rear wheel came off

Mick, you need to enter the 21st century.

...and 110 Nm is 81 foot-pounds.

21st century pppffffffffffffttttttttttttt. We ride Moto Guzzi's

I am well and truly ensconced in the current century.
But since working on French built aircraft I have found the rubbish SI measurements to be anything but confusing. So much so that the figures are often converted back to imperial to check we are in the correct ball park. Often in manuals we will have Decca Nm and Nm on same page. Pascals Kilopascals Bar and Mega Pascals in the same system descriptions.
Give me psi and foot pound any day.
A 1 foot long spanner with a weight of 30 pounds in the direction of rotation = 30 ft pounds torque , this is an easy concept to illustrate especially when dealing with appentii or trainees.
A Newton is a measurement in acceleration. WTF.

So disenchanted with the French aircraft manuals I now refuse to use even French derived words like fuselage ailerons and I have given up croissants.

I know I sound like a cranky old .... but hey

Having worked on Citroens, I share your frustration with the French predilection toward confusion with units of measure, on the same page, especially torque or pressure. Merde!

Wish you well Keener on an amicable resolution.

Hey, what are you pecker heads blabling about!!
I know one Pascal that's cool...

wardest wrote:

So disenchanted with the French aircraft manuals I now refuse to use even French derived words like fuselage ailerons and I have given up croissants.

Grisonut wrote:

I know one Pascal that's cool...

Bwahahaha

Hey Tocino thanks by the way...
I got my cables for Guzzidiag from Amazon today.
Amazon Prime is the shit, yo!!

Now load up GuzziDiag on you laptop, connect the cables and watch the TPS numbers change as you twist the throttle. Garage-time fun for hours! (OK, the real fun is the first time you try out one of Mark's maps)

For even more geek-hilarity get the bluetooth ODBC adapter and the Android app "ScanM5x" for your phone (provided you have an Android phone...)

I'll probably do it this weekend as I don't have time to mess with it now.
I'm not computer savy so I have to take my time and go through the "guzzidiag for dummies" thread. lol

Man that would be scary.
Great that you are all ok.
me thinks I'll check mine even though I use a torque wrench.

So    up date  for those interested ..
Parts are on order , rear caliper , rear brake hose , cable guide , 4 bolts for the rear wheel, speed sensor, rear wheel and disc ..plus other small bits and pieces ...
The wheel suffered a pretty good gouge from the caliper tearing into it and the disc is warped as well.
the hub , carc, etc is fine .

So I talked with the shop as to why the wheel fell off , and their thoughts and procedure etc.
First off they did torque to spec and paint marked the bolts on the hub, this was recorded on the service order when they did the tire change 3500 km ago..they are a great shop and I trust them..

When we did the research on line and by talking with other mechanics this has happened before, not only with Guzzi but with BMW when the bikes use the  four bolt system for fastening the wheel to the hub.. required Torque has changed over time with the BMW system because of failures but I do not believe Guzzi has had any updates as to torque settings.

IMO I  think the bolts them selves may be the culprit , if the steel in them is of dubious quality they may not tighten sufficiently ...bolts are in themselves springs  so when they are torqued they contract/stretch  creating tension against surface .if they are incorrect as to their metallurgy the torque supplied maybe be to little OR even to much ..

The bolts them selves if you check are not graded , there is no 8.8 ..10.9 .. etc..  stamp......so no spec.
mine were not any way ...
When there is no mark as to grade then its a crap shoot as to any specified torque ..

So we will use suggested torque,  safety wire the new bolts and use blue locktight ..
Cant say I blame me for doing so eh..

CHECK YOUR BOLTS ........THIS COULD HAPPEN TO ANYONE ..

Keener

This spring I had a coffee stop, and while there, my eye spotted that one bolt from five on the frontwheel of the just parked car was missing. I told it the owner, and she replyed: there was more vibration in the car this morning.

Maybe is an uneven bolt patern better to keep them on force?

If the steel is suspect (I laughed years ago when a friend complained about counterfeit bolts thinking he was joking - but alas no) then maybe using new bolts every time is insurance? Maybe the cheaper bolts aren't as "springy" the second or third time around? Or am I speaking nonsense?

+1 on safety wire.

Any chance you're not footing the entire bill on this?

I used 12.9 bolts on my hub mod.

ghezzi wrote:

I used 12.9 bolts on my hub mod.

Good idea ,,...where did you source them and are they a zinc dichromate ( yellow) plating.

Bolt & Industrial supplies. They are gloss black in appearance.
I used anti-seize on the threads as I don't want then to rust into the crownwheel, as I have a single axle nut for C/F wheel removal now. Torqued at 110Nm, 33mm wheel nut is 135Nm.

The heads of the 4 bolts are hidden and held captive inside my new alloy hubs, yet I coat them with a thin smear of Lanotec as well. You never see a rusty sheep, do you?

