Steering head, missing value

[FM-USA]

Might need an old-school slide-rule for this one?
I'm looking for the compressive value of the steering head bearings (SHB).
We know the SHB nut torque is 14lbs., what does that translate to the bearings compression?

[Rambozo]

Who needs a slide rule when you have the internet?
https://www.engineersedge.com/calculato ... e_calc.htm

[FM-USA]

Who needs a slide rule when you have the internet?
www.engineersedge.com/calculators/torque_calc.htm

I did run across one of those sights but when I input known values it spit out a high 3 digit number.
Using your URL suggestion I get a range of 70 - 85 lbs on the bearings, lubed to dry. SEEMS HIGH but I'm not a maniacal engineer.
( Norm Crosby, malapropisms of mechanical )

[Andy Cote]

I do not think that site is applicable to roller bearing forces. Clamping forces on a fixed joint are different than thrust/compression forces within a bearing.

What exactly are you trying to determine? If you are using roller bearings, tighten the retaining nut to the Honda specified torque value. If you are using tapered bearings, tighten the retaining nut to provide the handlebar running torque called out by the taper bearing instructions and check again after the specified run-in time.

[FM-USA]

That's the problem I'm having.
I'm going by and done exactly the Honda, Wing-Admin, and others directions in steering head tightening yet I still get a wheel wobble.
Which, BTW, some of there posts seem Copy/Paste.

I don't have galled bearing races, I've cleaned the cups and cones, they are pristine. Yes, I know how to check these parts.
The fork tubes are tight, wheel bearings are new and I've installed the Blackwing brace.
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[Rambozo]

While the forces in a bearing are not modeled by just compression, the preload is basically applied by just the clamping loads. Not sure where you got 70 pounds.(perhaps by entering foot pounds instead of inch pounds?)
I'm not sure what the exact diameter of the stem is, but with an estimate of 1" I get just about 850 pounds of preload.
As the bearings support about half the weight of the bike in static load that would be about 450 pounds, while going over bumps, I would expect dynamic numbers from near zero (wheel airborne) to lets say at least double that so 900 pounds. To insure the bearing clearance doesn't change, I would want that level of preload at the minimum. So the 14 ftlbs. or 168 inlbs. is right in the ballpark at 850 to 950 pounds. These are just back of the envelope numbers, but pretty close to what is expected.

Bearing brinelling and out of round should be checked with an test indicator or a CMM. By the time you can see visual damage they're beyond totally trashed for something like zero clearance steering bearings. The easier thing is just to replace them after a number of years/miles in service. While that may not be your problem, it's nice to have a known good baseline when trying to track down a vibration issue. Apart from physical damage, (bent forks, etc.) Many issues come down to tire wear problems. Having them trued up can sometimes be the last step that solves an hard to find issue.
Is your wobble confined to a set of speeds and loading, or all the time?

[Andy Cote]

Assume we are talking GL1500 as you say Blackwing and that's the only thing she sells under that name. Year and mileage?

New wheel bearings. Front and rear?

Since you visually examined steering head bearings, assume they are not new. How old are they? Tapered?

As RAMBOZO asked, under what conditions does the wobble occur?

When were fork seals last done or fork oil replaced? I remember you were looking for springs a while back. Did you change them? As RAMBOZO suggested, could be bent tubes.

Tell us about both tires. You still a Darksider?

Have you pulled the swingarm and replaced those bearings?

[FM-USA]

Wobble was the usual 30 - 40 mph. It's not a DARKSIDE issue and nor the wheel bearings nor loose or bent tubes nor lack of fluid change.
I've had a badly cupped front tire in the past. So bad a straight edge across two high points showed near 1/4" space, but that didn't produce wobble.

I changed the steering bearings late last fall. 'All Balls' brand and thru the winter had no issues.
But oddly I had to retighten the steering head nuts twice this past Spring. Yes they were torqued correctly and the near 5lb drag test was near spot on.
The wobble stopped for about month then returned, as I mentioned, twice.

Past 2 days checking everything I could in and around that stem. Mirrors, bright lights and blah-yadda... I found this.
The bearing cups were correct but the cones were not. The circumference was right but the cone height was about 0.30 short.
This caused the 14Lb torque to be off because that nut was bottoming out, or per say, ran out of threads. So I got a false torque reading.
Totally unknown why the steering bearings were tight then worked loose. Might have something to do with the running out of threads???
HOPEFULLY the cups race didn't break it's weld, if there is a weld.

Since I bought these bearings 3-4 years ago on a big discount sale, they're not return able. BTW: the package numbers were correct for this 1500.
So what I did was insert a fender washer to take up that missing 0.30 and now that Death Wobble IS GONE! (for now, I'll see in a month)

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[Andy Cote]

Glad to hear you identified the source and got the problem under control. Yeah, bottoming out the nut would be an big problem and prevent you from getting the proper running torque on the bars. Wondering if the "great deal" was really some knock off Chinese counterfeit junk.

[FM-USA]

Knockoffs, GREAT DEAL is possible but I could swear on a stack of Goldwings I checked the embossed numbers for matching.
The pkg was open, but they matched to a good used I had at the time and I test fit in the old cups at installation. NEVER thought height would be something to check, will now.

Figured, sorted and all is well . . . again.
This one was a PAIN!
But I now can remove the 'Top Tree' in 15 minutes... NOT including the signal canceler in the tube.

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