# Which bolts need grease ?



## swaltham (Jun 24, 2006)

In the past I've used grease on pedal threads but not on brake lever clamps. Now I'm putting a whole bike together.....and don't know when to use grease.

I would guess that crank arm bolts need it, disc brake rotors do not. Stem clamp needs it, how about brake caliper mounts ???

Please go easy on this noob with simple questions....there's a first time for everything.

Thanks, Sam


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## spencer the kalmyk (Dec 6, 2006)

I would say all bolts can use some grease....


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## Bobby12many (Apr 28, 2004)

spencer the kalmyk said:


> I would say all bolts can use some grease....


I agree.

When I build up or work on my bikes I make sure to clean the threads of every assembly/clamping bolt, then put a lil dab of sythetic grease on them (unless they are to be thread locked)

Makes life easier down the road and keeps moisture and possible corrosion from entering the threads.


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## vortexrok1 (Feb 25, 2008)

Every bolt ever..


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## nnn (Feb 1, 2005)

Yep, every single bolt unless it has to be specifically locked then use threadlocker obviously


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## flipnidaho (Aug 10, 2004)

Any fastener on a bike need some grease. Any fastener that is part of the braking system, I use blue loctite (rotor bolts, caliper mounting bolts, etc..). If you are using titanium bolts or a titanium frame, use anti-seize.


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## supercorsa (Jan 18, 2004)

flipnidaho said:


> Any fastener on a bike need some grease. Any fastener that is part of the braking system, I use blue loctite (rotor bolts, caliper mounting bolts, etc..). If you are using titanium bolts or a titanium frame, use anti-seize.


yup...


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## mtnbiker4life (Sep 19, 2005)

It really depends on the bolted joint, fastener type, and ride environment. Some things to take note with regards to using thread lubrication.

1. When a manufacture calls out a torque value it's usually without any thread lubrication. So to prevent over-torque it's best to use clean dry threads.

2. All hardware that is subjected to heavy shock and vibration use threadlocker #242....brakes calipers, rotor bolts, and suspension pivots.

3. Galvanic corrosion should be addressed if you ride in a wet/salt environment.

4. Stay away from those titanium rotor bolts that are sold over the net.....they are made of grade 5 titanium which are substandard for this application. Only use titanium hardware that is made out of 6Al/4V or 3Al/2.5V or any of those derivative's


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## collegemonkey7 (Apr 28, 2008)

*being thorough*

EVERY SINGLE BOLT YOU SEE!!!! If it holds a cable, grease it. If it adjusts something, grease it. If it clamps something, grease it. Its also important to know how to apply it. Grease the hole, not the pole.


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## Berkley (May 21, 2007)

If you don't grease it, it might creak. I hate it when there's a creak and I can't find it...


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## Otter (Feb 2, 2004)

I agree with what most are say....grease pretty much everything. One caveat though if the bolt is going to be near carbon fiber, be very careful NOT to get grease on the carbon.


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## hugh088 (Feb 1, 2004)

Anti sieze just on Ti. I use it everywhere except on bolts that use thread lock. It just works better then grease. Don't believe me, Google it and not just the manufactures sites.

"All hardware that is subjected to heavy shock and vibration use threadlocker #242" 
On a MTB that would be all of them. There you really need thread lock is parts that are subject to rotation. Suspension pivots are a big one and if you collect older Italian Road bike the bottom bracket on the right side. The torque of pedaling would back these out if they were not tight enough. On an older bike that had seen a lot of use the only way to keep them tight is a dab of locktite.


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## tomsmoto (Oct 6, 2007)

mtnbiker4life said:


> 1. When a manufacture calls out a torque value it's usually without any thread lubrication. So to prevent over-torque it's best to use clean dry threads.


unless you've got a real damn fine torque wrench, its probably off 5-15 *percent* anyway. most people dont care because honestly, 5-15% doesnt make a difference. torque is fairly critical on things that heat up significantly or require a gasket with multiple fasteners, and even then the importance lies in evenness of torque, not so much the absolute torque value (as long as its not excessively loose or tight).

cliff notes: you're not really going to overtorque a bolt due to some grease.


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## mtnbiker4life (Sep 19, 2005)

tomsmoto said:


> unless you've got a real damn fine torque wrench, its probably off 5-15 *percent* anyway. most people dont care because honestly, 5-15% doesnt make a difference. torque is fairly critical on things that heat up significantly or require a gasket with multiple fasteners, and even then the importance lies in evenness of torque, not so much the absolute torque value (as long as its not excessively loose or tight).
> 
> cliff notes: you're not really going to overtorque a bolt due to some grease.


I'm not sure where you got your information from but 15% will make a difference.....a difference between a broken fastener or a broken bone when you go over the bars. Maybe it's the engineer in me.....working in aerospace we held to very high standards. For example, we never put threads in bearing....because the threaded portion has a much less surface area than the unthreaded portion.......which offers less bearing. This greatly reduces both load carrying capacity and the fatigue restistance of the assembly.

http://www2.bsn.de/Cycling/Torques.html

"The general formula for calculating torque is: 
Torque = 0.2 x nominal diameter of screw x load where load is 80% of yield strength. Torque for bolts with nuts may be slightly higher. The load depends upon the friction cooeficient of the screw (and the material into which the fastener is attached) and the depth of the thread. Lubrication and/or platings can effect torque values by as much as 25%. Some platings increase torque and some actually decrease it. "

cliff notes: God arranged things so the unwary and the ignorant will get caught out. It's called Darwinism


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## lyndonchen (Nov 8, 2007)

You do have to reduce the torque spec for a lubricated bolt. iirc, at my former workplace we would specify 10% less torque on fasteners with antiseize.


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## 13pumps (Jun 16, 2006)

I agree with everything that mtnbiker4life states in both post in this thread. I work with TI, carbon fiber and aluminum every day. Correct Tq can be critical and lead to premature failure. I have posted many times on this site about the using calibrated Tq wrenches, especially on high end CF bikes. All of mine and my shops are calibrated annually to an ISO/ANSI Std within plus or minus 3% as required by the DOT.
Unless otherwise specified Tq is done with dry threads, lube usually is applied to the shanks and Loctite blue (242) to threads. I just read a bulliten put out on this exact topic. I will try and find it and post it. It is interesting. There are many place that do calibration on Tq wrenches and it is not expensive. Many of us have bikes worth many thousands so it makes sense to use the right tools.


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