Frame Headstock bearing seats damaged?

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AMCQ46
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Re: Frame Headstock bearing seats damaged?

Post by AMCQ46 »

Thanks for the frame offer Rob, First step will be to strip it down and check everything again and then I will see is I need a plan B.

having spent an hr looking at frames for the storm and images on ebay, they are fairly fecking solid round the headstock !!!
OK the forks were bent beyond repair ... but they are acting as the fuse to save the other parts of the bike, and then the std yoke is a weak point, so more energy would be absorbed there before the frame took the remainder.... and the front wheel was still OK.

..SO... I am back to believing that it will be hard work to damage that, so there must be something else I am missing.

I will start stripping it all back down and check it bit by bit till I understand this better.
AMcQ
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lloydie
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Re: Frame Headstock bearing seats damaged?

Post by lloydie »

Are you sure the new stem is seated fully home ?
Is your new wheel true ?
Are the forks set too low ?
Have you thought about standard Honda bearing ?
Have you joined me in the faggot club and can’t ride anymore ?
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AMCQ46
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Re: Frame Headstock bearing seats damaged?

Post by AMCQ46 »

Good questions Lloydie


Are you sure the new stem is seated fully home ? - yes but rechecking
Is your new wheel true - yes got the tyre fitter to confirm
Are the forks set too low ? - they are set with the same measurement from bottom of headstock to axle as I was running on storm forks, and the same sag, so should be close
Have you thought about standard Honda bearing ? - I was having the same thoughts last night, as I could run them with lots of preload
Have you joined me in the faggot club and can’t ride anymore ? - must be getting close, but I don't think that would make the bearings loose
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tony.mon
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Re: Frame Headstock bearing seats damaged?

Post by tony.mon »

Check the head bearing, as even a good make can have a duff one, a cracked outer race or similar.
It's not falling off, it's an upgrade opportunity.
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fabiostar
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Re: Frame Headstock bearing seats damaged?

Post by fabiostar »

just a silly one.and this also had me wondering, when i fitted the fairing back on mine with the 7 front end when i jumped up and down on the forks the first noise i heard was the lower yoke touching the lower fairing edge that needed trimmed...

its gotta be something silly ,as you say they are chunky round the headstock, i would have thought the wheel would have let go before the frame ovaled??
the older i get,the faster i was :lol:
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AMCQ46
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Re: Frame Headstock bearing seats damaged?

Post by AMCQ46 »

Ok, so it's all stripped down again, and defiantly no cracks, can't measure yet for ovality as I haven't got hold of an internal micrometer yet and vernier calipers are not accurate enough for this.
Confirmed that the inner race of bottom bearing is full seated in the stem, and the stem hasn't moved, so that is good

BUT

I might have found something that could have caused some parts of the problem..... The top yoke had a new sleeve fitted to bring it down in diameter to match the storm stem, but if I look at the underside of the std yoke there is a large 2mm lead in chamfer to the bore, and this wasn't copied onto my aprillia yoke with the new sleeve. That chamfer allows the yoke to clear the start of the next threaded section and seat down onto the bearing preload castle nuts below.
without the chamfers the top yoke was getting tightened down onto the top of the threaded section and not seating onto the bearing preload nuts, so they are able to slacken off on their own.

Doesn't explain why it was weaving, but it might be why I couldn't get the steering bearings to stop clunking
AMcQ
tony.mon
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Re: Frame Headstock bearing seats damaged?

Post by tony.mon »

The two locking nuts (they are held together by the lock tab between them, so an be considered as one nut) are held secure by the pressure of the top yoke nut brushing the top yoke into contact with them.
So for the two locked nuts to be able to turn that pressure must have disappeared.

Perhaps the bearings have reseated, leaving a gap between locking nuts and yoke, or the top yoke wasn't pulled down onto the lock nuts- this can happen if you tighten the top yoke clamp bolts before the top stem nut- but check that your stem hasn't pulled slightly out of the bottom yoke.

If you can't find the cause, mark the locked nuts to see if they move.

Weaving is usually caused by the locking nuts being slightly too tight. If they can undo, causing the clonk, they can also tighten, causing a weave -but not both at the same time.
If you're getting both together, there's another reason, assuming the two nuts stay locked together.
It's not falling off, it's an upgrade opportunity.
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AMCQ46
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Re: Frame Headstock bearing seats damaged?

Post by AMCQ46 »

tony.mon wrote: Thu Mar 29, 2018 8:39 am The two locking nuts (they are held together by the lock tab between them, so an be considered as one nut) are held secure by the pressure of the top yoke nut brushing the top yoke into contact with them.
So for the two locked nuts to be able to turn that pressure must have disappeared.
that's correct Tony, the set position of the castle nuts had 2 threads showing above them on the stem, so without the big chamfer, the top yoke was not pressing onto the castle nuts, it was wedged onto the larger diameter step on the stem for the castle nut threaded section.

