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-   -   Just realized the irony of disc brakes on an aero bike. (https://forums.thepaceline.net/showthread.php?t=234077)

Burnette 02-10-2019 10:23 AM

Truth
 
Quote:

Originally Posted by galgal (Post 2498811)
Would it not be *relevant* to mention whether you were or were not using disks as you sped past the very long train on your right:)

No, but I did leave out that my truck and my butt did look awesome.

rzthomas 02-10-2019 11:19 AM

Back on topic, disc brakes on TT bikes make sense because hydro hose can run through all sorts of complicated bends without impairing braking power or feel.

nickl 02-10-2019 02:50 PM

Dario Pegoretti
 
This quote has appeared many times on this and other forums and still rings true for many. Dario had a way to express himself quite succinctly, even with English as his second language.

'One of the main functions of disc brakes is to solve the problems of the carbon wheels manufacturers. Solve problems of the wheels is not my job.' --Dario Pegoretti

Mikej 02-10-2019 07:46 PM

Quote:

Originally Posted by Burnette (Post 2498523)
You, by yourself, have discovered what nobody in the whole world could. That you can sit on the couch and make stuff up to the point that you believe it true.

Hey, that’s how I balance my checkbook- so I can buy bike stuff. But lighten up an the op, we’ve all thought of something brilliant st dome point until it was typed out loud-

Hellgate 02-10-2019 08:00 PM

Harsh crowd...geez...

FlashUNC 02-10-2019 08:03 PM

https://media.giphy.com/media/tyttpH...R6dq/giphy.gif

Burnette 02-10-2019 08:12 PM

So True !
 
Quote:

Originally Posted by Mikej (Post 2499058)
Hey, that’s how I balance my checkbook- so I can buy bike stuff. But lighten up an the op, we’ve all thought of something brilliant st dome point until it was typed out loud-

If you look a few posts up you see that the Op has a sense of humor too and we both see eye to eye because we're both short! :)

zmalwo 02-11-2019 09:19 AM

Quote:

Originally Posted by nickl (Post 2498903)
This quote has appeared many times on this and other forums and still rings true for many. Dario had a way to express himself quite succinctly, even with English as his second language.

'One of the main functions of disc brakes is to solve the problems of the carbon wheels manufacturers. Solve problems of the wheels is not my job.' --Dario Pegoretti

Cannondale: "One of the main functions of threaded BBs is to maintain a problem free BB area. Adding additional weight to have a problem free threaded BB shell but look slightly heavier on my spec sheet is not my job."

Hawker 02-11-2019 09:36 AM

Quote:

Originally Posted by Bentley (Post 2498769)
Not understanding this

I think he's suggesting that rider aerodynamics and frontal area mean much more than disc brakes on an aero bike. I'm the guy on the right and I love drafting the guy on the left. :)

nickl 02-11-2019 10:10 AM

Quote:

Originally Posted by zmalwo (Post 2499192)
Cannondale: "One of the main functions of threaded BBs is to maintain a problem free BB area. Adding additional weight to have a problem free threaded BB shell but look slightly heavier on my spec sheet is not my job."

Apples and oranges comparison. Obviously, Dario made a great deal more sense even though he never claimed to be articulate in English.

'One of the main functions of disc brakes is to solve the problems of the carbon wheels manufacturers. Solve problems of the wheels is not my job.' --Dario Pegoretti

benb 02-11-2019 10:15 AM

Quote:

Originally Posted by rzthomas (Post 2498830)
Back on topic, disc brakes on TT bikes make sense because hydro hose can run through all sorts of complicated bends without impairing braking power or feel.

Nah.. they make sense because only the most pain loving home mechanic would fix a broken internal hydraulic hose instead of taking it to the approved bike dealer and paying a couple hundred bucks to have it done.

God that sounds bad! (Yes I get that in normal routine maintenance that hydraulic hose will be way less trouble and last way longer than brake cables run internally.)

echappist 02-11-2019 11:43 AM

out of all the new disc-brake equipped aero bikes, only the Cannondale seems to be worth the trouble.

Otherwise, manufacturers are contorting to get people to buy the disc-brake bikes. The 2016-2018 Trek Madone was a fine rim-brake bike, but that bike would have been faster than the 2019 disc version. So Trek made the 2019 rim-brake bike slower as well, just so they can say that their disc-brake equipped bike is faster than the corresponding, same-year, rim-brake bike.

Irony here is that a rim-brake Cannondale would likely be faster than the disc-brake C'dale, but I don't think C'dale would be debuting that bike any time soon.

vqdriver 02-11-2019 01:13 PM

relax guys. everyone's had shower thoughts that withered in the light of day.

besides, we all know coaster brakes are the most aero.

Mark McM 02-11-2019 01:28 PM

Quote:

Originally Posted by echappist (Post 2499282)
out of all the new disc-brake equipped aero bikes, only the Cannondale seems to be worth the trouble.

Otherwise, manufacturers are contorting to get people to buy the disc-brake bikes. The 2016-2018 Trek Madone was a fine rim-brake bike, but that bike would have been faster than the 2019 disc version. So Trek made the 2019 rim-brake bike slower as well, just so they can say that their disc-brake equipped bike is faster than the corresponding, same-year, rim-brake bike.

Irony here is that a rim-brake Cannondale would likely be faster than the disc-brake C'dale, but I don't think C'dale would be debuting that bike any time soon.

This seems to be borne out by a recent Tour Magazine test of the latest aero bikes. A link to the test and a discussion of it can be found here:

https://weightweenies.starbike.com/f...p?f=3&t=154692

Here's a summary of the results:

Quote:

All tested at 45kph:

2019 Cannondale SystemSix Disc - 203w
2016 Trek Madone - 204w
2016 Specialized Venge ViAS - 204w
2016 Cervelo S5 - 205w
2016 Felt AR FRD - 205w
2019 Cervelo S5 Disc - 206w
2016 Canyon Aeroad - 208w
2019 Specialized Venge Disc - 208w
2016 Giant Propel Advanced SL - 210w
2016 Scott Foil Premium - 211w
2016 BMC Time Machine - 211w
2016 Look 795 - 212w
2019 Trek Madone Disc - 212w
2019 Ridley Noah Fast Disc - 213w
The aero road bikes from every manufacturer in the test got slower when they redesigned it for disc brakes, except for Cannondale. But even for the Cannondale, they redesigned and re-optimized the entire bike, so who knows whether redesigning and re-optimizing around rim brakes wouldn't be faster still?

I've read the Cervelo white paper on the S5 Disc, which claims that the S5 Disc is faster than the previous S5 (no surprise there - every manufacturer claims their new bike is better than their old bike). But if you look closer, you'll see that they changed many aspects of the design (such as routing all the cables internally through the special stem, headset and fork). They mention how much power each change saved, and it adds up to more than the power saved by the whole bike - which implies that switching from rim to disc resulted in a power loss, for which they had to redesign other parts to make up for.

54ny77 02-11-2019 03:17 PM

It's a good thing these bikes will have discs, since with all the improved aero on the frame it might require greater application of brake forces to stop while coasting to a red light . At 5-8 mph, the average rider needs confidence they can stop comfortably and safely, with plenty of margin for error.


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