This is an interesting design - very elegant. I think most of what Hanibi is saying in his review is correct; however some of the losses could be mitigated at a cost.

Lubrication sticktion is another issue whenever you have that may moving parts in a lubricating film.

Years ago I purchased a Rohloff hub (14 planetary gear hub) and performed micro polishing of all the internal parts (remove most of the friction) to see if I could make it more efficient. My thought was to make a super smooth zero weight oil hub like theirs - placed inside a disc wheel and then you would just have one cog in back and one chain ring in front [no front mech]. Efficient and aero was the thought process.

I did a lot of work but ran out of energy on the project :-)

I'd love to take these Classified internals and micro finish all the internals and see what could be accomplished.

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Dan Kennison

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

As you say "surely".
Please point us to where Classified state the system's efficiency. I guess here:
https://www.classified-cycling.cc/...iciency-measurements
They rely on size of chainring/sprocket (larger - better, so a 50-25 is better than a 34-17) and less cross chaining (losses actually small (<1%)). But in the 0.7 ratio (in hub) there will be losses. In the turbulent flow behind the shoe/crank the FD drag contribution is rather small ( but helps sell 1x).
Wiki: "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%) of the energy being input is transmitted through the gearbox, rather than being wasted on mechanical losses inside the gearbox."
Hambini's analysis suggests how the epicyclic gearing works and makes the reasonable assumption of 96% efficiency (for the 0.7 ratio). Did you know/understand all this already?
In the FAQs:
"How efficient is the hub?
Very efficient!
More efficient than a 1x setup and as efficient as a 2x setup.
Compared to a 1x, less cross chaining is required, sprocket and chainring sizes are larger and thus chain tension, crank and hub bearing losses are lower.
Compared to a 2x; the fact that the 0.7 ratio of the hub still uses the large chainring in front, results in 30% less chain tension and thus lower chain, crank and hub bearing losses."

I'm not claiming to necessarily know one way or the other here - I wouldn't claim to be an expert on planetary gearbox efficiency or whether it can be improved beyond existing levels (quoted 96-97%).

What I do dispute however is if a questionable expert like Mr. Hambini can support his "analysis" having never actually seen a Classified system in person let alone tested it. As far as I'm concerned the video is just clickbait to appeal to his tin-hatted followers.

Meanwhile I don't see much data on the Classified side either. I'd like them to be more open about their testing and publish some numbers. Including the breakdown of savings between chainline improvements and aero gains set against any gearbox losses. Or if they do not or will not then surely someone independent can?

Glad you enjoyed the video. Though self-proclaimed 'no expert' you do seem, without any basis, to take a perjorative line on Hambini's generous effort to inform and opine. Should we just rely on the marketing? Or shout 'surely someone (independent) can test this'?
Roëll van Druten can shed light on this.

Couldn't agree more. I'd love to see it.

As for Hambini we're going to have to agree to differ on this. You'll have to forgive me for not giving any credibility to a proven bully who has been shown to have most likely falsified an "aero study" on wheels not to mention had to be visited by police over his misogynistic abuse of a female journalist. I'm sure some of his engineering know-how might be of use to the cycling world but he rather seems to have fallen into the trap of believing his own hype. Watch any of his videos now (trust me I've tried!) and he's just playing up to the crowd rather than adding much useful critique.

Do I understand right?

Classified says « very efficient »
Hambini says « I have no data but doubt it is »*
You say « I have no data but I doubt Hambini is right, because he has no data »


I think that’s an auto-kill. ;-D


*(that’s a summary of his video, he does not hide the fact that he has not measured, but at least he states his assumptions)

Indeed. Beware the bicycle industrial complex. A modern day Ralph Nader, Hambini is an inspired guardian of the common cyclist.

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________
It doesn't really matter what Phil is saying, the music of his voice is the appropriate soundtrack for a bicycle race. HTupolev

"I wouldn't claim to be an expert on 'anything'except being able to spot a questionable expert"
Here's a few seconds where Hambini points out that the Classified quoted efficiency is at 110rpm at a power of less than 50; basically (assumed) cherry picking a frantic but glass slipper scenario (torque ~4Nm - 170mm cranks).

Looks like they have a disc wheel now. According to the story there were some pros running it in Ibiza over the weekend. I had a go on the system at a show last month & sure enough it shifted back and forth really nicely. The guy on the stand said there was some more detailed efficiency testing that Classified have done but he wasn't from Classified himself so couldn't point me to it.

https://www.cyclingnews.com/news/new-classified-wheel-tech-spotted-in-ibiza-triathlon/

If the marketing and test data really stood up to scrutiny then GPLama and DCRainmaker would have been offered them for review by now. The fact that the “GO TO BIKE TECH REVIEWERS” on YouTube haven’t tested it speaks volumes.