Back by popular demand, the general all-things Road forum!
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MagicShite
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by MagicShite on Tue Jan 30, 2018 4:38 pm
benzebub wrote: ↑Tue Jan 30, 2018 11:23 am
AJS914 wrote: ↑Tue Jan 30, 2018 6:52 am
So how do you interpret the 238 watts Emonda vs. the 208 watts Madonne?
Is it like your FTP is 30 watts higher, for example?
the way I see it is that you have to put out 30 watt less to maintain a given speed on the Madone (I don't know what the reference speed is, I believe it is 40 km/h)
Anyone else with more insight can help chip in on this one?
30 watts seems ridiculously high.
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Shrike
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by Shrike on Tue Jan 30, 2018 5:19 pm
An extra 30 watts isn't that much faster due to the high level of wind resistance at 40km/h. Wind resistance increases with speed and it's not linear.
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morganb
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by morganb on Tue Jan 30, 2018 6:24 pm
Shrike wrote: ↑Tue Jan 30, 2018 5:19 pm
An extra 30 watts isn't that much faster due to the high level of wind resistance at 40km/h. Wind resistance increases with speed and it's not linear.
40km/h is mid 300W range if you have a reasonably aggressive position on the bike. That is easily the difference between a threshold and high tempo effort for a decent level racer.
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Vallinotti
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by Vallinotti on Wed Jan 31, 2018 1:36 am
spartan wrote: ↑Tue Jan 30, 2018 2:35 am
http://www.tour-magazin.de/raeder/rennr ... 45739.html
was able to get the some more data from images i found online.
* disc brakes penalty is minimal *
disc aero bikes
propel advanced sl disc with stock wheels(42f/65r) 209 watts. with zipp 404 disc wheelset 206 Watts !!! weight 7.4kg
specilized venge vias disc with stock wheels(roval clx64) 209 watts. weight 7.5 kg
merida reacto disc team-e with stock wheels(dt swiss prc 65) 210 watts weight 7.5 kg
caliper aero bikes
cervelo s5 with stock wheels (enve ses 4.5) 207 watts. weight 7.1 kg
madone 9.9 H2 with stock wheels(aeolus 5) 208 watts. weight 7 kg. please note aero penalty H1 vs H2 heatube !!
a straight out comparison between Dogma F10 vs F10 disc. the bike had zipp 303 vs zipp 303 disc
Dogma F10 disc 214 watts 7.5 kg
Dogma F10XL 213 watts 7 kg
ability to ride wider tires with superior rolling resistance the 1 watt diff is all but eliminated.
only issue with aero + disc is weight.
the lightest bike was trek emondal slr h2 721 gm as aero as a brick at 238 watts
new swork sl6 delivers on the aero 221 watts but light at 850gm
pinarello f10 is the KING of grand tour bikes class leading aero and great weight 881gm
it is quite meanless to test a H2 Madone whether there is the H1 with less frontal area
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TonyM
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by TonyM on Wed Jan 31, 2018 1:43 am
Vallinotti wrote:
it is quite meanless to test a H2 Madone whether there is the H1 with less frontal area
I suppose they tested the H2 as this is the version which is by far sold the most.
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MagicShite
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by MagicShite on Wed Jan 31, 2018 2:09 am
morganb wrote: ↑Tue Jan 30, 2018 6:24 pm
Shrike wrote: ↑Tue Jan 30, 2018 5:19 pm
An extra 30 watts isn't that much faster due to the high level of wind resistance at 40km/h. Wind resistance increases with speed and it's not linear.
40km/h is mid 300W range if you have a reasonably aggressive position on the bike. That is easily the difference between a threshold and high tempo effort for a decent level racer.
I find that kinda hard to believe too.
Dropping from threshold to high tempo effort would make a world's difference to me when trying to go for a break.
30 watts is huge when you're really hurting at the front.
Maybe just maybe equipment makes some level of difference. Well, time to take out the piggy bank.
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prendrefeu
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by prendrefeu on Wed Jan 31, 2018 2:30 am
Cervelo S5 still doing nicely...
and if I recall correctly (but I may be wrong), the S3 is only a few watts "slower" than the S5.
Exp001 || Other projects in the works.
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ichobi
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by ichobi on Wed Jan 31, 2018 5:50 am
Emonda needs 30 watts more because it is specced and tested with extremely shallow wheels, round bar and MASSIVE tubing. (Tour result compared bikes with default spec). You can see that 404 does help a little but there is a substantial gap still between the Madone and Emonda. T’s like comparing two end of the extreme. Madone is one of the most aero bike out there. Emonda has no aero properties at all even if you compare it with other all around bikes (say tarmac, r5, ultimate). The handlebar alone will eat 5-6 watts. 30 watts are a lot still but possible.
Btw according to Cervelo engineer their new R5 carbon bar is about 3 watts slower than the S5’s but 2-3 watts faster than your average round bar. They are REALLy comfy though you should try one out.
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RyanH
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by RyanH on Wed Jan 31, 2018 6:21 am
I need to dig through my aero testing thread as I detailed their protocol but I believe the reference speed is much higher than 40k/hr. They use a half mannequin which is why the watts are low which kind of misleads the reader into thinking the frames are contributing to a greater percentage difference of the overall watts than they would with a full rider. Off the top of my head, add 200w to all of these numbers to get what the real world watts would be, roughly. It puts things into perspective a bit better to understand that we're comparing 411w for one frame vs 406w for another. Not nearly as significant.
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cunn1n9
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by cunn1n9 on Wed Jan 31, 2018 8:05 am
Everytime they run these tests the data seems to change slightly. They did a test a while back on the F10 and found it was as fast as the Madone. Now there is a different result. There is not a big difference which tells me that the margin of error in the wind tunnel is probably around 10W and that all the bikes in the top tier - Madone, F8/10, S5, etc are so close it doesn't matter.
Thoughts?
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Marin
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by Marin on Wed Jan 31, 2018 9:22 am
cunn1n9 wrote: ↑Wed Jan 31, 2018 8:05 am
Everytime they run these tests the data seems to change slightly. They did a test a while back on the F10 and found it was as fast as the Madone. Now there is a different result. There is not a big difference which tells me that the margin of error in the wind tunnel is probably around 10W and that all the bikes in the top tier - Madone, F8/10, S5, etc are so close it doesn't matter.
Thoughts?
Thoughts: Bar height and angle, seat height and angle, cabling length, front tire size and even pressure will affect the test results.
So the same bike will probably post different numbers if set up even slightly differently.
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micky
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by micky on Wed Jan 31, 2018 9:53 am
Yeah, frontal area seems to be much more important than frame shape and that's why the Madone in H2 made so much difference compared to previous Tour tests.