Aero/Gains Thread
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Soldato
Pretty sure Revolver, and certainly Walker Brothers wheels are made in Ponteland up near Newcastle. Their discs definitely are as they're hand laid, made to order.
Soldato
Does being made in Newcastle make them more aero?
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Soldato
More than likely. The designs may actually be considered, rather than some open mould shape laced up by someone who probably couldn't tell you the first thing about their end user.
Soldato
I suppose since that Hambini test came out I've just got it in my head that rim is rim is rim. So short of running a front and rear disc, you might as well just have a rear disc, the deepest front you can handle in the wind, the fastest rolling tyres that don't light-bulb and not worry too much about the actual rim profile or who built it (providing it doesn't fall apart).
Marcin is running Revolver wheels as is Kyle Gordon who just done the long standing 50/100 mile records in Scotland last year.
Ribble/Huub WattBike are running WB wheels on road and track so they are more than proven by now.
I personally have no idea if a Chinese wheel is comparable either aero or quality wise.... I just know that none of the fast chaps touch them. I also do properly know that I would much rather speak with a lad in Newcastle about my wheel in the future than someone on the other side of the world
What I paid for this wheel is right in the ballpark of what it would cost for a new one from China anyway.
Ribble/Huub WattBike are running WB wheels on road and track so they are more than proven by now.
I personally have no idea if a Chinese wheel is comparable either aero or quality wise.... I just know that none of the fast chaps touch them. I also do properly know that I would much rather speak with a lad in Newcastle about my wheel in the future than someone on the other side of the world
What I paid for this wheel is right in the ballpark of what it would cost for a new one from China anyway.
Soldato
This is the test I'm referring too, interesting and controversial.
https://www.hambini.com/blog/post/bicycle-wheel-aerodynamics-which-one-is-fastest/
https://www.hambini.com/blog/post/bicycle-wheel-aerodynamics-which-one-is-fastest/
Soldato
Admittedly, I've only skimmed the article, looked at the graphs and read the conclusion so I may have missed the point:
The Hunt 50mm rim costs 10watts more than a Bontrager Aeolus 50mm rim at 30km/h.
The Reynolds aero 80 80mm rim costs 6watts more than a Mavic CXR80 80mm rim at 30km/h.
The conclusions even single out 2 manufacturers (Hunt and FLO) and say they are badly designed rims. I don't understand how you can take from that conclusion that all rims are equal?
Soldato
Well, those 2 data points (Hunt and Flo) could be anomalous and are the cause of all the controversy. If you take those out the general trend is towards deeper = faster with a handful of Watts between rims of similar depth. Hambini states these differences would be "difficult to detect". Also, you can see there are some Chinese rims mixing it up with the Pro Tour kit. If someone wants to buy a wheelset that's 2-3 times the cost for 3-4% gain then that's up to them. I'm just saying I don't see the point anymore and I'm definitely not at the sharp end of anything.
I don't know if @xdcx is running a rear disc but looks like a rear disc + 80mm front from Planet X would do the job. I don't know what data there is out there for Revolver wheels but seems like he's done the equivalent of buying a Venge because Sagan rides one.
I don't know if @xdcx is running a rear disc but looks like a rear disc + 80mm front from Planet X would do the job.
I don't know what data there is out there for Revolver wheels but seems like he's done the equivalent of buying a Venge because Sagan rides one.
Soldato
Things probably start to matter a touch more than "80mm front and disc rear looks better than a bunch of 50mm wheels" when you're competing in races that are often decided by a handful of seconds. There's clear documentation and testing which shows a fairly large variance in different discs regardless of tyre and frame interfaces, and so these things start to play a part when it matters. Not to mention decisions on tyres, tubes and pressures.
Fair enough if you're not competing and just want your bike to look nice with deep sections on the Saturday cafe ride, then I can see why you might save yourself a grand or so in the process. No need to constantly preach about it though.
Fair enough if you're not competing and just want your bike to look nice with deep sections on the Saturday cafe ride, then I can see why you might save yourself a grand or so in the process. No need to constantly preach about it though.
Soldato
It wasn't my intention to preach about it so I apologise and the aero thread is probably not the right place since marginal gains do matter to those here. I'll be keeping an eye out for xdcx's PBs next season though.
Soldato
I did intentionally include an example of 2 same depth rims with a difference in drag between them which were not from either Hunt or FLO.
It doesn't seem to me like there's anything groundbreaking in there? I thought it was common knowledge that, in general, deeper rims are more aero?
I'd agree with you that the marginal gains on offer are not worth the money for most of us but that test does show that there are real-world gains to be had for your money.
