It sounds great. Someone neutral may want to dive into the efficiency of the system.

i am sorry to break it to you the hub has been in existen for a couple of years now its just now its being added by enve

if you search youtube there are already reports on efficiency of it (check peaktorque)

Yeah this is old and not an enve product. Already in use by some Parcours athletes in tri races, I think.

Clickbait thread title: one might think the OP @Rocky M has been under a rock since last year.
Enve: https://enve.com/...ions/classified-hubs

Hambini offers a technical analysis last year (key takeaway: theoretically inefficient in the shorter gear lengths):
https://www.hambini.com/...m-technical-details/
"The net result is an efficiency of around 96% (optimistic guess for the classified hub) and a total deficit of 4% vs a 2X conventional setup in low gears (93.1% vs 97%). Many people familiar with epicyclic gearboxes think that is an optimistic amount and suggest the efficiency of the gearbox alone would be around 90%. That would equate to a 2X drivetrain at around 97% efficiency and the classified system at around 87% system efficiency."
Other aspects worth noting are: bearings in hub cannot be replaced (return to Classified), and bespoke (expensive) cassettes.
https://www.researchgate.net/publication/226757576_Theoretical_and_Experimental_Efficiency_Analysis_of_Multi-Degrees-of-Freedom_Epicyclic_Gear_Trains Roymech https://roymech.org/Useful_Tables/Drive/Gear_Efficiency.html

In fairness, Hambini never actually saw or tested a hub. It was all pure conjecture on his part. Whereas Peak Torque (who seems like an all-round more measured individual!) actually tested the system & came up with numbers far closer to Classified's published claims:

Part 1: https://www.youtube.com/watch?v=rPVG2RA97Pg
Part 2: https://www.youtube.com/watch?v=wU6S01uITB8

I saw the system at a bike show last year & was quite impressed by how it felt. That was only on a turbo trainer but it could handle the measly handful of watts I could put through it.

I know Ruth Astle is sponsored by them & think Kyle Smith was riding it last year too. It would be interested to know how they have found it and whether it has helped their racing.

I think there was already a long thread about these hubs. IIRC the takeaway was that the hub is fixed in the big ring equivalent, so no efficiency losses expected, but the internal system is probably less efficient than all but the most extreme crosschains. You still have ~half of the cross chain losses in a 1x system and that is compounded by the little ring equivalent losses in the hub. These losses being offset by improved aero from no front mech is unlikely.

I'm sure the hub can handle any amount of watts you put through it, that's not the issue. It's the imperceptible loss of efficiency. Put two empty water bottles on your bike and it'll still ride perfectly fine, you won't notice any difference, but you'll go a little bit slower.

Also no word on long term wear of those tiny little gears.

Previous thread: https://forum.slowtwitch.com/...ified%20hub#p8016031

Ganna just used the Classified hub in the Giro while nuking the Stage 7 TT. 66T single ring in front.

(granted Pogacar and G. Thomas is still to start).

This TT is the perfect use case for them. 45 min of high speed aero-dominated racing followed by 5 min of climbing.

Just back of the napkin math, if the hub only has 95% of the efficiency of a normal setup when in "little ring" and 100% efficiency when locked, then the you'd lose ~15 sec on the climb. Seems reasonable that the aero gains are more than that over 45min, and that riders would only use the "little ring" for the very steepest sections.

I am hearing more and more the decision had nothing to do with the aero savings. It was all efficiency and shifting. Aero was a very small part of the decision.

Not super surprised by this. Despite how much people like to talk about the supposed aero gains of 1x systems, almost every time people have shown data it was very minimal. Not an aerodynamicist, but it seems to me that with how your legs move through that area, it would negate any supposed frontal area gains. Have you done any specific 1x vs 2x testing?

I could see that. Also there have been a few high profile instances of dropped chains on TT climbs. Happened to Ben O'Connor in his Giro TT. It's hard to "ride the chain back on" when you're on a double-digit ramp.

I could see it being of value to know you can shift at 600W with zero risk.

A 66 on the front gives them the equivalent of a 46 small ring (0.7x66), a 20 tooth drop that is pushing it on the traditional way of doing things.

Intrigued. The prevailing wisdom is even the most extreme cross chaining is ~5w, and looking on Wikipedia they say epicyclic gears can reach 97% efficiency. Those numbers just don't line up. Cross chaining should be a solved problem for a team like Ineos. Set the chainring sizes to get you in the proper chain line for most of the stage, big ring for the flat and little ring for the climb.

Unless they were very concerned about a chain drop and thought a small loss was worth mitigating that risk? Still odd, because the riders used the FD once in whole stage.

I want to learn more about it, just confused how the math works out.

I don't see even that, I see the text, "The efficiency loss in a planetary gear train is typically about 3% per stage. This type of efficiency ensures that a high proportion (about 97%)...."

With no obvious reference to look up where that number comes from.

But it's saying *typical* loss is 3%. Not minimum loss. It is not, to me, specifying a hard cap on the theoretical or practical efficiency of epicyclic gearing.

