2019 Venge, Madone, Timemachine Road, SystemSix? No thanks, Chapter 2 Rere for me

Discuss light weight issues concerning road bikes & parts.
AJS914
Posts: 2255
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

silvalis wrote:
Wed Jul 11, 2018 11:11 am
I'd probably take an allez sprint over the 1st G venge.
I wonder how close you get to a Venge if you put an integrated cockpit on a Tarmac. If you use eTap, you can eliminate two cables.

by Weenie


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TonyM
Posts: 2621
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

Out of the white paper of the new Venge (other thread about the new Venge): Stock Tarmac vs. Stock Venge looks like 0.01 CdA advantage for the New Venge. If done at 30 mph (48.28 kmh) then for a cyclist riding at 18.64 mph (30 kmh) it would mean a saving of 3.47 watts of power to apply on the pedals (at 20 mph a saving of 4.29 watts). Humm, an advantage definitely but not significant for a road race except in the final sprint or for small riders with a lower FTP.

Jugi
Posts: 130
Joined: Sun Jun 24, 2018 8:10 am

by Jugi

TonyM wrote:Out of the white paper of the new Venge (other thread about the new Venge): Stock Tarmac vs. Stock Venge looks like 0.01 CdA advantage for the New Venge. If done at 30 mph (48.28 kmh) then for a cyclist riding at 18.64 mph (30 kmh) it would mean a saving of 3.47 watts of power to apply on the pedals (at 20 mph a saving of 4.29 watts). Humm, an advantage definitely but not significant for a road race except in the final sprint or for small riders with a lower FTP.
The Trainerroad guys did aero testing at a velodrome during spring, which they discussed on a podcast episode. If I remember correctly, a world class time trialist's overall CdA can be under 0.22. The "average Joe time trialist" is usually in a 0.25-0.27 ballpark. I don't remember whether they discussed road racer's CdA, but I'd hazard a quess the pros at TdF may be around 0.26-0.29 in their road racing suits depending on situation. The average road racer will most likely be over 0.30, and definetly clearly over with poor fitting kit.

The true benefit of an aero bike in the whole equation? Not much.




mag
Posts: 196
Joined: Thu Mar 16, 2017 12:23 pm

by mag

Speaking of the real world aero advantage in the peloton, this just popped out:
http://road.cc/content/news/244957-stud ... ly-thought

robeambro
Posts: 65
Joined: Sat Jul 07, 2018 6:21 pm

by robeambro

TonyM wrote:
Thu Jul 12, 2018 6:35 am
Out of the white paper of the new Venge (other thread about the new Venge): Stock Tarmac vs. Stock Venge looks like 0.01 CdA advantage for the New Venge. If done at 30 mph (48.28 kmh) then for a cyclist riding at 18.64 mph (30 kmh) it would mean a saving of 3.47 watts of power to apply on the pedals (at 20 mph a saving of 4.29 watts). Humm, an advantage definitely but not significant for a road race except in the final sprint or for small riders with a lower FTP.
Interesting.
Out of curiosity, does the paper have (or is this possible to find elsewhere) a similar comparison, but vs. a normal non-Aero bike? (I would search myself, but I would probably screw up the calcs)

While there is negligible difference between Venge and Tarmac (which are arguably two very similar bikes), it would be nice to have an idea on how significant (if at all) of an advantage there is in choosing a Venge over a, say, stock lightweight bike with little to no aero feature.

AJS914
Posts: 2255
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

So if there are only 3 or 4 watts between a Venge and Tarmac, I wonder how much of that you get back by putting an aero cockpit on the Tarmac.

spdntrxi
Posts: 1896
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

AJS914 wrote:
Fri Jul 13, 2018 4:48 pm
So if there are only 3 or 4 watts between a Venge and Tarmac, I wonder how much of that you get back by putting an aero cockpit on the Tarmac.
atleast half would be my guess

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TonyM
Posts: 2621
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

AJS914 wrote:
Fri Jul 13, 2018 4:48 pm
So if there are only 3 or 4 watts between a Venge and Tarmac, I wonder how much of that you get back by putting an aero cockpit on the Tarmac.
Yepp not that muchthen, maybe half??

The Venge is still better for a very fast ride like a TT or a sprint

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TonyM
Posts: 2621
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

robeambro wrote:
Fri Jul 13, 2018 3:47 pm
TonyM wrote:
Thu Jul 12, 2018 6:35 am
Out of the white paper of the new Venge (other thread about the new Venge): Stock Tarmac vs. Stock Venge looks like 0.01 CdA advantage for the New Venge. If done at 30 mph (48.28 kmh) then for a cyclist riding at 18.64 mph (30 kmh) it would mean a saving of 3.47 watts of power to apply on the pedals (at 20 mph a saving of 4.29 watts). Humm, an advantage definitely but not significant for a road race except in the final sprint or for small riders with a lower FTP.
Interesting.
Out of curiosity, does the paper have (or is this possible to find elsewhere) a similar comparison, but vs. a normal non-Aero bike? (I would search myself, but I would probably screw up the calcs)

While there is negligible difference between Venge and Tarmac (which are arguably two very similar bikes), it would be nice to have an idea on how significant (if at all) of an advantage there is in choosing a Venge over a, say, stock lightweight bike with little to no aero feature.

https://weightweenies.starbike.com/foru ... &start=375
New Venge.jpeg

alpha6cycles
Posts: 2
Joined: Mon Aug 06, 2018 12:06 am

by alpha6cycles

MAsshole wrote:
Sun Jul 08, 2018 3:08 am
Anyone have any time on the Rere? I know it's rather new but figured I'd ask.
Hi there,

I’m the Philippine distributor for Chapter2, also a reseller for Trek and before that, Specialized.

