DT Swiss specific hub grease, Dow Corning TP-42 not that good
So i have 2 DT Swiss star ratchet hubs that i was going to maintenance for the first time. DT Swiss "makes" their own specific grease for the Ratchets. The grease is made by Dow Corning. Its called Molykote TP-42. I found this company who sells a lot of Molykote products on Amazon. They did not have TP-42. i emailed them to see if i could buy some TP-42 (DT Swiss charges $25 for less than an once) .
This guy named Tony, who is a chemical engineer responds back about TP-42, how its not the best lube for metal on metal applications, and recommends a diff type of grease. He offers to send me an ounce for free to try out and write a review on. Will do this once i try it out. He hasn't shipped it yet.
He gave me a full on scientific analysis on TP-42, and told me what this other grease he is gonna send me is better. Ill post his analysis on the next post. Its super long.
Bicycle wheels rotate at between 60 rpm (recreational use) to 180 rpm (high-speed sprint), which are actually relatively low speeds in terms of grease performance, so almost any grease (except silicone based greases) would perform well on rotating equipment at those speeds. Of course, there are other performance factors to consider for a bicycle grease. The main characteristics that bicycle greases would need are water washout resistance due to constant weather exposure, and extreme (contact) pressure, or EP, capability, and smooth consistency yet with enough "cling" to stay on the parts.
In terms of consistency, the grease should not thin enough that it runs off, nor too thick so it doesn't gum up or "channel," meaning that it fails to cling to the rotating parts, and that it offers the least amount of drag or resistance. The most appropriate consistency for bicycle wheel components should be NLGI (National Lubricating Grease Institute) #2 grade which is the most common grade for greases. NLGI #1 might be considered in certain cases especially in cold weather and in sealed components where the grease is unlikely to be affected by weather or to be slung off or run off the part easily due to centrifugal force. The ASTM "unworked penetration" test number for TP-42 is 265-295 which corresponds to NLGI grade #2.
The EP capability is created in a grease by the use of additives, the most common EP additives are molybdenum disulphide ("moly", MoS2), graphite (natural flake graphite is preferred, and when we compound custom greases we only use premium ultra pure natural flake graphite with a fine particle size of 5 micron - the size of a red blood cell!), micronized PTFE (Teflon, polytetrafluoroethylene; should be smaller than 1 micron particle size), or powdered plastics/polymers which are the lowest cost alternative. Molykote TP-42 uses a plastic called polybutene which is a relatively low cost (and lower performance) additive compared with PTFE and Moly. In that regards, I would say TP-42 has an average EP performance.
Water washout resistance may be the most important consideration for a bicycle grease. There are various tests for water washout capability and the one used for TP-42 is a European DIN test (DIN 51 807 pt.1). In the test, glass strip is coated with the grease, which is placed into a water–filled test tube. The test tube is immersed in a water bath for three hours at a specified test temperature. The change in the grease is evaluated visually and reported as a value between 0 (no change) and 3 (major change) along with the test temperature. In the case of TP-42, the test result reported by Dow Corning in their literature is 2-90 ("change" of 2, at 90ºC). The result of "2" means that there is some change in the grease which, although this grease is recommended for contact with water and metal machining emulsions, the test result does not inspire a lot of confidence in me for bicycle applications. TP-42, based on the components reported by Dow Corning, appears to have a simple Calcium thickener base. Calcium greases are good for water washout resistance, but the best are Calcium Sulfonate thickener based. Moreover, this grease is recommended for "Sliding surfaces exposed to high pressure loadings and subject to the influence of water of metal machining emulsions." This means that it is not specifically recommended for bearings or rotating equipment applications, rather for sliding components.
So... I have a grease recommendation for you. We have two products available that I think would work very well. Our MicroLubrol™ WeatherMAXX™ ™ (both are our proprietary brand names) with PTFE (Teflon) or our WeatherMAXX™-MX with PTFE and Moly.
MicroLubrol™ WeatherMAXX™ has the following characteristics:
- Consistency: NLGI #2.
- Operating Temperature Range: -10ºF to 340ºF.
- Water Washout Resistance: <1% (VERY LOW!, has a Calcium Sulfonate Complex thickener), resistant to fresh AND salt water w/ outstanding corrosion and oxidation protection.
- Meets NLGI Service Classification GC-LB for automotive service and is excellent for bearings and rotating metal components.
- Recommended for extreme pressures, shock loads and continuous vibration.
- Excellent protection against oxidation and corrosion
- Does not contain heavy metals, phosphorus or chlorine.
WeatherMAXX™ is for standard heavy duty use, while WeatherMAXX™-MX with Moly offers better metal-to-metal protection although, like all greases that contain Molybdenum Disulphide, it is somewhat messy to use and may stain clothing that comes in contact with it and this can be a consideration when using it in exposed metal parts like some bycycle components.
Here is another followup email he sent when i mentioned that DT Swiss rebrands it and i was also considering Slick Honey .
As far as the DT Swiss rebranded TP-42, it is not just rebranded, but actually thinned ("admixed") with 5% mineral oil, which is easy for us to compound as well and I will consider whether we will offer a similar product also in the near future (I'm sure for way less than $20 for 20 grams!!). For the 5% admix we would use PAO (polyalfaolefin oil which is the best and is safest for rubbers and plastics. Our WeatherMAXX-MX I believe will be as good or better than TP-42 and even Slick Honey for the hub application and for any other metal-to-metal lubrication points on a bicycle. Slick Honey has two ingredients that are not as environmentally and safety friendly and are considered hazardous substances: Zinc Dialkyldithiophosphate and Antimony. WeatherMAXX-MX is a safe and environmentally friendly product yet is a superb lubricant and I am sure it will perform as well or better than those others. Also, Slick Honey uses Calcium Stearate as the thickener which is good, but not as good as Calcium Sulfonate Complex thickener as in our product which most higher performance water washout-resistant greases use.
That guy takes his grease seriously. I don't. I guess I'm one of those "grease is grease" kind of guys. I sure as heck wouldn't spend $25 for an ounce of any grease. I'd estimate that to be about what my annual grease expenditure is altogether. But, I don't have a $200 - $500 DT Swiss hub on any of my bikes either.
DT Swiss specific hub grease, Dow Corning TP-42 not that good
Doesn't this guy have work to do?
Sort of interesting though, thanks for posting
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The guy <i>is</i> doing his work. Good info. Understanding why we use what we use is always a good thing. Wish there were more helpful guys like that in other parts of the industry.
Did you get the sample? How is it working?
I've tried to do some searching for the product. Coming up empty on which lubricant it is.
Re: DT Swiss specific hub grease, Dow Corning TP-42 not that good
Since the DT grease is for use on Star Rachets, a sliding surface exposed to high pressure loadings, not bearings, sounds like TP-42 is the right stuff for the job.
Originally Posted by jton219
I did find a source for TP-42, but it was $190 + shipping for a five gallon bucket, and since I have 8-10 rebuilds, and still have over half left of my 1oz I'm ok with $1 every 3-4 months.
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