Advice Please: Head stock bearing tightening?
 

Hey All,

Looking for some help/info, to see if I've done something wrong? Bike is a K5 Naked

Couple of weeks ago i noticed that the front end was really really loose turning in, at slow speeds the front end was wanting to flop over straight away. Now i don't recall if the issue just appeared one day, or if it gradually got worse....

confirmed that the tyre pressures were right, 32psi and then investigated the steering stem by getting the front end off the ground and discovering there was basically 0 resistance, it was just freely flopping from side to side.

I couldnt make out and play or notchyness, so i put it down to the bearing needing tightened.

This is what i did:

1. Front wheel off the ground
2. loosened the fork clamps on the top yoke and removed the centre stem nut
3. Used a hammer and drift to knock the bottom adjuster nut clockwise till bar movement felt tighter (super accurate, honest!) think it was about half a turn, maybe a bit more?
4. knocked the top adjuster nut clockwise to lock the bottom nut
5. refitted stem top nut
6. lowered front end of bike and compressed forks a couple of times, then torqued the fork clamps.

now, the bike does feel better than it did, but there is still an eagerness to turn in at low speeds which doesn't feel right or nice.

I am wondering if i just need to repeat the process and tighten the bearing more (is there a way to tell when its tight enough)? or have i done something wrong in the process? or have i completely mis-diagnosed this, and i should take it to a garage?

apart from an ABBA+front lift kit, what is the best way of getting the front end up?
i had it on a rear paddock stand and then used my trolley jack under the engine.

Re: Advice Please: Head stock bearing tightening?
 

most likely cause is your front tyre is getting out of round.

if the tyre is wearing on the sides more than the crown then you have more of a triangle shape rather than an arc. when this happens it creates a ridge that has very little contact with the road when tipping in so feels a bit skittery at that point once past the ridge the bike wants to drop in violently due to the sides being flat.

you get the same feeling of tipping in with a crowned tyre but the bike will feel normal past the ridge with no violent dropping in.

the rear tyre can also influence how the front reacts as well.

Re: Advice Please: Head stock bearing tightening?
 

the rear tyre was new in March this year. and if it was the tyre, would that not manifest itself at higher speeds also? once i am above say 15mph, the feeling vanishes.

when i first got the bike with some worn out tyres on, you could definitely feel it when it rolled over the corner of the rear tyre, this isn't like that :s

Re: Advice Please: Head stock bearing tightening?
 

if its only at slow sped then it could actually be your input on the bars. try dragging the rear brake and see how you get on.

Re: Advice Please: Head stock bearing tightening?
 

I would go back and re-check your headstock bearings. If they're too tight they'll make it hard to avoid wobbles at low speed, because the subtlety will have gone from the movement. As long as you don't have any knock in the bearings, they're fine, they are not meant to provide any resistance to turning - quite the opposite!

You don't need the front wheel up to adjust them, just slacken the top bolt and adjust as you've described, checking the feel before you call it finished, then checking it again once it's all tightened up - sometimes tightening the locknut changes the bearing tension. It's a job you want to spend a bit of time on.

Regarding the flopping, is it on both lefts and rights? If it's mainly one side I'd check rear wheel alignment. Ride at 20-30mph, shut off throttle, hands off bars. See if it consistently wanders to one side (try it a few times).

Re: Advice Please: Head stock bearing tightening?
 

cant say I've noticed it being one side more than the other. ill try the hands free tests on the way home, see if there is any rhyme to it

Re: Advice Please: Head stock bearing tightening?
 

Overly squared tyres caused something similar on mine, it tipped in lovely to a point then fell in again like it had fallen off the edge.

I changed tyres(badly needed anyway) which made a massive improvement, then discovered the headstock bearings are knackered and notched

Re: Advice Please: Head stock bearing tightening?
 

It's the bearings. Too tight will cause wobble and weave at low speed. Too loose and you'll get clicking and vague steering. You can also encounter the feeling you're getting if the forks are twisted in the clamps or the spindle is too tight. But my money's on the bearings.

Bearings needs adjustment with the front wheel off the ground. You should also loosen the lower clamp pinch bolts so the forks can turn in the triples while making the adjustment.

Torque settings are high for the lock nut and the top triple clamp.

40Nm tends to be the torque setting for the steering nut, 80Nm for the lock nut, 90Nm for the top yoke.

Feel is important on the steering stem, at least more so with tapered bearings than the stock roller bearings...so are you definitely using roller bearings or have they been changed out for tapered? Tapered require a 0 preload so the steering nut should only just be nipped up from finger tight.

Re: Advice Please: Head stock bearing tightening?
 

Helpful to get a bit of a how to video

https://youtu.be/Vl5RznButY0

Re: Advice Please: Head stock bearing tightening?
 

Checked it over with a spare pair of eyes (cheers Lance!) and everything seems fine on the bearings front.

need to add some oil to my forks, so going to have the front end apart tonight, so will see if its any different when i get it back together again. fingers crossed!