A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

The death of rim brakes?



 
 
Thread Tools Display Modes
  #21  
Old March 11th 19, 01:21 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 6,826
Default The death of rim brakes?

On 3/10/2019 5:52 PM, wrote:
On Sunday, March 10, 2019 at 8:34:24 AM UTC-5, wrote:
I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal.

Deacon Mark


One of my issues is that I realize we will have rim brake bikes for awhile but I just hope to keep the nice looks and basic set up. If it is not broke don't fix the puppy. The one item I have never experience is the idea on a long descend you can blow a tube. In the flatlands that to me seems impossible. To blow a tube on a long descend does the speed have to be really fast like about 40mph or say at 25mph for a long time. The biggest descend I have done is about 7% grade total for about a mile and the last say 1/4 mile is got to 9%. I could easily feather the brakes to avoid heat but maybe my experience is really limited for true mountain riding. Can you just pull the brakes up pretty good to get to a speed that is comfortable. In my case this descend got me to about 43mph my top speed for sure. Had the it been longer I don't know long I could have continued before I got to damn scared.


Long, long ago I read a technical article in some bike magazine. (There
used to be real technical articles in bike magazines.) This one was
about brake energy (or really, power in the engineering sense of work
per unit time) and temperature rise during long descents.

The article explained that the braking power depended on brake force and
speed. For any given hill, you could always use the brakes to go super
slow. Brake force will be high, but speed will be low and power will be
low, leading to less temperature rise.

Alternately, you could descend very fast, braking only lightly or not at
all. Brake force will be low or zero. (There's also more aerodynamic
cooling.) This too will lead to less temperature rise.

The author claimed, using lots of calculations summarized in graphs,
that the greatest temperature rise occurred by using the brakes to keep
the speed about 30 mph or 50 kph.

Trouble is, this is exactly the speed lots of cyclists choose for long
descents. Any slower and they feel like slugs. Any faster and they get
scared.

I blew only one tire on a downhill, on the rear of our tandem, creeping
down a short ( 1/10 mile) steep grade well over 10%. We just rode the
bike to the bottom and I changed the tube. But I can see it would be a
problem if the front tire blew.


--
- Frank Krygowski
Ads
  #22  
Old March 11th 19, 01:24 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 6,826
Default The death of rim brakes?

On 3/10/2019 6:38 PM, wrote:
On Sunday, March 10, 2019 at 4:48:00 PM UTC+1, Sir Ridesalot wrote:
On Sunday, March 10, 2019 at 11:22:10 AM UTC-4, Frank Krygowski wrote:
On 3/10/2019 11:07 AM,
wrote:
On Sunday, March 10, 2019 at 2:34:24 PM UTC+1, wrote:
I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal.

Deacon Mark

Try to find a ATB without disc brakes. I think that is also gonna happen with road bikes.

Fashion is weird and powerful.

--
- Frank Krygowski


A few years ago I nearly bought a new disc brake equipped MTB when my buddy bought his Da Vinci disc brake equipped MTB. However, after having seen how his bike ate disc brake pads I decide not to replace my old MTB after all.

I wonder how the cost of replacement disc brake pads over a number of years compares to the cost of a new rim over those same number of years? I've never worn out an MTB rim but my buddy was going thorough a pair of disc brake pads every week or so and that was just from riding or paved roads or crushed limestone stone dust rail-trails. He was NOT using the brakes all that much either.

Three bicycle shops here in town could not figure out why his bike ate pads so fast and that includes the shop that specializes in cyclo-cross and MTB trails and has a cyclo-cross team.

Just weird. Rim brakes are fine for a lot of bicyclists yet it seems that once again a choice will eventually be denied to consumers.

On top of that, if your present bicycle is equipped with racks you'll most likely have to buy new ones that are disc brake compatible if you do buy a new bike. Those new racks aren't that cheap either.

Cheers


That is an unusual wear of pads.


I've said this before, but if you're heading out on a long tour with a
disc brake bike, take extra pads. We hosted a guy whose pads suddenly
wore out during a tour, leaving him without brakes until he could find a
bike shop on his route.


