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Why do some forks and frames have brake rotor size limits?



 
 
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  #301  
Old November 4th 17, 07:22 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,652
Default Why do some forks and frames have brake rotor size limits?

On Fri, 3 Nov 2017 20:27:32 -0700 (PDT), Sir Ridesalot
wrote:

On Friday, November 3, 2017 at 8:47:34 PM UTC-4, John B. wrote:
On Fri, 03 Nov 2017 07:53:04 -0700, Joerg
wrote:

On 2017-11-01 19:23, John B. wrote:
On Wed, 01 Nov 2017 13:56:24 -0700, Joerg
wrote:

On 2017-11-01 13:39, wrote:
On Wednesday, November 1, 2017 at 12:35:34 PM UTC-7, Joerg wrote:

A lever is never supposed to bottom out before the brake force on
respective wheel is maxed. If it did then he'd have faulty brakes
and I am sure he'd not have posted this. The guys look like serious
cyclists who know this.

How old are you again Joerg? With even the old Campy brakes it was
possible to bottom out the levers often without locking the wheels.


I clearly consider that a faulty brake system. In Germany they would
instantly disqualify a motor vehicle with such a flaw and not even let
you ride it off the TUEV test site.

But Jeorg, you aren't in Germany.


So that makes it ok to tool around in traffic with faulty equipment?


Goodness! You mean that if it isn't acceptable in Germany it is
automatically faulty and absolutely cannot be used in the rest of the
world?

Somehow, I don't think that you are correct.

--
Cheers,

John B.


I often wonder, after hearing ex-pat Germans complaining about how bad things are in their new country compared to back in Germany, why they left Germany in the first place.

Cheers


https://www.citylab.com/life/2017/04...-class/524193/

Median disposal income: by groups

Low income group:
Germany 20,980 U.S. 23,818
Middle income group:
Germany 44,901 U.S. 60,884
High income group:
Germany 98,394 U.SD. 135,708
--
Cheers,

John B.

Ads
  #302  
Old November 4th 17, 04:00 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,700
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-03 17:47, John B. wrote:
On Fri, 03 Nov 2017 07:53:04 -0700, Joerg
wrote:

On 2017-11-01 19:23, John B. wrote:
On Wed, 01 Nov 2017 13:56:24 -0700, Joerg
wrote:

On 2017-11-01 13:39, wrote:
On Wednesday, November 1, 2017 at 12:35:34 PM UTC-7, Joerg wrote:

A lever is never supposed to bottom out before the brake force on
respective wheel is maxed. If it did then he'd have faulty brakes
and I am sure he'd not have posted this. The guys look like serious
cyclists who know this.

How old are you again Joerg? With even the old Campy brakes it was
possible to bottom out the levers often without locking the wheels.


I clearly consider that a faulty brake system. In Germany they would
instantly disqualify a motor vehicle with such a flaw and not even let
you ride it off the TUEV test site.

But Jeorg, you aren't in Germany.


So that makes it ok to tool around in traffic with faulty equipment?


Goodness! You mean that if it isn't acceptable in Germany it is
automatically faulty and absolutely cannot be used in the rest of the
world?


A vehicle where the brake force is not at absolute max with full
actuation is faulty. Always.


Somehow, I don't think that you are correct.


So you honestly think that a bike where the levers bottom out while the
wheels are still not locked up is "safe to go"?

If that's true I am glad you are no longer maintaining aircraft. I have
a very different philosophy about safety.

--
Regards, Joerg

http://www.analogconsultants.com/
  #303  
Old November 4th 17, 05:51 PM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 2,814
Default Why do some forks and frames have brake rotor size limits?

On Saturday, November 4, 2017 at 8:00:38 AM UTC-7, Joerg wrote:
On 2017-11-03 17:47, John B. wrote:
On Fri, 03 Nov 2017 07:53:04 -0700, Joerg
wrote:

On 2017-11-01 19:23, John B. wrote:
On Wed, 01 Nov 2017 13:56:24 -0700, Joerg
wrote:

On 2017-11-01 13:39, wrote:
On Wednesday, November 1, 2017 at 12:35:34 PM UTC-7, Joerg wrote:

A lever is never supposed to bottom out before the brake force on
respective wheel is maxed. If it did then he'd have faulty brakes
and I am sure he'd not have posted this. The guys look like serious
cyclists who know this.

