The 411 on thread locker: Thread locking compounds, sometimes referred to as 'Loctite' despite it being a brand name, is an adhesive that can be applied to the threads of a fastener to keep it from loosening over time from vibration or shifting parts. This is especially useful on smaller bolts that require a relatively low torque such as rotor bolts, but can be put to use anywhere that a bolt can repeatedly loosen even though it has been properly torqued. Lubricating a fastener with grease, the swear-by for cycling mechanics, is done to allow a bolt or nut to be precisely torqued, and to ease removal down the road. Grease and thread locking compounds should never be mixed. While there are other ways to keep bolts from coming loose - cotter pins, lock washers and even safety wire - none of those methods are suitable for use on our expensive and lightweight mountain bikes. Thread locking compound is a thixotropic fluid, which means that its properties change under certain circumstances. For most types of thread locker, especially the blue colored version that is used on bicycle parts, this refers to a lack of oxygen that allows the fluid to set once the fastener has been tightened down to the correct torque. It is best to allow the locking compound a full 24 hours to fully set, although it will dry sooner than that.
Thread locking compound is available in both a stick (left) and liquid (right) compound, and is used to keep bolts from backing off. It can be used in a number of places, including brake caliper and rotor bolts, or can come in especially handy on places like stem bolts if you spend your days doing hot laps in the bike park and want to keep your rig running safe.
Blue is your friend: Medium strength Loctite is most often blue in color and can be used on many places on a mountain bike to keep bolts from coming loose. It is thought of as being 'removable' in that it shouldn't require excessive leverage or heat to break free, and requires roughly 115 in/lb of torque to loosen a typical bike-part fastener. It is available in a squeeze bottle with a needle tip that allows you to apply it only where needed, but it can also be bought in a tube, similar to a glue stick, that is great for applying to places where you don't want it to run onto other surfaces (
lever reach adjustment screws being a perfect example). Blue thread lock is ideally used on any steel fastener that has repeatedly loosened despite having having been tightened to the recommended torque. Safety is a primary reason for thread locking compounds, and international standards specify that brake rotor and caliper mounting hardware are treated with it so there is little if any chance of an improperly torqued fitting rattling loose. Same goes for shock mountain hardware or any threaded fitting on a rotating part. Thread locking compound is also the go-to for press-in or threaded parts that tend to develop creaks over time (
a touch of blue thread locker on some clean BB threads, for example).
What not to use: Thread locker is available in different compounds and strengths that are usually color coded, although most are not suitable for use on a bike: red thread locker requires 230 in/lb to loosen and should be thought of as permanent, meaning that it will likely require a large leverage tool to remove the bolt. There is really no reason to be using the red colored compound anywhere on your bike. Green thread locker is best at penetrating into nooks and crannies, and can be used to hold sealed bearings in place (
being careful to not get anywhere near the rubber seal) if the bearing bore is oversized. The green compound needs roughly 90 in/lb to crack lose, and should be used very sparingly.
Start by removing the trouble making bolt and giving it a thorough cleaning with an alcohol based spray, being sure to remove any old grease or grime. Do the same to the threads that accept the bolt, using a Q-tip if needed to clean it properly. Let it air dry and take a minute to inspect the bolt's threads for damage or stretching that may have been caused by over tightening.
Apply a small amount, usually just one drop, to the threads on the bolt. There is no need to go overboard, too much will only make a mess.
Thread the bolt back in, tightening it to the specified torque. Wipe away any excess thread locker that may be present. It is recommended to let the bike sit for 24 hours before riding to allow the compound to fully set.
Where to not use thread locker: Although blue thread locker can be put to use on many places, there are some where it shouldn't be applied. It should be avoided when working with titanium bolts, especially when they are being threaded into a dissimilar metal, such as steel or aluminum. Anti-seize is your best bet here because it will prevent galvanization, allowing you to easily remove the fastener down the road. We would also recommend that you skip using Loctite on aluminum bolts as well for the same reason, but it can also make removing fragile aluminum hardware difficult, leading to rounded or broken off heads. Here are some other places that shouldn't see thread locker:
• Chain ring bolts, especially aluminum versions (
use grease to allow you to loosen them later on)
• Most crank set bolts (
grease used here allows it to attain the proper torque)
• Pedal threads (
pedals won't loosen due to their reverse threading, but using grease will eliminate creaks and make them easier to remove)
• Axle threads on either front or rear thru-axles (
grease here prevents the two aluminum surfaces from galling)
• Any small hardware that hasn't repeatedly loosened (
M3 sized bolts or smaller, such as those used to attach the adjustment dials of a fork. Using thick grease here will prevent loosening and make them easier to remove)
Are you an arm chair thread lock expert? Want to add to what Mike has to say? Do it below!
