Tightening torque for taper roller head race bearings

[mangocrazy]

What is the general opinion on tightening torque for taper roller bearings? From what I can ascertain, tightening torque is much lower than for ball races, but how much less? Has anyone ever seen specific Nm or lb/ft value given, or is it all just done by 'feel'? The internet is awash with 'experts', but the general view seems to be that you torque the bearing adjuster down to around 25Nm to seat the bearings, then back off to the point that just minimal drag is felt when moving the steering across its arc (some say without forks mounted in the yokes).

Any suggestions?

[Le_Fromage_Grande]

What you've said, then ride it for a 100 miles and do it again, they bed in a little bit. It's easier to feel without the forks in the yokes, but makes no difference to the adjustment, and if you're in any doubt, do them a little tight, if it rides like it's got a steering damper, then they're too tight.

[mangocrazy]

On the VFR it's a real pain to get at the top race to adjust it, due to the way the forks are held (it's complicated...) So would it work if I adjusted them just fractionally tight initially so that they loosened off slightly to the correct torque as they bed in? I realise this is all a bit vague, but then so is most of the advice I've seen.

[Le_Fromage_Grande]

On the VFR it's a real pain to get at the top race to adjust it, due to the way the forks are held (it's complicated...) So would it work if I adjusted them just fractionally tight initially so that they loosened off slightly to the correct torque as they bed in? I realise this is all a bit vague, but then so is most of the advice I've seen.

That's what I do, but that's not the proper way to do it, I adjust them so they're right, no play, moving smoothly with no drag, then give them quarter of a turn to over tighten them, within a 100 miles they'll feel right.

Take it to a bike shop when you've done them and just ask them if they feel right, it takes 5 minutes to tell if they're adjusted correctly.

If your LC has taper races fitted (standard is quarter inch ball bearings) try over tightening them and go for a short ride, you'll feel it straight away, the bike won't want to steer and will follow road imperfections, too loose and will be scary wobbly handling.

The adjustment isn't that sensitive with tapers, with ball bearings the difference between tight, right and loose is about quarter of a turn.

[mangocrazy]

OK, cheers. That sounds like A Plan. As for the LC, I honestly can't recall whether I've ever replaced the head races and, if so, what I fitted. The steering/handling is fine (within obvious LC limitations) so it's not something I've looked at. A job for winter time, perhaps.

[mangocrazy]

That's what I do, but that's not the proper way to do it, I adjust them so they're right, no play, moving smoothly with no drag, then give them quarter of a turn to over tighten them, within a 100 miles they'll feel right.

When I adjust them, they go from smooth and will drop from the centre to either side completely freely, to firm (but still smooth) and needs finger pressure to get them to move even a centimetre, with just a few degrees of tightening. The thread on the spindle is not particularly fine (M20 x 1.5) and a few degrees of turn will make more difference than on a fine thread, but... How tight in terms of resistance to movement by hand would you go?

I've tightened the top nut down as best I can with a drift and hammer (it's a castellated nut, for which I don't have a socket) to seat the bearings but can't help thinking it needs more.

I've only got the bottom yoke in place - no top yoke, nothing attached to the bottom yoke and definitely no forks in place, by the way.

[Skub]

I could feel the head bearings loose through the bars on my Zed,it only took a very few degrees of tightening the C spanner nuts to remove that play.

I know these are a new fitting,so may need adjusting again after use,but I'd tread carefully.

[Skub]

Foggy's mechanic Slick Bass had a thing about head bearings. When he got them tightened the way he wanted,he tightened the top yoke nut just past finger tight and used loctite to keep it in place.

[mangocrazy]

Foggy's mechanic Slick Bass had a thing about head bearings. When he got them tightened the way he wanted,he tightened the top yoke nut just past finger tight and used loctite to keep it in place.

It's definitely one of those things where it's all about 'feel'. Very hard to explain in words.