Is 2018 the year proper race bikes with discs gain momentum?

Back by popular demand, the general all-things Road forum!

Moderator: robbosmans

mag
Posts: 616
Joined: Thu Mar 16, 2017 12:23 pm

by mag

^^ That means basically nothing. Those Enves are probably the only rims which are lighter in disc version than in rim version. Maybe there are some more, but those are very scarce at the moment (I was looking for some of the lighter disc brake wheels recently and there really isn't much to find). So when pdlpsher1 wrote that the disc rims are generally heavier he was right. Note the word "generally" - that's what matters here. You can selectively pick some off-values here and there in order to try to prove your point, but that doesn't really work and doesn't invalidate the whole data set. And yes, there's a room for improvement so one day pdlpsher1's claim about the weight will be wring, but it isn't the case at the moment.

And 40 pages and this thread hasn't progressed an inch. :-D Love it. Sometimes you start to think something is finally going to happen only to realize it was a small sign of step forward followed by a quick return to the return to the original positions. :-D

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



morganb
Posts: 732
Joined: Wed Mar 15, 2017 5:30 pm

by morganb

mag wrote:
Thu Apr 05, 2018 10:20 am
^^ That means basically nothing. Those Enves are probably the only rims which are lighter in disc version than in rim version. Maybe there are some more, but those are very scarce at the moment (I was looking for some of the lighter disc brake wheels recently and there really isn't much to find). So when pdlpsher1 wrote that the disc rims are generally heavier he was right. Note the word "generally" - that's what matters here. You can selectively pick some off-values here and there in order to try to prove your point, but that doesn't really work and doesn't invalidate the whole data set. And yes, there's a room for improvement so one day pdlpsher1's claim about the weight will be wring, but it isn't the case at the moment.

And 40 pages and this thread hasn't progressed an inch. :-D Love it. Sometimes you start to think something is finally going to happen only to realize it was a small sign of step forward followed by a quick return to the return to the original positions. :-D
The Roval disc rims are also lighter. Same with light bicycle if you want someone that sells rim only.

mag
Posts: 616
Joined: Thu Mar 16, 2017 12:23 pm

by mag

Are you sure? I was looking at CLX32 & CLX50 and their claimed weights are higher for disc brake versions (EDIT: but that was for the whole wheels, not just rims - so different hubs & spoke counts (16/21 or 24 vs 21/24) come into the play - just rims themselves may be actually slightly lighter). In any case - yes there are few lighter ones, but it's really just a few as of now. That should improve in the future though.

TobinHatesYou
Posts: 12457
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Reynolds Aero 65 Rim: 538g
Reynolds Aero 65 DB: 513g
Reynolds Strike Rim: 559g
Reynolds Strike DB: 540g
Reynolds Assault Rim: 477g
Reynolds Assault DB: 439g
Reynolds Attack Rim: 396g
Reynolds Attack DB: 377g

Venn Rev 507 TCC Rim: 505g
Venn Rev 507 TCD Disc: 485g
Venn Rev 35 TCC Rim: 430g
Venn Rev 35 TCD Disc: 395g

Alto CT52 Rim: 420g
Alto CTX52 Disc: 405g

From wheelbuilder.com:
Zipp 303 Firecrest Rim clincher: 500g
Zipp 303 Firecrest Disc clincher: 472g

Do I need to go on or do we need to keep making shit up?

The few disc rims that aren’t lighter from the lazier manufacturers simply weigh the same as their rim-brake counterparts because they’re the same exact rims with different surface dressings.

TiCass
Posts: 257
Joined: Thu Aug 04, 2016 1:13 pm

by TiCass

The added weight comes from the higher spokes count on the front wheel, beefier hub and thru axle... not from the rim itself.

TobinHatesYou
Posts: 12457
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Right, and not a single person was claiming disc wheelsets are lighter than rim-brake wheelsets.

Recap: People are musing about dumb topics like rotational weight on a bicycle. It was pointed out the effects of rotational weight (again not important) are greatest at the rim...where in the case of disc-brake wheels there is actually less weight.

