Rim brake vs Disc Brake Aero test.
12-11-14, 11:56 PM
#101
Senior Member
Seriously, if you are the type of person who's going to drag ass all the way down a huge hill, then you'll ruin caliper brakes as well. Carbon rims are notorious for their braking issues. This is a solution. /thread
__________________
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter
12-12-14, 12:21 AM
#102
Senior Member
I'm starting to see why Bob is so perplexed about the polarized attitude surrounding disc brakes.
My mind was made up when I saw a dude in my bike club, former motorcycle racer, about 230lbs with a custom steel road bike and disc brakes. He was flying down hills, right on the edge of traction, brakes singing. It was a sight to see. Best descender I've seen on the amateur level by a wide margin. Combine that with my knowledge of the braking disabilities of carbon rims, which I have experienced directly, and it's easy to conclude that disc brakes definitely have a place on road bikes.
__________________
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter
12-12-14, 12:28 AM
#103
Mr. Dopolina
Thread Starter
Join Date: May 2007
Location: Taiwan
Posts: 10,217
Bikes: KUUPAS, Simpson VR
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 149 Post(s)
Liked 117 Times
in
41 Posts
Disc specific rims are already lighter by 5%~10%. (-30g~60g) So now we are around 300g or less.
Hubs currently being used are designed for MTB and 203mm rotors which means they are completley overbuilt for road. I expect to see the hub numbers cut in half with hubs desgned for 140mm rotors only.
Front forks don't need to be any heavier; The layup needs to be adjusted to address stresses in specific directions. (No gain?)
Going from 20H radial to 24H 2x on the spokes on the front wheel will add a whopping 10g~20g or so.
With a season or two for development that difference could easliy be under 250g by 2016. That's less than the weight of your water bottle after a few good sips. What do you get for that? Better braking in all conditions for those who feel they need it.
Oh, and MTB guys go through axles because they pound through stuff? They do jumps and big drops, non? They ride off road and in a manner a road bike will never, ever see?
You're doing nothing to advance the conversation. If you're not interested in road discs, fine. No-one is forcing you to use them. So please stop.
12-12-14, 12:49 AM
#104
Senior Member
Join Date: Dec 2010
Location: Above ground, Walnut Creek, Ca
Posts: 6,681
Bikes: 8 ss bikes, 1 5-speed touring bike
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Likes: 0
Liked 4 Times
in
4 Posts
From weight weenies "Weight: Comparing the shifters and brake systems only, R785 adds 342 grams to standard Ultegra 6870."
Disc specific rims are already lighter by 5%~10%. (-30g~60g) So now we are around 300g or less.
Hubs currently being used are designed for MTB and 203mm rotors which means they are completley overbuilt for road. I expect to see the hub numbers cut in half with hubs desgned for 140mm rotors only.
Front forks don't need to be any heavier; The layup needs to be adjusted to address stresses in specific directions. (No gain?)
Going from 20H radial to 24H 2x on the spokes on the front wheel will add a whopping 10g~20g or so.
With a season or two for development that difference could easliy be under 250g by 2016. That's less than the weight of your water bottle after a few good sips. What do you get for that? Better braking in all conditions for those who feel they need it.
Oh, and MTB guys go through axles because they pound through stuff? They do jumps and big drops, non? They ride off road and in a manner a road bike will never, ever see?
You're doing nothing to advance the conversation. If you're not interested in road discs, fine. No-one is forcing you to use them. So please stop.
Disc specific rims are already lighter by 5%~10%. (-30g~60g) So now we are around 300g or less.
Hubs currently being used are designed for MTB and 203mm rotors which means they are completley overbuilt for road. I expect to see the hub numbers cut in half with hubs desgned for 140mm rotors only.
Front forks don't need to be any heavier; The layup needs to be adjusted to address stresses in specific directions. (No gain?)
