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Plugs, Anti-Sieze, ABS and Wasting People's Time
- Subject: Plugs, Anti-Sieze, ABS and Wasting People's Time
- From: "Tom Brown" <tbrown@xxxxxxxxxxx>
- Date: Fri, 11 Nov 2005 00:18:06 -0600
As Tom Cutter explained in the first reply about anti-sieze and I'll restate
for him so he doesn't have to waste any more time on this...
Anti-Sieze makes the threads slicker. When the threads are slicker and you
tighten to a given torque, you're actually pulling a lot harder and putting
more stress on the threads...as if putting near double the torque on without
Think about it. It's an inclined plane/lever with a given amount of
surface friction that makes a set radial resistance when the threads are
tightened "enough". That resistance translates into the recommended torque.
When you take away surface friction with anti-seize, you have to tighten
down a lot more to create the same drag (torque reading) on the wrench.
I'm not going to get into a battle of words here. I'll just tell you that
what TC said is true and let you figure out why if this doesn't make sense.
However, a lot of people don't use a torque wrench to tighten plugs. They
just tighten a new plug 1/4 turn past where it's "home" on the new crush
washer around the plug. In that case, you're not depending on a torque
wrench reading and the 1/4 turn will still be 1/4 turn. Same stress on the
threads with or without the Anti-Seize, but will feel like less torque in
your hands as you turn the wrench. As long as you can resist the temptation
to tighten it "a little further because it just doesn't feel tight", you're
not over torquing....
...But then your bike's cylinder heads have threads full of anti-seize and
will nearly forevermore have a lower friction coefficient than the clean
threads that were in mind when the engineers decided what torque setting to
cite for tightening your plugs. This means anyone who uses a torque wrench
to put plugs on your bike will be in danger of overcooking your threads.
Anti-seize is really useful stuff for many things. I like it for coating
the surface, lightly, between the flats on the aluminum rims and the flats
on my rear hub (steel) to combat corrosion and galvanic reaction. (I use the
silvery stuff that matches the wheels, not that sticky copper snot) It does
stop some rust. As TC said, it's great for exhaust bolts because their so
ripe for corrosion.
I also used it for rebuilding an old British Leyland engine from a Saab 99
once. It's the only thing that will prevent galvanic reaction on the head
studs and the half iron/half aluminum block surfaces. I don't use it on lug
bolts unless I'm fairly sure that I'm going to be exclusively in charge of
torque and the vehicle in question is going to be outside for extended
periods between tire changes. I am, in this case, very careful with my
torque values, decreasing them about 1/3. So far, no wheels have fallen
The case could also be made that, if the threads are corroded and rough,
they will not tighten enough using the recommended torque. The answer to
that is, if the threads are corroded and rough, clean them up before you
tighten them onto anything or you'll booger them up for sure and shorten
their useful life immensly.
Tom Cutter is a professional mechanic who knows his stuff. Even if he were
not, I'd agree with him on this thread issue. I know it to be true from
experience and from simple physics. He knows it to be true from repairing
lots of stipped threads full of anti-seize. We're lucky to have him on the
list. He's more than helpful.
In the ABS situation with Bob downing his bike to save a bicyclist from
serious harm, all he's saying is that, while ABS helps you stop faster in an
emergency, it's limiting in other ways. I think we can all agree on that.
ABS IS a little bit limiting. Sliding the bike on purpose, for instance,
isn't practical anymore. Sometimes, when you hit a bump in the road while
stopping for a light, there's this helpless feeling while the ABS kicks the
braking out and hasn't got its bearings back. It's a good thing for most
street situations, especially emergency situations, but it's not perfect and
has some minor costs in feel for non-emergency riding. Anyone who's used
it knows this.
If I had a bike with BMWs first ABS system, I might consider taking it out.
It's really slow and can cause as much trouble as it saves. I'm not
completely convinced it's worth keeping on the old bikes.
3rd BMW bike with ABS, 2nd with servo ABS,
100K+ combined miles on 3 Oilhead RTs.
'00 Aprilia Mille R with Excellent non-ABS brakes.
Have nice garage, have owned and worked on numerous BMW cars and bikes since
1976, run a tool and die/metal stamping business, know a thing or two about
tools, threads and fixing stuff, am not a professional BMW mechanic, but
still do a lot of my own work on my bikes and cars. I'm not a mechanic-god,
but I know what I'm talking about here.