RIM BRAKE FRAMES = OBSOLETE!

Questions about bike hire abroad and everything light bike related. No off-topic chat please

Moderators: robbosmans, Moderator Team

bobones
Posts: 1271
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Mr.Gib wrote:
Sun Apr 30, 2023 1:02 am
bobones and blutto - how big are you guys? I have theory that under a certain weight, maybe under 140 or 150 lbs (65 - 68 kg) disc brakes are amazing but any heavier and the issues start to build. (Of course everyone deal with the noise in the wet.)
I'm bang on 11st / 70 kg at the moment and around 5'10.5. I'm 58 years old and took up cycling again in my mid 40s but had a few 'racers' in my teens and early twenties.My threshold power is 270 w building towards 280-290 by summmer, and I have zero natural talent or athletic ability and no sprint whatsoever. I ride outdoors 7 days a week more often than not and will probably surpass 10k miles for the year again. I have never raced, but ride for fun and fitness and use Xert to help me train.

I only ride on tarmac: no gravel, MTB or track for me. I have 6 road bikes (rim steel, rim titanium, rim carbon full fenders, rim aero, rim light climber, disc endurance w/fenders) 5 of these are SRAM AXS or mixed SRAMano AXS, but the steel bike is 11-speed Shimano R7000 - it usually sits on my turbo. I do all my own bike maintenance and build wheels occasionally, but I am not an engineer like so many on here seem to be! All my bikes are set up tubeless with waxed chains.

I tend to only ride in Scotland, which isn't particularly mountainous, but is rarely flat either. The west, where I live, is frequently wet and always seems to be windy.

As a canny Scot, value for money is always a priority, and all my bikes have evolved from some kind of bargain buy. I haven't bought a complete new bike since 2011, never spent more than £1.8k on a frameset, and my most extravagant cycling purchase has been a set of WTO 60s (or maybe a it was a set of EE brakes). Like many, I am a bit of a pefectionist when it comes to my bikes, so I don't usually tolerate noise, which is why the disc bike gets on my tits so much in the rain.

I know you didn't ask for a full bio, but there you have it :mrgreen:

Flasher
Posts: 258
Joined: Fri Mar 27, 2009 8:10 pm

by Flasher

It would appear that you didn't get the "Disc brakes are perfect" memo, but don't worry you'll soon be getting the one marked 'It must be your fault, have you ever set up a brakes before?"

by Weenie


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

www.starbike.com



bobones
Posts: 1271
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Flasher wrote:
Sun Apr 30, 2023 12:58 pm
It would appear that you didn't get the "Disc brakes are perfect" memo, but don't worry you'll soon be getting the one marked 'It must be your fault, have you ever set up a brakes before?"
To be fair I am not experienced in setting up disc brakes, but I am all ears and still waiting on the solutions from the cognoscenti for fixing the wet noise problem.

In the meantime, I thought I'd take my truly obsolete steel bike off the turbo and go out for a ride. The weather is garbage here again, but what the hell, I stuck on some fenders and basic carbon wheels I built from AliE parts and paired them up with Wiggle's ultra cheap Lifeline blue carbon pads. I must be crazy putting my life in danger like that, but guess what, braking in the wet was totally unremarkable, zero issues, quiet too. I wasn't enjoying the ride on 25 mm tyres at 80 PSI but after dropping to 60 it was like floating on air, and it put a smile on my gaunt and usually scowling face.

Image

I didn't have my GoPro with me, but if I go back out I'll record it for comparison sake.


User avatar
Mr.Gib
Posts: 5577
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

blutto wrote:
Sun Apr 30, 2023 2:01 am
....race weight was about 170 lb +/-....and still in the ball park
bobones wrote:
Sun Apr 30, 2023 7:54 am
I'm bang on 11st / 70 kg at the moment
Well, I guess my theory isn't that solid. The best I have been able to do with wet weather noise is Galfer standard pads on Juin Tech GT with Sram rotors. My Dura Ace hydro with stock L05a pads and XT rotors are damn noisy in the wet.

My theory might be more relevant with big guys on proper descents that demand full power braking. No way the big guys have the same experience as the little ones. Though at 170 lb/76 kg, I have no complaints. Maybe 170 lbs is adequately light.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

blutto
Posts: 229
Joined: Thu Jun 21, 2012 5:09 pm

by blutto

TobinHatesYou wrote:
Sat Apr 29, 2023 11:50 pm
eli76141 wrote:
Sat Apr 29, 2023 8:47 pm

Exactly. Nobody says it's a tech issue.

bobones backed off the term modulation, but still claims disc brakes have worse “lever feel.”

blutto is even more specifically suggesting that braking forces traveling through deflecting, elongating, resonating spokes is causing a muted brake feel and/or lag.
....btw its just not dumb ole blutto spewing such nonsense cause if you look at the way front wheels are now being built to accomodate a disc braking system you will find that, unlike the radially spoked rim brake front wheels of yore , the front disc wheels are often built with more robust cross patterns or in the case of Campagnolo, the G3 pattern normally reserved for stresses the rear wheel endures....read , they are likely being built that way to try to deal with the stresses I've been talking about ( and btw, in the process sacrificing the aerodynamic advantage of radial spoking to provide more needed strength....so with that signicant loss and the aerodynamic loss associated with the disc brake assembly the disc revolution turns the all-important leading edge of a bike into something kinda more akin to an open parachute...ain't progress grand, eh.. )....