How old are you again Joerg? With even the old Campy brakes it was
possible to bottom out the levers often without locking the wheels.


I clearly consider that a faulty brake system. In Germany they would
instantly disqualify a motor vehicle with such a flaw and not even let
you ride it off the TUEV test site.

But Jeorg, you aren't in Germany.


So that makes it ok to tool around in traffic with faulty equipment?


Goodness! You mean that if it isn't acceptable in Germany it is
automatically faulty and absolutely cannot be used in the rest of the
world?


A vehicle where the brake force is not at absolute max with full
actuation is faulty. Always.


Somehow, I don't think that you are correct.


So you honestly think that a bike where the levers bottom out while the
wheels are still not locked up is "safe to go"?

If that's true I am glad you are no longer maintaining aircraft. I have
a very different philosophy about safety.


Aside from ABS, I agree -- and as a matter of fact, getting my new and awesome Trek up and running, the rear caliper brake (direct mount) bottomed out at the lever without locking up the wheel. WTF? That's no good. It's a complex brake, but the problem was simple -- the last run of the cable housing was about a half-inch too short. I dropped in a new section, did some minor adjustment and voila -- I'm skidding down the road, which actually isn't too difficult because the pavement is wet.

It's odd being on rim brakes after being on discs exclusively for the last four months, since my SuperSix bit the dust. I haven't ridden the bike much because its been raining, and I just got it, but I do worry about braking a spoke with the pads running so close to the rim. Cables are simple, though. I don't look forward to bleeding the hydraulics -- something I haven't done yet.

-- Jay Beattie
  #304  
Old November 4th 17, 07:55 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,700
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-04 09:51, jbeattie wrote:
On Saturday, November 4, 2017 at 8:00:38 AM UTC-7, Joerg wrote:
On 2017-11-03 17:47, John B. wrote:


[...]

Somehow, I don't think that you are correct.


So you honestly think that a bike where the levers bottom out while
the wheels are still not locked up is "safe to go"?

If that's true I am glad you are no longer maintaining aircraft. I
have a very different philosophy about safety.


Aside from ABS, I agree -- and as a matter of fact, getting my new
and awesome Trek up and running, the rear caliper brake (direct
mount) bottomed out at the lever without locking up the wheel. WTF?
That's no good. It's a complex brake, but the problem was simple --
the last run of the cable housing was about a half-inch too short. I
dropped in a new section, did some minor adjustment and voila -- I'm
skidding down the road, which actually isn't too difficult because
the pavement is wet.


It should also be lockable with a guy 50lbs heavier than you, wearing a
large backpack and planted fully on the seat.


It's odd being on rim brakes after being on discs exclusively for the
last four months, since my SuperSix bit the dust. I haven't ridden
the bike much because its been raining, and I just got it, but I do
worry about braking a spoke with the pads running so close to the
rim.



How can the pads get into the spokes? That could cause a major OTB crash.


Cables are simple, though. I don't look forward to bleeding the
hydraulics -- something I haven't done yet.


It's not that bad. Even on my MTB (lots of shaking, laying it down, et
cetera) with about 2k miles/year it didn't have to be done more than
once a year for the rear and every other year for the front. I can't get
the proper bleed nipples for my Promax Decipher calipers, they need
long-neck M5 thread.

So I just "burp" them. I set the respective lever level, open the
reservoir lid and affix toilet paper all around with a rubber band. Then
I squish them carefully lots of times until no more bubbles show up and
the pressure point feels nice and firm. Carefylly because I don't want
to spritz DOT4 on the garage floor. Good to wear old clothes when doing
that. One trick to top up the reservoir is to use a straw and a finger
on top for siphon. Of course, all this only works if your brake levers
have a reservoir where a more or less flat lid can be removed.

The rear never feels totally firm probably because of the long hose.
However, I can always lock it up before the lever gets uncomfortably
close to the handlebar. It's just that I like a nice hard pressure point.

I'd have nipples made but the calipers seem to be nearing EOL. They
begin to show sluggish retraction until warmed up by several miles of
hilly trail riding. Thinking about the Shimano M675 once they go but
only if Hangzhou Novich makes ceramic-based pads for these. I don't want
the stock resin pads.