Going from 20H radial to 24H 2x on the spokes on the front wheel will add a whopping 10g~20g or so.
With a season or two for development that difference could easliy be under 250g by 2016. That's less than the weight of your water bottle after a few good sips. What do you get for that? Better braking in all conditions for those who feel they need it.
Oh, and MTB guys go through axles because they pound through stuff? They do jumps and big drops, non? They ride off road and in a manner a road bike will never, ever see?
You're doing nothing to advance the conversation. If you're not interested in road discs, fine. No-one is forcing you to use them. So please stop.
and if we don't know or can't reach a consensus, it's possible that we've already passed our destination and need to turn back.
come on... you guys just love to argue.
12-12-14, 07:27 AM
#105
Senior Member
Join Date: Jun 2013
Location: EU
Posts: 194
Bikes: Ax Lighntess Vial EVO D (+ Paduano Fidia)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yes, frame increase in weight as do whole bike. You can even view data of how different mounts of rim brakes changes anything in respect to aero. If you want light, you will like rim brakes as the disc brake bikes increase in weight quite alot (for a WW).
12-12-14, 08:46 AM
#106
Mostly Harmless
Join Date: Jul 2008
Location: Chittenango, NY
Posts: 56,589
Bikes: Have two wheels
Mentioned: 169 Post(s)
Tagged: 2 Thread(s)
Quoted: 13710 Post(s)
Liked 4,524 Times
in
2,503 Posts
12-12-14, 09:05 AM
#107
Senior Member
Join Date: Jul 2013
Location: Somewhere in TX
Posts: 2,266
Bikes: BH, Cervelo, Cube, Canyon
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 212 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
You're doing nothing to advance the conversation. If you're not interested in road discs, fine. No-one is forcing you to use them. So please stop.
12-12-14, 09:16 AM
#109
Senior Member
Join Date: Jul 2013
Location: Somewhere in TX
Posts: 2,266
Bikes: BH, Cervelo, Cube, Canyon
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 212 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
Let's inject some reality into Bob's constant flow of numbers pulled out of his imagination.
Just In: Zipp 202 Firecrest Clincher Disc Brake Wheelset
202 disc set without rotors: 1512 claimed
202 rim brake set: 1395 claimed
And of course the author can't help but add some of that cult-like disc brake optimism at the end.
342 grams
117 grams
plus heavier skewers (can't use light ti on disc brakes)
plus beefier frames
=at least 500 grams of weight difference.
Note that mountain bikes didn't START with through-axles. But over time riders realized that they were needed.
Just In: Zipp 202 Firecrest Clincher Disc Brake Wheelset
202 disc set without rotors: 1512 claimed
202 rim brake set: 1395 claimed
Zipp points out that while many have heralded the arrival of disc brakes as a way to make rims lighter [aka, people who failed high school physics], the rim still needs to hold the tire and survive impacts. That means the rims have stayed the same weight, at least for now
342 grams
117 grams
plus heavier skewers (can't use light ti on disc brakes)
plus beefier frames
=at least 500 grams of weight difference.
Note that mountain bikes didn't START with through-axles. But over time riders realized that they were needed.
12-12-14, 09:50 AM
#110
Senior Member
Join Date: Aug 2007
Location: Sacramento, CA
Posts: 1,711
Bikes: S-Works SL3 Tarmac, Allez E5, Leader 735TT, others
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
It’s no surprise it’s the lightest disc-equipped road bike we’ve ever had through the office, hitting 6.9kg on the road.cc Scales of Truth. That’s because there is really no weight increase on the disc version of the Tarmac frame, and because it’s laden with top-end kit. That kit includes a Shimano Dura-Ace Di2 groupset and RS785 hydraulic disc brakes, with 140mm rotors at both ends.
