# grease bolts on new stem?



## jbourne84 (Apr 8, 2010)

I just put a new stem on my bike but i didnt use any grease or anything on the bolts, then i read that the instructions wanted me to put something on the bolts. how important is this? do i need to take it apart and grease them?


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## Berkeley Mike (Jan 13, 2004)

I grease them.


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## gmcttr (Oct 7, 2006)

Yes, take it apart and grease them. That way, a few years down the road you won't have to post up and ask how to get the stem off because the bolts are seized and the heads stripped out.:thumbsup:


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## wbmason55 (May 30, 2010)

They should be greased. Can also use blue Loctite.


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## Ricko (Jan 14, 2004)

jbourne84 said:


> I just put a new stem on my bike but i didnt use any grease or anything on the bolts, then i read that the instructions wanted me to put something on the bolts. how important is this? do i need to take it apart and grease them?


I think it'd be a good idea, otherwise it might come back to bite you in the arse a year down the road when you try to take it apart.

I generally "butter up" any two mating metal parts when I assemble, it makes future dissassembly a whole lot easier.:yesnod:.


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## crisillo (Jul 3, 2004)

Berkeley Mike said:


> I grease them.


ditto


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## CHUM (Aug 30, 2004)

yup - grease

I also reduce the torque settings by 10% when i use greased threads...

my .02


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## deadatbirth (Jul 23, 2007)

CHUM said:


> yup - grease
> 
> I also reduce the torque settings by 10% when i use greased threads...
> 
> my .02


why may i ask would you do that?

i grease all my bolts, particularly the heads. dont forget to grease the star nut bolt too. thats more important then greasing the stem bolts


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## Finch Platte (Nov 14, 2003)

Don't forget to liberally grease your brake rotors, too. :thumbsup:


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## CHUM (Aug 30, 2004)

deadatbirth said:


> why may i ask would you do that?


advice from a friend who has more experience than I do....

and it works (for me)



deadatbirth said:


> i grease all my bolts, particularly the heads. dont forget to grease the star nut bolt too. thats more important then greasing the stem bolts


you run a chance of the stem bolts 'galling'...then having to drill out if you don't grease them.

greasing the star nut bolt is insignificant as it is not 'loaded' heavy (only used to seat the crown race onto the headset)....and I don't think will ever squeak (purty sure).

And FWIW - *never* grease the bolts that hold you brake calipers on - those require blu-loctite. there are also other bolts on your rig that should not be greased...

my .02


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## Gasp4Air (Jun 5, 2009)

My rule of thumb is to grease anything threaded that I want to get out again and is not part of a brake assembly. For brake bolts (calipers, discs, etc) I use blue loctite.


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## dan0 (Oct 12, 2005)

Thompson recommends greasing the threads only, lubricating the threads allows an accurate torque reading as there will be be minimal friction. 
using a torque wrench is equally as important


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## gmcttr (Oct 7, 2006)

CHUM said:


> yup - grease
> 
> I also reduce the torque settings by 10% when i use greased threads...
> 
> my .02





dan0 said:


> Thompson recommends greasing the threads only, lubricating the threads allows an accurate torque reading as there will be be minimal friction.
> using a torque wrench is equally as important


Right or wrong, it is my understanding that torque values are typically arrived at using clean and lubed threads. Therefore, I use full value on greased bolts.


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## unicrown junkie (Nov 12, 2009)

I have always greased my stem bolts for years, and when I put my Surly Cross Check together last year with a Cinelli stem and bars it was no exception.

But for some frellin' reason the damn thing kept coming loose over the first six months, despite torquing and such. Now nine months later the problem is no longer, go figure. Must have been operator error since all is well now.


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## Berkeley Mike (Jan 13, 2004)

Reduce torque settings on greased threads?

My dad, a mechanic of 45 years, would just roll his eyes and ask if you used white grease or green grease; pull my finger.

At the same time 10% is within the error of any sample of torque wrenches so if that makes you happy, go for it. Mechanics can appear to be an exact science but any one who has been around mechanics knows that the spirit of the machine comes from the heart. Otherwise how does one resolve the fact that two highly experienced mechanics with years of experience can disagree on the simplest things.


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## deadatbirth (Jul 23, 2007)

CHUM said:


> advice from a friend who has more experience than I do....
> 
> greasing the star nut bolt is insignificant as it is not 'loaded' heavy (only used to seat the crown race onto the headset)....and I don't think will ever squeak (purty sure).


well take it from me, who apparently has more experience than you. if the mfg says a specific torque rating, then go to that rating. just because you have grease on it doesnt make the torque value any lower. 

and i never said anything about the preload bolt having any extra load on it. sweat and water tend to migrate its way down the cap and bolt causing it to rust and can make it a PITA to remove. ive seen more bikes then i can count with this problem.
and that bolt's main purpose is to preload your bearings.


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## sopwithcamel (Oct 2, 2007)

You also want to use a product like Finishline Fiber Grip if you are clamping onto any thing Carbon Fiber.


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## shamethellama (Aug 21, 2011)

deadatbirth said:


> well take it from me, who apparently has more experience than you. if the mfg says a specific torque rating, then go to that rating. just because you have grease on it doesnt make the torque value any lower.