I just got the 8" rotor size extenders for the caliper mounts, way ahead
of the arrival the estimated. $2.86 a pop including fast air shipping
from China. Could not believe it. I looked up and down and it seems you
can't even buy those adapters in the US.

--
Regards, Joerg

http://www.analogconsultants.com/
  #305  
Old November 4th 17, 09:50 PM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 2,814
Default Why do some forks and frames have brake rotor size limits?

On Saturday, November 4, 2017 at 11:55:18 AM UTC-7, Joerg wrote:
On 2017-11-04 09:51, jbeattie wrote:
On Saturday, November 4, 2017 at 8:00:38 AM UTC-7, Joerg wrote:
On 2017-11-03 17:47, John B. wrote:


[...]

Somehow, I don't think that you are correct.


So you honestly think that a bike where the levers bottom out while
the wheels are still not locked up is "safe to go"?

If that's true I am glad you are no longer maintaining aircraft. I
have a very different philosophy about safety.


Aside from ABS, I agree -- and as a matter of fact, getting my new
and awesome Trek up and running, the rear caliper brake (direct
mount) bottomed out at the lever without locking up the wheel. WTF?
That's no good. It's a complex brake, but the problem was simple --
the last run of the cable housing was about a half-inch too short. I
dropped in a new section, did some minor adjustment and voila -- I'm
skidding down the road, which actually isn't too difficult because
the pavement is wet.


It should also be lockable with a guy 50lbs heavier than you, wearing a
large backpack and planted fully on the seat.


It's odd being on rim brakes after being on discs exclusively for the
last four months, since my SuperSix bit the dust. I haven't ridden
the bike much because its been raining, and I just got it, but I do
worry about braking a spoke with the pads running so close to the
rim.



How can the pads get into the spokes? That could cause a major OTB crash.


Poorly written. What I mean is that if you break a spoke and get a wobbly rim, then it's hard to clear the pads -- even with QR cams open. That's not a problem with discs.

-- Jay Beattie.
  #306  
Old November 4th 17, 10:02 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,700
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-04 13:50, jbeattie wrote:
On Saturday, November 4, 2017 at 11:55:18 AM UTC-7, Joerg wrote:
On 2017-11-04 09:51, jbeattie wrote:


[...]

It's odd being on rim brakes after being on discs exclusively for
the last four months, since my SuperSix bit the dust. I haven't
ridden the bike much because its been raining, and I just got it,
but I do worry about braking a spoke with the pads running so
close to the rim.



How can the pads get into the spokes? That could cause a major OTB
crash.


Poorly written. What I mean is that if you break a spoke and get a
wobbly rim, then it's hard to clear the pads -- even with QR cams
open. That's not a problem with discs.


Yes, that is another reason for having disc brakes on MTB. After the
first few hundred miles of serious use the rims wobble like those on
Russian trucks. Even the rear rim of my road bike does, can't completely
tension it out anymore. It's probably because of too much dirt road use
and heavy loads.

--
Regards, Joerg

http://www.analogconsultants.com/
  #307  
Old November 4th 17, 11:01 PM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 3,588
Default Why do some forks and frames have brake rotor size limits?

On Saturday, November 4, 2017 at 5:02:25 PM UTC-4, Joerg wrote:
On 2017-11-04 13:50, jbeattie wrote:
On Saturday, November 4, 2017 at 11:55:18 AM UTC-7, Joerg wrote:
On 2017-11-04 09:51, jbeattie wrote:


[...]

It's odd being on rim brakes after being on discs exclusively for
the last four months, since my SuperSix bit the dust. I haven't
ridden the bike much because its been raining, and I just got it,
but I do worry about braking a spoke with the pads running so
close to the rim.


How can the pads get into the spokes? That could cause a major OTB
crash.


Poorly written. What I mean is that if you break a spoke and get a
wobbly rim, then it's hard to clear the pads -- even with QR cams
open. That's not a problem with discs.


Yes, that is another reason for having disc brakes on MTB. After the
first few hundred miles of serious use the rims wobble like those on
Russian trucks. Even the rear rim of my road bike does, can't completely
tension it out anymore. It's probably because of too much dirt road use
and heavy loads.

