Balancer (intermediate split) gear questions

ntst8

ntst8

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Spring - in earlier posts there have been comments about the spring being easily overstretched, and that Norton (as they were) reduced the tension on the spring from that originally intended. Is there any knowledge on whether they were just using an under specced spring (for instance mild steel instead of high tensile) or whether there are other design issues at play?

General - I have talked with someone who mostly builds car engines but but who had, a number of years back, worked on a very early 961. He was very anti the split balancer gear in the primary, felt that it was a time bomb which would eventually cause destruction and his recommendation was to do away with the spring and lock up the gear. I don't plan to follow that recommendation, but as these gears seem not to be unusual i am not sure whether just didn't like them in general (i wasn't smart enough to ask at the time), or he had a problem with this particular design and whether the design changed from the initial models . Any thoughts welcomed.
 
I think a Time Bomb is a bit dramatic - the spring may loosen up with time but as stated in other posts there are now quite a few owners putting the amount of miles on their bikes without problems which most owners will never reach. At the NOC meet there seemed to be agreement that the most unappealing aspect of the bike was the mechanical noise and strangely there was a comment made that my 2017 bike was quieter than many. There were a few suggestions of alternative solutions with cush type mechanisms but they don't have the same backlash reducing properties. Of course the split gear principle will only accommodate a certain amount of backlash so maybe some bikes are beyond this tolerance? If the problem is just about the noise then how about some sound deadening?
 
Dont recall them overstretching....more just snapping.
If I recall correctly, the biggest impact on primary noise when trying to nobble the bike through euro4, was 75w90 in the primary/gearbox. They tried sound deadening, it didnt react well with the oil....to say the least haha.
 
Thanks for the feedback, other than correctly setting the split gear spring tension i wasn't planning any mods, just wondering about some of the issues.
 
Stu Bodycote said:
Dont recall them overstretching....more just snapping.
If I recall correctly, the biggest impact on primary noise when trying to nobble the bike through euro4, was 75w90 in the primary/gearbox. They tried sound deadening, it didnt react well with the oil....to say the least haha.
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V interesting so what was the snapping about? There is not exactly a lot of movement. Or was it another pre-tensioning assembly issue?
Re noise - so best place for the sound deadening is in yer lug 'oles then!
 
Folks, as you may have read elsewhere I currently have my primary apart. Upon inspection of the intermediate gear I noticed the dimples on each gear are aligned, but according to the Richard-7 manual they should be set one gear tooth offset (lower pre tension). I seems to remember Stu mentioning that the factory changed the pre tension after spring failures. So does that mean my spring is now overstretched and useless?

Does anybody have a new spring they could measure the end gap on please?
If mine is found defective, does anybody have one they would be willing to sell?

Cheers,

cliffa.
 
cliffa said:
Folks, as you may have read elsewhere I currently have my primary apart. Upon inspection of the intermediate gear I noticed the dimples on each gear are aligned, but according to the Richard-7 manual they should be set one gear tooth offset (lower pre tension). I seems to remember Stu mentioning that the factory changed the pre tension after spring failures. So does that mean my spring is now overstretched and useless?

Does anybody have a new spring they could measure the end gap on please?
If mine is found defective, does anybody have one they would be willing to sell?

Cheers,

cliffa.
Click to expand...
Have you tried Thiel for parts ?
 
TonyA said:
Have you tried Thiel for parts ?
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If I can ascertain if my spring is shot and nobody on here has a spare one they are willing to sell, Thiel will be my next port of call. Mine feels like it has enough spring, but I just need to compare the end gap with a new one to be sure.
 
I have an unused spare ready for fitting which i could measure up, but we have just gone back into lock down here and i won't have access at least until the weekend.
 
ntst8 said:
I have an unused spare ready for fitting which i could measure up, but we have just gone back into lock down here and i won't have access at least until the weekend.
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That would be great please Iain, but no rush whenever you can. I measure 16.3 mm on mine.

Keep Well.
 
Unused one measured at 14.02mm gap, bought as a spare from Norton pre TVS.
They do just look like mild steel sadly.
 
Thanks Iain, that's great. I don't think I'm going to worry about a couple of mm. ( even if I could get a replacement :( )
 
Cliffa , I think yours is over-stretched. Mine was nearly like new after 6,000 miles . You should replace it. I know we can't get the parts !
 
TonyA said:
Cliffa , I think yours is over-stretched. Mine was nearly like new after 6,000 miles . You should replace it. I know we can't get the parts !
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Hi Tony, I would love to but after waiting almost a year for a simple price enquiry from Norton I don't hold out much hope of getting new one. Interestingly mine does look like tempered steel though.

I'm half tempted just to refit it without the split gear to see what it sounds like without. It can't be a lot worse can it?
 
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For comparison my original now measured at 15.1mm gap, now replaced.
 
Ollie has 50 in stock !!

But he tells me that mine is ok, as the spec. is 14 -16mm, and each one of the 50 he has are different.
 
Good news thanks, looks like I still have a spare then .
 
Iain, I've noted some wear on one side of the main gear collar where the split (scissor) gear spins, how does yours look ?
 
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