Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Disque Break Pads: Ware them down to the boan?

Search
Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Disque Break Pads: Ware them down to the boan?

Thread Tools
 
Search this Thread
 
Old 03-16-22, 11:50 AM
  #26  
Polaris OBark
ignominious poltroon
Thread Starter
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 4,086
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2254 Post(s)
Liked 3,469 Times in 1,820 Posts
Originally Posted by surak
Not based off any casual search I've done, and that's also forgetting that there's a 3x price difference between pads vs rotors.
On Amazon, L03A pads are $80, which is more than I have ever paid for an Ultegra rotor.

(I have a backup stash of rotors, too. I wrongly wrote J03A, which are currently available at a semi-reasonable price.)
Polaris OBark is offline  
Old 03-16-22, 11:57 AM
  #27  
Polaris OBark
ignominious poltroon
Thread Starter
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 4,086
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2254 Post(s)
Liked 3,469 Times in 1,820 Posts
Here is the problem. I am taking these off while they still technically have a bit of life left in them, and it seems kind of wasteful in a time of scarcity.


Polaris OBark is offline  
Likes For Polaris OBark:
Old 03-17-22, 02:48 PM
  #28  
BikeLite
Senior Member
 
Join Date: Oct 2005
Posts: 1,174
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 381 Post(s)
Liked 145 Times in 93 Posts
whatsa boan
BikeLite is offline  
Old 03-17-22, 03:40 PM
  #29  
soyabean
Senior Member
 
soyabean's Avatar
 
Join Date: Feb 2022
Location: GMT-5
Posts: 963
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 560 Post(s)
Liked 419 Times in 277 Posts
Originally Posted by BikeLite
whatsa boan
It's Bad 2 Da Boan.
soyabean is offline  
Likes For soyabean:
Old 03-17-22, 03:54 PM
  #30  
Iride01 
I'm good to go!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 15,076

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 6246 Post(s)
Liked 4,847 Times in 3,343 Posts
Originally Posted by Polaris OBark
Here is the problem. I am taking these off while they still technically have a bit of life left in them, and it seems kind of wasteful in a time of scarcity.


So how are you measuring those to determine they are worn? It's only the pad thickness that you go by. With calipers, zero them out on the base the pads are mounted to, then measure the entire thing which will give you the pad thickness relative to where you zeroed the calipers.


https://si.shimano.com/pdfs/dm/DM-R8050-01-ENG.pdf

What do you do to get that many worn out pads? That's like 24 years of cycling for me! <grin>
Iride01 is offline  
Likes For Iride01:
Old 03-17-22, 04:18 PM
  #31  
soyabean
Senior Member
 
soyabean's Avatar
 
Join Date: Feb 2022
Location: GMT-5
Posts: 963
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 560 Post(s)
Liked 419 Times in 277 Posts
Originally Posted by Iride01
What do you do to get that many worn out pads?
Long downhills.

The ones that can take you well over 30 mph.

And folks that don't want broken bones.
soyabean is offline  
Likes For soyabean:
Old 03-17-22, 06:17 PM
  #32  
Polaris OBark
ignominious poltroon
Thread Starter
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 4,086
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2254 Post(s)
Liked 3,469 Times in 1,820 Posts
Originally Posted by Iride01
So how are you measuring those to determine they are worn? It's only the pad thickness that you go by. With calipers, zero them out on the base the pads are mounted to, then measure the entire thing which will give you the pad thickness relative to where you zeroed the calipers.


https://si.shimano.com/pdfs/dm/DM-R8050-01-ENG.pdf

What do you do to get that many worn out pads? That's like 24 years of cycling for me! <grin>
About 90% are mine. The sick thing is I've gone through many more. I do about 3000 ft of steep downhill (up to 22% grade) and 3000 ft of uphill on my usual ride/commute (just did so today, about 25 miles), on narrow winding roads in the redwoods, so I brake a lot. Couple that with sub-clinical paranoia, and I have personally depleted the word's supply of J03A and its predecessors.


I am measuring the pad + backing and subtracting from that sum the backing only, using digital calipers (the functional equivalent of re-zeroing, but mine don't do that). I've been changing them at about 0.9mm net thickness, which is what the instructions I read said to do. They must have revised the instructions, which would make sense, because the bone-shaped wear pattern is visible at 0.5mm.

The good thing about that collection/hoard is I can go back and put them in and wear down about 0.3 or 0.4 mm more in many instances. (I would put them in the back so as not to die.)

That pretty much answers my question, if they have revised the advisory to change when worn to a net thickness of 0.5mm.

Last edited by Polaris OBark; 03-17-22 at 06:28 PM.
Polaris OBark is offline  
Likes For Polaris OBark:
Old 03-18-22, 02:27 AM
  #33  
BikeLite
Senior Member
 
Join Date: Oct 2005
Posts: 1,174
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 381 Post(s)
Liked 145 Times in 93 Posts
Originally Posted by soyabean
It's Bad 2 Da Boan.
i shoulda noan that
BikeLite is offline  
Old 03-18-22, 08:05 AM
  #34  
Iride01 
I'm good to go!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 15,076

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 6246 Post(s)
Liked 4,847 Times in 3,343 Posts
Polaris OBark

Just notice that I was only showing that as a reference for how to measure. And that my example is from the DM for the Ultegra R8050 series which covers my BR-R8070 brakes. So find the manual for your brakes to get the minimum recommended pad thickness.

https://si.shimano.com/

If you go through that many pads, then maybe you'd be better off wearing them down to nothing and just accepting that you might have to replace the entire brake every so often. Or find someone that can give you a really good deal if you buy brake pads by the gross. <grin>
Iride01 is offline  

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.