Axs and osp: drivetrain inefficiency vs aero

Discuss light weight issues concerning road bikes & parts.
talltales
Posts: 90
Joined: Mon Mar 11, 2019 10:43 pm

by talltales

Imo, AXS will mostly just burn a much bigger hole in your pocket and for that reason you may try to prolong its use past the sell by date. - THAT is a sure fire way of reducing efficiency. If thats the case, you are likely better of just getting 105, replacing parts as often as needed.

by Weenie


wingguy
Posts: 4307
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

Stueys wrote:
Sun Oct 06, 2019 12:23 pm
I think sram said their flat top chain design was designed to offset the loss of drive efficiency from the smaller cogs.
I didn’t see any of that in the marketing. Just that it was to keep it strong enough.

RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

talltales wrote:
Sun Oct 06, 2019 12:51 pm
Imo, AXS will mostly just burn a much bigger hole in your pocket and for that reason you may try to prolong its use past the sell by date. - THAT is a sure fire way of reducing efficiency. If thats the case, you are likely better of just getting 105, replacing parts as often as needed.
Haha. I like that logic. I had thought of something similar. Same goes for tolerating more wear and tear over time hurting shifting quality.

mikemelbrooks
Posts: 52
Joined: Wed Jun 16, 2010 10:58 pm

by mikemelbrooks

philipeleven wrote:
Sat Oct 05, 2019 3:08 pm
bigger chainring reduce friction between outer and inner plate of chain, but increase friction between chainring and chain. the sweet point is somewhere between 15-25T, so AXS chainring reduce friction actually.
Do you have a source for this? I understand that making a chain articulate more around a smaller sprocket can increase friction but how does a larger chainring increase friction?
If you look at page six it shows a 53tooth ring having lower friction that a 39? This is with the chainrings aligned to the sprockets.
https://www.ceramicspeed.com/media/3502 ... report.pdf

Nautiboy
Posts: 13
Joined: Wed Jul 09, 2014 3:54 am

by Nautiboy

MaxPower wrote:
Sun Oct 06, 2019 7:07 am
Nautiboy wrote:
Sun Oct 06, 2019 4:16 am
RocketRacing wrote:
Sat Oct 05, 2019 11:42 am
I was watching the fastfitnesstips video where he made an argument for oversized pully wheels slowing you down over kona... when aero is factored in (30s over the bike course).

It made me wonder about the criticism of axs losing efficiency due to smaller chainrings/cogs. The smaller cogs should speed things up marginally with aero. But... axs also has larger pully wheels... at least slightly larger. I suspect the main issue for drag is medium and long rear cages.

All marginal gains/losses, but it is an interesting thought experiment.
Hi there, we can research or refer to all available data and video reviews out there but nothing beats doing our own "butt tests without being too overly technical about it" :D . For one, drivetrain efficiency is the most critical aspect for me versus aero-dynamic. Just buy the best aero bike on the market(which i have a few) and once the rider is on it, it almost nullify the advantages from the get-go. And what matters to the cyclist is the power output must be efficiently optimised and translates to tires rolling efficiency. Without an Oversized Pulley, my Garmin's data and body sensors always point towards a less than optimal performance.....so I will never leave home without it : )
BMC1.jpg

BMC2.jpg
Do you have experience with different manufacturers of osp?
I like the look of them and are thinking about it.
Shifting must be like factory setup though and the bearings must be able to take punishment (bad weather).
Hi Max, I have on 4 different brands including ceramicspeed. As mentioned, dun leave home without it. If you are keen in getting your hands on a Ridea...send me a PM...let me help you.

mrlobber
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Location: Where the permanent autumn is

by mrlobber

If you have cash burning, SLF Motion is coming out with an AERO oversized pulley system:
https://slf-motion.myshopify.com/collec ... ero-system

North of $500, of course.
Retired bikes: Cervelo S5 2015 / Felt AR FRD 2014 / Cannondale SS HM 2014 / Scott Addict SL 2014 / Scott Plasma Premium 2014 / Orbea Orca 2008 / Look 596 /

aeroisnteverything
Posts: 201
Joined: Fri Aug 24, 2018 4:43 pm

by aeroisnteverything

mrlobber wrote:
Fri Oct 18, 2019 9:49 am
If you have cash burning, SLF Motion is coming out with an AERO oversized pulley system:
https://slf-motion.myshopify.com/collec ... ero-system

North of $500, of course.
Oh joy. That looks fun to clean. Probably ok for top tier TT set up but not a daily thing. If you put this on a "normal" bike, the likely outcome is that your jockey wheels get dirty, you don't see it because it's all encased in a cocoon, and suffer increased friction loss as a result.