I think you've also missed the point in including the planet x disc wheel too. You can't conclude that it's a good disc when it was the only one tested.
It doesn't seem to me like there's anything groundbreaking in there? I thought it was common knowledge that, in general, deeper rims are more aero?
I'd agree with you that the marginal gains on offer are not worth the money for most of us but that test does show that there are real-world gains to be had for your money.
I think you've also missed the point in including the planet x disc wheel too. You can't conclude that it's a good disc when it was the only one tested.
Soldato
In the 50kph test your example does shrink to a difference of 3W.
I don't think I said it was ground breaking but the test protocol is trying to produce a more realistic model than the typical 'put object in tunnel and blow on it from multiple angles' approach. Hambini doesn't have an agenda either unlike tests by the manufacturers themselves or by websites/publications that may or may not be receiving bungs.
The test doesn't show that the PX disc is the best disc, but it says to me unless you aren't allowed to ride a disc due to rules, why wouldn't you?
I don't think I said it was ground breaking but the test protocol is trying to produce a more realistic model than the typical 'put object in tunnel and blow on it from multiple angles' approach. Hambini doesn't have an agenda either unlike tests by the manufacturers themselves or by websites/publications that may or may not be receiving bungs.
The test doesn't show that the PX disc is the best disc, but it says to me unless you aren't allowed to ride a disc due to rules, why wouldn't you?
while im not aerodynamic expert, i am fluid dynamic engineer by trade (i worked at rolls royce and also consultancy firms sub-contracted to rolls royce). my understanding of Hambini's conclusion is that if the tyre is too light-bulb shaped or if the interface between tyre and rim are not well designed, it causes air flow to detach from the rim. This means a low pressure area will develop just after the detachment, hence drag. This also means the air no longer travels along the depth of the rim, hence ((almost)) renders it pointless. This was partly demonstrated when Mavic launched those "lips cover" for their CXR wheels a couple of years back which smooths out the transition between tyre and rim.
Generally speaking, the larger the detachment, the lower the pressure in the void which causes a stronger vacuum (it never is a true vac, it's almost always partial vac), hence larger pulling back forces (drag). If there is nothing the designer can do to make the transition smooth, then one of the ways to get around this is to introduce a small "trip", this will cause a small detachment but can be recovered much sooner than not having one/larger uncontrolled detachment. You can see this done with a few products on the market at the moment (or at least they claim thats the theory behind it), Aerocoach socks, Ridley Noal/Jane series, some of the skin suits also have these small trips.
Generally speaking, the larger the detachment, the lower the pressure in the void which causes a stronger vacuum (it never is a true vac, it's almost always partial vac), hence larger pulling back forces (drag). If there is nothing the designer can do to make the transition smooth, then one of the ways to get around this is to introduce a small "trip", this will cause a small detachment but can be recovered much sooner than not having one/larger uncontrolled detachment. You can see this done with a few products on the market at the moment (or at least they claim thats the theory behind it), Aerocoach socks, Ridley Noal/Jane series, some of the skin suits also have these small trips.
Soldato
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Out of curiosity guys, seeing as I don't have a fancy helmet, bike, wheels, or aggressive position on the bike I'm wondering how my TTs would compare... Anyone here have any data around the 260W FTP mark?
27mile TT I did a few months ago.
1:15
262w
21.5mph
27mile TT I did a few months ago.
1:15
262w
21.5mph
Soldato
Depends hugely on kit and how aero you are. I know people doing 19s off those watts for a 10, for me I needed 340w+
Soldato
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I'd say high 23 low 24 depending on course.
I've put a 24.06 out on a hilly as hell course with a good few turns. My ftp this summer was around 300w at 75ish kg but that time I did before i wasn't as fit so somewhere nearer your watts. Flat out and back course would be better of course
I've put a 24.06 out on a hilly as hell course with a good few turns. My ftp this summer was around 300w at 75ish kg but that time I did before i wasn't as fit so somewhere nearer your watts. Flat out and back course would be better of course
Soldato
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That's my point... I'm wondering how much I'm giving away in position and kit.
I made it to 69kg for ironman, this was around 3 weeks after so I'd guess 70-71kg, after a 12 hour night shift and a donner kebab.
So 3.75w/kg for the hour
3.89w/kg was my 20 minute best
I had the 'gotta pull a marathon from somewhere' mantra going on for the bike fit... So it's pretty relaxed. I think removing the arm pad spacers and an aero helmet would help massively.
Soldato
260w got me sub hour on a pretty terrible 25 course. I was going 22s for a 10 on similar roads at 10 mile power (c280w). Similar weight to yourself.