2020 Aethos Sub UCI weight Specialized.

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Moderator: robbosmans

What defines the rumoured UCI Illegal Specialized

Doesn't Exist
75
24%
More aero than the Venge
39
12%
Lighter than the Tarmac SL6
139
44%
More aero than the Venge AND lighter than the Tarmac SL6
36
11%
Not sure
27
9%
 
Total votes: 316

Arnomatic
Posts: 62
Joined: Mon Feb 24, 2020 12:44 pm

by Arnomatic

4.7kg Aethos used by Rebecca Richardson at the UK national hill climb champs. Just feautured on the BikeRadar channel. Too tasty not to share!
Attachments
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by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
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idinfo68
Posts: 135
Joined: Wed Nov 05, 2014 9:35 pm
Contact:

by idinfo68

Arnomatic wrote:
Mon Nov 08, 2021 4:15 pm
4.7kg Aethos used by Rebecca Richardson at the UK national hill climb champs. Just feautured on the BikeRadar channel. Too tasty not to share!
30 x 25 (?) and no comfort at cokpit...!
www.baron-noir.com

Specialized Aethos SUB5
Specialized Tarmac SL8 - 5.35 kgs
Specialized Tarmac SL6 - 5.16 kgs
Scott SPARK RC 900 SL SUB 8
Specialized Epic HT - 6.18 kgs

FlatlandClimber
Posts: 2491
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

Definitely brutally light, but does it not have a power meter?
30x25 doesnt appear that efficient of a gearing on an 11% climb.
Lastly, probably a grippier rear tire would have been faster...
Cervelo P5 Disc (2021) 9.1kg
Factor Ostro Gravel (2023) 8.0kg
S-Works SL8 (2023) 6.3kg

*weights are race ready, size 58/L.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT, Crux, Aethos, SL7

maquisard
Posts: 3772
Joined: Thu May 01, 2008 8:51 pm
Location: France

by maquisard

Yes, seems a very strange choice to go small chainring, small cassette. The efficiency of using a large chainring and cassette would easily offset any weight cost of this setup.

Also agreed completely on rear tire!

BigBoyND
Posts: 1347
Joined: Mon May 31, 2021 1:51 am
Location: Berlin, DE

by BigBoyND

FlatlandClimber wrote:
Mon Nov 08, 2021 8:54 am
The biggest part of the money goes to Specialized and the retailer you buy it from, so you can rest assured, that America gets to spend it on a new fighter jet or something.
Yes, most. If you don't think the remaining $200-500 matters, thats fine, but some people care.

Tifosiphil
Posts: 359
Joined: Wed Nov 14, 2018 11:09 pm

by Tifosiphil

FlatlandClimber wrote:
Mon Nov 08, 2021 4:41 pm
Definitely brutally light, but does it not have a power meter?
30x25 doesnt appear that efficient of a gearing on an 11% climb.
Lastly, probably a grippier rear tire would have been faster...
Probably could be using a more efficient gear but I seem to remember her saying that the cassette was just what she uses on the standard set up so a slight cost saving. She was running a crank based PM on the other side

FlatlandClimber
Posts: 2491
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

I understand these racers aren't "Money no object". However, I don't know how sensible it is to spend 5 grand on a disc brake frame and set it up with ultra high end components, that only make sense for this specific discipline, to then "skimp" on the cassette.
Tiny chainring + tiny cog + the bad chainline of 1x with being forced to almost exclusively use the outer most ring + being forced to ride a pretty low cadence has to cost *BIG* watts.
According to Strava, the segment is 900m Long with 13% average. Her finish time was 4:13. Around 12.9kph average.
My guesstimation is, something like an 7.5kg Open Up with GRX 610 46/30 11-34 or SRAM Force WIDE 43/30 10-36 and a all season low pressure rear tire would not have been a slower option...

Still love a crazy light Aethos though.
Cervelo P5 Disc (2021) 9.1kg
Factor Ostro Gravel (2023) 8.0kg
S-Works SL8 (2023) 6.3kg

*weights are race ready, size 58/L.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT, Crux, Aethos, SL7

BikeTyson
Posts: 422
Joined: Fri Oct 15, 2021 3:16 pm

by BikeTyson

Article says its a 32t front chainring, and only 5 cogs in the back. Looks like she used spacers like a single speed to create a 5 cog cassette with a centered chainline.