Cheers
Last edited by blutto on Sun Apr 30, 2023 6:27 pm, edited 2 times in total.

blutto
Posts: 229
Joined: Thu Jun 21, 2012 5:09 pm

by blutto

Mr.Gib wrote:
Sun Apr 30, 2023 3:15 pm
blutto wrote:
Sun Apr 30, 2023 2:01 am
....race weight was about 170 lb +/-....and still in the ball park
bobones wrote:
Sun Apr 30, 2023 7:54 am
I'm bang on 11st / 70 kg at the moment
Well, I guess my theory isn't that solid. The best I have been able to do with wet weather noise is Galfer standard pads on Juin Tech GT with Sram rotors. My Dura Ace hydro with stock L05a pads and XT rotors are damn noisy in the wet.

My theory might be more relevant with big guys on proper descents that demand full power braking. No way the big guys have the same experience as the little ones. Though at 170 lb/76 kg, I have no complaints. Maybe 170 lbs is adequately light.
....which brings up something I've given some thought to....as in, what is the target range weight wise for the design of bike components ?....any ideas, cause my personal experience catalogues a plethora of broken bike bits, from rear wheel rims, rear hubs, freewheel assemblies, stems, crankarms, several drive-side rear drop-outs ( and none of these issues directly related to crashes )....which lead me to believe they were building for someone lighter, like in the 120-150lb range...

...so maybe 170lb is the bike racer equivalent of a nose tackle....?....

Cheers

TobinHatesYou
Posts: 12456
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Of course a disc-brake wheel needs to be built stiffer to protect itself from destruction, but to suggest you can feel those differences under braking it is hilarious. Even if we include aspects you did not mention like pad movement inside the caliper, we’re talking about *maybe* 1mm worth of play, aka 1mm of lag in terms of stopping distance. Aka .0001 seconds at 30km/h going from a perfectly designed rigid disc-brake+wheel system to what we have in real life.

If you can feel this difference as a muted/unresponsive braking feel, congratulations.

Now consider the friction and elongation in a cable-actuated brake vs non-compressible fluid in a hydro brake as well, and this discussion becomes even more ridiculous.

blutto
Posts: 229
Joined: Thu Jun 21, 2012 5:09 pm

by blutto

TobinHatesYou wrote:
Sun Apr 30, 2023 6:40 pm
Of course a disc-brake wheel needs to be built stiffer to protect itself from destruction, but to suggest you can feel those differences under braking it is hilarious. Even if we include aspects you did not mention like pad movement inside the caliper, we’re talking about *maybe* 1mm worth of play, aka 1mm of lag in terms of stopping distance. Aka .0001 seconds at 30km/h going from a perfectly designed rigid disc-brake+wheel system to what we have in real life.

If you can feel this difference as a muted/unresponsive braking feel, congratulations.


....it would be little different from feeling the difference btwn a 3-cross and a 4-cross rear wheel under acceleration, which is quite easy to do...

...and wondering what would cause a front wheel to destruct ?....like I've seen rim front wheels survive a lot of stress but destruction was not a regular item on the menu....so how is disc wheel use that different to require a novel design to prevent destruction ?....stiffer to respond to what exactly ?....going from from radial to G3 shows someone is anticipated a whole lot of stress from something...and when that someting is being transferred from the mechanism to the tire it is passed thru the spoke which in that capacity is being asked to act like a lever....but as we all know a spoke does act like a good lever because it exhibits a great deal of flex in that capacity....and that flex will not allow an instantaneous transfer of stuff, it will , as a poor lever flex, and that flex will have a time frame which be felt as a lag....and that time frame will vary with amount of force applied to it so its not a constant ....and stuff like that really messes up modulation...

...so yeah a mitt full of disc brake produces gobs of stopping power....but that feathering a brake function, where modulation dwells, not so much....and btw having too many gobs of power, like anything that overwhelms the tire, is just a waste that is really not needed...

