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markstertt

Swing arm flex issue

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markstertt
In my prior post on 'Sprockets misaligned' I mentioned that a contributing factor was a rather large gap between the rear wheel assy. and the inside of the swing arm. In my case this gap is approximately .065" of an inch and is easily taken up as you torque down the rear axle nut but what I didn't know was that as the rear of the swing arm is squeezed inward on the wheel assembly the front ears (pivots) of the swing arm, swing outward. In the relaxed position, wheel axle nut NOT torqued, the front pivots have about .025" lateral or side play before their outboard ends touch the inside of the arms chrome dust/grease caps but as soon as you tighten down the rear axle nut this clearance disappears as the front of the swing arm flexes outward, rubbing on the inside of the chrome caps...not good.
 
 
To alleviate this, I installed an .063" washer along with the left side wheel spacer leaving only a few thousandths of an inch gap between wheel assy. and swing arm, now when I torque down the axle nut the front of the swing arm maintains its original .025" lateral clearance. I didn't care for this much play so I carefully ground .010" off the left side bearing sleeve/spacer to reduce side play to .015", much nicer less slop. I also added an additional pivot bearing to the right side of the swing arm as it only has one from the factory while the left side comes with two due to that being the drive side and it resists the chain pull and spreads the load better across 2 bearings. So why not the right side also, what the heck, necessary? no, but easy and cheap.  And while I was at it I also installed 2 of the forward pivots inner grease seals in the outboard ends, under the chrome dust/grease caps, no waters getting in there and the dust caps are now mostly redundant as far as protection goes.
 
I would say that if you have more than .005"-.010"  clearance between swing arm inner surface and wheel spacer with the axle nut loose then you might want to shim it out or turn up a new thicker wheel spacer...definitely if more than .040" or 1mm, just my opinion of course.
 
Rear wheel assembly to swing arm gap (mine .065") with axle nut completely loose, wheel pushed to right side of swing arm.
 
Front of bike is to the left.
DSCN1252.jpg
 
 
With above pictured gap removed by tightening axle nut, the forward ends of the swing arm flex outward and the
swing arm no longer has any lateral or side clearance. 
Notice the contact wear between swing arm outboard end and inside of chrome dust/grease seal, both sides
exhibit the  same wear pattern but with the axle nut loose there is .025" clearance total between chrome end caps
and swing arm pivot ends. After removing excessive rear wheel gap with an .063" washer in addition to left side wheel
spacer and the axle nut is tightened, I still have my .025" pivot end side clearance.
DSCN1234.jpg
 
 
Pressing in a second right side swing arm pivot bearing to match the 2 in the left or drive side.
I followed this up with a grease seal in both lt. and rt. O.B. positions to duplicate inboard set up.
DSCN1237.jpg
 
 
 
image hosting services

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ralph
Maybe a quality control thing mine is a noticeably tight fit.
Just had a look at mine the chain is running right down the
middel of the sprockets, was thinking you may have had a spacer missing
but from whet I can see with the wheel fitted it looks the same.
 
 

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YZEtc
When the rear wheel axle nut is completely loosened, is the swingarm pivot nut tightened to specification?
 
Those marks on the inside of the swingarm end cap are normal.

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markstertt
Ralph, yes all stock components present and accounted for, not hard to imagine there being production tolerances off one way or the other with a multi pc. stamped steel, welded together swing arm assembly...I had the same issue with a C&J track frame only the opposite direction, legs to close together and couldn't get the wheel in.
 
YZEtc, those marks on the inside of the end caps are not normal in this case, normal would be a symmetrical wear pattern on both the cap and the end of the swing arm pivot and yes the pivot nut was torqued to spec. As you probably know the swing arm pivot bearing/sleeve/bolt and frame make a stack up with a given dimension between end caps and the swing arm pivots side to side total dimension has to be smaller (the resultant side clearance) to fit into this stack up, in my case this side play was .025" and the pivots ran parallel to the pivot bolt and bearing sleeves, however, when torqueing down the wheel axle nut and pulling the aft end of the legs of the swing arm together then the flexible swing arm bends at the center forward perpendicular cross weldment pivoting the bearing ends outward with the forward O.B. edges of the pivots contacting the end caps asymmetrically & taking up all and more of my original .025" forward side clearance and also no longer staying parallel to bearing spacer & thru bolt. All this is easily measured and just as easily corrected by eliminating the excessive rear wheel side clearance...if indeed your bike has excessive clearance to start with as mine did...if not, then don't worry about it but if you do then you may want to check things out.
 
