Biking To-Do List: November 2020

First, yes, I still owe you all 2 posts on the theory and practice of half-step gearing, which is slow going at the moment, but I'm working on it. 

Second, I decided to repack an old set of Shimano Ultegra 6700 carbon pedals and was shocked to find there is no main bearing, and the "needle bearing" isn't a needle bearing at all, it's a home-brew dual ball bearing where the cups are ground into the ends of a ~ 12mm steel barrel, and those balls are teeny tiny, like something out of a Swiss watch. We're talking flat-sided toothpicks for handling all 36 of these 3/32 little devils. The PD-R8000 is made exactly the same way.

Third, I'm still trying to figure out a way to salvage my old bike's headset by using a thicker grease meant to resist being hammered out of the contact area (pound-out). Turns out there's a grease sold by AmsOil made specifically for this purpose used in heavy duty off-road earth-moving equipment - Synthetic Polymeric Off-Road Grease, NLGI #2

Think articulated joint in the center of a bucket loader rolling over rough ground with a bucket load of ore and a huge weight stack at the extreme other end of the machine. (these guys couldn't get laid in a mattress factory, but watch the video anyway) You'd want the thicker NLGI #2 grease for headsets retrofitted with sealed bearings with much smaller engagement areas than the original press-in ball bearing cups.

This, and repacking my Ultegra pedals led me to a lengthy investigation of grease, and especially, compatibility of greases with different bases (they're not), because I bought some of Park Tool's PPL-1 Polylube poly-urea grease, and I wanted to be sure it would play nice with other (primarily lithium-based) greases. Park Tool says it does. My research says NO. 

BTW, the base isn't the lubricating agent. The base is the stuff that gels and suspends an oil, and slowly weeps the oil onto a bearing over time, but it's NOT the primary lubricant (some additives like moly or graphite provide lubrication as well). That is to say, the base is what makes something a grease instead of an oil. There's a fairly wide window of bearing speeds and loads where grease works, and bicycle bearings are way, way inside that window. Easy-peasy. 

10% ball bearing failure @ 45,000hrs

By way of contrast, high speeds, high loads, and high heat make active lubrication under pressure with oil absolutely necessary for ICE engine main "bearings", which aren't bearings at all, but bushings with oil galleys cut into them, while hypoid gears' very high pressure loads in manual transmissions require very thick oil that can stand up to molecular shearing, but no active, pressurized lubrication system is needed there.

At any rate, I leaned a ton of interesting and important information about grease, when it's used, and how to select it. There's a really brilliant blog post in this if I'm up to the challenge. I do want to assure you all though that I'm very happy with all the RX-es I've made on this blog, and in particular, I still think for ball bearings running at the speeds (50-250 rpms) and pressure loads of bicycle hubs, BBs, headsets (my special need notwithstanding) and pedals, pure Teflon grease directly on the balls, cups & cones, and Teflon fortified grease to displace dust, water, etc in the rest of the grease cavity, makes the best possible lubrication. 

 If this changes I'll shout it from the rooftops, but I don't see that happening for decades. FinishLine makes both the pure Teflon grease and the Teflon fortified grease. I bought some Krytox GPL 205 10yrs ago and paid $65, but it's gotten cheaper. I still have about 1/4 left, so yes, I use it sparingly, but it will never leave you metal to metal and is chemically inert, so it won't react to metal, plastic, paint, etc. If you're riding disk brakes and the hub is soaking up a lot of heat, PTFE grease is about as good as it gets.

With COVID-19 running rampant everywhere again, as predicted, please do take care to stay safe at all times - 90% of the time will get you killed with this remorseless executioner.

Look Carbon Keo Blade Pedals - CrMo

THANKSGIVING UPDATE: I had to repack these brand new pedals 6 weeks after receiving them as they were squeaking badly. YMMV, but why take the chance? Get the special 5-tooth tool if you can find it, but repack these bearings before even mounting them. They come with almost NO grease, I assume to keep claimed weight to the bare minimum, but that's a very poor trade-off IMHO.