There was a brain worm I had about an Ineos drop. Finally remembered it. Ethan Hayter, 2022 Worlds TT. Fastest through the first split, then dropped a chain trying to shift into the 60T (Shimano FD). Had to do a full bike change.

Finished 4th.

That could leave scars in the psyche of the Ineos people making equipment decisions.

Fair, I was probably biased by memory of the last thread.

But-even if we believe Classified's claim of 99% efficiency, (dubious IMO), do we also believe that the loss is overcome by better efficiency in some other non-aero way? It's still a 1x setup at its core, the proposition would have to be that the keeping the chain inline as opposed to on the biggest cog is a bigger gain. Friction Facts showed big/big to be ~2w worse than optimal, and you can't even reach such a great on 1x.

No. And all data I have seen is quite old (previous gen stuff)

Well, I have a new guess at how/why Pogacar was able to put so much time into Ganna on the climbing section.

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Dimond Bikes Superfan

I think I could get them down to 99% if the internals were hardened steel gears and misc sliders etc.. Starting at about Rockwell 45 hardness. It is more difficult on soft metals.

I purchased a planetary Rohloff hub a few years back to see what we could do to reduce the friction. I think it was an equivalent 14 speed. Out of the hub the gears were about 7.0 micro inches "peak to valley" Ra7.0; not bad and typical of well made parts - we processed the parts and ended with about Ra2.2. That's about as good as we can do full production parts.
For "one off" pieces and a lot of effort we can get down to Ra 1.75ish.

We put the Rohloff hub back together and ran a light weight oil - it was cary smooth. So, I know we could do it but it takes some post machine processing and I don't know if they "can", "do" or "know how" to do that.

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Dan Kennison

facebook: @triPremierBike
http://www.PremierBike.com
http://www.PositionOneSports.com

OTOH, Ineos had 3 of the top 4 places!

This is really cool, I have so many questions.

The Rohloff looks similar enough in tooth count and design that you could approximate the Classified as a 2-gear version of it. The gear tooth shape as I understand is basically a solved problem, it's just imperfections and wear.

Did the Rohloff use 6 planet gears or 3? It's hard to tell from pictures

How many hours did it take to make a gear this smooth? Classified is needing to make 8 of these on every hub. I'm not saying they made a super version for testing and a cheap version for production, but it would be trivial to do so.

Would a harder metal help at all? I'd imagine you'd want to harden to the point of brittle failure.

How long does this polished surface last? If it gets worn down within minutes then it's kinda meh. But if it can maintain the finish for a few hundred k....



Also, since it came up, I'm obligated to say "You don't need a Rockwell test to characterize my hardness and penetration depth"

So - I’m out of the country right now on my iPhone, but I’ll pull up the testing when I get back.

I’ve done a lot of baked powdered metal parts and they turn out fine as long as they are case hardened. Hard just makes it easier for us. Think auto transmission engagement “T”’s. We did 10’ of millions for GM.

I do batch runs so we could do batches if 20 lbs of parts easily. We can do any metal but it takes time to refine the formula based on the item so volume of a specific item makes more sense when we look at doing an item. I do all that testing and formulation myself so it’s about getting my lazy butt to work.

We started with Formula Atlantic race car gears, CV’s, lobes, springs, lifters, crank shafts and latter did complete engine blocks - etc.. then wind turbine shafts, bike chains, anything metal that you want smooth. Massive reduction in heat.

The batch size is just a calculation of parts surface area volume/ chemical mix, media and machine capacity. So I can do a lot at a very low cost. More volume - lower cost. We did the transmission parts for .05 cents each but they sent us a lot of parts.

It does not wear out like a coating. We physically reduce the peaks so you end up with valleys for oil retention and little or no peaks. I would say the hub parts would last for 5k miles on a bike.

Our batches take about 3 hours to go from rough inbound to super smooth finished; plus packaging etc..

This is a video showing how we do chains - its not really how we do it because we did not want to show anyone the real process but you will get the idea :-) https://www.premierbike.com/...peed-optimized-chain

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Dan Kennison

facebook: @triPremierBike
http://www.PremierBike.com
http://www.PositionOneSports.com

Garant Thomas mentioned on his recent podcast that he was using the Classified hub though he could not remember the name of the hub..... so it is in the big leagues. I imagine with the Ineos Budget they could make the hub more efficient as described here.

I really like the concept of it and particulatly the 70% reduction and instant change.

Being able to run say, a 56t ring and get an effective 39 inside ring, would be great. (having just dropped a chain off the top and the bottom during a tri race. Sram....)

Downsides to me at the moment would be;
Proprietary cassettes that only go to 11 (so the 56 is only marginally better than a SRAM 50/10 ratio at 5.09 v 5). If you could get a 10/33 cassette, then that wouldbe great.
Weight - i understand there's a weight penalty, but is this a huge consideration in tri? Probably no more than te weight of an additional water bottle?
The efficiency - discussed at length above

I'd definitely look closely at it if i changed bikes.