Head bearing torque/front end vibes

3623 Views 14 Replies 5 Participants Last post by Sebastian1000, Aug 3, 2016

barwell1992

Discussion Starter · Jul 28, 2016

Hi all,

i have a 2005 zx10r with 10,000 miles on the clock.

I have just replaced the stock head bearings with some taper roller bearings as the original ones were damaged.

Can anyone recommend a torque setting for these, i currently have them at 30nm but seem to still get short sharp vibes on the front end when travelling over small bumps at lower speeds.

Steering is smooth to turn and requires minimal effort, no obvious play is evident when the fronts lifted. i am heavy at around 115kg, i have 4 lines showing on the pre-load adjusters 7 click's out on compression with around 35mm sag(inc rider). and 33psi on the front tyre.

suspension is smooth when in motion, maybe a little stiction at the top of the travel.

the front brakes do drag a little meaning the wheel isn't that free to spin.

Does anyone have any recommendations?

Thanks
Dan

Reactions: 1

1 - 15 of 15 Posts

SkyDork

· #2 · Jul 28, 2016

There is no torque settings and no way to easily measure it if there was a setting. The bearings are considered properly tightened when there is no free play in the steering and no binding from side to side. If you're getting clunking over bumps, then you can try tightening them a bit more. Go in small increments. 1/8th turn at a time.

Reactions: 1

White Fang

· #3 · Jul 29, 2016

SkyDork said:
There is no torque settings and no way to easily measure it if there was a setting. The bearings are considered properly tightened when there is no free play in the steering and no binding from side to side. If you're getting clunking over bumps, then you can try tightening them a bit more. Go in small increments. 1/8th turn at a time.

Maybe even less than 1/8 with tapered rollers as they tend to tighten quickly and give less than ball bearings. Otherwise as the man said. The bearings will settle in the races and need to be adjusted after installation so this is not unusual.

Reactions: 1

barwell1992

Discussion Starter · #4 · Jul 29, 2016

Ok thanks both, I'll give it ago.

barwell1992

Discussion Starter · #5 · Jul 29, 2016

So after getting the bike in the air again, i'd say it was actually too tight previously :-/ i will test ride and post back.

Reactions: 1

LDH

· #6 · Jul 29, 2016

You should tighten them just enough so that with the front of the bike supported and the front wheel off the ground the handlebars have just a little friction on them when you push them from lock to lock. You do not want the handlebars so stiff they do not move on their own, but you do not want them flopping back and forth freely either.

Additionally you have to account for the force being applied when you tighten the stem nut too. Theoretically the stem nut does not affect the double collar locking nuts below the top triple clamp, but anyone that has ever installed a top clamp will tell you that is bullshit and there is some guesswork involved in getting just the right amount of tightness to it so that the end work is just right...

Reactions: 1

Sebastian1000

· #7 · Jul 29, 2016

Good food for thought. I have recently done the frame swap and had some guesswork for this same scenario...as I also replaced/upgraded the oem ball bearings with All-Balls tapered roller bearings. I referred to 14-1 in the bible and 2-35

22-1039 All Balls Racing Just curious what bearings you are running?

I initially was thinking I might have went too tight...but I am not observing any oddness of the front end. No binding, notchiness, clunking of any kind...no movement in the stem when front is off the ground. Moves freely from side to side but does not fall or flop. I suppose I should look forward to keeping an eye on this but so far so good. I would be curious to hear more on possible symptoms and indications as they relate to the stem by you guys with more experience. Good stuff

See less See more

barwell1992

Discussion Starter · #8 · Jul 29, 2016

well I've followed the workshop guide and ended up at around 15nm no play apparent with the front off the floor, the bars now move with a small push but don't flop unless pushed.

ill test ride and report back.

I'm thinking its either something lose on the bike causing the vibes or the forks need a rebuild (again i cant feel play in these)

and how are you all torquing the lower triple bolts ? i struggle to get a torque wrench in, so there currently done by hand, they are close to 30nm just not exact, but i don't think its this as the vibe was there prior to me doing the head bearings.

So far the bits I've checked for this vibe are..

