Disc discoloration on brand new bike
#26
Full Member
Join Date: Jan 2022
Location: Albuquerque NM USA
Posts: 492
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Liked 304 Times
in
194 Posts
The rotor looks like overheating to me. But some of that color seems to be flaking off. So, I'm thinking some residue was left on the rotor that has turned that color. You might try cleaning it. If it comes off, then it's not the discoloration of the rotor metal from overheating. If there was some residue left on the rotor, perhaps this also contaminated the pads and explains the lack of braking power you expect.
You bought it new, so you could ask the shop about it.
As for brake rub, disc brakes are finicky and it can take some adjustments to finally get the things centered and not rub. Also, some rotors just seem to be bad. Get them set with no rubbing, do a ride, now rubbing for no good reason. I think you can get some with various stresses built into them and they just do weird things every time they get thermal cycled from use.
As for your saddle tilt, do what works for you. I'm 100% certain your saddle tilt has nothing to do with your brake discoloration and also nothing to do with the topic of this thread.
You bought it new, so you could ask the shop about it.
As for brake rub, disc brakes are finicky and it can take some adjustments to finally get the things centered and not rub. Also, some rotors just seem to be bad. Get them set with no rubbing, do a ride, now rubbing for no good reason. I think you can get some with various stresses built into them and they just do weird things every time they get thermal cycled from use.
As for your saddle tilt, do what works for you. I'm 100% certain your saddle tilt has nothing to do with your brake discoloration and also nothing to do with the topic of this thread.
Likes For Mtracer:
Likes For njkayaker:
#28
Klaatu..Verata..Necktie?
Join Date: May 2007
Location: SF Bay Area
Posts: 17,992
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10445 Post(s)
Liked 11,929 Times
in
6,105 Posts
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#29
Klaatu..Verata..Necktie?
Join Date: May 2007
Location: SF Bay Area
Posts: 17,992
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10445 Post(s)
Liked 11,929 Times
in
6,105 Posts
For a small amount of cash, you can get a metal version of this
https://cyclepal.co.uk/products/cycl...41198340800675
There are cheaper versions too.
https://cyclepal.co.uk/products/cycl...41198340800675
There are cheaper versions too.
So, I have several lifetimes' supply!!
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#30
Klaatu..Verata..Necktie?
Join Date: May 2007
Location: SF Bay Area
Posts: 17,992
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10445 Post(s)
Liked 11,929 Times
in
6,105 Posts
Now that I think a bit more about it, the bike doesn't have to have travelled far for the rotors to have been hot enough for the steel to start turning color. It only needs to have gotten that hot ONCE, which a 250# guy coming down long hill could do.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#31
Senior Member
Thread Starter
Join Date: Mar 2021
Posts: 1,995
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 2700 Post(s)
Liked 486 Times
in
351 Posts
I think genejocky's correct; the discoloration is an artifact of heating, the friction of pads against the metal along the disc rim keeps it from remaining there. Inside the pad path the heat leaves the telltale discoloration.
https://www.bikeforums.net/15364878-post8.html
I'd look for warp in the discs showing this coloration, may be why pads are rubbing. Heat could also come from pad friction if they're improperly adjusted, something you have some control over. If they're warped from excessive heating you may want to source replacements before riding – and braking hard – over too many more miles.
https://www.bikeforums.net/15364878-post8.html
I'd look for warp in the discs showing this coloration, may be why pads are rubbing. Heat could also come from pad friction if they're improperly adjusted, something you have some control over. If they're warped from excessive heating you may want to source replacements before riding – and braking hard – over too many more miles.
guys I would know if my saddle tilt doesnt work/is a mistake. I ride a lot, like 100 miles a week minimum just living my life on top of any recreational riding I might do. I don’t wear padded bike shorts, so it is less slippery.
Last edited by LarrySellerz; 11-05-23 at 07:12 PM.
#32
Should Be More Popular
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 43,067
Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix
Mentioned: 560 Post(s)
Tagged: 2 Thread(s)
Quoted: 22610 Post(s)
Liked 8,934 Times
in
4,164 Posts
Likes For datlas:
#33
Senior Member
Join Date: Jan 2020
Posts: 2,352
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 680 Post(s)
Liked 949 Times
in
556 Posts
Easiest way to stop brake rub: get one of those thick business cards. Fold it in half. Take the wheel out, put the folded card over the disc. Re-install the wheel, sliding the card and rotor in between the pads. Loosen the caliper mounting screws enough that the caliper moves freely. Squeeze the brake lever and hold it while you tighten the caliper mounting bolts down. Remove the wheel and card and tighten the mounting bolts to spec (usually 5-6 Nm). Reinstall wheel and spin. Rub should be gone. If you do choddo's paper trick you should see white on either side of the rotor.
#34
Senior Member
Join Date: Mar 2022
Location: Missoula MT
Posts: 1,767
Bikes: Handsome xoxo, Serotta atx, Canyon Endurace CF8
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 904 Post(s)
Liked 1,899 Times
in
849 Posts
2600 miles so far and some fast down hills and no discoloration on mine. knock on wood zero rub.
#35
Senior Member
Join Date: Jan 2020
Posts: 2,352
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 680 Post(s)
Liked 949 Times
in
556 Posts
ut e tandem weighs about 420 pounds with us and our stuff. and 9 seconds ob braking on a 18% grade will do the discoloration. had to go back to the ice-tech rotor as those short breaking sessions are too much for regular rotors.
Likes For fooferdoggie:
#36
Klaatu..Verata..Necktie?