I just wanted to share this 'cause and effect' issue with others in case they came across the same thing. I now wonder how rigid the -07 Tracers cast aluminum swing arm is and if it would be an easy retrofit to the FZ-07? I know some on this forum were interested in it for it's added length.
 
 

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r1limited
Curious, did you not mention you were the 2nd owner? In today's manufacturing, unless its China, I doubt that a gape of 064 of an inch would occur. In the old days hell yes as the chrome molly 41xx tubing would flex and blah blah blah. That swing arm would have taken a bit of a hit to tweak it that amount IMO. The percantage of getting that only one that came off the conveyor belt out of tolerance? well it happens.

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markstertt
Ha ha, who says only one came off the assembly line with .060" clearance, I find that a lot of guys don't notice or even know enough to question what they see if they are even willing to do any work on their own bike. I'll admit I didn't notice this at first either but when I pulled the swing arm to drill it for my spool adapters, then the asymmetrical wear on the inside of the dust caps caught my eye and then I continued to check to find the cause and fix it.. Yes, I'm the second owner but the bike never took a hit and the swing arm isn't really tweaked until the rear axle nut is torqued to pull in that gap. Like I mentioned before, a stamped steel, multi pc., welded swing arm would have many opportunities to be a tad off especially in the width of gap at the end of those long arms. I weld a bit of 4130, it's easier to make things crooked than straight.
 
I'll bet there are guys out there right now that even if they see they have a 'somewhat' large gap, they won't go to the trouble to measure it much less to see what's happening at the other end with their pivots...even after I've reported on what happens. Just roughly speaking, if you have a rear wheel spacer to swing arm gap of .050" then when you tighten down the axle nut you will spread the front out almost half that much or about .020"-.025" and if the needle bearings were originally parallel to their spacers, then once spread they won't be.
 
If you think todays tolerances are closer then you probably haven't taken much of this bike apart to see. I would say the cnc machining on the engine components is probably top notch but the frame to engine, frame to components etc. is slightly on the large hole/gap side to allow for easy assembly on the line, they can't afford to make fitments like you would on a custom hand built bike. Jack up the rear and lift up and down on the back wheel and feel the little 'click click' in the swing arm linkage pivots 'caused by oversize holes, bolts with not enough shank length etc. and unshimmed component side play all add up to a little slop...most people don't care and will get rid of the bike way before any of the parts wear becomes a problem....I'm just having fun beating this dead horse, sorry if I ramble on.

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YZEtc
Just to make sure I understand this correctly:
 
When the swingarm pivot nut is torqued down properly, you still have a side gap of .025 inch at the swingarm pivot (between the swingarm end cap and the footrest bracket).
 
Is this what you are saying?

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markstertt
Just to make sure I understand this correctly: 
When the swingarm pivot nut is torqued down properly, you still have a side gap of .025 inch at the swingarm pivot (between the swingarm end cap and the footrest bracket).
 
Is this what you are saying?
No, the footrest bracket is part of the stack up, leave the footrest bracket off for easier visualization, replace it with a thick washer (both sides) for correct stack up and measuring, at the same time turn the swing arm chrome endcap around backwards so that once the pivot bolt nut is torqued you can then insert a feeler gauge in between the dust cap and end of swing arm to measure the side clearance of the pivot end of the swing arm. You must have some clearance here so as not to bind up the swing arm. Any positive clearance will do, mine stock had .025" until I torqued down the wheel axle nut, then all this clearance disappeared and the ends of the swing arm pivots rubbed on the inside of the chrome dust caps as the leading edge of the pivots arced outwards. Squeeze the rear, spread the front...simple as that. Now once I installed a .063" washer between the inner face of the aft swing arm and wheel spacer eliminating the 'rear wheel' side clearance, as viewed in my first picture, then the above spreading of the front doesn't occur because tightening of the axle nut can no longer squeeze the rear (no gap) together and I still had my .025" clearance at the front, so now all is good. 
I'm sorry I didn't take more pictures but I've explained this the best I can...it's not a real big deal but something that's nice to recognize and correct when you're playing around in this area.
 
