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[Christian Frankl]

Hi,

a few days ago I was changing the front sprocket of my FX. Part of that work was to remove the swingarm.
As I was dismounting the swingarm, I was surprised to see, how the swingarm is kept in position.
Not only that the bearings are ball-type instead of needles, but the screw nuts left and right of the swingarm were made as a bushing, fitting into the bearing.
On the outer side of the swingarm-bearing (looking to the frame) there was no second bushing. So - if you tighten the Screw later,
you will start to pull the bearing out of its seat. Strange solution of an easy duty, as I think.
Or maybe in my FX parts are missing?
Additional, all bearings were out of order, after 1600kms of use, about 50% of them offroad use. Sealing against mud and water is insufficient.

What do you think about the system, how the swingarm is mounted?

Best regards,


Chris

[rayivers]

Chris,

I haven't had my swingarm off, but i have spares of the pivot bushings (Zero calls them 'stub axles') and bearings (KML 6204RD, double-sealed).  I think the bearings must be pressed into the swingarm so the center bearing race just contacts the frame on the left and right, then the bushing/stub axle holds the center race to the frame when tightened? If the bearings were installed correctly in the swingarm I would think the only force would be on the bearing centers when the bushings are tightened.

I wonder if there are any double-sealed tapered roller bearings that can be substituted?

Ray

[Christian Frankl]

Hi Ray,

when I was dismounting the swingarm, all bearings were pressed in line with the surface of the swingarm.
And so i pressed the new bearings in. I´m just complaining, because I think with other bushings or a "seat" inside the swingarm
it is possible to keep the bearings free of axial force.


Chris

[rayivers]

Hi Chris,

Maybe the 2013 frame is different from the 2014?  In my bikes the bearings appear to be pressed into seats in the frame which prevent movement in the frame direction, and the bearings protrude from the inside frame walls about 1mm so the center bearing race contacts the swingarm.  In this setup, tightening the bushings should just pull the already-touching center race and swingarm together tighter, with almost no movement. However... the swingarm is centered by the bearing balls, and any side force on the rear wheel will be transmitted directly into them.  The 6204's are deep-groove bearings which is good, but I also found some 30204 tapered roller bearings that might be made to work:

http://cad.timken.com/item/tapered-roller-bearings-ts-tapered-single-/tapered-roller-bearings-ts-tapered-single-metric-2/item-25559

They are 1.25mm wider and unsealed, so some work would definitely be involved.  The 2014 frame has seals on the outer bushing ends, but the swingarm side would need a seal of some kind and the swingarm itself would probably need machining, etc.  Perhaps the swingarm could also be machined for a ring seal or thick O-ring at the same time.

Ray