Torque for Pivot bolt on a Morewood Shova?

[Skylark]

Does anyone know what the torque is on the pivot bolt in the single pivot on a Morewood Shova?

 

It's an 8mm bolt into the aluminum Spi2 pivot shaft, being aluminium its wise not to thumbsuck the torque. Having recently also started using torque wrenches I can see the wisdom and peace of mind gained when using the correct torque on fasteners.

 

Even a ballpark torque would be acceptable, keeping in mind the bolt tightens into what is essentially an aluminium nut so I'm assuming the standard 25Nm torque spec'd for an M8 8.8 hi ten bolt will be excessive.

Edited November 18, 2018 by Skylark

[BaGearA]

Lock tight and 8nM should be good until you can confirm

[Skylark]

Bump anyone know the actual torque specs for the Shova swingarm pivot bolt?

[dave303e]

tighten till it strips then back it off 1/4 turn?

 

What is the pitch of the thread?

Is it a bolt or a cap head or a torx?

 

Personally I would also tend towards less torque with a tiny dot of Loctite 222

 

quite helpful -

http://www.futek.com/boltcalc.aspx?mode=metric

[Skylark]

tighten till it strips then back it off 1/4 turn?

 

What is the pitch of the thread?

Is it a bolt or a cap head or a torx?

 

Personally I would also tend towards less torque with a tiny dot of Loctite 222

 

quite helpful -

http://www.futek.com/boltcalc.aspx?mode=metric

Thanks, that's an awesome link, it also factors in the fastener material.

[rudi-h]

Does anyone know what the torque is on the pivot bolt in the single pivot on a Morewood Shova?

 

It's an 8mm bolt into the aluminum Spi2 pivot shaft, being aluminium its wise not to thumbsuck the torque. Having recently also started using torque wrenches I can see the wisdom and peace of mind gained when using the correct torque on fasteners.

 

Even a ballpark torque would be acceptable, keeping in mind the bolt tightens into what is essentially an aluminium nut so I'm assuming the standard 25Nm torque spec'd for an M8 8.8 hi ten bolt will be excessive.

 

i don't know what it should be, but you CANNOT use the torque spec for a 8.8 high tensile bolt!

 

A Grade 8.8 bolt gets its designation from it being 800 MPa steel with a yield strength of 80% of that, so it's a 640MPa yield strength alloy steel bolt...  Gr 10.9 would mean 1000 MPa steel with 90% yield strength, i.e. 900 MPa yield strength etc.

 

6061 tempered Aluminium has a yield strength of around 240 MPa (this is my guess of the bolt alloy), so i'd say you should work on max 1/3 of the torque from your M8 (Gr 8.8) torque table.  If you use a thread lubricant, you can typically deduct another 20%, so i'd say start at 5 or 6 Nm with a tiny bit of grease to be safe (at least from the perspective of damaging the bolt).  If it comes loose, then you might have to tighten a little more, but max should be no more than 8 Nm.

Edited November 20, 2018 by rudi-h

[Skylark]

Thanks Rudi, that's some good info

[duanelr]

Don't know the exact torque. But I had the exact same bike and used to take that pivot bolt and sleeve out plenty to service and re-grease etc. When putting it back I would put teflon grease on the bolt and threads, and hand tighten to as far as what is comfortable using only your hand using the allen key size that fits that screw. (cant remember the size)

 

Now this is as far as can come from an exact science, but the point is tighten as much as you can without using another tool or lever arm or without getting all white knuckled and putting all your weight on it and working up a sweat ... (you guys know what i mean by now, sorry i'm actually afrikaans ) If it is like an 18mm allen key you would expect to be able to tighten it more than when it is a 4mm allen key that you are using. 

 

I had my bike for like 6 years and that pivot never came loose, bent, cracked or anything. I weighed 85kg back then and did hakahana enduros so was pretty tough on the bike - no issues. 

 

Hope this makes sense.