Too portly for me.... *sarcasm*
12-12-14, 09:58 AM
#111
ka maté ka maté ka ora
Join Date: Oct 2008
Location: wessex
Posts: 4,423
Bikes: breezer venturi - red novo bosberg - red, pedal force cg1 - red, neuvation f-100 - da, devinci phantom - xt, miele piste - miche/campy, bianchi reparto corse sbx, concorde squadra tsx - da, miele team issue sl - ultegra
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 25 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
12-12-14, 11:01 AM
#112
Senior Member
Join Date: Jul 2013
Location: Somewhere in TX
Posts: 2,266
Bikes: BH, Cervelo, Cube, Canyon
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 212 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
6.9kg for a $12,500 bike is porky.
Last edited by Jiggle; 12-12-14 at 11:05 AM.
12-12-14, 11:38 AM
#113
Senior Member
Join Date: Aug 2007
Location: Sacramento, CA
Posts: 1,711
Bikes: S-Works SL3 Tarmac, Allez E5, Leader 735TT, others
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
You can add your value judgement to the final number as you see fit. What cannot be denied is that any disc brake bike is 1 pound heavier than if it had rim brakes. That, of course, assumes that corners aren't cut in pursuit of a weight goal that negates the supposed stopping advantages of the discs.
6.9kg for a $12,500 bike is porky.
6.9kg for a $12,500 bike is porky.
12-12-14, 11:40 AM
#114
Senior Member
Join Date: Jun 2013
Location: NYC, duh Bronx.
Posts: 3,578
Bikes: Salsa Ti Warbird- 2014/ November RAIL52s
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
You can add your value judgement to the final number as you see fit. What cannot be denied is that any disc brake bike is 1 pound heavier than if it had rim brakes. That, of course, assumes that corners aren't cut in pursuit of a weight goal that negates the supposed stopping advantages of the discs.
6.9kg for a $12,500 bike is porky.
6.9kg for a $12,500 bike is porky.
What size is the frame in the article? I glanced over it and didn't notice...
If anything a 15# disc equipped bike could easily be built for half the price, hell I daresay a third...
12-12-14, 11:51 AM
#115
Senior Member
Join Date: Dec 2009
Posts: 4,700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 5 Times
in
4 Posts
Let's inject some reality into Bob's constant flow of numbers pulled out of his imagination.
Just In: Zipp 202 Firecrest Clincher Disc Brake Wheelset
202 disc set without rotors: 1512 claimed
202 rim brake set: 1395 claimed
And of course the author can't help but add some of that cult-like disc brake optimism at the end.
342 grams
117 grams
plus heavier skewers (can't use light ti on disc brakes)
plus beefier frames
=at least 500 grams of weight difference.
Note that mountain bikes didn't START with through-axles. But over time riders realized that they were needed.
Just In: Zipp 202 Firecrest Clincher Disc Brake Wheelset
202 disc set without rotors: 1512 claimed
202 rim brake set: 1395 claimed
Zipp points out that while many have heralded the arrival of disc brakes as a way to make rims lighter [aka, people who failed high school physics], the rim still needs to hold the tire and survive impacts. That means the rims have stayed the same weight, at least for now
342 grams
117 grams
plus heavier skewers (can't use light ti on disc brakes)
plus beefier frames
=at least 500 grams of weight difference.
Note that mountain bikes didn't START with through-axles. But over time riders realized that they were needed.
Jeez.
12-12-14, 12:03 PM
#116
Senior Member
Join Date: Dec 2009
Posts: 4,700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 5 Times
in
4 Posts
You can add your value judgement to the final number as you see fit. What cannot be denied is that any disc brake bike is 1 pound heavier than if it had rim brakes. That, of course, assumes that corners aren't cut in pursuit of a weight goal that negates the supposed stopping advantages of the discs.
6.9kg for a $12,500 bike is porky.
6.9kg for a $12,500 bike is porky.
There's no inherent reason a disc-brake bike has to weigh more than a rim-brake bike. The overall braking loads are the same.