The footrest brackets/plates do add outboard support to the swing arm but with the plates oversized and in 2 places, elongated bottom holes then this support is not as good as it could be for a race bike but just fine for 99.9% of owners on the street.
 
 
 
 

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r1limited
Ha ha, who says only one came off the assembly line with .060" clearance, I find that a lot of guys don't notice or even know enough to question what they see if they are even willing to do any work on their own bike. I'll admit I didn't notice this at first either but when I pulled the swing arm to drill it for my spool adapters, then the asymmetrical wear on the inside of the dust caps caught my eye and then I continued to check to find the cause and fix it.. Yes, I'm the second owner but the bike never took a hit and the swing arm isn't really tweaked until the rear axle nut is torqued to pull in that gap. Like I mentioned before, a stamped steel, multi pc., welded swing arm would have many opportunities to be a tad off especially in the width of gap at the end of those long arms. I weld a bit of 4130, it's easier to make things crooked than straight. 
I'll bet there are guys out there right now that even if they see they have a 'somewhat' large gap, they won't go to the trouble to measure it much less to see what's happening at the other end with their pivots...even after I've reported on what happens. Just roughly speaking, if you have a rear wheel spacer to swing arm gap of .050" then when you tighten down the axle nut you will spread the front out almost half that much or about .020"-.025" and if the needle bearings were originally parallel to their spacers, then once spread they won't be.
 
If you think todays tolerances are closer then you probably haven't taken much of this bike apart to see. I would say the cnc machining on the engine components is probably top notch but the frame to engine, frame to components etc. is slightly on the large hole/gap side to allow for easy assembly on the line, they can't afford to make fitments like you would on a custom hand built bike. Jack up the rear and lift up and down on the back wheel and feel the little 'click click' in the swing arm linkage pivots 'caused by oversize holes, bolts with not enough shank length etc. and unshimmed component side play all add up to a little slop...most people don't care and will get rid of the bike way before any of the parts wear becomes a problem....I'm just having fun beating this dead horse, sorry if I ramble on.
It has been my experience welding anything from aluminum to Nuclear reactors ( ya I worked for GE Nuclear Energy Division there are 6 Reactors in the world with my Initials welded in the Base Control room flooring) I put a few beads down in my day that crooked finished products is for the armature Just My Opinion. 
To be clear my FZ has literally no spacing, and what may be considered poor design may in fact be by design as variances are always calculated in and tolerance can be simply x - y within tolerance.   No keeping in mind my comment on that 1 in a million being out of tolerance, perhaps I was not clear on that part for the rational mind to logically look at the probability I was correct :)  With that said the probability of said distance being a defect can may and well be by design and thus as a production level gonna make a million of these bikes and the chance of that 1 guy going bonkers over .065 of an inch will be hilarious :)  Ya Engineers think weird stuff up
 

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faffi
 I worked for GE Nuclear Energy Division there are 6 Reactors in the world with my Initials welded in the Base Control room flooring
Scream! :o  When is he next spaceship to Mars? O_o We must flee when there is still time!  P-)
 
 
 
 
 
Sorry, mate :D - seriously, you have my highest respect as a welder as mad skills must be required to be allowed to weld nuke reactors  8-)

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r1limited
 I worked for GE Nuclear Energy Division there are 6 Reactors in the world with my Initials welded in the Base Control room flooring
Scream! :o  When is he next spaceship to Mars? O_o We must flee when there is still time!  P-)  
 
 
 
 
Sorry, mate :D - seriously, you have my highest respect as a welder as mad skills must be required to be allowed to weld nuke reactors  8-)
Hahahahahahaha well define skills we all were certainly mad back then ;) 