 

I bought a pair of new Look Keo Carbon Blade CrMo pedals, as my Shimano Ultegra were getting pretty ratty, and the Look are $50 cheaper these days. In fact, you can get the Ti Ceramic Look Keo Carbon Blade pedals online for less than the list price of the Shimano Ultegra carbon. SMH. Not this guy.  $135 from Colorado Cyclist with the FALL discount (out of stock now I see), no tax, no shipping charges. 

They mount the same, but are positioned much differently, so it took a bit to get them dialed in, and is still a work in progress in truth. You CANNOT unclip from the Look pedals by twisting your heel inwards, which is my habit with my L foot, the one I always disengage. That's been problematic, but hoping with time my muscle memory will adjust. 

UPDATE: You CAN disengage by twisting your heel inward, but it takes ~ 3X the force. Weird, as the mech looks symmetrical. 

After the cleats wore into the pedals a bit, after about 25 miles I guess, I like them a lot. With 4.5 degrees of float they feel "liquid". They may be slightly less prone to hot-spots too, and I do think the bearings are a bit better, even the stainless ones on the CrMo version.

How I came to this decision is a bit of a long story with a happy ending. A friend was asking about bottom bracket bearing upgrades, and I pointed out that while people tend to obsess about those bearings, the bearings in pedals bear EXACTLY the same amount of force, but are much, much smaller bearings, so a better upgrade would be pedals. 

He then asked me about pedals, and I have him some basic guidance, like good pedals have large stainless steel (very hard, usually stainless, which can be as hard as 475 Brinell hardness, used in making steel plate targets for shooting practice) plates under the balls of your feet so they don't wear out. I sent him a pic of my Ultegra R8000 carbon pedals, but looking at the pics I noticed the left pedal's clip mech in the back was looking pretty ratty, and it started to bug me. 

 

After 6-7yrs, getting kind of ratty...

I conducted a Google Safari, looking around for good pedals for him and was intrigued by Look's Keo Carbon Blade pedals, which ditched the steel torsion springs in back for what Look calls a leaf spring, which is made of carbon fiber. They come in various tensions, 8, 12, 16 & 20 which you install "permanently" until you get sick of looking at them or just want to change the tension for some reason. Then you unscrew a rod and install a different "Blade" for a different tension, or the same one if you like the looks of the newer blade. They have a special TDF version, for example. Some have a pronounced carbon weave pattern, others are just black with decals.

 

While the lower weight was interesting from a design perspective, what I liked more was the over-sized main bearing next to the pedal arm. It's a cartridge bearing, very much like you'd find in the front wheel hub of your factory wheel. The outboard bearing is a tapered roller bearing, the same as the wheel bearings on your car. You can find the wrench to service the pedals, and a Ti axle to boot for a bargain price of $8.90 (with shipping) here on Ebay. I include it here just for the pics. The product may be crap, or fantastic. I have no clue. They're supposed to shave 22 grams off the already light CoMo pedals with the included ceramic cartridge bearings. Again, the roller bearing is molded into the pedal, so it cannot be replaced.

 Needle point roller bearings, the kind used by Look, are designed to take high axial and radial loads, as they have a lot of contact surface and are tapered in the direction of the axial load. Look's are embedded in the carbon pedal, and the machined taper on the spindle comprises the cone of the bearing, so only the tapered CroMo shaft, or Titanium if you've got an extra $150 bucks (you do get ceramic bearings for that price too) lying around, can be replaced, not the embedded bearing. 

You can service both bearings by cleaning and applying new grease. As the tapered roller bearing is moving pretty slow relative to a car, I would highly recommend using Teflon grease on it and then a Teflon-fortified wheel grease to fill the rest of the space in the pedal body to keep water and dust out. 

I have no experience with it, but Park's new PPL-1 PolyLube 1000 grease might be a good choice too. As for the cartridge bearing, Chris King is on record as recommending Mobil 1 motor oil for his wheel bearings. I'd choose something rather thick, and perhaps "Extended Performance for High Mileage" which has seal preservatives in it. Now you just have to figure out how to get old oil out of, and new oil into, sealed bearings. (???) The only thing I can think to do is use an electric drill to turn the bearing in a bath of new oil. Let me know if you have a tried & true method.

 

Happy trails!