But as you say, that doesn't say why it was weaving, but that could be down to a separate geometry issue.

Next step is to put the front end back in with the top yoke correctly chamfered, set the bearings again and do more test rides to confirm I can get rid of the clunk
AMcQ
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sirch345
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Re: Frame Headstock bearing seats damaged?

Post by sirch345 »

AMCQ46 wrote: Sun Mar 25, 2018 6:25 pm And what is annoying me was that I should have worked it out after the original rebuild with Storm forks before I invested in the sexy new front end.
Clues were there, as after every test ride I needed to adjust the steering head brgs and then in its first big ride for OP storm Scotland, they started OK, but mid way through the friday ride up, the were were already as loose as feck, not just under braking, you could feel it over bumps as well. I stupidly assumed that I had not managed to press the bearings home properly [even though I never had any troubles the last 3 times I have fitted Tapers to a Storm], and rather than try and get them set correctly, I stripped the bike down and started then USD conversion....... GGGGRRRR fuc=kity feck !!!!!
AMCQ46 wrote: Sun Mar 25, 2018 10:21 pm malc, it's defiantly the steering bearings moving as you can easily feel the relative movement if you put your finger between the cover on the top adjuster nut and the frame when you push it back and forwards.
The more I think about this the weirder it gets.
So just to recap, you can easily feel movement if you put your finger between the cover on the top adjuster nut and the frame when you push it back and forwards, but you also say the same symptoms were there with the replacement Storm forks........................... very strange :eh:
AMCQ46 wrote: Wed Mar 28, 2018 10:48 pm Ok, so it's all stripped down again, and defiantly no cracks, can't measure yet for ovality as I haven't got hold of an internal micrometer yet and vernier calipers are not accurate enough for this.
Confirmed that the inner race of bottom bearing is full seated in the stem, and the stem hasn't moved, so that is good

BUT

I might have found something that could have caused some parts of the problem..... The top yoke had a new sleeve fitted to bring it down in diameter to match the storm stem, but if I look at the underside of the std yoke there is a large 2mm lead in chamfer to the bore, and this wasn't copied onto my aprillia yoke with the new sleeve. That chamfer allows the yoke to clear the start of the next threaded section and seat down onto the bearing preload castle nuts below.
without the chamfers the top yoke was getting tightened down onto the top of the threaded section and not seating onto the bearing preload nuts, so they are able to slacken off on their own.

Doesn't explain why it was weaving, but it might be why I couldn't get the steering bearings to stop clunking
Glad to hear you have found one thing that is not right, fingers crossed rectifying that helps,

Chris.
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AMCQ46
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Re: Frame Headstock bearing seats damaged?

Post by AMCQ46 »

the top yoke is now chamfered like the std honda part and the bearings all reseated and tensioned, then front end put back together....

only a very short test ride before the heavens opened, and I was also running with no fairing [to reduce the faffing about if I needed to take it apart again], but the clunk is gone at the moment :D

didn't really get to test the weave too much, as a) i was not wearing bike gear, just my garage scruffs [which are more flappy than leathers so will affect the air flow] and b) there was no fairing c) the roads were a bit damp and with the lack of protective gear I didnt stay above 3 figures for too long.
there might have been something there, but nothing super obvious and no tank slappers.

so I will check the wheel alignment next and then put the bodywork back on and see if I can get some more miles at the weekend.

fingers crossed I was just putting 2 and 2 together and making 5
AMcQ
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Duffy1964
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Re: Frame Headstock bearing seats damaged?

Post by Duffy1964 »

Sounds like you have cracked it Al well done fella


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Yellow 1997 Storm R.I.P. Orange 2000 Streetfighter (Rufus), Red & Silver 1968 Triumph Trophy 650, Blue 2003 Storm Project, Red 2007 Montesa Cota Trials 250 & 1959 BSA D7 175cc Bantam Trials Project
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sirch345
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Re: Frame Headstock bearing seats damaged?

Post by sirch345 »

All sounding good so far Al :thumbup: hopefully that has cured it,

Chris.
tony.mon
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Re: Frame Headstock bearing seats damaged?

Post by tony.mon »

Duffy1964 wrote: Tue Apr 03, 2018 6:15 pm Sounds like you have cracked it Al well done fella Image


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No, it sounds like he HASN'T cracked it!
It's not falling off, it's an upgrade opportunity.
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fabiostar
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Re: Frame Headstock bearing seats damaged?

Post by fabiostar »

looking good at the min then?? :clap:
the older i get,the faster i was :lol:
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AMCQ46
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Re: Frame Headstock bearing seats damaged?

Post by AMCQ46 »

tony.mon wrote: Tue Apr 03, 2018 8:46 pm
Duffy1964 wrote: Tue Apr 03, 2018 6:15 pm Sounds like you have cracked it Al well done fella Image


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No, it sounds like he HASN'T cracked it!
my thought exactly :lol:
AMcQ
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