User avatar
wheelbuilder
Posts: 1193
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

This thread has been absolutely, positively epic. I will go ahead and admit that I have been slightly swayed towards acceptance of disc. When they first started appearing and gaining traction I truly thought they were an abomination. For fat, slow, timid Fondo riders. As they have proliferated the industry and my local riding scene, I am getting used to them. I will be the first to admit, and will admit it to anybody.... disc brakes perform better as a braking tool in every aspect over rim brakes. There can be no doubt about that. That doesn't mean that for "some" riders like myself rim brakes are not effective and totally fine. The only thing I take issue with is there were some insinuations earlier in this thread that rim brake riders may be "creeping down hills" and must live "in the flat lands". I live in the exact same area as Tobinhatesyou, and a couple other members in this thread. We belong to the same club even. I can manage just fine on rim brakes with carbon clinchers and have for a long time. I can hang with most people, and my only KOM's are on descents. I don't feel like I need disc brakes, but I don't begrudge anyone using them. See you out there!
Never cheer before you know who is winning

spdntrxi
Posts: 5791
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

MoPho wrote:
Thu Apr 05, 2018 5:09 am
spdntrxi wrote:
Thu Apr 05, 2018 3:19 am
if you disc brake fanboys can feel the modulation.. then pdpsher can feel the rotational weight..... get it ? both are relative so you cant have it both ways.


Nice try but your fingertips are the most sensitive part of your body for detecting pressure, your legs not so much.



.
again you are assuming you know how everyone else "feels" maybe I have something wrong with my nerves in my hands... I dont find them all that sensitive. My legs on the other hand no pun intended.

I have nothing against discs... just waiting for things to get sorted out a little more. My next bike will probably be disc
2024 BMC TeamMachine R Building
2018 BMC TImeMachine Road
2002 Moots Compact-SL- getting aero look makeover
2019 Parlee Z0XD - "classified"
2023 Pivot E-Vault - completed project, full Xplr package

CEVelo
Posts: 116
Joined: Tue Mar 24, 2015 5:22 pm

by CEVelo

Simple answer is YES. Just look at the retail assortment of road bikes (start to look like 50/50 rim/disc or higher), Discs also appearing in the pro peloton. End of discussion. Personally still on rim breaks for the simplicity of mechanics and ability to readily use other wheelsets etc., but surely next bike will be disc. There is zero evidence that a disc bike is any bit slower, truly fast riders dont obsess about a few grams here and there, they smoke the rest of us regardless of equipment.

dvq
Posts: 181
Joined: Mon Sep 25, 2017 1:36 pm

by dvq

mag wrote:
Thu Apr 05, 2018 10:20 am
And 40 pages and this thread hasn't progressed an inch. :-D Love it. Sometimes you start to think something is finally going to happen only to realize it was a small sign of step forward followed by a quick return to the return to the original positions. :-D
Likely there's no progress because there's 40 pages of the same people with strong opinions hammering away internet arguments instead of going outside to ride.

User avatar
ak47
Posts: 286
Joined: Thu Aug 30, 2007 2:57 pm

by ak47

CEVelo wrote:
Thu Apr 05, 2018 4:33 pm
There is zero evidence that a disc bike is any bit slower, truly fast riders dont obsess about a few grams here and there, they smoke the rest of us regardless of equipment.
Number one evidence is the number of pro riders who started Tour of Flanders this year on a disc brake bikes. This number is 0. ZERO. These guys basically know that disc brakes ARE slower.

LiquidCooled
Posts: 218
Joined: Mon Oct 02, 2017 5:46 am

by LiquidCooled

It's amusing reading when folks cite what the pros use as proof of superiority. In 5 years, when the entire peloton is on discs, will they claim:

a) Discs brakes are indeed superior, or

b) Who cares what the pros use? There may be many reasons why the pros ride the brakes they do other than those brakes being the superior tech.

Which will be the path of their hypocrisy?
2017 Giant TCR Advanced Pro 0 Disc
2003 Cannondale R1000 (CAAD7)

TurboKoo
Posts: 651
Joined: Wed Oct 29, 2008 7:55 pm

by TurboKoo

ak47 wrote:
CEVelo wrote:
Thu Apr 05, 2018 4:33 pm
There is zero evidence that a disc bike is any bit slower, truly fast riders dont obsess about a few grams here and there, they smoke the rest of us regardless of equipment.
Number one evidence is the number of pro riders who started Tour of Flanders this year on a disc brake bikes. This number is 0. ZERO. These guys basically know that disc brakes ARE slower.
Keep in mind that these guys also don’t ride with aero bikes even if they know those are faster. Pros don’t pick the best equipment but the most trusted in race situation.
Cannondale SuperSix
Shimano 9270

mfastenau
Posts: 1
Joined: Tue Apr 03, 2018 4:38 pm

by mfastenau

One thing I've not seen mentioned is the cost issue, if you are buying to a certain price point adding discs is going to drop you down a level in components. This in turn will double the weight penalty, 105 bike with discs is a lot heavier than Ultegra with rim brakes......I do realize that most people here don't worry about cost as much as the average weekend cyclist but still is a factor.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



User avatar
C36
Posts: 2471
Joined: Fri Mar 03, 2017 3:24 am

by C36

MoPho wrote: MoPho
C36 wrote:
Wed Apr 04, 2018 9:17 pm
Disc have ONLY disadvantages except on the way down under certain conditions.
How can we rationally say "i will take disc in all cases"
...uh, the same way you can say you will take rim brakes in all cases?