Image

FlatlandClimber
Posts: 2491
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

Okay, nevermind what I said about chainline then. Still a little confusing to prioritize things in this way.
Cervelo P5 Disc (2021) 9.1kg
Factor Ostro Gravel (2023) 8.0kg
S-Works SL8 (2023) 6.3kg

*weights are race ready, size 58/L.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT, Crux, Aethos, SL7

Lina
Posts: 1060
Joined: Sat Sep 01, 2018 9:09 pm

by Lina

How much wattage savings from better efficiency are you expecting there'd be with a larger chainring and cassette? These aren't 9/10t cogs we're talking about.

FlatlandClimber
Posts: 2491
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

Not a huge amount really. Don't think there is more than 1Watt in there.
The chainline would have really been a much bigger factor. I tend to forget these bike are modified to a greater degree than I would want to go.
The biggest gain potentials I see are:
- larger cogs
- wider grippier rear tire.

With the climb being wet that day, and over 15% average for 600 of its 900 total meters in length, traction is a big factor. Obviously a wider rear tire can help there. However, the rather "big" gear of 30/25 will force the rider out of the saddle more frequently or force you into an unnaturally low seated cadence. Getting out of the saddle on such a climb can be problematic. Standing pedaling against the high inertia on a climb means you'll pedal at high torque, so tire slippage is very likely.
I don't even know if that was a problem of hers, just heard that several people that day struggled with that, and that the winner had a Pirelli 4S rear tire.

Probably enough off topic.
Cervelo P5 Disc (2021) 9.1kg
Factor Ostro Gravel (2023) 8.0kg
S-Works SL8 (2023) 6.3kg

*weights are race ready, size 58/L.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT, Crux, Aethos, SL7

maquisard
Posts: 3772
Joined: Thu May 01, 2008 8:51 pm
Location: France

by maquisard

FlatlandClimber wrote:
Tue Nov 09, 2021 3:44 pm
The chainline would have really been a much bigger factor. I tend to forget these bike are modified to a greater degree than I would want to go.
Because you are sensible and understand the whole system. Many riders add custom modifications to bikes in the belief they are making it better. In many cases they are making things worse. It is better to take simple pragmatic steps such as the rear tire and gearing choice you suggested. These will make much better improvements than larger jockey wheels or missing cogs on the cassette.

Butcher
Shop Owner
Posts: 1925
Joined: Sun Jan 03, 2010 4:58 am

by Butcher

Sometimes it's not what matters but what you think that matters. It's amazing what people can do when they have to. Kids under the car, no problem, I will lift the car off the kid. Could they do it again, no.

So if you know you have the bestest of the best, lightest of the light, then it's possible that your brain could operate in a way to make the win happen.

Many times, it's just a mental thing. She placed well.

maquisard
Posts: 3772
Joined: Thu May 01, 2008 8:51 pm
Location: France

by maquisard

Unless it breaks during the race or the chain falls off...

Anyway, off topics, onwards!

BigBoyND
Posts: 1347
Joined: Mon May 31, 2021 1:51 am
Location: Berlin, DE

by BigBoyND

FlatlandClimber wrote:
Tue Nov 09, 2021 3:44 pm
Not a huge amount really. Don't think there is more than 1Watt in there.
The chainline would have really been a much bigger factor.
By "much bigger factor" how much do you think it is?

Look at the table for 5 cog misalignment, which is the max misalignment on 11sp 1x. It suggests 1.4W:
https://ride.diamondback.com/friction-p ... rivetrains

Both of these factors are overblown. 1W for small cogs and 1.5W for cross-chaining, resulting in 2.5W difference between best-case and worst-case.

Now multiply that 2.5W by the amount of time you spend in that cross-chained 11t position (1 - 10%?) to get average losses for the ride (0.02 - 0.2W?). These are so miniscule I don't even know why it's a topic at all. Intuition fails us here, I guess.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
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