Classified hub - Is this the new big thing?

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Pato
Posts: 66
Joined: Wed Apr 22, 2020 12:14 pm

by Pato

@RoadDonk82, that's a good analysis but I disagree with the mtb design. Sram has designed shit gear ratios in mtb even though mtb riders don't like it. Their 11 speed cassete is already s...t, basically a 11-36 with the addition of a 42t and replaced the 11 for a 10.
When Shimano later came out with their 1x cassete it was an 11-36 with a 40, maintaining a perfect gear ratio for each step. Not happy about it, Sram responded with their 12x. Instead of a proper re-design, like they should have, they decided it was a great idea to add a 52t on top of the 42, which was already flawed to begin with.
Shimano 12x has a 10-45 with perfect jumps between gear and a 10-51 equally good.
Sram is just lazy engineering their cassettes with the marketing claim on total gear range BS, and they tried to apply the same on AXS. Reality is they are being lazy and cheap.

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Miller
Posts: 2764
Joined: Thu Sep 21, 2006 8:54 pm
Location: Reading, UK

by Miller

Road.cc reporting today that classified has come out with a 13sp cassette for Ekar.

TobinHatesYou
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by TobinHatesYou

So Classified took Ekar, which didn’t have range problems…and gave it range problems…

Ekar’s largest official chainring is 42t. Ratio makes a 44t. Classified’s 11t limitation severely limits the top end. Compound this with the fact that many gravel bikes have 1x chainring size limits, not a great package.

44x11 ain’t big enough for racing Mid South, Unbound, etc. or any mixed surface races really.

I assume Powershift v2 will package the planetary gears in a way that allows 10t cogs and that the module will be a drop-in replacement with the existing hub shells.

BigBoyND
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Joined: Mon May 31, 2021 1:51 am
Location: Berlin, DE

by BigBoyND

RoadDonk82 wrote:
Fri Mar 17, 2023 9:46 am
It seems to me there is a lot of confusion about how gear ratios work in this thread. Let me comment on a few...
Yeah I agree with the the gear-distance point (as I also tried to explain).

What I don't agree with in your post is the relevance of std deviation since I don't spend equal time in all gears. You lower the average change in cadence by having smaller jumps in the middle of the cassette (where you spend more time) and larger on the ends.

Also, average % is relevant in this comparison because Sram has tighter gearing at the front (13t vs 16t) which requires a broader gearing in the back for the same system range. That increases the % gearing difference across sram's cassette.

ichobi
Posts: 1793
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

This is good discussion going on here. In general and going back to sram philosophy a bit - for axs i do think they make the perfect sense, unless you are a pro (ironically the red axs is ridden by the pros). I discuss this in the context around the time the axs cane out - 4 years ago. Axs has two merits (keep in mind the intended customer, amateur riders)

Two merits
- 13t difference in front chainring = no big jump between the rings but more importantly the downsizing of the front ring allow for more time in the big rings even with slightly steep gradient. This is how sram would counter the “lower efficiency than competitors product” as quite likely you would be in a small front ring at the same gradient.

- close to 1:1 ratio without big jump in cassette - really the merit of 12 speed design, this no longer applies given all 3 brands have 12 speed now but at the time canpy eps was expensive and hard to source with no affordable choice for pm option.

So take it all together if you choose your axs set up carefully you will be in the big ring most of the time and use that 33t as a bailout option only. Given you will be in the big ring the efficiency point is a wash (they would argue).

So theoretically it seems perfect and convenient but in reality when you do concern about efficiency, the flat top chain is measurably 1-3 w slower than da chains (zerofriction test), plus the 10t when you have to use it. But this is where standard deviation doesnt apply since you are unlikely to be in the biggest and smallest sprocket most of the time.

This also illustrate, in real use, why it’s hard to compare efficiency of the sram system to lets say dura ace.

This all goes out the windows of course if you are pros or race. That small front chain ring and 10t will really haunt you. When sram came out with pro version chainrings it looks almost like an admission of failed design. Now everything is heavier with one useless sprocket.

Personally the tradeoff was very good for me.

While not directly related to classified it would be interesting to see the nuance in real life usage and how can we make solid comparison in efficiency between the system.

StiffWeenies
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Joined: Sun Feb 28, 2021 3:39 pm

by StiffWeenies

TobinHatesYou wrote:
Fri Mar 17, 2023 9:14 pm
So Classified took Ekar, which didn’t have range problems…and gave it range problems…

Ekar’s largest official chainring is 42t. Ratio makes a 44t. Classified’s 11t limitation severely limits the top end. Compound this with the fact that many gravel bikes have 1x chainring size limits, not a great package.

44x11 ain’t big enough for racing Mid South, Unbound, etc. or any mixed surface races really.

