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MikeL
2nd February 2004, 22:41
Here's something to think about:

I did my first Track Time at Pukekohe on Sunday. Had an awesome time, can't wait to go again, but that's another story. Went with a mate (not a KBer but an experienced rider although like me he had never been on the track before). At the bike inspection he was told the chain on his Fireblade was a bit tight so he adjusted it. We did 3 sessions and then during the next break he asked another guy to have a look at his bike and give him some advice about his suspension settings. The guy then exclaimed "Holy Shit" and pointed to the axle nut which was just about to come off. It was literally hanging by a thread. After we had psyched ourselves out speculating on what would have happened if the wheel had come off at various points round the track, we tried to work out why the nut was loose. I had sat on the bike for him while he did the adjustment so didn't see what he was doing and can't say whether he tightened the nut properly. He says he can't remember doing it up but if he had it would have been tight, so the most likely explanation is that he got distracted and simply forgot to tighten it. He was understandably quite shaken up by the whole incident.
Now here's the most important question: was it chance, coincidence, fate or something else that prevented a disaster??
Answers from CK and Zed will be particularly appreciated! :whistle:

curious george
2nd February 2004, 22:59
Dunno. Just damn lucky it was caught before it broke :eek5: :eek5: :eek5:
The wheel nut gods must be upset.

Jackrat
2nd February 2004, 23:01
Hmmmmm,Me thinks he would of worked it out when he was left with a split pin to put somewhere.He did have a split pin yeah??? :whistle:
Sorry Mike couldn't help that.
But anyway what stopped it coming off?? :sweatdrop ,Don't belive in fate,Maybe he was being watched over,Maybe it was luck.
What ever, it's sure something to think about.
I hope the next thing he bought was a split pin :yes:

Antallica
3rd February 2004, 06:40
Wasn't his time to go.... man that would scare the shit out of anyone. :thud:

Motu
3rd February 2004, 07:34
This sort of thing happens a lot in the repair game - makes us look like a bunch of dickheads and can be bloody dangerous too! Alloy wheels coming loose is the latest thing going wrong.

Of course we have to blame the guy who tightened the nut - they always say ''but I did tighten it!'' yeah right.But it's happened to me too,and I know I tightened the thing correctly,sometimes having to pay a towage and out of town repair bill.

What's happening here? it never used to happen on the old British and Australian cars we worked on years ago...are we getting old and doddery? For me I think Japanese fasteners can't take too many stress reversals,or when tightened to a possibly incorrect torque they will loose tension and come loose,it just happens too many times to be poor workmanship.A bit of crap under bolt head or on the threads - with the alloy wheels,we no longer just slam them up tight as we can get them with a hammer gun,we use a torque limiter or a torque wrench,but with the lower,but correct torque,the wheel doesn't seat correctly and loosens up after a few days - like,if we forgot to tighten the wheels they would be loose when it left the shop,not a week later.

But for your axle bolt we have to allow for heat of the moment - a nervous rider on a track day is not very focused,I'd say he may have missed that one.And as Jackrat pointed out....the split pin? if the pin was in it wouldn't come loose,no matter what.

GPz
3rd February 2004, 07:50
It would be a timely reminder when any work/adjustments are made on your bike.
Even if it has been serviced by a reputable Dealer.
They can miss things like not tightening up the pinch bolt on the front axle and routing one of the spark leads between the frame and the tank. I found both faults after i had riden from Tauranga to Wanganui on boxing day, a couple of years ago. the loose axle wasn't noticable but the miss in the engine was what made me check the bike over.
Second note, don't get your bike serviced the day before you take it on holiday.

wkid_one
3rd February 2004, 08:01
Don't know of many sports bikes running cotter pins on the main axle bolts.

Can drill them yourselves.

I would hasten to at that at the track - he would have been unlikely to have a torgue wrench with him either?

My best guess is that he didn't tighten it up at all. As with heat and friction - metal expands - so if anything - even done up partially tight - after three sesssions - it would have been unlikely to become as loose as that.

bluninja
3rd February 2004, 09:08
Don't know of many sports bikes running cotter pins on the main axle bolts.

Can drill them yourselves.

I would hasten to at that at the track - he would have been unlikely to have a torgue wrench with him either?

My best guess is that he didn't tighten it up at all. As with heat and friction - metal expands - so if anything - even done up partially tight - after three sesssions - it would have been unlikely to become as loose as that.
LMAO at WKID....if what you say is true, then all this lockwiring of racebikes is a waste of time...V-twins especially don't vibrate things loose till they fall off.

Nuts can work loose over time....people should probably check key items on their bike each week to make sure they haven't loosened and do a pre-ride check so they don't ride off with flat tyres, loose/tight chain, no brakes, or bits just about to come off.