And it could be argued that ALL BRAKES have only disadvantages except on the way down. Silly comment [\quote]

You are playing dumb here, we talk on relative not absolute. disc brakes compared with rim brakes have disadvantages on the flat, on the way up and only represent benefits (over rim brakes, in case you got lost) certain conditions on the way down (need high-deceleration or long technical descents or some bad weather conditions).
No I won't take rim brakes all the time, I don't recall making this claim: few messages above a couple was looking for a bike that will give them more confidence in descents, not for performance but for confort and safety.
MoPho wrote:
I did (twice) test a supersix evo hm disc... and I own my second supersix evo hm... Le Cycle in France compared 3 identical bikes in disc and rim brakes... Canyon recognised it and so did a friend at Cannondale: ALL confirm That DISCS FRAMES DO NOT REACT AS WELL AS RIM BRAKES (sorry for the caps but still don't understand how is this not a main point).
I had a Giant TCR rim brake prior to my TCR disc, couldn't say there is much of a difference, but the bikes are never truly identical. How a bike reacts is subjective and really hard to prove or identify differences.
But you're right, most people won't compare directly, which is why your comment about not "reacting" as well, even if true, doesn't matter and is not the main point.

Is this for real? Did you just say "well yes disc brakes frames may have worse dynamic properties than their equivalent rim brakes, but unless you compare you won't see the difference then who cares".
"Bikes are never the same" well read again what I mentioned the bikes compared were the same and when two engineers from two brands tell you "the disc brake frame is not as reactive as the rim brake" I think it is clear.
"This is not the main point" well the same bike with different brake system behave differently is kind of the main point at the moment of picking a bike that will spend 99% of the time doing something else than braking.
Now I get your point, pick the first bike you see and go have fun don't think more since you don't care how different bikes behave.
MoPho wrote:
It's called physics... on flats, the feeling is a lot stronger than the real gain. On climbs it does make a real difference (edit running the maths) 1.6s/km at 9% slope.
Sorry, but most people would be hard pressed to feel the difference of the added weight of disc and those that say they can, that is questionable.
The physics is irrelevant to my point which was that if you are not relying on winning races for your paycheck (and I'll even give you amateur racing at the sharp end of the stick), why do you care so much about saving a few seconds on a climb from weight savings? Is it ego? Why not just try and train harder, or lose the pound of weight on your body? .

It is called optimisation, just more than 100 years than Engineers try to make bikes faster.
Do you have a road bike rather or a touring bike? Do you have 25-28 tires or 32-38? Why have you made some choices that bring more performance and suddenly for a less reactive frame and heavier, less aero setup it suddenly doesn't matter?

TobinHatesYou wrote: I had to laugh at the comment earlier that disc only has disadvantages except in certain descending situations. Really guys? Just distill it to this.

“Disc’s only advantage is being the better, more advanced braking technology.”
Are you in the business of only doing downhills? Last time I checked I spend a lot more time on the flats and uphill where my rim brake frame behave better and the descents that need hard braking are quite limited (and yes I live in an area where I climb above 3000m each weekend)
"More advanced braking technology", you have plenty of more advanced tech, why don't we have them on bikes? Why don't we have dual front disc like on bikes, why don't we have carbon to carbon braking systems like on car-racing? Why don't we have electromagnetic brakes like on trains?
Just cause your glorified braking system is like all the others à comprise. And among all those compromises the gains disc offers are limited to descents where you need to brake a lot (I get the confort of braking with one finger) and under poor weather conditions. Putting it in front of weight, maintenance, disc rub, wheel changes, wheels stiffness and even aero. I am not seeing how this superior braking system brings a better package during my 100miles ride.
cassard wrote:if you follow the real physics principles, at constant speed on flat, it's impossible to feel a 600g difference on the bike. If you do feel a difference, it's in your head.
spdntrxi wrote:rotational mass is physics.. so if he can feel it then why not believe him too is all I'm saying.

remember others are throwing terms like constant speed .static this and that... in pdrpushers defense he did not use those terms.
I should have phrased it differently, accelerating on flat, weight has close to no impact (measurable but we talk about mm to cm) but people can feel it "more" compared to the real difference. Obviously at constant speed the only impact on weight would be on rolling resistance (linear increase with weight) that nobody will ever feel. .


Envoyé de mon iPhone en utilisant Tapatalk

Locked