CeramicSpeed Over sized pulleys, BB, and Headset on my R5. Everything is much smoother and quieter them stock. The Headset is the sleeper value, even at $300 MSRP. Super smooth, and absolutely adjustment and rattle free. 4-6 year warranty seals the deal.

I think the basic gist is:
1) Oversize means a less tight angle for the chain, and as such supposedly less friction
2) Ceramic Bearing also reducing a bit friction (in the bearings v. non-ceramic one)


That being said, I believe this is one of the investment with the worst Watts/$$ ratio.. but they do look cool IMHO :)

Thanks! Yeah I’m quite familiar with the idea that the actual savings is very minimal, I just wasn’t even sure why there are any claimed savings.

So, can you stick oversized pulleys on any Sram or Shimano RD or is there a compatibility issue such that you need to buy entire RD Cages?

You would need a new cage if you want OS pulleys.

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And then hope it doesn't shift worse

This was a big lightbulb moment for me when I first heard it. Especially when rotating cranks without a chain. They move easy and spin a couple times then stop. But there is a difference when under a load as the bearings are more likely to actually roll instead of slip as well as some subtle thermal expansion factors that tighten up the system and make the grease in them a little more "slippery" that you just don't get by flicking a pully with your finger or spinning your crank.

It's pretty easy to freak out about your BB installation if it doesn't sit there and spin for a full minute after you give your cranks a spin. :)

Honestly, this should be the only reply and the thread should be locked. People don't buy OSPW and fancy ceramic bits for performance. They buy them as bike bling...

At Imola the TT bike photo gallery seemed to reveal a few. I did not look into if they were on the bikes out of personal preference or sponsor obligation though.

But........Ganna.......no OSPW system.

Derailleur pulleys are loaded about the same either way, though. With other bearings the loaded condition will add friction... but if the friction is high without a load, it will only get worse when loaded. If seals and new grease are causing friction I wouldn't worry. If it's misalignment and corrosion though...

Shimano Durace and maybe XTR (the cartridge bearing ones anyway) test very well, but not the others. So do other cartridge bearing pulleys. No need to spend a lot.

This. I helped a friend do aero testing on his OSPW and they were marginally slower than standard Shimano pulleys; I assume because of the additional size.

We also think that the Shimano kit had more consistent accurate shifting.

What type of bearings are in your headset?

The price. Obviously if it costs more it will be better. Duh!
Also stock groupset components rarely have any ceramic, carbon or titanium parts. We all know these materials make you faster, it doesn't really matter how you use them....

Surely this is meant in jest?
$300 headset bearings are your value tip?
You do realise the headset bearing is only there to allow you steer the bike?
Standard steel bearings are perfectly adequate. I can't see any reason whatsoever to spend a fortune on expensive "upgrades".
If you've noticed a significant improvement in smoothness, I'll bet it's because the original headset was poorly adjusted or maintained. Not because the new one is a superior solution.
I find it hard to think of a less appropriate place to spend money on exotic bearing materials.
My stock headsets have typically been smooth, and adjustment and rattle free too. I don't know if there's more than a 1 year warranty but why would I worry about it when a replacement costs maybe $30?
Some things are worth investing in, others are just solutions for non-existent problems.

I'm surprised that conventional testing could pick something in this area of the bike up ? (that far back, that turbulent and that small). What was the difference in CdA ?