And as to what Motu said....I've always been told to re-check wheels nuts for tightness after you've driven the vehicle following your wheel being taken off. Like most people I often forget.

TTFN

merv
3rd February 2004, 12:11
Now I haven't sulked round the pits lately or been to a track day but I was of the understanding that the days of scrutineering were over at MNZ events - liability issue being that if their scrutineer said the bike is OK then he is liable if something goes wrong and he can be shown to have missed it.

Now is that the case? If so why are they still scrutineering at track days?

How tight was the chain that it needed adjusting i.e. loosening off? Was the guy being a bit pedantic to ask for that?

Now he is bloody lucky if he did three sessions, because you'd think with a loose nut the axle would have already moved forward under power on the chain side and the wheel could have jammed in the swing arm tossing him off. Fireblades must have pretty good chain adjusters if it didn't allow the wheel to move in the swingarm with such a loose axle nut.

merv
3rd February 2004, 12:13
It would be a timely reminder when any work/adjustments are made on your bike.
Even if it has been serviced by a reputable Dealer.
They can miss things like not tightening up the pinch bolt on the front axle and routing one of the spark leads between the frame and the tank

That's why I do all my own work if I can to be sure of things. My screw up, my problem.

bluninja
3rd February 2004, 12:22
Now I haven't sulked round the pits lately or been to a track day but I was of the understanding that the days of scrutineering were over at MNZ events - liability issue being that if their scrutineer said the bike is OK then he is liable if something goes wrong and he can be shown to have missed it.

Now is that the case? If so why are they still scrutineering at track days?


There is still scrutineering at MNZ race meets. The Pacific MCC over the winter just let you sign your Lie Sheet, but they are now scrutineering at the summer series at Taupo. Normally if you are asked to fix or adjust something, you have to go back to have the item rechecked once you've down it.

Jackrat
3rd February 2004, 12:22
Well I went into the city this morning to buy some bits for my little black consumer of oil seals,While I was there I checked out the rear of about fifty new and near new bikes.So I guess I owe Mike a big (SORRY MATE)
At lest 75% of the bikes I looked at did not have castle nuts on the rear.
They instead had a nylock type nut.
I think next time I will stick to the subject a bit closer :Oops:

wkid_one
3rd February 2004, 13:51
LMAO at WKID....if what you say is true, then all this lockwiring of racebikes is a waste of time...V-twins especially don't vibrate things loose till they fall off.

Nuts can work loose over time....people should probably check key items on their bike each week to make sure they haven't loosened and do a pre-ride check so they don't ride off with flat tyres, loose/tight chain, no brakes, or bits just about to come off.

And as to what Motu said....I've always been told to re-check wheels nuts for tightness after you've driven the vehicle following your wheel being taken off. Like most people I often forget.

TTFN
But - I was referring to the fact that there is no way it should be that loose after only 3 sessions at Puke.....without it having BEEN LOOSE in the first place. Read my wording.....

I know first hand as to the dislodging ability of the twin.......

Motoracer
3rd February 2004, 14:08
This is like the time a couple of weeks back when my front sproket nut came off. I just don't feel safe anymore without a lock pin or some kind of a fail safe mechanism backing up a vital nut or a bolt on a bike.

wkid_one
3rd February 2004, 14:15
This is like the time a couple of weeks back when my front sproket nut came off. I just don't feel safe anymore without a lock pin or some kind of a fail safe mechanism backing up a vital nut or a bolt on a bike.
Christ......that would have been entertaining

Motu
3rd February 2004, 14:20
I once nearly lost it big time on the firt tight bend at Puke - the scrutineer told me to adjust my front brake as it was coming too far into the grip...but it was adjusted for my small hands,not his big ones.First corner I grabbed a handful of brake and locked the front up.Deadjusted it on the backstraight.Don't let someone else tell you how to set up your own bike.

Motoracer
3rd February 2004, 14:27
Christ......that would have been entertaining

Not quite *Phew*. The nut came off and the sproket jumped off the drive shaft. Luckly it hung on to the end of it thoe so my new chain and sproket set were intact for long enough for me to realise what happend and come to a stop.

