Head stock bearing pre load

[Drumnagorrach]

I changed my headstock bearings a good while ago and haven't ridden the old Funduro most of the summer . When I got back on it a few weeks ago I found it a bit unnerving as it fell into corners ,compared with the Yam SR 500 . Tyre pressures were a bit low so I took both back and front up to 2.5 bar and it did improve a bit ,so I then put a bit of pre load onto the headstock bearings . Not enough to stop the forks falling to one side if the bike is tilted slightly ( as once described to me by a BMW tech for setting old R 100s without a friction gauge ). Seems a lot better but wondered if a BMW workshop manual gives a figure for pre load . As I remember it the figure for the R series was in kilo poids .

[kuyajonathan]

Recall subject of discussion here few yrs ago, Should be details in FAQ's

[stevedixey]

Pre-load tends to be used for taper roller bearings as the wider rollers are prone to skidding if not preloaded properly. All that is required is that there is no fore \ aft movement of the parts when assembled. Remember forks can wear so giving a "false" reading of movement. My start point is that the built up assembly should turn once eased over centre (no cables etc to handlebars as these cause drag). The adjustment can be got at fairly easily without dismantling and I just go by trial and error then until I get the feel I want. Also, use decent bearings by FAG or SKF or the other big names. If you dig around in my past posts I did a fair bit of digging on this topic a few years ago now as bearings is one of my specialist areas in engineering maintenance.

[kr4mo]

Recall subject of discussion here few yrs ago, Should be details in FAQ's

The shop manual I have says to tighten the adjuster nut to 25NM then slacken the nut 60 degrees.