--
- Frank Krygowski
  #23  
Old March 11th 19, 02:24 AM posted to rec.bicycles.tech
Roger Merriman[_4_]
external usenet poster
 
Posts: 162
Default The death of rim brakes?

Frank Krygowski wrote:
On 3/10/2019 6:15 PM, Roger Merriman wrote:
Frank Krygowski wrote:
On 3/10/2019 3:51 PM, jbeattie wrote:
On Sunday, March 10, 2019 at 8:22:10 AM UTC-7, Frank Krygowski wrote:
On 3/10/2019 11:07 AM, wrote:
On Sunday, March 10, 2019 at 2:34:24 PM UTC+1, wrote:
I keep reading see all the bikes coming out and basically all disc
brakes. I cannot believe rim brakes are going to be gone but maybe I
am just kidding myself. I frankly hate the disc brake look and
certainly for a long time parts will be around but are these rim brakes a dead deal.

Deacon Mark

Try to find a ATB without disc brakes. I think that is also gonna
happen with road bikes.

Fashion is weird and powerful.

For off road, discs are clearly better. It is not even debatable.
Discs are better for some road applications as well...

Agreed - but what is the magnitude on "better"?

As I've said, we're deep into diminishing returns on bikes. Sales
literature pushes people to buy a 17 pound bike instead of a 19 pound
one, so the bike+rider weight diminishes by 1%. Get Dura-Ace instead of
105 because the shifts are 20 milliseconds faster. Ditch your front
derailleur and reduce your aerodynamic drag.

In real life, stopping "better" almost never means anything practical.

but clearly rim brakes are fine for dry weather road riding with
aluminum rims. I'm sure they will be around forever.

Yes, and those of us who don't have to do panic stops in the rain on 10%
downhills don't have to respond to this market churning.

I have a Gravel bike, it replaces the CX bike. At that size of tyre your on
canti which for a CX race is fine, but rapidly feel underpowered on big
hills even in the dry, on tarmac.

Discs make 30-40mm road bikes much less of a compromise.

I agree that in the dry rims particularly good dual pivots are great brakes
but unless that’s your Sunday best bike that only sees dry roads, it seems
foolish to plan for best case.


Well, the rim brakes on my various bikes are the ones that were used for
_every_ case since 1976. The only brake failure I ever experienced was
before them, on my first super-cheap 10 speed with chrome steel rims,
during a pouring thunderstorm. I had to overshoot the turn I was
planning to make.

I don't care if people prefer discs. But it bothers me when
manufacturers or others start implying that rim brakes are inadequate
for even ordinary riding.


I think it’s been more rider than manufacture lead, partially if you’re
grown up with MTB which have had big stonking Hydro systems for years, I
can remember a number of younger guys with their first road bike commenting
on the lack of brakes in comparison.

Stuff changes roadies do tend to be generally more conservative than MTB so
I’d not be surprised if rim brakes survive in some form, after all you can
get rim braked MTB still only cheap hardtail but it’s been 15/20 years now?

So I could see rim brakes surviving in some form, apart from anything else
there is a lot of road bikes with rim brakes out there! But I could see
even a few new bikes which aren’t BSO like MTB using rim brakes being
continued to be made if only niche.

Roger Merriman

  #24  
Old March 11th 19, 03:10 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default The death of rim brakes?

On Sun, 10 Mar 2019 20:21:40 -0400, Frank Krygowski
wrote:

On 3/10/2019 5:52 PM, wrote:
On Sunday, March 10, 2019 at 8:34:24 AM UTC-5, wrote:
I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal.

Deacon Mark


One of my issues is that I realize we will have rim brake bikes for awhile but I just hope to keep the nice looks and basic set up. If it is not broke don't fix the puppy. The one item I have never experience is the idea on a long descend you can blow a tube. In the flatlands that to me seems impossible. To blow a tube on a long descend does the speed have to be really fast like about 40mph or say at 25mph for a long time. The biggest descend I have done is about 7% grade total for about a mile and the last say 1/4 mile is got to 9%. I could easily feather the brakes to avoid heat but maybe my experience is really limited for true mountain riding. Can you just pull the brakes up pretty good to get to a speed that is comfortable. In my case this descend got me to about 43mph my top speed for sure. Had the it been longer I don't know long I could have continued before I got to damn scared.