Past Tech Tuesdays:
Technical Tuesday #1 - How to change a tube. Technical Tuesday #2 - How to set up your SRAM rear derailleur Technical Tuesday #3 - How to remove and install pedals Technical Tuesday #4 - How To Bleed Your Avid Elixir Brakes Technical Tuesday #5 - How To Check And Adjust Your Headset Technical Tuesday #6 - How To Fix A Broken Chain Technical Tuesday #7 - Tubeless Conversion Technical Tuesday #8 - Chain Wear Technical Tuesday #9 - SRAM Shift Cable Replacement Technical Tuesday #10 - Removing And Installing a HeadsetTechnical Tuesday #11 - Chain Lube ExplainedTechnical Tuesday #12 - RockShox Totem and Lyric Mission Control Damper ModTechnical Tuesday #13 - Shimano XT Crank and Bottom Bracket InstallationTechnical Tuesday #14 - Straightening Your Derailleur HangerTechnical Tuesday #15 - Setting Up Your Front DerailleurTechnical Tuesday #16 - Setting Up Your CockpitTechnical Tuesday #17 - Suspension BasicsTechnical Tuesday #18 - Adjusting The Fox DHX 5.0Technical Tuesday #19 - Adjusting The RockShox BoXXer World CupTechnical Tuesday #20 - Servicing Your Fox Float ShockTechnical Tuesday #21 - Wheel Truing BasicsTechnical Tuesday #22 - Shimano Brake Pad ReplacementTechnical Tuesday #23 - Shimano brake bleedTechnical Tuesday #24 - Fox Lower Leg Removal And ServiceTechnical Tuesday #25 - RockShox Motion Control ServiceTechnical Tuesday #26 - Avid BB7 Cable Disk Brake SetupTechnical Tuesday #27 - Manitou Dorado Fork RebuildTechnical Tuesday #28 - Manitou Circus Fork RebuildTechnical Tuesday #29 - MRP G2 SL Chain Guide InstallTechnical Tuesday #30 - Cane Creek Angleset InstallationTechnical Tuesday #31 - RockShox Maxle Lite DHTechnical Tuesday #32 - Find Your Tire Pressure Sweet SpotTechnical Tuesday #33 - Three Minute Bike Preflight CheckTechnical Tuesday #34 - MRP XCG InstallTechnical Tuesday #35 - Stem Choice and Cockpit SetupTechnical Tuesday #36 - Handlebars - How Wide Affects Your RideTechnical Tuesday #37 - Repairing A Torn TireTechnical Tuesday #38 - Coil spring swapTechnical Tuesday #39 - Trailside help: Broken Shift CableTechnical Tuesday #40 - Installing a Fox Float Air-Volume SpacerTechnical Tuesday #41 - Replace the Seals on Your 2011 RockShox Boxxer World Cup ForkTechnical Tuesday #42 - Clean and Lubricate Your Fox F32 Dust Wiper SealsVisit
Parktool.com to see their entire lineup of tools and lubes
I would prefer it over Loctite as Loctite's bond needs to be 'broken', whereas that threadlocker does not. I've had a pivot bolt or two come loose after re-installation, despite the threadlocker on the bolts (which gets crushed over time). So now I apply Loctite every time I strip my linkages down. This means I have to 'break' the Loctite which sometimes means putting a decent amount of pressure on a relatively soft aluminum CNCed bolt head.
I understand your point about torque settings.
Where can I buy it, or is there a good substitute?
2. Threadlock can be used on threads where oil and grease is present.
3. Loctite 243 is yer man for most, if not all bicycle fastener applications.
4. You're welcome.
Lot of SRAM/Park references & obvious, blatant product placement in there, other brands of bicycle components are available.
Also maybe a mention of heat will allow any locktite to be more easily removed.
Sure, I agree with the last statement. But a lubricant will reduce the friction between the threads of the fastener and thus increases the torque applied to the bolt/nut. Unless its a wet-torque specification where you're supposed to used a lubricant. This can easily destroy or set a component up for fatigue/later damage.
Otherwise an informative article! Keep it up. Sorry for being picky, but I can't help it.
www.intermotive.net/Tech%20Tip/Tech%20Tip%20-%20Jan%2008.pdf
en.wikipedia.org/wiki/Bolted_joint
And no. The torque won't increase after the grease has been washed away, but the torque during the installation will be incorrect, compared to what your torque wrench reads.
This is why when you change the friction you effectively change the tension the bolt applies on the materials it holds together, even though the torque is the same. If you replace "torque" with "tension" then your statement of applying a lubricant allowing the bolt to receive the tension becomes absolutely correct. The problem as dannythekiwi has stated it is that torque specification only apply to a specific thread friction (lube vs no lube). In situations where lube is part of the torque spec, going dry would mean you aren't applying appropriate tension, the torque is whatever your torque wrench reads when you stop cranking.
If we reverse the above situation where the torque rating was specified for a dry bolt, and you lube it, the same torque will put excess tension that could make components fail.
Also, it's worth noting that the colour of these compounds, whilst fairly set, is not hard and fast. The stuff that I use is Tru-Loc and the light is red, the medium blue and the strong (stud lock) is dark green. Medium strength nut/screw/threadlock is what you're after guys.
Rule of thumb: Every bolt, every thread on your bike should have either grease, loctite, or anti-seize on it.
@ Carlos - Pedals seizing so bad that the axle turns out of the crank arm is no doubt a very rare thing. Grease the threads, don't apply thread locker.