I was so lucky that this happend on the motorway as well and not going around a corner cause when the nut came off, the seal came off too. Which meant that the all the gear box oil pissed on my rear tire.

marty
3rd February 2004, 14:36
after having a couple of (major) offs at BMX due to stuff breaking or not being tight enough, i now do a quick check of all the obvious bits before i ride. it takes 10 seconds, and could save my life. another thing that i do, if i'm riding somewhere and notice a problem, if i don't have time to fix it before i ride next, i'll put a post-it note on the dash to remind me before i tuck off into the distance again. this is a good one if you change onto the reserve tank on the way home, then forget you did so next time you ride......

one time at bmx i took my son's bike, turned it upside down to park it, and noticed the whole headset was about to break off - probably next time it was jumped! needless to say i always check that area now. i always check wheel alighnment, brakes, and that the front wheel nuts have got thread out past the nut. i use pink nail polish to paint a line across the nut/axle combo. i have white (twink) on both wheels of the aprilia - on the right side, so i can see it when it's on the stand.

as i had a fun time at the right left right corners at kaipaki church (near mystery creek) with oil dumping from an overfilled gearbox onto the back tyre, i ALWAYS check the tyre for shinyness - i never clean the tyre (i do the rim though) so that stands out if it has oil on it.

an easy quick test is to sit on the bike with the front brake on, and rock the bike front and back - if there's any loose front bits you should feel them - esp. brakes/bearings/headset.

that's the obvious stuff from me.... :)

SPman
3rd February 2004, 17:06
Just checked my bike .....my bike has a split pin on the rear axle. And its NOT THERE!!!!
Hmm - was there before it went for a service 3 weeks ago!

merv
3rd February 2004, 18:11
Well I went into the city this morning to buy some bits for my little black consumer of oil seals,While I was there I checked out the rear of about fifty new and near new bikes.So I guess I owe Mike a big (SORRY MATE)
At lest 75% of the bikes I looked at did not have castle nuts on the rear.
They instead had a nylock type nut.

Yep even the dirt bikes just have nylocks now too and that's since I bought my first XR Honda in 1983. The old XL's had split pins and castle nuts before that.

Zed
3rd February 2004, 22:44
Here's something to think about_:
Now here's the most important question: was it chance, coincidence, fate or something else that prevented a disaster??
Answers from CK and Zed will be particularly appreciated! :whistle:
Hi Mike,

Personally I think that everything happens for a reason...and every mistake we make should be a learning experience too!

Wow, it sounds like your mate had a real close encounter there, because of negligence maybe, but what a change in attitide it will make for the next time you get on the track and all other such instances. I'm sure you guys will never forget it. :shifty:


Zed

MikeL
4th February 2004, 07:22
Hi Mike,

[color=darkgreen][b]Personally I think that everything happens for a reason...

Zed
Thirty years ago I would have rejected that assertion as unprovable and unscientific. I still think it's unprovable and unscientific, but I no longer reject it.
Where we would differ is on explaining the precise nature of that reason...
The devil's in the detail!
Mike

onearmedbandit
4th February 2004, 09:38
Ha, I think it was Motu who said that this never used to happen on American/British vehicles, and is possibly a result of the Japanese fasteners. Try remembering a bit stronger there Motu, I've seen and heard of many of American/British crap falling off or breaking. However, the Japanese are fantastic at taking an idea and perfecting it.

I myself would any day of the week hop on a Japanese superbike and feel safe rather than anything the brits or yanks made.

Motu
4th February 2004, 10:57
Bits falling off British bikes was mainly from vibration,most modern bikes don't do that anymore,although high frequency secondaries are still with us.They were also old and nuts and bolts mangled by ignorant owners - we don't have ignorant owners these days do we?

A lot of fasteners on modern vehicles are what we call torque to yield,this means they are actualy tightened until they stretch...and they stay stretched and need to be replaced every time they are removed.If we want want to get anal about this then every fastener should be replaced if removed.

A typical result of this happened this very minute - a broken wheel stud.The wheel is removed many times in the life of a vehicle,slammed on with a hammer gun till she's dead tight,over time the stud become longer,the thread pitch is now different to the thread in the nut....with the speed of the air gun the stud and nut weld together - and shear off.Happens often,and of course we are the bad guys because we broke it.But this is only a recent problem,we have been doing it this way for years with no problems,a few years ago I did maintenence on a 1938 Chev that was a daily runner - 60yrs of ham fisted mechanics removing wheels,but still on the original wheel studs.No,the computer has computed the stresses for a 7 year life span,and that's the life of the component,rule of various sized thumbs no longer applies.

Not to say the Poms or Yanks didn't make crap,just a different sort of crap that comes from Asia.

Coldkiwi
5th February 2004, 06:34
I agree Mike.. its not proveable or scientific... but by cripes, the empirical evidence in my life points to it!

Wkid... all of my bikes have had rear split pins. I'd be freaked adjusting the chain for that very reason because I don't own a torque wrench (nor does my useless owners manual give me a torque to use anyway) so I basically hang on it and then put the pin in.

Sp man raises a shocker too... mechanics seem averse to putting split pins back in! I've had to ask two different shops to replace them when I've gone to pick up the bike from tyre/sprocket changes. Always worth a check and besides, the one they pull out is inevitably rooted so they'll give you a new one :)