...maybe the next shiny bauble will be an ABS type disc system, but the problem with this is ABS actually lengthens the stopping distance and really messes with modulation....or the next big move could be to replace fast low crr tires we currently enjoy with studded tires, like with the best ones having carbon or titanium spikes to reduce weight and increase cash flow ( which may totally mess up crr but hey that is the price of progress eh, because when you really have to stop, you really gotta stop, crr be damned )....

Cheers

TobinHatesYou
Posts: 12456
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

.0001s of lag in the system at 30km/h. Whatever you think you’re feeling is likely in your head, especially considering the braketracks flex under load, thick rim-brake pads deform more than disc-brake pads, and sleeved cables have friction, etc.

blutto
Posts: 229
Joined: Thu Jun 21, 2012 5:09 pm

by blutto

TobinHatesYou wrote:
Sun Apr 30, 2023 10:14 pm
.0001s of lag in the system at 30km/h. Whatever you think you’re feeling is likely in your head, especially considering the braketracks flex under load, thick rim-brake pads deform more than disc-brake pads, and sleeved cables have friction, etc.
....its in my hands actually , you know those things that operate the brake levers, and often in a modulating fashion....

Cheers
Last edited by blutto on Sun Apr 30, 2023 11:02 pm, edited 1 time in total.

spdntrxi
Posts: 5790
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

blutto wrote:
Sun Apr 30, 2023 10:57 pm
TobinHatesYou wrote:
Sun Apr 30, 2023 10:14 pm
.0001s of lag in the system at 30km/h. Whatever you think you’re feeling is likely in your head, especially considering the braketracks flex under load, thick rim-brake pads deform more than disc-brake pads, and sleeved cables have friction, etc.
....its in my hands actually , you know those things that operate the brake levers....

Cheers
yeah but without your brain...... nevermind :noidea:
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

blutto
Posts: 229
Joined: Thu Jun 21, 2012 5:09 pm

by blutto

spdntrxi wrote:
Sun Apr 30, 2023 10:58 pm
blutto wrote:
Sun Apr 30, 2023 10:57 pm
TobinHatesYou wrote:
Sun Apr 30, 2023 10:14 pm
.0001s of lag in the system at 30km/h. Whatever you think you’re feeling is likely in your head, especially considering the braketracks flex under load, thick rim-brake pads deform more than disc-brake pads, and sleeved cables have friction, etc.
....its in my hands actually , you know those things that operate the brake levers....

Cheers
yeah but without your brain...... nevermind :noidea:
...so first its in my head, and now it isn't....gosh youse guys sound dazed and confused....which btw often happens when you try to impose a theory onto reality and then reality kicks you in the teeth...

Cheers
Last edited by blutto on Sun Apr 30, 2023 11:19 pm, edited 1 time in total.

spdntrxi
Posts: 5790
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

blutto wrote:
Sun Apr 30, 2023 11:07 pm
spdntrxi wrote:
Sun Apr 30, 2023 10:58 pm
blutto wrote:
Sun Apr 30, 2023 10:57 pm
TobinHatesYou wrote:
Sun Apr 30, 2023 10:14 pm
.0001s of lag in the system at 30km/h. Whatever you think you’re feeling is likely in your head, especially considering the braketracks flex under load, thick rim-brake pads deform more than disc-brake pads, and sleeved cables have friction, etc.
....its in my hands actually , you know those things that operate the brake levers....

Cheers
yeah but without your brain...... nevermind :noidea:
...so first its in my head, and now it isn't....gosh you sound dazed and confused....which btw often happens when you try to impose a theory onto reality and then reality kicks you in the teeth...

Cheers
dude this is my first reply to you in this thread :noidea: You are the one saying its not in your head :noidea: I ride both rim and disc.. If I'm racing, disc is preferred by a large margin.
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

blutto
Posts: 229
Joined: Thu Jun 21, 2012 5:09 pm

by blutto

spdntrxi wrote:
Sun Apr 30, 2023 11:11 pm
blutto wrote:
Sun Apr 30, 2023 11:07 pm
spdntrxi wrote:
Sun Apr 30, 2023 10:58 pm
blutto wrote:
Sun Apr 30, 2023 10:57 pm


....its in my hands actually , you know those things that operate the brake levers....

Cheers
yeah but without your brain...... nevermind :noidea:
...so first its in my head, and now it isn't....gosh you sound dazed and confused....which btw often happens when you try to impose a theory onto reality and then reality kicks you in the teeth...

Cheers
dude this is my first reply to you in this thread :noidea: You are the one saying its not in your head :noidea: I ride both rim and disc.. If I'm racing, disc is preferred by a large margin.
...yeah sorry about the typo....was being fixed as you posted....carry on , hope you have a successful race season...

Cheers

TobinHatesYou
Posts: 12456
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

I’m still amazed someone thinks they can feel one ten-thousandths of a second. And yes, that’s all in your head.

by Weenie


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

www.starbike.com



Post Reply