I see! Well the foil is very bloody stiff. I understand its one of the lesser of the aero road bikes out there, but gee she sprints really nicely
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Re: New Tour tests of 2015 aero road bikes [jackmott]
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Re: New Tour tests of 2015 aero road bikes [Dunbar]
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Dunbar wrote:
jackmott wrote:
duncan wrote:
Maybe that's the consequence of fattening up the head- and downtubes to increase stiffness.
Or of having mechanical cables instead of di2?
Though I think difference would be minimal with that handlebar
According to Felt the mechanical cables add 7w@25mph on the AR. On the AR that's with the cables running into the downtube vs. behind the stem with electronic. The S5 runs the derailleur cables behind the stem which is more aero. But still, I'd bet di2 S5 saves at least 2-3w at 30mph. I believe Superdave said the drag of cable housing is proportional to the length of cable housing exposed to the wind.
I'm working on getting 2-3 watts saved on my Di2 set up with a little drillium.
-SD
https://www.kickstarter.com/...bike-for-the-new-era
Re: New Tour tests of 2015 aero road bikes [jackmott]
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jackmott wrote:
Well if you believe that you fully aero bikes aren't stiff enough or comfy enough, then a semi aero bike makes sense. If you can't get a fully aero road bike down to the minimum weight limit, and you tend to make your move on big climbs, then a semi aero frame might make sense.
If you just like having a light bike for the fun of it, then an semi-aero bike makes sense.
If I had tour de france talent, and was racing a mountain stage, I might look and see whether the R5 would let me run deeper wheels at the weight limit and be overall faster than the S5 with shallow wheels.
semi aero bikes are usually cheaper than their full aero counterparts. An R3 is a lot cheaper than an s5
coates_hbk wrote:
curious to your input- what is the purpose of the semi-aero then? If you were choosing a roadie, depending on the geography where you ride, wouldnt you only choose an aero or light bike? is the semi-aero simply the 'first step' to the current generation aero bikes?
Ps- i have a foil and i love how that thing sprints!
But a stock AR FRD is already 6.8kg and it only needs a swap to GP4000 to make it fastest among those tested. So if you chose an R5, which wheel would you use to bridge the delta between the frames?
-SD
Re: New Tour tests of 2015 aero road bikes [cyclenutnz]
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cyclenutnz wrote:
Ex-cyclist wrote:
Do you know what the delta was between the s2/3 and s5. I don't have the raw data. I know Damon said if they were set up identically he said it was around .005 CdA.Unsurprisingly that was one of the first data sets I digitised
If I apply a symmetrical distribution, centred on 8deg and covering the full sweep it yields a weighted average difference of 0.0045. Obviously wheels are different but other bikes show them to be very close in performance.
It would appear that, unlike many in the industry, Damon doesn't just make numbers up. Also gives more credibility to this test.
Except that in the Tour test the S2 had standard round bars and the S5 had the new Cervelo aero road bar, while Damon was talking about the difference only from changing frame and forks. So again this suggests that either the Hadrons are faster than the 404s, or the Tour tests are failing to identify a significant improvement from the aero road bars.
Re: New Tour tests of 2015 aero road bikes [duncan]
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duncan wrote:
Except that in the Tour test the S2 had standard round bars and the S5 had the new Cervelo aero road bar, while Damon was talking about the difference only from changing frame and forks. So again this suggests that either the Hadrons are faster than the 404s, or the Tour tests are failing to identify a significant improvement from the aero road bars.They haven't shown a big advantage for any of the aero road bars. Perhaps the effect is lost in the turbulence created by the pedalling dummy. Though that in itself could be very informative.
Re: New Tour tests of 2015 aero road bikes [cyclenutnz]
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cyclenutnz wrote:
If I apply a symmetrical distribution, centred on 8deg and covering the full sweep it yields a weighted average difference of 0.0045. Obviously wheels are different but other bikes show them to be very close in performance.
It would appear that, unlike many in the industry, Damon doesn't just make numbers up. Also gives more credibility to this test.
Is that a gaussian centered on 8deg? Can you post a pic of the distribution?
http://cds-0.blogspot.com
Re: New Tour tests of 2015 aero road bikes [cyclenutnz]
[ In reply to ]
cyclenutnz wrote:
duncan wrote:
They haven't shown a big advantage for any of the aero road bars. Perhaps the effect is lost in the turbulence created by the pedalling dummy. Though that in itself could be very informative.If you look at the AR FRD (aero bar) vs AR3 (round bar) there is a difference below about 15 degrees of yaw. Not a huge difference but a few watts. It's hard to say how much of that is the aero bar and how much was electronic vs. mechanical cable routing. I do wish Tour would have used the Zipp 404 on both the low cost and high end version of the bikes as a control.
Re: New Tour tests of 2015 aero road bikes [cyclenutnz]
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cyclenutnz wrote:
GreenPlease wrote:
1. The Swiss Side Hadrons are, basically, identical to 404FCs..... but with aluminum brake tracks :)Worth noting that the lack of a well in the rim bed of the Hadrons can be limiting for tyre choice. Even with loose tyres you still need to have good technique and strong hands to deal with a flat.
Would like to get a feel for the effect on rolling resistance of putting tyres on such massive rims as the Jet+, there may be tradeoffs here.
In theory the wider rim should result in a more circular contact patch. This should also reduce Crr because the casing flexes less. I say "in theory" because people like Tom Arndt (might have misspelled that) haven't seen the reduction in Crr you might expect. This also means there is no increase in Crr for the glass half crowd.
Re: New Tour tests of 2015 aero road bikes [grumpier.mike]
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grumpier.mike wrote:
In theory the wider rim should result in a more circular contact patch. This should also reduce Crr because the casing flexes less. I say "in theory" because people like Tom Arndt (might have misspelled that) haven't seen the reduction in Crr you might expect. This also means there is no increase in Crr for the glass half crowd.For a while I was considering lacing a 20 and 23mm rim side by side so I could remove hub/spoke effects from testing. Decided I didn't care quite that much.
Wider rims stiffen the casing by removing the bulb effect, there is still a lot we don't know about the real effect on performance of wider rims.
A while back I wrote an article on my site showing a comparison of GP4000s 23 v 25 on a 23mm rim combined with Zipp aero data to get a more holistic performance comparison - wider tyre was faster in most situations in that case.
a 25mm rim may flatten the sidewall so much that the tyre has to be run 20psi lower to gain equal comfort, effect of that on CRR is unknown (at least in the publicly available info) at this point.
^Well said.