Bicycle bearing grease lab test help
- Thread starter CycleGremlin
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- Jul 18, 2020
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They do this for hour record attempts and key time trials because it's been demonstrated that the dust cap actually creates more rolling resistance than the hub itself. In Eddy's day this was based on pure conjecture, but now that it can be easily measured, it turned out they were right... And keep in mind, track events are pretty sterile environments.
Even for key outdoor TT's, the top riders will often pull the rubber seals from cartridge bearings, and the seal itself has more drag than the entire bearing assembly. Keep in mind, we're talking fractions of a watt here (both hubs have a total of ~2.5W on an average set of hubs). You can save about 1-1.25W by pulling the seals. Yes, that difference goes down over time, but depending on conditions you can get 1-2 hours of run time before the hub becomes less efficient due to dirt ingress. If you look at the bikes of the top world's competitors (Ganna, et al) they are typically running Ceramic Speed bearing with the seals removed on hubs, BB and derailleur pulleys.
This sounds ridiculous, but I'm reminded of a why I was consulting with who lost a Master's World Championship TT title by less than half a second. It's fair to say a difference that small would have made the difference.
It’s a common practice in the pro peloton to substitute oil for grease and no seals to cut down on friction - but that was before ceramic bearings and bushings made it into the “mainstream”(in quotes since they are still expensive for the hoi polloi - until it makes it down to Shimano 105 and SLX/Deore or SRAM Rival and NX). Probably is still true today - I know of a bike mechanic who did quite a few USAC cat 1/2 bikes I can pick his brain about when I see him. Shimano’s Dura-Ace 7500 series cranks with the Octalink BB was barely “sealed” unlike the Ultegra 6500/105 5500 version - you can easily take the seals off and strip down the BB to axle and roller needle bearings.
Chris King recommends a semi-fluid grease for their hubs, in the past they said use Mobil 1 10W-30 or synthetic ATF. Of course, Chris King calls annual servicing. Shimano’s Agip grease doesn’t shear down to a soupy mess like Park Polylube does.
That reminds me: last summer I was servicing the bottom brackets on our tandem, a year 2000 Santana with around 15,000 miles. While they were perfectly smooth as butter, turning the spindle with my fingers had more friction than is normal for road bikes. The bottom bracket had no marks for manufacturer, part or serial. I called Santana and they said it is a custom bottom bracket made for them by Shimano. He said they are heavy duty made to last forever, so while they have more friction than normal road bikes, if they turn smoothly then they are fine. He said with the cranks installed, if you flick-spin them and get 2 rotations, they're like new. And reminded me that all their frames have a lifetime warranty and they had replacements if I needed them, as they keep parts available even decades back. He added that on the professional track racing tandem that he built, he can flick-spin the cranks then go get a cup of coffee, come back and they're still spinning. Totally different bottom bracket, no seals, oil instead of grease, made for efficiency, it doesn't have to last for years, or even a full season of racing.
- Joined
- Jul 18, 2020
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The majority of the pro peloton are on bog standard parts from their sponsor. It's only the top guys getting ceramic bearings and pulling seals etc. The truth is, the average Master's racer is often on more fancy gear than guys paid to ride their bikes for a living. Team resources are surprisingly tight. When you hear stuff about some guys providing their own gear because they don't want to use team stuff, this is completely true. Right now I'd say Ineos and Jumbo are the only teams fitting out all of their riders with the top-shelf kit. US domestic teams? It's basically "whatever we can get for free".
These days though, the big thing isn't bearings, it's low-friction chains. Whereas there are fractions of a watt to be gained with bearings, there can be a 5W difference in lubricant alone--and a a worn chain can double that. I've personally measured a 20W difference between an old, dirty chain and a new but worn-in chain with a fast lubricant. I think most top guys now are using waxed chains for key events (TT's, mountain stages, one-day classics).
True, this. Also tires.
When I was trying my hand at racing, even in Cat 5, I saw cats on S-Works Tarmacs or Cervelo S5s with full Dura-Ace/Ultegra Di2 and Zipp 404 rims. I volunteered at the local crit and in the Pro/1/2 men’s and women’s race as well as the Masters men/women were riding on expensive hardware, even stuff banned by the UCI like all carbon cockpits.
Yea. I saw a Facebook targeted ad for Absolute Black’s Graphenlube - a graphene lube available as a DIY wax bath or drip. Supposedly Ineos is using it. Shimano’s making a big deal with Sil-Tec chains, I’m no racer but I notice a difference with a Shimano chain vs. a SRAM chain. Tires are also a big deal these days, rolling resistance matters - MPGs in a car, watts on a bike.
