F650GS SH bearings

[philandktb]

Anyone help? We are in Townsville QLD Oz. Kates steering head bearings
have had it after 13k. Going in for repair tomorrow but by non BMW techs.
Remember from Haynes WS manual there is a special adjustment procedure
after replacement of the bearings. Can anyone tell me what that procedure is. I know
that incorrect adjustment can destroy the new bearings in next to no time.

 

[Timolgra]

Tighten the round nut to 25Nm then back it off 60 degrees

EDIT: just found this which may be of use.
http://faq.f650.com/GSFAQs/GSSteeringHeadBearingReplacementFAQ.htm

 

[philandktb]

Thanks Timo Sounds good, must get the pressure right. What about the big circular disc
with the serated edge? Is that the main adjuster or something else to puzzle
us mortals?

 

[Timolgra]

Thanks Timo Sounds good, must get the pressure right. What about the big circular disc
with the serated edge? Is that the main adjuster or something else to puzzle
us mortals?

Hi, read the link I sent. It suggests 3 ways of achieving the correct 'tightness'

The BMW shop manual provides torque values for the adjusting ring. However, unless you have the special BMW socket, you cannot torque the ring. It seems there is a general goal in mind: the bearings should be just tight enough to allow the handlebar to move left or right under it's own weight, but not TOO loose. Below are three descriptions to help you achieve this goal. The first method is from the BMW manual, while the second two methods are methods that do not require the special BMW socket. Note that correct torque values cannot be achieved without the socket.

Adjusting the Steering Head Bearings (From BMW Manual)

Slacken round adjusting nut with pin-wrench adapter, BMWNo. 31 6 521, then tighten to 25 Nm.
Turn forks back and forth twice from lock to lock, and leave the forks at the full left lock position.
Mark a 40 mm (1.58 in) arc with adhesive tape or similar (arrow) around the circumference of the locking plate at the steering head.
Align the mark on pin-wrench adapter, BMWNo. 31 6 521, with the right-hand end of the marked arc.
Note: 40 mm (1.58 in) around the circumference of the locking plate corresponds to an angle of rotation of 60°.
Turn the round nut clockwise until the pointer on pin-wrench adapter, BMW No. 31 6 521, reaches the left-hand end of the marked arc.
Remove the mark/adhesive tape from the locking plate.
Check the mating faces of the fork bridge and knurled nut, rub down with an oilstone if necessary and clean.
Tighten the counter-tube.
Install fork bridge.
Firmly tighten locknut.
Tighten the clamping screws of the fork bridge.
Check play and freedom of movement.
Lift front wheel clear of the ground and perform final check:
With the front wheel off the ground, the weight of the forks must be enough to turn the steering all the way to the left and right full lock positions as soon as the handlebar is moved away from the straight-ahead position.
If local points of stiffness are detected when the handlebar is moved to and fro, renew the steering head bearings.
Adjusting the Steering Head Bearings (By Flash, #412)

Tightening Steering Head Bearings - 101
Tighten the lower nut until it is pretty tight. Move the forks back and forth, lock to lock a few times. They SHOULD feel too tight. These are tapered roller bearings and need to be preloaded a little bit. But not THAT much. Back off about a sixth of a turn. Do the forks flop by their own weight (wheel installed, tire not in contact with the ground) when you knock them just a little off center? If so, that is TOO LOOSE. Tighten it up just a skosh. When you give it a good TAP, it should turn to the lock and then bounce slightly. It might do one side better than the other due to cable tension. When the triple clamp and handlebars are installed, does it STILL behave this way? It might have tightened up when the top clamp nut was tightened. If it is just a LITTLE bit too tight, take it for a ride. It will loosen up slightly with some use and some wear, but not much. If it is certainly too tight, DO NOT RIDE. Pull the clamp off and loosen the nut 1/16 to 1/8 of a turn and try again.
Adjusting the Steering Head Bearings (From by Oyvind #1052)

The manual states that the adjusting ring should be tightened to 25 Nm, and then slackened 60 degrees, or 40mm as measured around the circumference of the ring. This is pretty hard to do w/o the proper BMW tool, though. I guess the idea is to just tighten the adjusting ring up good to make sure the bearings are properly seated, and then slacken until the steering moves freely. It's probably a good idea to reattach the fork and front wheel before adjusting, since the most important criteria is that, with the front wheel off the ground, the weight of the wheel and fork must be able to turn the steering all the way to the left and right full lock position. I tightened the adjusting ring until the steering just couldn't move by itself, and then slackened it just a little more than needed. The latter is important, since the steering will tighten up just a wee bit more when the counter pipe is tightened.

 

[philandktb]

Hey thanks thats brilliant and all I need to know.
Lets hope we get a good job done for our 300 bucks.