--
Regards, Joerg

http://www.analogconsultants.com/


Is that your 600EX equipped road bike? It wasn't designed/intended for carrying loads on dirt roads. Abuse of equipment by doing so.

If the wheel is knackered it should be replaced or completely respoked with a new rim. But then again, if you did that you won't have something else to complain about when that wheel finally does fail - probably miles into your ride.

Cheers
  #308  
Old November 4th 17, 11:27 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,700
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-04 15:01, Sir Ridesalot wrote:
On Saturday, November 4, 2017 at 5:02:25 PM UTC-4, Joerg wrote:
On 2017-11-04 13:50, jbeattie wrote:
On Saturday, November 4, 2017 at 11:55:18 AM UTC-7, Joerg wrote:
On 2017-11-04 09:51, jbeattie wrote:


[...]

It's odd being on rim brakes after being on discs exclusively
for the last four months, since my SuperSix bit the dust. I
haven't ridden the bike much because its been raining, and I
just got it, but I do worry about braking a spoke with the
pads running so close to the rim.


How can the pads get into the spokes? That could cause a major
OTB crash.

Poorly written. What I mean is that if you break a spoke and get
a wobbly rim, then it's hard to clear the pads -- even with QR
cams open. That's not a problem with discs.


Yes, that is another reason for having disc brakes on MTB. After
the first few hundred miles of serious use the rims wobble like
those on Russian trucks. Even the rear rim of my road bike does,
can't completely tension it out anymore. It's probably because of
too much dirt road use and heavy loads.

-- Regards, Joerg

http://www.analogconsultants.com/


Is that your 600EX equipped road bike? It wasn't designed/intended
for carrying loads on dirt roads. Abuse of equipment by doing so.


It is designed for heavy use. When I bought it that was one of my
requirements and, not surprisingly, the first questions the custom shop
owner asked. A reason why it has wider rims than they usually do.


If the wheel is knackered it should be replaced or completely
respoked with a new rim. But then again, if you did that you won't
have something else to complain about when that wheel finally does
fail - probably miles into your ride.


When have I complained about the rear rim?

A vehicle built to travel on roads must be capable to continue travel on
typical roads. Dirt roads are a typical part of a route in most parts of
the world. Like in our area:

https://goo.gl/maps/mDaf5Uv3t6N2

Of course you could say to yourself, well, I am on a bicycle which is an
inferior vehicle so I better turn around and use the car instead. For me
a bicycle is not just a rolling gym. It is foremost a transportation device.

BTW, that road bike is from 1982 and has about 70k miles on it. How many
has yours?

--
Regards, Joerg

http://www.analogconsultants.com/
  #309  
Old November 5th 17, 02:01 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 2,814
Default Why do some forks and frames have brake rotor size limits?

On Saturday, November 4, 2017 at 3:27:28 PM UTC-7, Joerg wrote:
On 2017-11-04 15:01, Sir Ridesalot wrote:
On Saturday, November 4, 2017 at 5:02:25 PM UTC-4, Joerg wrote:
On 2017-11-04 13:50, jbeattie wrote:
On Saturday, November 4, 2017 at 11:55:18 AM UTC-7, Joerg wrote:
On 2017-11-04 09:51, jbeattie wrote:

[...]

It's odd being on rim brakes after being on discs exclusively
for the last four months, since my SuperSix bit the dust. I
haven't ridden the bike much because its been raining, and I
just got it, but I do worry about braking a spoke with the
pads running so close to the rim.


How can the pads get into the spokes? That could cause a major
OTB crash.

Poorly written. What I mean is that if you break a spoke and get
a wobbly rim, then it's hard to clear the pads -- even with QR
cams open. That's not a problem with discs.


Yes, that is another reason for having disc brakes on MTB. After
the first few hundred miles of serious use the rims wobble like
those on Russian trucks. Even the rear rim of my road bike does,
can't completely tension it out anymore. It's probably because of
too much dirt road use and heavy loads.

-- Regards, Joerg

http://www.analogconsultants.com/


Is that your 600EX equipped road bike? It wasn't designed/intended
for carrying loads on dirt roads. Abuse of equipment by doing so.


It is designed for heavy use. When I bought it that was one of my
requirements and, not surprisingly, the first questions the custom shop
owner asked. A reason why it has wider rims than they usually do.