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wheelsONfire
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Location: NorthEU

by wheelsONfire

Why don't i believe all these things have a benefit in real world conditions!?
Everybody wants to go faster, isn't it time to see ourselves as the limiting factor?
E-bikes must be the answer if we truly want to notice anything :-)
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

ichobi
Posts: 971
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

wheelsONfire wrote:Why don't i believe all these things have a benefit in real world conditions!?
Everybody wants to go faster, isn't it time to see ourselves as the limiting factor?
E-bikes must be the answer if we truly want to notice anything :-)
And why does it have to be a binary choice? You can improve yourself AND your equipment at the same time....

Sent from my Pixel 2 XL using Tapatalk


RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

mrlobber wrote:
Fri Oct 18, 2019 9:49 am
If you have cash burning, SLF Motion is coming out with an AERO oversized pulley system:
https://slf-motion.myshopify.com/collec ... ero-system

North of $500, of course.
Might be i teresting for my tri bike assuming some wind tunnel data comes out that is favorable. At 45km/hr it all helps... but 0.5w or something at that speed and i would pass.

RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

ichobi wrote:
Fri Oct 18, 2019 3:10 pm
wheelsONfire wrote:Why don't i believe all these things have a benefit in real world conditions!?
Everybody wants to go faster, isn't it time to see ourselves as the limiting factor?
E-bikes must be the answer if we truly want to notice anything :-)
And why does it have to be a binary choice? You can improve yourself AND your equipment at the same time....

Sent from my Pixel 2 XL using Tapatalk
I am also always looking to make me and my bike faster. Aside from upgrading my legs, the biggest upgrade in speed for me has been buying a tri bike. Different planet for aerodynamics (and speed).

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wheelsONfire
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Location: NorthEU

by wheelsONfire

ichobi wrote:
Fri Oct 18, 2019 3:10 pm
wheelsONfire wrote:Why don't i believe all these things have a benefit in real world conditions!?
Everybody wants to go faster, isn't it time to see ourselves as the limiting factor?
E-bikes must be the answer if we truly want to notice anything :-)
And why does it have to be a binary choice? You can improve yourself AND your equipment at the same time....

Sent from my Pixel 2 XL using Tapatalk
Sure, but mostly for non pro, it's part of vanity. If we really wanted to progress towards compromiseless speed, we would go for a Tri bike.
It's mostly about position.
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

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wheelsONfire
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Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

I should add one thing, if a dude is top trained, i can see the idea of going for aero components, i really can.
But still, it is a Tri bike that would make the change towards higher speed.
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

bm0p700f
in the industry
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Location: Glermsford, Suffolk U.K
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by bm0p700f

This is not even 1st world problems. There are too many variables on a ride to ever determine if one groupset or another is quicker. All you can do is work out a theoretical advantage at particular yaw angles which may or may not translate into a real world gains.

by Weenie


RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

wheelsONfire wrote:
Sat Oct 19, 2019 8:57 am
I should add one thing, if a dude is top trained, i can see the idea of going for aero components, i really can.
But still, it is a Tri bike that would make the change towards higher speed.
Slower riders get more seconds on course saved for going aero. Simply because they are on course longer. Also, as a smaller rider, my cda and power is lower. So for me, a 5w drag reduction is more relevant (on percentage gain) than a larger rider losing the same 5w, but putting out 50w more power on average. It is interesting to look on strava leaderboards, and see my power output vs a competator, even on similar wind days, and tri bikes... and i am beating them with less power.

I have a weight weenie bike for climbing... but it is mostly intellectual masterbation, rather than vanity, as i know 3 or so lbs saved means almost nothing vs say tire choice. But it makes part of my brain happy.

I actually got a tri bike reciently for intellectual masterbation in regards to maxamizing aero. I wanted something engineered for max aero, with disregard for uci rules. I have yet to weigh it, maybe i never will. All upgrades have fit (aero) and speed (aero) in mind. It is my aero weenie bike. And there is no vanity to it (i think it looks incredible though). Quite the opposite as i am now a MAMIL with a big goofy tt helmet. But i can cruise at 45km/hr, and i can crush times with it. Flying somewhere to get wind tunnel time is next on my wish list.

But all the while, i have also added 100w to my ftp in the last year. The rider is a constant work in progress.

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