Long, long ago I read a technical article in some bike magazine. (There
used to be real technical articles in bike magazines.) This one was
about brake energy (or really, power in the engineering sense of work
per unit time) and temperature rise during long descents.

The article explained that the braking power depended on brake force and
speed. For any given hill, you could always use the brakes to go super
slow. Brake force will be high, but speed will be low and power will be
low, leading to less temperature rise.

Alternately, you could descend very fast, braking only lightly or not at
all. Brake force will be low or zero. (There's also more aerodynamic
cooling.) This too will lead to less temperature rise.

The author claimed, using lots of calculations summarized in graphs,
that the greatest temperature rise occurred by using the brakes to keep
the speed about 30 mph or 50 kph.

Trouble is, this is exactly the speed lots of cyclists choose for long
descents. Any slower and they feel like slugs. Any faster and they get
scared.

I blew only one tire on a downhill, on the rear of our tandem, creeping
down a short ( 1/10 mile) steep grade well over 10%. We just rode the
bike to the bottom and I changed the tube. But I can see it would be a
problem if the front tire blew.


Phuket, Thailand has several extremely steep hills on the western side
of the island, steep enough that it is difficult to push a bike up
them.

Out of curiosity I did push the bike up one and coasted down the
eastern side.

Having read all the hoopalla about the rims getting hot and tires
blowing I stopped about half way down and felt the rims... they were,
perhaps, a bit warmer than ambient temperature.

But. As the east side of the hill is a series of "S" turns one can't
just coast down the mountain but must slow down every hundred yards or
so to make the next corner so my braking was a series of pretty hard
brake applications followed by, perhaps, an equal period of coasting.

I have since used that method when descending hills and an occasional
check shows that the rims do not get excessively hot.

--
Cheers,
John B.


  #25  
Old March 11th 19, 04:46 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 6,826
Default The death of rim brakes?

On 3/10/2019 10:10 PM, John B. Slocomb wrote:
On Sun, 10 Mar 2019 20:21:40 -0400, Frank Krygowski
wrote:

On 3/10/2019 5:52 PM, wrote:
On Sunday, March 10, 2019 at 8:34:24 AM UTC-5, wrote:
I keep reading see all the bikes coming out and basically all disc brakes. I cannot believe rim brakes are going to be gone but maybe I am just kidding myself. I frankly hate the disc brake look and certainly for a long time parts will be around but are these rim brakes a dead deal.

Deacon Mark

One of my issues is that I realize we will have rim brake bikes for awhile but I just hope to keep the nice looks and basic set up. If it is not broke don't fix the puppy. The one item I have never experience is the idea on a long descend you can blow a tube. In the flatlands that to me seems impossible. To blow a tube on a long descend does the speed have to be really fast like about 40mph or say at 25mph for a long time. The biggest descend I have done is about 7% grade total for about a mile and the last say 1/4 mile is got to 9%. I could easily feather the brakes to avoid heat but maybe my experience is really limited for true mountain riding. Can you just pull the brakes up pretty good to get to a speed that is comfortable. In my case this descend got me to about 43mph my top speed for sure. Had the it been longer I don't know long I could have continued before I got to damn scared.


Long, long ago I read a technical article in some bike magazine. (There
used to be real technical articles in bike magazines.) This one was
about brake energy (or really, power in the engineering sense of work
per unit time) and temperature rise during long descents.

The article explained that the braking power depended on brake force and
speed. For any given hill, you could always use the brakes to go super
slow. Brake force will be high, but speed will be low and power will be
low, leading to less temperature rise.

Alternately, you could descend very fast, braking only lightly or not at
all. Brake force will be low or zero. (There's also more aerodynamic
cooling.) This too will lead to less temperature rise.