If the wheel is knackered it should be replaced or completely
respoked with a new rim. But then again, if you did that you won't
have something else to complain about when that wheel finally does
fail - probably miles into your ride.


When have I complained about the rear rim?

A vehicle built to travel on roads must be capable to continue travel on
typical roads. Dirt roads are a typical part of a route in most parts of
the world. Like in our area:

https://goo.gl/maps/mDaf5Uv3t6N2

Of course you could say to yourself, well, I am on a bicycle which is an
inferior vehicle so I better turn around and use the car instead. For me
a bicycle is not just a rolling gym. It is foremost a transportation device.


No, what we say is that an 80s Euro sport bike with what, MA2s or something like that and probably 32 spokes and a 600EX hub (just guessing here) is not the best wheel for hauling your 500lb CPUs on a wagon road. Plenty of people ride off road to get from one place to another, usually on more robust equipment -- like a trekking bike or a CX bike.

-- Jay Beattie.
  #310  
Old November 5th 17, 03:07 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 5,472
Default Why do some forks and frames have brake rotor size limits?

On 11/4/2017 9:01 PM, jbeattie wrote:
On Saturday, November 4, 2017 at 3:27:28 PM UTC-7, Joerg wrote:
On 2017-11-04 15:01, Sir Ridesalot wrote:
On Saturday, November 4, 2017 at 5:02:25 PM UTC-4, Joerg wrote:
On 2017-11-04 13:50, jbeattie wrote:
On Saturday, November 4, 2017 at 11:55:18 AM UTC-7, Joerg wrote:
On 2017-11-04 09:51, jbeattie wrote:

[...]

It's odd being on rim brakes after being on discs exclusively
for the last four months, since my SuperSix bit the dust. I
haven't ridden the bike much because its been raining, and I
just got it, but I do worry about braking a spoke with the
pads running so close to the rim.


How can the pads get into the spokes? That could cause a major
OTB crash.

Poorly written. What I mean is that if you break a spoke and get
a wobbly rim, then it's hard to clear the pads -- even with QR
cams open. That's not a problem with discs.


Yes, that is another reason for having disc brakes on MTB. After
the first few hundred miles of serious use the rims wobble like
those on Russian trucks. Even the rear rim of my road bike does,
can't completely tension it out anymore. It's probably because of
too much dirt road use and heavy loads.

-- Regards, Joerg

http://www.analogconsultants.com/

Is that your 600EX equipped road bike? It wasn't designed/intended
for carrying loads on dirt roads. Abuse of equipment by doing so.


It is designed for heavy use. When I bought it that was one of my
requirements and, not surprisingly, the first questions the custom shop
owner asked. A reason why it has wider rims than they usually do.


If the wheel is knackered it should be replaced or completely
respoked with a new rim. But then again, if you did that you won't
have something else to complain about when that wheel finally does
fail - probably miles into your ride.


When have I complained about the rear rim?

A vehicle built to travel on roads must be capable to continue travel on
typical roads. Dirt roads are a typical part of a route in most parts of
the world. Like in our area:

https://goo.gl/maps/mDaf5Uv3t6N2

Of course you could say to yourself, well, I am on a bicycle which is an
inferior vehicle so I better turn around and use the car instead. For me
a bicycle is not just a rolling gym. It is foremost a transportation device.


No, what we say is that an 80s Euro sport bike with what, MA2s or something like that and probably 32 spokes and a 600EX hub (just guessing here) is not the best wheel for hauling your 500lb CPUs on a wagon road. Plenty of people ride off road to get from one place to another, usually on more robust equipment -- like a trekking bike or a CX bike.


Wasn't Jobst noted for taking his standard road bike on goat paths few
mountain bikers would travel? That shows the standard equipment can
handle such duty, if things are done right. The margin of safety is there.

Thing was, Jobst was smart enough to travel light, and therefore stay
within the margin of safety. I strongly suspect that if he had to schlep
heavy equipment on rough terrain, he'd have built wheels that were up to
the task. He certainly wouldn't have used wheels intended for light
duty, then whined about how bad bicycle technology was. Jobst wasn't
much of a whiner.

--
- Frank Krygowski
 




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