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markstertt
Ha ha, who says only one came off the assembly line with .060" clearance, I find that a lot of guys don't notice or even know enough to question what they see if they are even willing to do any work on their own bike. I'll admit I didn't notice this at first either but when I pulled the swing arm to drill it for my spool adapters, then the asymmetrical wear on the inside of the dust caps caught my eye and then I continued to check to find the cause and fix it.. Yes, I'm the second owner but the bike never took a hit and the swing arm isn't really tweaked until the rear axle nut is torqued to pull in that gap. Like I mentioned before, a stamped steel, multi pc., welded swing arm would have many opportunities to be a tad off especially in the width of gap at the end of those long arms. I weld a bit of 4130, it's easier to make things crooked than straight. 
I'll bet there are guys out there right now that even if they see they have a 'somewhat' large gap, they won't go to the trouble to measure it much less to see what's happening at the other end with their pivots...even after I've reported on what happens. Just roughly speaking, if you have a rear wheel spacer to swing arm gap of .050" then when you tighten down the axle nut you will spread the front out almost half that much or about .020"-.025" and if the needle bearings were originally parallel to their spacers, then once spread they won't be.
 
If you think todays tolerances are closer then you probably haven't taken much of this bike apart to see. I would say the cnc machining on the engine components is probably top notch but the frame to engine, frame to components etc. is slightly on the large hole/gap side to allow for easy assembly on the line, they can't afford to make fitments like you would on a custom hand built bike. Jack up the rear and lift up and down on the back wheel and feel the little 'click click' in the swing arm linkage pivots 'caused by oversize holes, bolts with not enough shank length etc. and unshimmed component side play all add up to a little slop...most people don't care and will get rid of the bike way before any of the parts wear becomes a problem....I'm just having fun beating this dead horse, sorry if I ramble on.
It has been my experience welding anything from aluminum to Nuclear reactors ( ya I worked for GE Nuclear Energy Division there are 6 Reactors in the world with my Initials welded in the Base Control room flooring) I put a few beads down in my day that crooked finished products is for the armature Just My Opinion. 
To be clear my FZ has literally no spacing, and what may be considered poor design may in fact be by design as variances are always calculated in and tolerance can be simply x - y within tolerance.   No keeping in mind my comment on that 1 in a million being out of tolerance, perhaps I was not clear on that part for the rational mind to logically look at the probability I was correct :)   With that said the probability of said distance being a defect can may and well be by design and thus as a production level gonna make a million of these bikes and the chance of that 1 guy going bonkers over .065 of an inch will be hilarious :)   Ya Engineers think weird stuff up

r1limited, I'm not exactly sure where you're coming from but I never said it was a 'poor' design or a 'defective' part though I did imply it could be a combination of manufacturing tolerance extremes that led to my issue and if your inference that I'm the one guy who's gone 'bonkers' over .065" wheel to swing arm clearance then you missed the reason for my post and also the part where I said it was 'no big deal' and easily corrected. I did point out that the design and construction of a multi piece welded assembly such as the -07 swinger could lead to such a condition as I experienced, even parts welded in a jig can come out with stresses that will alter dimensions when removed from said jig. 
You may have noticed that my post wasn't slamming the bike, which I happen to really like, my post wasn't asking for help either but was only sharing what I found and how I resolved it so that if others came across the same condition then they would have some shared knowledge to be able to say, ah ha! this is something that others (or at least one other) have experienced and I should probably take care of it since it may cause issues with the pivot end of the swing arm. Take it for what it's worth, or not.
 
 
 
 
 
 
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r1limited
@markster intent is lost in typed words :( I agree with your assessment, it seems though my intent was not to ridicule but to bring attention to assumed on my part an obsession over .065 thousands of an inch. Sometimes, these tolerances mean something and as I stated by design, my flaw in my explanation was to add a possible by design strengthening, that compresses the swing arm to a more ridged tolorance. Think of it as a SR-71 Blackbird designed that it leaks fuel on the tarmac but at speed all those leaks conform to a by design tolorance at speed. So the FZ07 is the SR-71 only with 2 wheels
 
Ya thats a big jump but WTF

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markstertt
Yes big jump but I do like titanium, anyway, thanks for clarification...Mark

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