Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[jotjotde]

Hi guys,

As indicated in some of my posts, I am considering substituting some of the original fixings for something better protected against corrosion.

Looking at my bike's rear, the nuts fixing the sprocket to the wheel are an obvious point. Those are 5 flanged nuts size M10 with a 1.25 thread (NOT! 1.5).

Anyone here knowing, what tightening torque Energica recommends for these? The manual isn't helping here.

Tables in European standards tell me up to 57 Nm.

[smithy]

Hi guys,

As indicated in some of my posts, I am considering substituting some of the original fixings for something better protected against corrosion.

Looking at my bike's rear, the nuts fixing the sprocket to the wheel are an obvious point. Those are 5 flanged nuts size M10 with a 1.25 thread (NOT! 1.5).

Anyone here knowing, what tightening torque Energica recommends for these? The manual isn't helping here.

Tables in European standards tell me up to 57 Nm.

57nm would be a pretty safe torque for the M10 nuts on the rear spocket....our aviation engineering manual specifies 64nm for 9.8 graded M10 bolts/nuts.

Smithy

[Pard]

40 Nm

From Energica when I asked the same question.

[jotjotde]

Great! Thanks a lot for that info, guys !

I will use 50 Nm and apply some mid-strength Loctite for safety.

[Pard]

When I am unsure of a factory torque spec and cannot get the recommended value confirmed, it is sometimes helpful to use your torque wrench and creep up on a suspected value by testing already fastened bolts. 

Start at 30Nm, and test the existing torque on the sprocket factory assembled nuts and see what you get.

[jotjotde]

Too late, Pard  I already finished. But thanks anyway!

[Pard]

Beautiful work!  Love the colors.  Looks clean enough to eat off!

[Specter]

That reminds me, I need to tighten my chain again,  but it's 98 degrees out....   guess Ill do some night work

I like the idea of creeping up on an existing nut, but over time, won't torgue values kind of tighten up?  Like the lugs on your tires, when you go to change that tire you are like, I know damned well I did NOT put these $$#$#s on this tight!!

Aaron

[jotjotde]

@Pard:
Thx for the praise  I abhor greasy chains, that's why I switched to a Regina HPE chain and dry lube.

@Aaron:
I know what you mean and I think I found the reason for what you call torque tightening - it's corrosion. Moisture plus deicing salt plus whatever is on the street seeps between the surfaces of nut/bolts/threads, doing it's nasty work there.
In engineer school they tell you that nuts/bolts/threads are never to be greased bc that would decrease the friction and consequently weaken the screw connection.

Solution (at least for me) is the use of thread sealant fluid e.g. Loctite 542 or Petec 97215. Alternatively, low-strength thread lock would do the trick. You only need a drop or two. I bought a small 15 gram flask approx. 10 years ago and it's still not empty - I use it on my cars and bicycles and I am happy with it.

[Specter]

See THAT is the problem with Engineers.
Never grease nuts / bolts / threads.  I bet none of those propeller heads ever had to take one off that's been in the field for 4 years!

It weakens the bond, well one could also argue that the extra slipperiness, makes you actually twist it more to achieve your torque so you have compensated for the change the lube will make to the overall strength of that bond.

If something is not going to be taken apart again, ok don't lube but if you need to tear it apart, replace parts etc sometime down the road, do yourself a favor and use a bit of anti seize or something.

personally I don't think ANY engineer should ever be allowed to get a degree, without actually putting together and making it actually WORK... the contraption they designed that looks great on paper   and NO they do NOT get to bug the field tech for hints and pointers either !!   

Aaron