Friction of threads is a component in torque specs, right? Grease decreases friction on the threads. That would mean mean that applying a certain torque to a greased bolt would actually yield more clamping force than the same torque applied upon a non-greased bolt. Wouldn't that mean that the torque values at the bolt would have to differ between greased and non-greased threads in order to maintain equal clamping force?

I'm just asking those with more experience than I.


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## onemission (Aug 11, 2010)

Anti seize or blue loctite is what I use on fasteners.


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## dan0 (Oct 12, 2005)

shamethellama said:


> Friction of threads is a component in torque specs, right? Grease decreases friction on the threads. That would mean mean that applying a certain torque to a greased bolt would actually yield more clamping force than the same torque applied upon a non-greased bolt. Wouldn't that mean that the torque values at the bolt would have to differ between greased and non-greased threads in order to maintain equal clamping force?
> 
> I'm just asking those with more experience than I.


yes


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## CHUM (Aug 30, 2004)

you guys go bug rensho - he's the one i took the advice from...and it works for me...

so there...

meh.


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## dan0 (Oct 12, 2005)

CHUM said:


> you guys go bug rensho - he's the one i took the advice from...and it works for me...
> 
> so there...
> 
> meh.


under torqueing wont break anything but it may come unscrewed
grease just makes sure that any friction wont skew the reading.
threaded fittings are designed to stretch a bit when tightened, too much and they strip or break, too little and they wont say in

so there...


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## CHUM (Aug 30, 2004)

dan0 said:


> under torqueing wont break anything but it may come unscrewed
> grease just makes sure that any friction wont skew the reading.
> threaded fittings are designed to stretch a bit when tightened, too much and they strip or break, too little and they wont say in
> 
> so there...




...


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## rensho (Mar 8, 2004)

Here's a good reference chart. I'm sure there are many others.

Basic physics says the force required to tighten a bolt is directly correlated to the coefficient of friction. If you lube it, or if it is dirty, the torque needed or spec'd will/should vary greatly. Some folks back off 15-25% for lubed bolts. I went conservative and said 10%.

The poster above is also correct that 10% is within a margin of error of most torque wrenches, assuming you use one in the correct range.

I think part of the confusion is that MFGs only list 1 torque spec, and they don't say dry or lubed. It is typically for dry.

Physics:
ROCKCRAWLER.com - Fastener Tech - Calculating Torque Specs
Basic reference: (I ride a yz250f and this is my other home. ;-)
Torque Wrech ft/lbs... Dry bolt vs. Oily bolt - ThumperTalk


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## NorKal (Jan 13, 2005)

Finch Platte said:


> Don't forget to liberally grease your brake rotors, too. :thumbsup:


And peanut butter the brake pads.  Smooth, not chunky.


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## milehi (Nov 2, 1997)

Everything you need to know about tourqe values, fasteners, installation and lubes.

ARP-bolts.com | ARP - World-leading Fastener Technology


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## Jason B (Aug 15, 2008)

Vader said:


> Everything you need to know about tourqe values, fasteners, installation and lubes.
> 
> ARP-bolts.com | ARP - World-leading Fastener Technology


Nice. This even goes into what Chum was talking about (reducing torque by 10% when lubed). Thanks for the link. 
Some + rep coming your way.


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## dan0 (Oct 12, 2005)

Jason B said:


> Nice. This even goes into what Chum was talking about (reducing torque by 10% when lubed). Thanks for the link.
> Some + rep coming your way.


I think you have it backwards, you should increase torque when you have no lube , as you have more resistance and friction on dry threads, and you should always use lube on the threads.
by your method you assume that the torque specs. are for dry, when most are not


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## dan0 (Oct 12, 2005)

rensho said:


> Here's a good reference chart. I'm sure there are many others.
> 
> Basic physics says the force required to tighten a bolt is directly correlated to the coefficient of friction. If you lube it, or if it is dirty, the torque needed or spec'd will/should vary greatly. Some folks back off 15-25% for lubed bolts. I went conservative and said 10%.
> 
> ...


from Thompson
Grease all of the bolt threads and the nut threads inside the steerer clamp
before assembly. All 6 bolts are identical.

most bolts on a bicycle are either loctited or greased either way they are lubed before torqueing. Torque settings are for ideal conditions i.e. clean smooth threads , so if a thread is lubed you should get close to ideal torque. if its not then you have to compensate by using more torque. although I would rather use lube and the right amount of torque. 
Look at it this way, if the bolt/ hole is dry, how do you know where the friction is comming from?
could be the top 1/8'" or the bottom 1/8" of the bolt. if its the top, then you're not getting the proper stretch of the mating surfaces and no matter what the torque reading , its wrong
. when you lube the threads you should get the proper mating and torque reading, so no compensation is needed.
BTW loctite will also lubricate when wet


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## rensho (Mar 8, 2004)

dan0 said:


> from Thompson
> Grease all of the bolt threads and the nut threads inside the steerer clamp
> before assembly. All 6 bolts are identical.
> 
> ...


Agreed. For Thomson, they do say to grease and so we'd assume the torque values follow suit for greased.

Thomson is in a different league of bike component MFGs than most others. They really do care about quality.


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## Metalized (Apr 1, 2009)

Blue loctite, unless you plan to change your stem out frequently. It really sucks to have those bolts come loose out on the trails.


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## dan0 (Oct 12, 2005)

Metalized said:


> Blue loctite, unless you plan to change your stem out frequently. It really sucks to have those bolts come loose out on the trails.


never lost one that was properly torqued


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