I have several thousand miles on the Tere - enjoyed it immensely at Tour de Bintan - and a little over 300 on the Rere. Ride quality is surprisingly good, about the same as the Tere and it’s just as snappy. Chapter2 claims it’s anywhere from 10-20% faster than the Tere depending on yaw angle, and I can somewhat vouch for it. The bike just slices downhill and and holds speed more easily. Mike Pryde says the Tere is a little stiffer at the BB because the Rere has a thinner airfoil downtube, but I’m not a megawatt sprinter so i can’t really tell. I’m on the fence whether I will
Use it for crit racing because the pearl white finish is too beautiful to risk crashing haha.

The geometry is more aggressive than the Tere with a slightly steeper seat tube and lower stack height, so it’s great for time trialling and fast, rolling course races. Kind of like the Allez Sprint but with a longer reach (I run a 90 on the Rere, 120 on the Sprint).

I love the Tere for long training rides with tons of climbing, the Rere for fast rides /races of 4 hours or less. My Tere with Record and Knight Composite 35 clinchers is 14.5lbs; Rere with R8000 and same wheels is 15.2. Not bad at all.

The disc versions are set to come out end of August.

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silvalis
Posts: 467
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

alpha6cycles wrote:
Mon Aug 06, 2018 12:50 am

The geometry is more aggressive than the Tere with a slightly steeper seat tube and lower stack height, so it’s great for time trialling and fast, rolling course races. Kind of like the Allez Sprint but with a longer reach (I run a 90 on the Rere, 120 on the Sprint).
Interesting.
What size frame? When I was playing with the geo calculators a while back I’d have said the reverse - the sprint geometry is much longer and lower than the Rere
Chasse patate

Stueys
Posts: 194
Joined: Sat Nov 22, 2014 1:12 pm

by Stueys

TonyM wrote:
Sat Jul 14, 2018 2:22 am
robeambro wrote:
Fri Jul 13, 2018 3:47 pm
TonyM wrote:
Thu Jul 12, 2018 6:35 am
Out of the white paper of the new Venge (other thread about the new Venge): Stock Tarmac vs. Stock Venge looks like 0.01 CdA advantage for the New Venge. If done at 30 mph (48.28 kmh) then for a cyclist riding at 18.64 mph (30 kmh) it would mean a saving of 3.47 watts of power to apply on the pedals (at 20 mph a saving of 4.29 watts). Humm, an advantage definitely but not significant for a road race except in the final sprint or for small riders with a lower FTP.
Interesting.
Out of curiosity, does the paper have (or is this possible to find elsewhere) a similar comparison, but vs. a normal non-Aero bike? (I would search myself, but I would probably screw up the calcs)

While there is negligible difference between Venge and Tarmac (which are arguably two very similar bikes), it would be nice to have an idea on how significant (if at all) of an advantage there is in choosing a Venge over a, say, stock lightweight bike with little to no aero feature.

https://weightweenies.starbike.com/foru ... &start=375

New Venge.jpeg
Interesting. So if I read that right then wheels and cockpit close the difference between tarmac and venge by half? Which leaves you with a 2.1w Venge advantage at 20mph (using the numbers above). Actually fairly negligable....

alpha6cycles
Posts: 2
Joined: Mon Aug 06, 2018 12:06 am

by alpha6cycles

silvalis wrote:
Mon Aug 06, 2018 1:10 am
alpha6cycles wrote:
Mon Aug 06, 2018 12:50 am

The geometry is more aggressive than the Tere with a slightly steeper seat tube and lower stack height, so it’s great for time trialling and fast, rolling course races. Kind of like the Allez Sprint but with a longer reach (I run a 90 on the Rere, 120 on the Sprint).
Interesting.
What size frame? When I was playing with the geo calculators a while back I’d have said the reverse - the sprint geometry is much longer and lower than the Rere
Small (53). That’s the strange thing. On the charts the Sprint may well be longer and lower, but when I got the Rere fitted to me, 90 is the ideal stem length (reach is about the same as the Tere, but lower stack).

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silvalis
Posts: 467
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

Weird. Unless the velogicfit charts are extremely wrong, I have no idea how you are getting the same reach assuming same position.

Allez: 380mm Reach 514mm stack 73deg HTA + 120mm stem
Rere: 369mm Reach 524mm Stack 72deg HTA + 90mm stem.

with a 10mm headset/spacer the calculator tells me that the allez is 40mm longer reach to the bars.

I assume your seat position is the same on both, unless your fitter decided for more weight over the front? Except the Rere has a longer front-centre,..
Chasse patate

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