80s Campy SR Front Break Blow off
#1
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
80s Campy SR Front Break Blow off
Really surprised me because my recent Tommasini Racing 80s Campy SR Front Break made a ping / pop while I was descending at about 20 and not even on the brakes. The lug nut evidently popped from the tighten pressure and I realized what happened when I saw the front break hangon over the bars.
Surprising since this was my 2nd shakedown ride. First ride was 10 miles no braking issue. Second ride at about 20 miles. Guess old lug nuts can break anytime but to sorta explode with a pop and send the brake flying over the bars.
I would think it would just crack and give out when being used, not pop off after approx 30 miles of use.
How common is this ?
Guess this is why builders should always to a few shakedown rides of longer distances.
Sure glad I was not on a steep long hill where the front break would really be necessary, like my SoCal rides.
This was flat Dallas
Check out my memory pic:
Surprising since this was my 2nd shakedown ride. First ride was 10 miles no braking issue. Second ride at about 20 miles. Guess old lug nuts can break anytime but to sorta explode with a pop and send the brake flying over the bars.
I would think it would just crack and give out when being used, not pop off after approx 30 miles of use.
How common is this ?
Guess this is why builders should always to a few shakedown rides of longer distances.
Sure glad I was not on a steep long hill where the front break would really be necessary, like my SoCal rides.
This was flat Dallas
Check out my memory pic:
#2
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Likes: 0
Liked 1,102 Times
in
747 Posts
Did the bolt break, the nut fracture or did the nut just unthread from vibration? Nutted brakes are usually fastened with a Nyloc or similar anti-vibration nut to prevent vibration loosening.
#3
Senior Member
'Brake' not break. Your brake broke. It was your second ride on that bike and the bar tape looks that bad?
#4
Senior Member
Join Date: Sep 2020
Location: Eastern Poland
Posts: 745
Bikes: Romet Jubilat x 4, Wigry x 1, Turing x 1
Liked 206 Times
in
151 Posts
When I strip and rebuild bikes I look at every component, and then, as you say, give them a shakedown ride.
I also recommend buying bags of typical nuts, bolts and washers and replacing as you go.
I also recommend buying bags of typical nuts, bolts and washers and replacing as you go.
#5
Senior Member
Really surprised me because my recent Tommasini Racing 80s Campy SR Front Break made a ping / pop while I was descending at about 20 and not even on the brakes. The lug nut evidently popped from the tighten pressure and I realized what happened when I saw the front break hangon over the bars.
Surprising since this was my 2nd shakedown ride. First ride was 10 miles no braking issue. Second ride at about 20 miles. Guess old lug nuts can break anytime but to sorta explode with a pop and send the brake flying over the bars.
I would think it would just crack and give out when being used, not pop off after approx 30 miles of use.
How common is this ?
Surprising since this was my 2nd shakedown ride. First ride was 10 miles no braking issue. Second ride at about 20 miles. Guess old lug nuts can break anytime but to sorta explode with a pop and send the brake flying over the bars.
I would think it would just crack and give out when being used, not pop off after approx 30 miles of use.
How common is this ?
#6
Old fart
Join Date: Nov 2004
Location: Appleton WI
Posts: 25,043
Bikes: Several, mostly not name brands.
Liked 3,675 Times
in
2,077 Posts
Get a longer nut to get more thread engagement on the mounting bolt:
https://www.biketoolsetc.com/index.c...=WB-BRAKENUT19
https://www.biketoolsetc.com/index.c...=WB-BRAKENUT19
#7
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
The bar tape is very nice quality leather that is securely taped with double sided tape.
Do you not like how it was wrapped ?
I did not have a length that was long enough to complete one side so actually two sections for each side.
#8
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
That was a nut, not a lug nut. Examine the bolt carefully to see if the threads are stripped. If not, replace the nut along with the appropriate washers for that brake. It is very rare for a nut to fail in the sort of use you describe unless it was either stripped or not properly tightened.
The bolt was still inserted into the fork crown and examination shows threads still look fine.
BTW, the bolt was the 19mm type shown by JohnDThompson post shows above.
I was also able to screw the bolt onto the break screw most of the 19mm length. It feels tight and I can not wiggle it.
Im still amazed it popped out and there are no signs of thread damage.
I will buy a NOS campy replacement to play it safe.
Last edited by joesch; 02-09-21 at 09:31 AM.
#9
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Likes: 0
Liked 1,102 Times
in
747 Posts
The threads are clean, no sign of stripping.
The bolt blew off on the downhill descent so cant examine but must have split apart.
BTW, the bolt was the older type that did not fit into like JohnDThompson post shows above.
The bolt blew off on the downhill descent so cant examine but must have split apart.
BTW, the bolt was the older type that did not fit into like JohnDThompson post shows above.
#10
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
Any signs that the bolt itself broke off? If the bolt is the same length as it was when you installed the brake I'd put a fair bit of money on the fact the nut vibrated off. A broken or fractured nut is VERY unlikely. And, yes, these are "nutted" brakes, not recessed as John showed.
#11
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 16,142
Bikes: Tarmac Disc Comp Di2 - 2020
Liked 5,404 Times
in
3,729 Posts
How common is it? Probably not common enough or everyone will be checking them every ride.
Stupid things happen all the time though. Just not always the same stupid thing.
Stupid things happen all the time though. Just not always the same stupid thing.
#12
Junior Member
I think the bar tape wrap job looks great!
#13
Junior Member
Please post a close-up of the bolt.
Can't really be sure from the above picture, but it looks like possibly the threads on the end of the bolt are stripped.
Can't really be sure from the above picture, but it looks like possibly the threads on the end of the bolt are stripped.
#14
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
Last edited by joesch; 02-12-21 at 08:08 AM.