Mid and lower Fairings - nothing lose
Exhaust headers - broken spring (Arrow full system new spring on order)
Tank - all ok
airbox - all ok
Rear wheel - was out of align, bearings all ok
Front wheel - all ok
suspension settings - all ok
rear all ancillary bits - all ok

so i'm running out of ideas if its not the head bearings.

could it be the front intake tube ?

See less See more

barwell1992

Discussion Starter · #9 · Jul 31, 2016

So did 50miles yesterday and I've still got this vibe, ended up stripping the whole front end down, cleaning the calipers, checking each fork leg for run out and play, checking all fairing bolts, checking the intake, inspected the head bearings again, re-torqued them (anywhere between 10 and 20nm seems fine, the closer to 10nm and you get more head shake) checked all ancillaries and found absolutely nothing wrong. Check frame for cracks under magnification. Still nothing.

The only thing I think it could be is the top out Spring(s) in the forks or stiction, I might rebuild the forks and go from there. Or the other thing it could be is the front tyre.

Any suggestions ?

Sebastian1000

· #10 · Jul 31, 2016

A vibe.

What does the tire look like? Is it oddly wearing? Cupped? Out of balance? Pressure? This vibe is exacerbated by speed and always present or absent and then presents when a speed is reached? To be clear this is an oscillation type vibe? You said you cleaned the calipers...what did the pads look like? And the rotors? Pad and rotor wear uniform? Forks at uniform height in trees? Forks adjustments uniform from one to the other? I would not think stiction/springs would cause such a vibe. I would think that something rotating was out of whack. Something warped , unevenly worn, not balanced, etc...

Just throwing some stuff out there. I don't claim to have great experience with this type of stuff...hopefully someone who has had and remedied this type of issue can chime in.

See less See more

barwell1992

Discussion Starter · #11 · Jul 31, 2016

Should there be nuts on these ??

Lower right of attached pic, neither left or right has nuts on seems a little odd not to.

See less See more

barwell1992

Discussion Starter · #12 · Jul 31, 2016

^ next to the white block conector

barwell1992

Discussion Starter · #13 · Jul 31, 2016

Sebastian1000 said:
A vibe.

What does the tire look like? Is it oddly wearing? Cupped? Out of balance? Pressure? This vibe is exacerbated by speed and always present or absent and then presents when a speed is reached? To be clear this is an oscillation type vibe? You said you cleaned the calipers...what did the pads look like? And the rotors? Pad and rotor wear uniform? Forks at uniform height in trees? Forks adjustments uniform from one to the other? I would not think stiction/springs would cause such a vibe. I would think that something rotating was out of whack. Something warped , unevenly worn, not balanced, etc...

Just throwing some stuff out there. I don't claim to have great experience with this type of stuff...hopefully someone who has had and remedied this type of issue can chime in.

Tyre looks ok, had a few bobbles the other day from some sprinted riding, i removed those and felt very little difference.

tyre is wearing evenly, pressures are good, and it doesn't feel out of balance.

speed has no affect, its there from 0-70mph after that its hard to tell.

pads and rotors are good, brakes seem to bind less now, wheel spin's three or four times without stopping, previously it was half a turn (spins and spins and spins with no calipers on so bearing's are good, with no side to side play)

forks are the correct height and uniform.

forks have been adjusted and set correctly.

Its not an oscillation type of vibe, only happens when going over undulations in the road or cracks, id almost say its on the rebound stroke that it vibes.

Just a bit about my background, i used to work for ohlins, and trained as a race mechanic, i currently work as a development engineer designing parts for F1 amongst other things , and this still has me completely baffled lol

I've just rebuild the front of the bike from bare frame up, i did find a few lose body panels and possibly some missing nuts (see above) but nothing out of the ordinary, lets hope it was something silly and its been sorted by the rebuild.

Thanks

See less See more

barwell1992

Discussion Starter · #14 · Aug 2, 2016

Think I've sorted it, the top nut appears to be coming lose, replacement has been ordered.

Sebastian1000

· #15 · Aug 3, 2016

barwell1992 said:
Think I've sorted it, the top nut appears to be coming lose, replacement has been ordered.

Good to hear. I was hoping more would chime in...o well. Happy riding

1 - 15 of 15 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.