 |
||||
|
|
||||
|
||||
| No. 4 ~ OCTOBER 03, 2001 | ||||
| The
Grease by Carlos |
||||
|
After having put the grease "bit" on hold for a month, I was finally able to get the information I had collected in some order. I wanted to get away from the adjustment banter every once in a while and get a bit geeky. Lubrication is something I consider to be the other half of bike maintenance. Once adjusted, components work well but without lube, they'll end up as wind chimes and paper weighs. even the most "tech" components, if not lubed properly, will die a creaking, ticking, groaning, seized up, death. An amazing amount of R&D goes into making lubricants. unfortunately for us, meaning, those who ride and fix bikes, the geeky tech talk can only go so far. After several phone conversations with the people at Exxon/Mobile, Pennzoil/Quaker State, Sherwin/Williams, and Finish Line, I came to realize that we, as cyclists, are at the very bottom of the lubricant consumer hierarchy. We're beat out by satellites, earth moving vehicles, computers, refrigerators, VCRs, sewing machines, and food mixers. Robert Minworth, head of the R&D and manufacturing division that makes Tri Flow, at Sherwin/Williams states "you could take a gallon of crude oil and lube an entire bike and it would function just fine. used motor oil, too. anything really, as long as it reduces friction and heat build up. and on a bike, that's easy to do." the generalization, he admitted, was a bit coarse but proved a point. Bicycles don't generate high speed or load ratings to justify using specially formulated, pricey, grease. Jim Laurier at Finish Line mentioned, "we look at two possible applications when we select a grease: high speed/low load or low speed/high load. Bikes fall into the low speed/low load category. Grease selection isn't critical, unless we're dealing with bottom brackets, in which case we recommend Ti Prep, so we formulate with general use in mind." There are several different grease formulas/types, or complexes. lithium, aluminum, calcium, bentone, and synthetic are the most common. each complex has a special properties such as water resistance, cling, pressure, packability, flash point, op-temp, viscosity, base, ISO cat..... I'll stop here since it's bound to get as interesting as waiting for a pane of glass to puddle (glass is a liquid, remember?). So what do we really need to know about lubricants? we need to know what to use, where, and why. Lets start with basics. grease and oil. are they the same? are they different? Can you substitute one for the other? Yes, yes, and yes. Grease is the carrier or medium by which oil is applied to certain components. The grease itself has no lubricating properties and it's only job is to make oil cling to the part or component to which it is applied. Take, for instance, the chain. no one greases their chain. Although, if you had no oil, grease would work just fine. But grease is sticky and messy and probably wouldn't get to the bearings of the chain where it's needed most. So where do you put oil and where do you put grease? Here's the list: oil: chain (OR newer wax based lubes), cables/housing, shifter internals, fork damping cartridges, freehub internals, and shock pistons/valves. grease: anything with bearings or bushings, anything with threads (aside from what's mentioned above). Oil is best for components with lots of little moving parts that have nooks and crannies such as a Rapid Fire shifter. Oil is light enough to lubricate the necessary parts and still allow for free movement of said parts. On the other hand, oil is useless when applied to a headset. Even the seals on the high end headsets don't have a preload (the tightness of the seal against cartridge housing) high enough to keep in liquids. Grease works best in parts that are under heavy (relative to cycling) loads. Bottom brackets and hubs are a good example. oil would seep out too quickly or break down leaving you at the next stop to Creaky Parts-ville. Grease is also ideal for most threaded parts. The most common problem occurs when someone tries to remove or loosen a seized bolt, chances are they'll strip the head or break the tool. There is one final type of product that isn't a grease but that is used quite often on bottom bracket threads. Anti-seize is a complex of several metals and a small percentage of oil, used to prevent the fusing of metal parts (galling) at the molecular level. The two most common types of anti-seize are copper and aluminum complex. Finish Line and Versa Chem both offer a quality, nuclear grade (yeah, that's right, nuclear), copper complex, anti-seize. These types 13 and 14 fall into this category because their flash point (point of ignition by extreme heat) is well above 2000F degrees. These two properties alone make anti-seize ideal for use on bottom brackets and bottom bracket shells. While steel, titanium, and aluminum are the most commonly used metals for the construction of bike frames, they are also some of the most reactive when mated to any other metal. Galling becomes a concern in areas like the bottom bracket, bottom bracket shell, and in some rare cases, seatposts. Carbon fiber frames don't make the list but all such frames have an aluminum sleeve that houses the BB shell's threads. While many mechanics restrict the use of anti-seize to titanium frames, it's clear to see that there are benefits in the use of this product in frames made of aluminum, steel, and magnesium. As a final note, I'd like to mention that, while there is no need to own 12 different types of lubricants, we should have at least one tube of grease, one drip bottle of oil, and one tube of grease formulated for forks/shocks, on hand. These item along with the list of tools posted in the Fix It section will lay the foundations for a well stocked toolbox. Kvestions? Confusion? Comments? Speak it on the boards. |
|||
