Steering head bearing adjustment.

[Charley]

Adjusted the head race bearings and on tightening up the top nut it stripped. Poo!
Then I started looking at it. 7.2 mm of thread isn't much for an M24 nut with fine thread at 85Nm I thought.
Then I looked further and noticed the 2.7mm thick washer or so it seems, on top of the ring nut.
I don't see the washer in the parts book, if that is a washer on top of the ring nut. and if it wasn't there I'd have closer to 10mm for the top nut.

Any thoughts or confirmation of existing set up appreciated.

New top nut ordered.

 

[sfcpiet]

The washer should not be there... can't see if you have stock headlight mounts, the washer will have an impact on their fit between the yokes.

Not necessary to tighten the nut excessively, just needs to nip up the adjuster nut. Yoke clamp provides rigidity.

piet

 

[andre g]

Charley, have in mind when you tighten the upper nut, I think 85 Nm are not necessery, the lower c nut will pressed down in the thread and thighten the bearings aditionally.
Maybe it is necessary to loose the c nut again about 2 to 5 degrees and fix the upper nut again. My opinion is not to have to much pressure in the bearings, better to be on the loose side.

Andre

 

[Vince]

The above is correct regarding tightening. It helps to have a thin C spanner to hold the lower castellated nut when nipping the upper nut up.

 

[Charley]

The washer should not be there... can't see if you have stock headlight mounts, the washer will have an impact on their fit between the yokes.

Not necessary to tighten the nut excessively, just needs to nip up the adjuster nut. Yoke clamp provides rigidity.

piet

Thank you Piet,
I believe that if I take out any washer between the ring nut and top yoke I may have issues with the standard headlamp mounts.
I will check this very point in the morning.
Thank you. C

 

[Charley]

Charley, have in mind when you tighten the upper nut, I think 85 Nm are not necessery, the lower c nut will pressed down in the thread and thighten the bearings aditionally.
Maybe it is necessary to loose the c nut again about 2 to 5 degrees and fix the upper nut again. My opinion is not to have to much pressure in the bearings, better to be on the loose side.

Andre

Thank you Andre,
Just the information I need. It did seem a lot of torque on such a nut/thread.

During my last ride, there was a bit of speed wobble suggesting too loose steering bearings to me, so I have tighten just a touch as the ring nut was easy to turn. Hardly any torque required on the 50 mm C spanner even before I loosened off the top nut.

I will have another go tomorrow after cutting off the damaged thread. The Top nut is deep enough to accommodate the stem thread, sufficiently until I get a new nut. At least enough to test my adjustments.

Thank you. C

 

[martymoose]

Speed wobble also check:
Tyre wear
Tyre pressures
Wheel balance weights
Swing Arm bearings

Hope you're not using Dunlop's.......

 

[Charley]

Speed wobble also check:
Tyre wear
Tyre pressures
Wheel balance weights
Swing Arm bearings

Hope you're not using Dunlop's.......

Hi Marty,
Beatrix is fitted with near new Bridgestone BT 46s at the correct pressure. Or they were at the correct pressures when I left for my weekend away.
I’ll check wheel balance as since the tyres were fitted, I’ve also fitted new brake discs so maybe’s things have changed. Good point.
Bearings and swing arm are all good.

Thank you. Your points have made me think and reminded me of the disc change.
Cheers, C

 

[piranha-bro2]

The above is correct regarding tightening. It helps to have a thin C spanner to hold the lower castellated nut when nipping the upper nut up.

No need to hold the castellated nut when tightening the top nut, Vince. Zero chance the top nut can cause movement below the top triple clamp (ie it can't rotate). Correct that the setting tension on the castel nut is paramount to getting the sweet spot in bearing adjustment. I'd hazard a guess that 80% of people overtighten their steering head bearings because they haven't factored in how significantly compression from the final top nut nip up (85nnm?! ) transfers to the castel nut ... result: too tight.

Almost impossible to feel correct tension with the wheel in place (elevated) and still very difficult with forks in place ... ideally done when only triple clamps are fitted.

 

[Sir Sidney Ruffdiamond]

Lightly tapping the castellated ring with a punch - as above - once I replaced the Jota bearings I had to make a few adjustments after a few miles but it was easy to do - checking there was no notchy ness in the movement of the bars side to side

 

[CLEMTOG]

Speed wobble also check:
Tyre wear
Tyre pressures
Wheel balance weights
Swing Arm bearings

check also that the floating fork leg bottom is actually floating before being clamped, this can be left or right as callipers can be in front of or behind the forks, but for sure the floating side is the one with the tommy bar in the axle, everything is pulled up to the other side by the axle nut, once the floating one has settled, tighten up the clamp bolts. full description elswehere do a search. I know of several triple riders who did not know this after decades of ownership, and one locally who may have a brake binding problem because his floating fork is either bolted ridgid (by the axle nut) or is floated off to one side.
CLEM

 

[Charley]

Speed wobble also check:
Tyre wear
Tyre pressures
Wheel balance weights
Swing Arm bearings

check also that the floating fork leg bottom is actually floating before being clamped, this can be left or right as callipers can be in front of or behind the forks, but for sure the floating side is the one with the tommy bar in the axle, everything is pulled up to the other side by the axle nut, once the floating one has settled, tighten up the clamp bolts. full description elswehere do a search. I know of several triple riders who did not know this after decades of ownership, and one locally who may have a brake binding problem because his floating fork is either bolted ridgid (by the axle nut) or is floated off to one side.
CLEM

Thank you Clem. All good advice.
Bike has been handling fine for the past three years, so just a small adjustment made.
My question is more about the inclusion of the washer above ring nut.
I’ve measured the headlight support tubes and with rubbers (new a few years ago) and the support rings and I’m thinking that this is the reason the washer, to keep the yokes as parallel as possible. Thus the slightly shorter available thread on the stem.
Your notes on the forks are well written and your points noted.
In principle, the axle fastening is the same as my 1977 BMW so no problem there.
Thanks. C