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Old 01-09-07 | 01:31 PM
  #63  
Pete Hamer
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Joined: Dec 2005
Posts: 415
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From: Minnesota
Originally Posted by quattrotom
It seems to me that based on the previous link at SKF (specifically diagrams 1 and 2) that bicycle applications with low load would be fine in the green and yellow zones taking into consideration this quote: "Values for the low temperature performance limit are different for roller and ball bearings. Since ball bearings are easier to lubricate than roller bearings, the low temperature performance limit is less important for ball bearings."

This suggests to me that most NLGI 2 automotive greases would be fine. I found an additional link that explains some of the ASTM Tests: http://www.usaindustrialgroup.com/oilanalysis.htm

From this, it appears that Pour Point is a useful characteristic: "Determination of the lowest temperature at which a petroleum product may be used if fluidity is necessary to the application."

I personally have been using Valvoline greases for my bearings (because I use it on my cars). I've used the Durablend ($3 for a 1lb tub):
http://www.valvoline.com/pages/produ....asp?product=3
The Pour Point is listed as -18C under the Product Specs link.

It appears that the full synthetic works to an even lower temp:
http://www.valvoline.com/pages/produ...asp?product=59
The Pout Point is listed as -80F (which is -62C), although the viscosity index is higher 135 vs 110.

Based on all of this I think I'll stick with Valvoline Durablend at $3/tub. Does anyone else have any other conclusions on a good grease at a good price?
I found two good websites (one was the NLGI website) that stated that Polyurea grease is "best for ball bearings". I haven't been able to figure out the exact reason though. I think it has something to do with the fact that ball bearings apply rather high loads to the grease.

All the websites about grease agrew that the most iportant part of a grease is the oil viscosity that the grease is made from Low viscosity=low speed, high viscosity=high speed.

I agree that most NLGI 2 greases will be fine. One interesting note, I keep reading that Polyurea and Lithum are incompatible. Also, I keep reading that Polyurea is compatible with elastomers. I don't know if that means other greases aren't.
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