Wheel/rim issue.

Couple questions. For the 5/6th gen wheels, rear, the lip along the centerline, I assume it supposed to be uniform the entire circumference? Or was it milled to balance imperfections? I'm not talking a chunk.

I ask because if I have the wheel spinning I can see a very slight movement that I believe is a bend. However I don't see any bend at either lip. The tire seems to indicate there is an unevenness as if you watch closely the top of the tire raises and lowers very slightly, 1/32 or so. Lastly if I watch the side profile from the back it looks like the sprocket side is true but theres once again a very small movement on the opposite side.

Do to the nature of tires I cant rely on the tire as a good reference. There could be a flat spot, could be that the edge of the sidewall isnt true to begin with. Tires are 3 weeks and 1000 miles old.

As a side note I have concerns about the shaft being the culprit as well but as one side of the tire is not showing any wobble and the other is.... admittedly the shaft is cheaper so maybe that's why I was thinking this. Lol

 

Do you have the means of removing the wheel and taking it to a shop to have its balanced checked? Or for that matter, a way to check the balance yourself? I don't think the center line is milled or anyway involved with the balancing of the wheel, I could be wrong but that would seem quite a step for any manufacturer to take. If the lips of the rim do not seem to be out of true or round, it's more than likely the tire that is causing the unevenness.

If you're anywhere near Anaheim, California I invite you to come by and I'll take a look at it for you. We can follow the standard social distancing practices. I even have N95 masks here in the garage if you don't have a mask to wear.

 

Easiest way to check. Put bike on centre stand or rear stand, zip tie a pencil to the REAR lower subframe so the nib can ONLY JUST touch the rim. rotate the wheel..
It will be obvious.
Can also use a sharpie...

 

The service manual says allowable runout is 2mm for both radial and axial runout.... I find that a little excessive, should be half that IMHO. You should check both radial and axial at the tire bead... if the pencil check gives you concern, find a dial indicator......

 

Please explain run out. If we are talking a perfect circle and it essentially having an off center axis thus +/- 1mm or are we saying 1mm total so +/- .5mm?

As it stands I have a "dent" in the rim on each side that is aprox 1-2mm. It's not visible to the eye until I used a fixed object just touching the wheel as I spun it.

There is a spot between two spokes on the inside and a spot between the adjacent spokes on the outside. There is also a noticable "movement" in the height of the tire if observed from the side watching the top surface as it spins. Again 1-2 mm.

On the inside I seem to notice the raised centerline had "movement" but it doesn't correspond to the dents I've found. At any rate all above mentioned are damn near impossible to see without a reference point and close observation.

Given theres damage to the wheel how best to proceed? Given cost I'd like to try a used wheel thought there are risks. Given the relatively new tires, 1,000 mile and month old, should I remount them or worry about flat spot damage?

Lastly what about axle shaft damage as a result? Or am I over concerned given the very limited wheel damage?

 

personally, if the wheel is balanced then ride the tires off it...

 

But its "hopping" I think anyway. It's likely the cause of my vibration at 80-100mph. And I'm pretty sure some at lower speeds.

I've near exhausted any other possible explanations

 

Easiest way to find out would be to tape ( secure) a pencil or like to the chain guard with the end just touching the wheel and gently turn wheel. The ideal tool would be a dial test indicator.

 

You are going to need a dial indicator, and have the wheel clamped in say a wheel balancer. You may be seeing deflection from your "dents" right at the edge of the rim, but what counts in the case of "out of round" is where the bead seats, so inboard of the "rim" portion as you look at the inside of the wheel with the tire off. You can measure the top side of that, which is again inboard of the rim on the large OD of the wheel. That is radial runout, total allowable from smallest to largest is 2mm by spec.
Lateral runout is any wobbling of the wheel in a sideways direction, again, if the rim is dented, measure this near where the rim face meets the larger diameter of the wheel (there is a radius there, just off that). Again largest to smallest shouldn't be more than 2mm.
Minor denting is OK, and as Diving Pete says, if it is balanced well, go ride the tires off it.
One other thing you can do is check the radial runout of the tire in the center of the tread. I don't want to give you a number here, but if it's obviously out of round, that might be felt as "hopping".
You can take the wheel to a wheel straightening place, at least they will give you runout readings and advise further, likely give you a quote to straighten if it needs it.

 

Unfortunately it's not just the lip but the outside edge of the inner rim. If that makes sense. I checked along the corner that's formed along whe rim.

So I should not be concerned about subsequent damage that an out of round wheel tire combo might cause or is that not likely? I'm almost inclined to just ride it till it needs new tires again if I dont have cause to worry. If nothing else it will keep me from speeding... as much.

 

Take it to a good shop with a new generation balance machine - they truly are now state of the art., the machine will tell the operator if it’s screwed or not. In which case you will then at least know..

 

Ok, so with that I'm curious, given the style of our rear wheels can I simply take it to a shop with a standard car type road force balancer? The center hub hole looks small so I wasnt sure if its doable or not.

 

There is an attachment that is used to properly mount our rear wheels to a balancing machine. I have no idea where someone would get one but I am sure any meaningful tire shop knows where to look for one. If they are not prepared to at least look for one, then they are not deserving of you business.

Good luck.

 

Didn't you state in an earlier post you had both front and rear tires balanced twice at a motorcycle shop? If so wouldn't they have noticed a bent rim?

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Was and am rather upset they didn't. However I've done alot of research and it seems that small bends like mine are often unnoticed. They spin balance out just fine unless they used a road force balancer. Unfortunately I've yet to find anything to suggest any such thing is used for motorcycles. Seems we get static or standard spin balance only.

 

Are the 5th generation and 6th generation suspension bits the same? Swing arm, forks, fork internals, wheels, shocks, etc?

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No, there are differences. The forks on a 6 Gen are 43mm on the 5 Gen they are 41mm. Shock length is a slightly different length as well. The internals, I can't say but they're kind of geared toward the same "middle of the road" settings. My recollection is that the triangle and dog bone are also different. The 6 Gen does have a slightly longer wheel base so it may have a longer swing arm as well, haven't delved too much in to those differences though.

 

Just wondering. It's odd that my 5th generation and his 6th are suffering from a similar vibration problem.

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Given I did full fork and bearings up front and given every other thread I've come across has ended up looking to the rear end I'll bet there is something there. If not a wheel issue its gotta be in the rear bearings or shaft. I've got a thread on it and I'll update as things happen.


I don't think suspension unless yours is worn and caused irregular tire wear.

 

No. I have a thread just like yours, started last year. Everything new- tires, sprockets, chain, fork internals.

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