the old one to experiment with to make it stronger (or should I say, fit for purpose)...
 
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I guess that's why they are called high TENSILE but I would still challenge you to bend one.

No telephone books??? Here in leafy Solihull we recently burned someone as a witch for using a telephonic apparatus without any connecting wires!
God....... you're as backwards as always! :(
 
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This thread reminds me of a muti world sidecar champion who went to pick up a new sidecar chassis for himself he turned up carring a stronger rose joint in his hand to replace the weaker one that they were still using, because he broke one during one GP. costing him the race.
 

Stephen_Spencer

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This thread reminds me of a muti world sidecar champion who went to pick up a new sidecar chassis for himself he turned up carring a stronger rose joint in his hand to replace the weaker one that they were still using, because he broke one during one GP. costing him the race.
Anyone got Poirot‘s number. Gonna give him a call, see if he can work this one outo_O
 
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