Tapered head bearings tightening torque

[SpongeBob]

Hi guys,

Sorry I know that's been discussed before, but I can't find the post with the info I'm looking for.

I remember a  couple of posts where someone described tightening torques when installing tapered head bearings and how that should be quite different compared to ball bearings-- something like 'to contact, not more' -- hence installation/torques a bit different compared to what is given in the workshop manual.

Thanks!

[hard road]

never used them, always use feel 

[Speedy1959]

My 2007 has taprered bearings as standard...
All I can say is that "less" is more..
In other words take up the slack and then gently tweak, then back off slightly..
Sorry this isnt much help at all...
But nip up any play then undo maybe a 1/8th turn..
I took my my bike out and listened for any clonking..
There was a little bit so I tigntened the bearings a tad.

Basically you cant harm by under tightening..
But you definitely can harm by over tightening !!

[Andre]

https://gsx1400owners.org/forum/index.php?topic=7459.msg99107#msg99107

This is how I do it for needle bearings (edit -should read "tapered roller bearing" ) :

After installing the lower fork bridge, tighten the steering stem adjusting nut with approximately 3-5Nm (3-5Nm vs. 45 Nm - that's the main difference for needle  vs. ball bearings)


Next, the upper fork bridge is mounted and the steering stem head nut (the chrome nut) put on and slightly tightened. Insert the stanchions into the bridges, align in height and clamp the upper fork bridge.

Assemble the vehicle wheel, brake, etc.(see the * below), except for clamping the lower ones
Tighten the steering stem head nut(65 Nm).

Rotate the fork from stop to stop several times so that the rollers in the bearing are pushed back and now rest against the rims of the inner ring.

Here is how I test for correct tightness (IMO much more accurate than with the spring scale):

Front up so the wheel is off the ground and fork can be pivoted. Turn the fork to a stop (*), then positioned away from the stop to half-turned, then let go of the handlebars, now the fork must drop to the stop. Then turn the fork to the center and from center turn to half set, let go, the fork must stop and must not fall against the stop.

(*) With the wire loom installed completely into the lamp housing this method (as well as the one in the service manual) is inaccurate as the loom exerts force. Also throttle cables and clutch hose need to be out of the way.

Should you need to change the bearing setting, loosen the steering stem head nut and
adjust the adjusting nut in small steps (half the groove width) then tighten the steering stem head nut again with the same torque and check again (check only with
tightened steering stem head nut) the setting should be correct.

Tighten the clamp screws of the lower fork bridge.

Here is how I test for correct tightness (IMO much more accurate than with the spring scale):

Front up so the wheel is off the ground and fork can be pivoted. Turn the fork to a stop (*), then positioned away from the stop to half-turned, then let go of the handlebars, now the fork must drop to the stop. Then turn the fork to the center and from center turn to half set, let go, the fork must stop and must not fall against the stop.

(*) With the wire loom installed completely into the lamp housing this method (as well as the one in the service manual) is inaccurate as the loom exerts force.

Quote from: KiwiCol on June 15, 2020, 18:43:18

I'm finding it hard to understand what you're saying here @Andre.  First part I get, from the stop take the bars half way to centre, they should drop back to the stop.  The next bit I can't understand.  From centre take the bars to the same half way position & they should stay there, not fall against the stop.

How does that work then?  You're saying from the same position in an arc, depending on how it got there, the bars will either stay put or fall against a stop.    That's the bit that's hard to comprehend.

@KiwiCol  understood correctly what I wrote! The part you don't comprehend is the same part I don't comprehend 

It does not sound logical. But that's how it works! I can't explain the physics/mechanics behind this.

I got this info from a guy whose business is precision bearings for steering stems and swing arms. I went by recommendation and faith. Dropped the faith by seeing it myself when I adjusted to his instructions. That's how it worked and still does after 18000 km
(just went into the garage and checked as my bike is currently in a state where I can do that).

I didn't buy his products or service, just used the info he provides to adjust the steering stem when I upgraded from ball bearings to roller bearings. I am not sure if this method works with ball bearings but shouldn't matter as everyone that cares about this has changed to roller bearings anyway.

Sorry, forgot. Besides the loom it is also advisable to get the throttle cables and clutch hose out of the way.