The BMW guys have a different school of thought regarding anti-seize/grease on wheel bolts which I am subscribed to.

Picture by CycleRob
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My R1150R (bought used) wheel bolts were coated generously with anti-seize when I removed the rear wheel for tyre change, two out of four were stretched beyond yield point when measure against new bolts.
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I replaced all of them with new bolts fom BMW and torqued them dry.
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+1 What Phang said.

tocino wrote:

If the steel is suspect (I laughed years ago when a friend complained about counterfeit bolts thinking he was joking - but alas no) then maybe using new bolts every time is insurance? Maybe the cheaper bolts aren't as "springy" the second or third time around? Or am I speaking nonsense?

+1 on safety wire.

Any chance you're not footing the entire bill on this?

I am getting cost on all parts and a break on labour rates , I am satisfied with this arrangement as I believe that the proper torque was done by them initially ..no anti seeze was used they were torqued dry..

Phang ..question for you are the new bolts graded? any marks on the bolt head stamped saying 8.8 etc...
I sell bolts (fasteners) they are always graded ..sae and metric ..
from what I know if a bolt is not graded it means that there is no spec so they can be dubious as to carbon content etc .
seems strange to me that these bolts are not spec ..I would think they should be especially in a high stress situation .
Also I would agree using a lubricant is never a good idea for accurate torque setting , bolts will stretch and eventually fail if over torqued .
That is another feature of graded bolts as they are very consistent as to their metallurgy ..
Graded bolts should not be considered as good, better , or best by grade as well ..all grades have their specific  qualities as to application.

keenerkeen07 wrote:

Phang ..question for you are the new bolts graded? any marks on the bolt head stamped saying 8.8 etc...
I sell bolts (fasteners) they are always graded ..sae and metric ..
from what I know if a bolt is not graded it means that there is no spec so they can be dubious as to carbon content etc .
seems strange to me that these bolts are not spec ..I would think they should be especially in a high stress situation .

I don't remember I see any marking on the BMW wheel bolts, they are probably proprietary parts that BMW doesn't bother to mark them

I am quite surprise to see a mere 30% over-torque will stretch a bolt beyond yield? I had car wheels bolts tighten by ham-fisted mechanic using mighty pneumatic impact wrench, those bolts were torqued to easily 200% of the recommended torque spec but they look fine when I removed them and I reused them for a couples of years without any problem until I sold the car.

Phang wrote:

keenerkeen07 wrote:

Phang ..question for you are the new bolts graded? any marks on the bolt head stamped saying 8.8 etc...
I sell bolts (fasteners) they are always graded ..sae and metric ..
from what I know if a bolt is not graded it means that there is no spec so they can be dubious as to carbon content etc .
seems strange to me that these bolts are not spec ..I would think they should be especially in a high stress situation .

I don't remember I see any marking on the BMW wheel bolts, they are probably proprietary parts that BMW doesn't bother to mark them

I am quite surprise to see a mere 30% over-torque will stretch a bolt beyond yield? I had car wheels bolts tighten by ham-fisted mechanic using mighty pneumatic impact wrench, those bolts were torqued to easily 200% of the recommended torque spec but they look fine when I removed them and I reused them for a couples of years without any problem until I sold the car.

BMW, Guzzi all mfg  out source their fasteners.. So the suppler/vendor is responsible for the grade of the bolts by spec issued by Guzzi in this case ...as to why they are not stamped as to grade is puzzling perhaps Guzzi  
and the vendor have reached and agreement as to a standard that has been guaranteed by the supplier and no mark is required OR they are of a lower quality that does not require a grade marking (not a good thing) but possible.
Personally I would never use a bolt again in a high stress area  that was over torqued , what you cannot see can hurt you.
30 % is a lot for any bolt , huge if its a non graded one because their properties are unknown.
My .02 cents
Keener

Oh dear. I recently took off my rear wheel to change the tyre after a major puncture. The bolts were effing tight and took some undoing. When I replaced them I smeared each in Coppaslip. Tightened them until they felt extremely tight (tighter perhaps than I'd tighten my car wheel bolts to and they never come loose), but probably not as tight as they were before I removed them.

I'll check them tomorrow. But should I take them out and clean off the coppaslip?

Vince C wrote:

I'll check them tomorrow. But should I take them out and clean off the coppaslip?

I would. Use a torque wrench to tighten them. 110Nm. (82 ft-lbs).

beetle wrote:

Vince C wrote:

I'll check them tomorrow. But should I take them out and clean off the coppaslip?

I would. Use a torque wrench to tighten them. 110Nm. (82 ft-lbs).

definitely ...They should be torqued clean and dry to 82 ft lbs..also clean the female threads in the hub aswell
Use brake clean....to help
Further I would inspect the bolts to check to see if they have been stretched by being over torqued ...if so replace them.