The author claimed, using lots of calculations summarized in graphs,
that the greatest temperature rise occurred by using the brakes to keep
the speed about 30 mph or 50 kph.

Trouble is, this is exactly the speed lots of cyclists choose for long
descents. Any slower and they feel like slugs. Any faster and they get
scared.

I blew only one tire on a downhill, on the rear of our tandem, creeping
down a short ( 1/10 mile) steep grade well over 10%. We just rode the
bike to the bottom and I changed the tube. But I can see it would be a
problem if the front tire blew.


Phuket, Thailand has several extremely steep hills on the western side
of the island, steep enough that it is difficult to push a bike up
them.

Out of curiosity I did push the bike up one and coasted down the
eastern side.

Having read all the hoopalla about the rims getting hot and tires
blowing I stopped about half way down and felt the rims... they were,
perhaps, a bit warmer than ambient temperature.

But. As the east side of the hill is a series of "S" turns one can't
just coast down the mountain but must slow down every hundred yards or
so to make the next corner so my braking was a series of pretty hard
brake applications followed by, perhaps, an equal period of coasting.

I have since used that method when descending hills and an occasional
check shows that the rims do not get excessively hot.


Omega and others make temperature indicator dots. They turn black and
stay black when their rated temperature is reached.
https://www.omega.com/pptst/TL-C5_LABELS.html
They're single use products.

Back when Jobst was with us, there was talk of sticking these on some
rims and doing tests, but I don't recall if anyone actually did that, or
what the results were.


--
- Frank Krygowski
  #26  
Old March 11th 19, 07:02 AM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 4,001
Default The death of rim brakes?

On Sunday, March 10, 2019 at 11:46:16 PM UTC-4, Frank Krygowski wrote:
Snipped
Back when Jobst was with us, there was talk of sticking these on some
rims and doing tests, but I don't recall if anyone actually did that, or
what the results were.


--
- Frank Krygowski


Jobst and Carl Fogel are both missed.

Cheers
  #27  
Old March 11th 19, 07:10 AM posted to rec.bicycles.tech
Tosspot[_3_]
external usenet poster
 
Posts: 1,249
Default The death of rim brakes?

On 3/11/19 1:24 AM, Frank Krygowski wrote:
On 3/10/2019 6:38 PM, wrote:
On Sunday, March 10, 2019 at 4:48:00 PM UTC+1, Sir Ridesalot wrote:
On Sunday, March 10, 2019 at 11:22:10 AM UTC-4, Frank Krygowski wrote:
On 3/10/2019 11:07 AM,
wrote:
On Sunday, March 10, 2019 at 2:34:24 PM UTC+1,
wrote:
I keep reading see all the bikes coming out and basically all disc
brakes. I cannot believe rim brakes are going to be gone but maybe
I am just kidding myself. I frankly hate the disc brake look and
certainly for a long time parts will be around but are these rim
brakes a dead deal.

Deacon Mark

Try to find a ATB without disc brakes. I think that is also gonna
happen with road bikes.

Fashion is weird and powerful.

--
- Frank Krygowski

A few years ago I nearly bought a new disc brake equipped MTB when my
buddy bought his Da Vinci disc brake equipped MTB. However, after
having seen how his bike ate disc brake pads I decide not to replace
my old MTB after all.

I wonder how the cost of replacement disc brake pads over a number of
years compares to the cost of a new rim over those same number of
years? I've never worn out an MTB rim but my buddy was going thorough
a pair of disc brake pads every week or so and that was just from
riding or paved roads or crushed limestone stone dust rail-trails. He
was NOT using the brakes all that much either.

Three bicycle shops here in town could not figure out why his bike
ate pads so fast and that includes* the shop that specializes in
cyclo-cross and MTB trails and has a cyclo-cross team.

Just weird. Rim brakes are fine for a lot of bicyclists yet it seems
that once again a choice will eventually be denied to consumers.

On top of that, if your present bicycle is equipped with racks you'll
most likely have to buy new ones that are disc brake compatible if
you do buy a new bike. Those new racks aren't that cheap either.

Cheers


That is an unusual wear of pads.