Join Date: May 2007
Location: SF Bay Area
Posts: 17,992
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10445 Post(s)
Liked 11,929 Times
in
6,105 Posts
That's funny, because Shimano hydros are the only disc brakes I have, and it works just fine.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#38
Senior Member
Join Date: Jan 2020
Posts: 2,352
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 680 Post(s)
Liked 949 Times
in
556 Posts
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
#39
Senior Member
Thread Starter
Join Date: Mar 2021
Posts: 1,995
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 2700 Post(s)
Liked 486 Times
in
351 Posts
also: open invitation to anyone who has issue with my bike’s setup to race me. Canada road and highway 92. If you’re in the area and want to talk smack, give me a time and I will be there.
#40
Klaatu..Verata..Necktie?
Join Date: May 2007
Location: SF Bay Area
Posts: 17,992
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10445 Post(s)
Liked 11,929 Times
in
6,105 Posts
I ageee that the discoloration is an artifact from heating. What I disagree with is the contention that this discoloration is all over the disc and is being weared away by the rotor. It’s a very interesting Idea, but I don’t think it is happening I think the discoloration is local to that area. My gut tells me there not uniform discoloration on the rotor.
guys I would know if my saddle tilt doesnt work/is a mistake. I ride a lot, like 100 miles a week minimum just living my life on top of any recreational riding I might do. I don’t wear padded bike shorts, so it is less slippery.
guys I would know if my saddle tilt doesnt work/is a mistake. I ride a lot, like 100 miles a week minimum just living my life on top of any recreational riding I might do. I don’t wear padded bike shorts, so it is less slippery.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#41
Senior Member
Thread Starter
Join Date: Mar 2021
Posts: 1,995
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 2700 Post(s)
Liked 486 Times
in
351 Posts
Please feel free to suggest a reason, apart from being abraded off, why a piece of steel heated to the right temperature in normal air would not change color, which is such a reliable process that it has been used to color watch hands (for example) for more than 150 years.
what is the rotor made of, stainless? Very low thermal transfer in that material compared to other metals, it makes sense to me that only part of it could get hot.
#42
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,366 Times
in
947 Posts
Your reputation here would be greatly enhanced by you saying less.
Last edited by njkayaker; 11-06-23 at 04:46 PM.
Likes For njkayaker:
#44
Senior Member
Join Date: Jul 2009
Posts: 5,956
Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3958 Post(s)
Liked 7,312 Times
in
2,951 Posts
Likes For tomato coupe:
#45
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,366 Times
in
947 Posts
This is not saying less.
Regarding the rotor, we have a well-known brand with simple components that thousands of people are using versus you, who has provided numerous examples of cluelessness. Ask yourself: which one is likely to be right?
Last edited by njkayaker; 11-05-23 at 10:40 PM.
Likes For njkayaker:
#46
Senior Member
Join Date: Dec 2019
Location: South Shore of Long Island
Posts: 2,801
Bikes: 2010 Carrera Volans, 2015 C-Dale Trail 2sl, 2017 Raleigh Rush Hour, 2017 Blue Proseccio, 1992 Giant Perigee, 80s Gitane Rallye Tandem
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1088 Post(s)
Liked 1,028 Times
in
724 Posts
Does the other rotor have the same coloration? Might have been a result of the final heat treatment of the rotor or just meant to add an effect. It is unlikely to have this develop from a slight rub that's so small it doesn't effect the effort needed to maintain speed. So either the rub is worse than you're claiming or something else did it and you need to watch how much you're dragging the brake on steep descents.
#47
Senior Member
Join Date: Jul 2006
Location: Jacksonville, FL
Posts: 6,888
Bikes: Trek Domane SLR 7 AXS, Trek CheckPoint SL7 AXS, Trek Emonda ALR AXS, Trek FX 5 Sport
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 769 Post(s)
Liked 1,749 Times
in
1,017 Posts
If the bike is brand new, I would take it back to the shop to make sure the brakes are adjusted correctly if you are concerned.
Likes For jaxgtr:
#48
Klaatu..Verata..Necktie?
Join Date: May 2007
Location: SF Bay Area
Posts: 17,992
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10445 Post(s)
Liked 11,929 Times
in
6,105 Posts
I think the discoloration is from heat. What I’m pushing back against is the idea that the whole thing or much of it is being heated up and discolored, and most of the discoloration is being abraded off and we are only left with the pictured stuff on the inside. I suspect that only the inside is heating.
what is the rotor made of, stainless? Very low thermal transfer in that material compared to other metals, it makes sense to me that only part of it could get hot.
what is the rotor made of, stainless? Very low thermal transfer in that material compared to other metals, it makes sense to me that only part of it could get hot.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#49
Senior Member
Thread Starter
Join Date: Mar 2021
Posts: 1,995
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 2700 Post(s)
Liked 486 Times
in
351 Posts
Does the other rotor have the same coloration? Might have been a result of the final heat treatment of the rotor or just meant to add an effect. It is unlikely to have this develop from a slight rub that's so small it doesn't affect the effort needed to maintain speed. So either the rub is worse than you're claiming or something else did it and you need to watch how much you're dragging the brake on steep descents.
#50
Senior Member
Thread Starter
Join Date: Mar 2021
Posts: 1,995
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 2700 Post(s)
Liked 486 Times
in
351 Posts
i suppose that another way of phrasing my question is “is this discoloration indicative of the braking surface being more on the inside of the rotor than it is supposed to be.” Where the actual braking surface is the key to my quandary