And by relieving the rim of having to provide a braking surface that has to dissipate a lot of heat, there's a good chance a disc-brake bike could be lighter.
All your ranting is based on, "The FIRST time it was done, it's heavier."
And for some reason, you seem to think that MUST always be true.
Why don't you go weigh the first TVs and compare them to how much TVs - TVs that are MUCH larger - weigh now.
12-12-14, 12:09 PM
#118
Senior Member
Join Date: Dec 2010
Location: Above ground, Walnut Creek, Ca
Posts: 6,681
Bikes: 8 ss bikes, 1 5-speed touring bike
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Likes: 0
Liked 4 Times
in
4 Posts
Wow. Did your dog get stolen by a door-to-door disc brake salesman?
There's no inherent reason a disc-brake bike has to weigh more than a rim-brake bike. The overall braking loads are the same.
And by relieving the rim of having to provide a braking surface that has to dissipate a lot of heat, there's a good chance a disc-brake bike could be lighter.
All your ranting is based on, "The FIRST time it was done, it's heavier."
And for some reason, you seem to think that MUST always be true.
Why don't you go weigh the first TVs and compare them to how much TVs - TVs that are MUCH larger - weigh now.
There's no inherent reason a disc-brake bike has to weigh more than a rim-brake bike. The overall braking loads are the same.
And by relieving the rim of having to provide a braking surface that has to dissipate a lot of heat, there's a good chance a disc-brake bike could be lighter.
All your ranting is based on, "The FIRST time it was done, it's heavier."
And for some reason, you seem to think that MUST always be true.
Why don't you go weigh the first TVs and compare them to how much TVs - TVs that are MUCH larger - weigh now.
12-12-14, 12:19 PM
#119
I'm doing it wrong.
Join Date: Jun 2009
Posts: 4,875
Bikes: Rivendell Appaloosa, Rivendell Frank Jones Sr., Trek Fuel EX9, Kona Jake the Snake CR, Niner Sir9
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 9742 Post(s)
Liked 2,812 Times
in
1,664 Posts
12-12-14, 12:45 PM
#120
Senior Member
Join Date: Oct 2010
Posts: 182
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Likes: 0
Liked 26 Times
in
10 Posts
12-12-14, 01:11 PM
#121
Senior Member
Join Date: Jun 2013
Location: NYC, duh Bronx.
Posts: 3,578
Bikes: Salsa Ti Warbird- 2014/ November RAIL52s
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
No doubt, when I'm doing the hydration thing in prep for a long ride that's easy.
The tunnel vision weight hangup with cyclists in general is pretty hysterical. Far more factors are involved when it comes down to overall practical performance.
12-12-14, 01:13 PM
#122
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
I look at a bike like this and think, yeah...that's a cool looking bike for a modern road race bike (although one that actually has some color would be cooler looking) but then my eyes go to the front wheel and I just think fugly, fugly, full on ugly. Those disks just kill the look of that bike.
12-12-14, 01:15 PM
#123
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
12-12-14, 01:20 PM
#124
Senior Member
Join Date: Jun 2013
Location: NYC, duh Bronx.
Posts: 3,578
Bikes: Salsa Ti Warbird- 2014/ November RAIL52s
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
and that's why the weight argument becomes bull**** at the diminishing point of return so many evangelize here...
What remains to be seen is how the different, and reasonably argued, superior performance of discs impacts riding in real world conditions.
What remains to be seen is how the different, and reasonably argued, superior performance of discs impacts riding in real world conditions.
12-12-14, 03:49 PM
#125
Banned
Join Date: Mar 2008
Posts: 2,664
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
I look at a bike like this and think, yeah...that's a cool looking bike for a modern road race bike (although one that actually has some color would be cooler looking) but then my eyes go to the front wheel and I just think fugly, fugly, full on ugly. Those disks just kill the look of that bike.
Please keep disc brakes on commuters/grocery getters.
Don't want them on my pure bred roadies.