I've said this before, but if you're heading out on a long tour with a
disc brake bike, take extra pads. We hosted a guy whose pads suddenly
wore out during a tour, leaving him without brakes until he could find a
bike shop on his route.


I'm wearing out discs (every 4 years) faster than pads. What am I doing
wrong?

  #28  
Old March 11th 19, 07:13 AM posted to rec.bicycles.tech
Tosspot[_3_]
external usenet poster
 
Posts: 1,249
Default The death of rim brakes?

On 3/11/19 1:10 AM, Frank Krygowski wrote:

snip

Well, the rim brakes on my various bikes are the ones that were used for
_every_ case since 1976. The only brake failure I ever experienced was
before them, on my first super-cheap 10 speed with chrome steel rims,
during a pouring thunderstorm. I had to overshoot the turn I was
planning to make.

I don't care if people prefer discs. But it bothers me when
manufacturers or others start implying that rim brakes are inadequate
for even ordinary riding.


Why did we ever move away from chromed steel rims? Cheap and easy to
manufacture, lasted for ever (you still see them about!) and looked great!


  #29  
Old March 11th 19, 07:19 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default The death of rim brakes?

On Mon, 11 Mar 2019 07:13:52 +0100, Tosspot
wrote:

On 3/11/19 1:10 AM, Frank Krygowski wrote:

snip

Well, the rim brakes on my various bikes are the ones that were used for
_every_ case since 1976. The only brake failure I ever experienced was
before them, on my first super-cheap 10 speed with chrome steel rims,
during a pouring thunderstorm. I had to overshoot the turn I was
planning to make.

I don't care if people prefer discs. But it bothers me when
manufacturers or others start implying that rim brakes are inadequate
for even ordinary riding.


Why did we ever move away from chromed steel rims? Cheap and easy to
manufacture, lasted for ever (you still see them about!) and looked great!


And you had to drag your feet to stop :-)

--
Cheers,
John B.


  #30  
Old March 11th 19, 04:34 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 6,826
Default The death of rim brakes?

On 3/11/2019 2:13 AM, Tosspot wrote:
On 3/11/19 1:10 AM, Frank Krygowski wrote:

snip

Well, the rim brakes on my various bikes are the ones that were used
for _every_ case since 1976. The only brake failure I ever experienced
was before them, on my first super-cheap 10 speed with chrome steel
rims, during a pouring thunderstorm. I had to overshoot the turn I was
planning to make.

I don't care if people prefer discs. But it bothers me when
manufacturers or others start implying that rim brakes are inadequate
for even ordinary riding.


Why did we ever move away from chromed steel rims?* Cheap and easy to
manufacture, lasted for ever (you still see them about!) and looked great!


I suspect the main reason was weight. But there were tremendous
differences in braking when wet. The incident I mentioned was an
example. The rain was pouring down heavily. I coasted down a slight hill
intending to turn right into a little road at the bottom. But the brakes
had no effect for perhaps five seconds or more. I rolled right past that
little road.

Those were probably the worst style of chrome steel rims. They featured
little pits on their braking surface, perhaps intended to provide
roughness and aid braking, I don't know. But they acted as little water
reservoirs, keeping the brake pads from wiping the rims dry.

I've heard that there were hard-to-find brake blocks that worked well
with wet chrome steel rims, but I've never seen them in the flesh, let
alone tested them.


--
- Frank Krygowski
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
DuraAce 7800 brakes v. 6600 brakes RS Techniques 4 February 1st 09 06:13 AM
Delta Brakes for sale, capy c group brakes vintage! [email protected] Marketplace 0 December 1st 08 01:47 PM
Generic Brakes vs Dura-Ace 7700 brakes ? RS Techniques 19 June 10th 06 01:30 AM
ANyone fail cast tender eye, death be to you, death come quickly whoreBanger Australia 0 June 3rd 06 11:47 AM
disc brakes on front, v-brakes on rear Per Elmster Mountain Biking 24 October 21st 03 10:42 PM


All times are GMT +1. The time now is 09:33 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 CycleBanter.com.
The comments are property of their posters.