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Interesting debate regarding tapered vs, roller bearings. I just replaced the headset bearings in my Supertenere because they developed a flat spot or became indexed as we said at the bicycle shop I worked at. I was surprised to find out that the bearings in the S10 were tapered roller bearings from the factory. They were replaced at 36,000 miles and likely failed because when I bought the bike new, I took them apart to grease them, as I read in a forum that Yamaha was stingy with grease. I discovered that they were in fact very greasy from the factory and I had no way to properly torque them so I kinda did them by "feel". So, it would seem that Yamaha believes in roller and ball bearings in the steering head.
All that being said, I still have the waggle on decel with no hands on the bars (on the FJR,not the S10) . Maybe I'll up the final torque a Lb. or two as suggested above but for now I'll just keep my hands on the bars.
 

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2015 FJR-1300ESF
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36k seems early to wear out tapered roller steering bearings. Or is that reasonable life for a heavy-ish bike?

I don't have a solid metric for how long the bearings should last. I only got about ~10k miles on the tapered rollers I installed in my old Vstrom, because the bike was totaled.
 

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I had them replaced at a reputable Yamaha shop and the tech told me that 36K was very early to need replacement. He said it was likely caused by me overtorqueing them when I messed around with them. In fact he himself has a Supertenere reportedly with 80K with original factory tapered roller bearings. The storel of the morey: don't mess with them unless you have the equipment to re-torque them properly.
 

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I had them replaced at a reputable Yamaha shop and the tech told me that 36K was very early to need replacement. He said it was likely caused by me overtorqueing them when I messed around with them. In fact he himself has a Supertenere reportedly with 80K with original factory tapered roller bearings. The storel of the morey: don't mess with them unless you have the equipment to re-torque them properly.
They ought to last forever even if you seriously over torqued them. Tapered bearings are made to deal with the loads in a truck axle, hard to believe that you could get anything but kinda stiff steering from over torquing. You certainly are not going to get any wear or crush them.
 

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They ought to last forever even if you seriously over torqued them. Tapered bearings are made to deal with the loads in a truck axle, hard to believe that you could get anything but kinda stiff steering from over torquing. You certainly are not going to get any wear or crush them.
Seemingly, but after 36K miles they had definitely become indexed. I noticed it when trolling along at very low speeds. The bike was difficult to ride straight without wandering back and forth. From what i know about bicycles I recognized that as a sign of badly indexed steering bearings. I jacked up the front of the bike and sure enough when I swung the bars back and forth it would lock right into a position just just barely off center. I was actually hoping it was just a front tire, which is worn kind of uneven, but no such luck. All good now with the new bearings, even with the lumpy tire.
The funny thing is I know I didn't over tighten them a ton because they felt smooth and easy to turn when I did it. Maybe it's possible that I under tightened them and there was a tiny bit of inperceptible play that caused them to index so early.
 

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Also the loads on a steering bearing are incredibly high. Imagine the force on those bearings when braking hard with the front brake. All that force from the weight of the bike times the Velocity being multiplied further by the leverage of the fork.
 

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Also the loads on a steering bearing are incredibly high. Imagine the force on those bearings when braking hard with the front brake. All that force from the weight of the bike times the Velocity being multiplied further by the leverage of the fork.
Not nearly as much force as having one corner of a 5000lb car bouncing on them with every bump;)
 

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Not nearly as much force as having one corner of a 5000lb car bouncing on them with every bump;)
Maybe they wear quicker in a static application like a steering head because they are essentially in the same spot all the time where in a wheel bearing or axle they are spinning and constantly "spreading the load". around. fisics is Phasinating.
 

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Maybe they wear quicker in a static application like a steering head because they are essentially in the same spot all the time where in a wheel bearing or axle they are spinning and constantly "spreading the load". around. fisics is Phasinating.
I suspect this is so. To me it emphasizes that tapered roller bearings are the best choice for this application.
 

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I've had steering head shake on both ball and tapered bearings. The shake happens less with the tapered bearings and only on severely and unevenly worn tires, like when well past the wear bars and worn more one side than the other. I keep tire pressure at 40 front and 42 rear.
 

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I have a 56 liter Givi that I only use when traveling and the bike feels a bit skittish when it's in place especially if it's overload, which it usually is :rolleyes: . I get used to it pretty quick and do thousands of miles at a time with it, so it's no big deal. But I've always felt that additional weight hanging back there high behind the back wheel must be the cause. It certainly unloads the front wheel a bit. I don't tend to ride with no hands very much, so I've never noticed a shake, but as skittish as it feels, it wouldn't surprise me.
 
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