I assume Powershift v2 will package the planetary gears in a way that allows 10t cogs and that the module will be a drop-in replacement with the existing hub shells.
Stone has 46, 48 and 50T chainrings for Ekar 123BCD

so we're looking at what is effectively 50/35 11-36T 13s

RoadDonk82
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Joined: Wed Feb 08, 2023 2:43 pm

by RoadDonk82

What I don't agree with in your post is the relevance of std deviation since I don't spend equal time in all gears. You lower the average change in cadence by having smaller jumps in the middle of the cassette (where you spend more time) and larger on the end
So take it all together if you choose your axs set up carefully you will be in the big ring most of the time and use that 33t as a bailout option only. Given you will be in the big ring the efficiency point is a wash (they would argue).
I imagine this is what SRAM designers were thinking. The problem is it only works if you ride somewhere generally flat with occassional short (even if steep) hill you may want an emergency gear for. If you ride in the mountains though you will be spending long time going up. Anywhere from 30 minutes to several hours on a climb. You don't want "bailout" gear for that. You want to spin at comfortable cadence with changing gradient. Afterall you will spend about 3x more time in those easy gears than you will going fast. If you look at pro riders who upload their rides with cadence data, for example Remco, you will see they spin evenly durig those long climbs with 80-90rpm cadence. I want the comfortable spin as well and to have that I need close to 1-1 gear and decently close gears near it. Remco uses something along the lines of 54-40 with 11-30 (I suppose). If you are around 4W/kg rider and want to have similar experience to him when it comes to gear ratios and cadence you want something like 50-34 with 11-34 cassette (or even 48-32 in front).

Now, here are the ratios for new 12 speed Shimano cassette:
12 speed cassette
['11 ', '12 ', '13 ', '14 ', '15 ', '17 ', '19 ', '21 ', '24 ', '27 ', '30 ', '34 ']
['1.091', '1.083', '1.077', '1.071', '1.133', '1.118', '1.105', '1.143', '1.125', '1.111', '1.133']
average jump: 1.108
Std dev: 0.024
to get close to 1-1 with SRAM you would opt for something like 46-33 and 10-33 cassette. 10-33 cassette offers those ratios:
['10 ', '11 ', '12 ', '13 ', '14 ', '15 ', '17 ', '19 ', '21 ', '24 ', '28 ', '33 ']
['1.100', '1.091', '1.083', '1.077', '1.071', '1.133', '1.118', '1.105', '1.143', '1.167', '1.179']
average jump: 1.115
Std dev: 0.034
16.7% and 17.9% jumps are not fun if you are actually using the cogs for significant time and not only the jumps, it's just hard to find a gear so you can go up that mountain without either grinding or spinning too fast.
It's "bailout" philosophy - works on flats, sucks in the mountains.

I had two experiences on the road where I thought "wow, this jump is uncomfortable". One was when I was using 11-34 cassette on my gravel bike and changed from 13 to 11 cog. It just terrible on a 11 speed and prompted me to change the cassette to 11-32. 11-34 is the only cassette Shimano produced with this jump and didn't repeat the mistake with 12 speed (they chose to plug two big holes at the cost of a bit bigger jumps in the middle). Another experience was on a rental SRAM Rival AXS bike: I agree you stay in the big ring longer. I agree it's great on flats or mild gradients one way or another. Once you go up the mountain though it sucks as the jumps are huge.

I imagine this is not a problem for pros as 10-30 cassette is actually quite good:
12 speed cassette
['10 ', '11 ', '12 ', '13 ', '14 ', '15 ', '17 ', '19 ', '21 ', '24 ', '27 ', '30 ']
['1.100', '1.091', '1.083', '1.077', '1.071', '1.133', '1.118', '1.105', '1.143', '1.125', '1.111']
average jump: 1.105
Std dev: 0.022
Pros are strong so they will happily use that 39-30 as their last gear and still spin up the 8% grade and have close gears when the gradient changes. For amateurs though, even quite fit amateurs the experience is going to be completely different though. With Shimano it's going to be very similar if you opt for smaller front rings and 11-34 cassette.

basilic
Posts: 1028
Joined: Wed Jan 05, 2011 8:05 am
Location: Geneva, Switzerland

by basilic

TobinHatesYou wrote:
Sun Feb 26, 2023 7:48 am
You don’t understand gear-distance.
Ha! neither do I. What does it mean?
I've read the about gear-inches in English, but in France/Switz./Italy the concept is unknown. We talk about "development" = distance traveled for one crank revolution.
But gear inches are much too short.

StiffWeenies
Posts: 613
Joined: Sun Feb 28, 2021 3:39 pm

by StiffWeenies

Just thinking aloud here

What if you took the Classified hub and paired it with a 2x groupset to create a 3x setup?

Take 54/40 chainrings, when on the small ring activate Classified's 0.7 reduction gear for a virtual 28T. 54/40/28 would be like a throwback to old school 52/39/30.

pair it with Classified's 11-28T 12s cassette and you have yourself a 1:1 bailout gear with better chainline than a 1x crankset

and if a SW-RS801 satellite switch could be modded to work with the handlebar unit, you can have yourself an OEM looking installation on a compatible cockpit like Pro Vibe Evo or BLKTEC R8

ghostinthemachine
Posts: 780
Joined: Thu May 07, 2015 9:18 pm

by ghostinthemachine

Used to see it a lot BITD. Crusty old tourists with a SA 3 or 5 speed hub gear, 5 speed freewheel and a triple.

Range of gears from about 10" through to 140+"

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