#15
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 16,142
Bikes: Tarmac Disc Comp Di2 - 2020
Liked 5,404 Times
in
3,729 Posts
Well that pic is showing the bolt. The other thing is a barrel nut or brake nut.
#16
Half way there
Join Date: Sep 2015
Location: North Carolina
Posts: 2,962
Bikes: Many, and the list changes frequently
Liked 890 Times
in
533 Posts
Can't imagine that this barrel nut would just crack on its own. Perhaps you cracked it by over-tightening? But still, I'd doubt that it would launch without braking. I'd guess that your brakes were dragging enough to pull the caliper through the cracked nut.
#17
Junior Member
Also is the nut the right size. Was it the original nut?
#18
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 16,142
Bikes: Tarmac Disc Comp Di2 - 2020
Liked 5,404 Times
in
3,729 Posts
Now if there was some confusion on the OP's part as to what is a nut or bold and that is now cleared up. Then they should refer back to post #6
A longer nut that goes almost to the opposite internal side of the fork crown might help. If it already did, then I'd put it back on or get a new one and then see if the brake gets loose again. If it doesn't loosen, then pour some scotch until that desire to know why disappears.
A longer nut that goes almost to the opposite internal side of the fork crown might help. If it already did, then I'd put it back on or get a new one and then see if the brake gets loose again. If it doesn't loosen, then pour some scotch until that desire to know why disappears.
#19
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
Bolt, Screw, whatever you prefer to call it Maybe its just out of focus, or the way the light is hitting the threads, but those threads just don't look right. They look like they are flat. Can you confirm if the threads are flat, or are they sharp like new threads should be?
Also is the nut the right size. Was it the original nut?
Also is the nut the right size. Was it the original nut?
It is the light hitting the threads. I checked with a magnifier rotating against the light and the threads look good.
Did the same for the mounting bolt and it looks good.
Not sure if original Campy bolt so I have ordered another not knowing what else to do other than swapping out complete brake, which I maybe forced to do if this happens again. Sure wish I had a probable cause.
#20
Senior Member
Thread Starter
Join Date: Sep 2017
Location: Hotel CA / DFW
Posts: 1,858
Bikes: 83 Colnago Super, 87 50th Daccordi, 79 & 87 Guerciotti's, 90s DB/GT Mtn Bikes, 90s Colnago Master and Titanio, 96 Serotta Colorado TG, 95/05 Colnago C40/C50, 06 DbyLS TI, 08 Lemond Filmore FG SS, 12 Cervelo R3, 20/15 Surly Stragler & Steamroller
Liked 839 Times
in
543 Posts
Now if there was some confusion on the OP's part as to what is a nut or bold and that is now cleared up. Then they should refer back to post #6
A longer nut that goes almost to the opposite internal side of the fork crown might help. If it already did, then I'd put it back on or get a new one and then see if the brake gets loose again. If it doesn't loosen, then pour some scotch until that desire to know why disappears.
A longer nut that goes almost to the opposite internal side of the fork crown might help. If it already did, then I'd put it back on or get a new one and then see if the brake gets loose again. If it doesn't loosen, then pour some scotch until that desire to know why disappears.
#21
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 16,142
Bikes: Tarmac Disc Comp Di2 - 2020
Liked 5,404 Times
in
3,729 Posts
Because I can't tell if the threads on the bolt are damaged, that is why I suggest the longest nut that fits.
#22
Senior Member
Likes For cxwrench:
#23
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,341
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Liked 4,188 Times
in
2,471 Posts
I think one challenge this thread has is the use of the word "popped". It leads some to think the recessed nut cracked/broke. Did it? Post 8 states "The bolt was still inserted into the fork crown and examination shows threads still look fine." To me this reads as the nut not being damaged. So what is it? Broken nut or just a nut that loosened and unthreaded completely? Unthreading is far more likely. But this process is not a quick one. Certainly not the process that "pop" would best describe.
BTW the image of the caliper mounting/center bolt suggests some thread form flattening. This is often from a threaded fitting being stressed while loose. The nut "floats" on the bolt causing the threads to become somewhat rounded. Andy
BTW the image of the caliper mounting/center bolt suggests some thread form flattening. This is often from a threaded fitting being stressed while loose. The nut "floats" on the bolt causing the threads to become somewhat rounded. Andy
__________________
AndrewRStewart
AndrewRStewart
#24
BMX Connoisseur
Join Date: Jun 2016
Location: Canada
Posts: 774
Bikes: 1988 Kuwahara Newport, 1983 Nishiki, 1984 Diamond Back Viper, 1991 Dyno Compe
Liked 108 Times
in
69 Posts
I had it happen once or twice on my vintage BMX bikes bitd and it was two things. 1) I was missing the little lock washer between the nut and the spacer. As a kid I'd take the brakes off and loose it 2) Because back then I also didn't know how to align brakes properly. I didn't tighten down the nut enough because I would leave it loose so it wouldn't rub on one side of the wheel. With this being a recessed nut it's possible it's a different situation
#25
Senior Member
I think one challenge this thread has is the use of the word "popped". It leads some to think the recessed nut cracked/broke. Did it? Post 8 states "The bolt was still inserted into the fork crown and examination shows threads still look fine." To me this reads as the nut not being damaged. So what is it? Broken nut or just a nut that loosened and unthreaded completely? Unthreading is far more likely. But this process is not a quick one. Certainly not the process that "pop" would best describe.
BTW the image of the caliper mounting/center bolt suggests some thread form flattening. This is often from a threaded fitting being stressed while loose. The nut "floats" on the bolt causing the threads to become somewhat rounded. Andy
BTW the image of the caliper mounting/center bolt suggests some thread form flattening. This is often from a threaded fitting being stressed while loose. The nut "floats" on the bolt causing the threads to become somewhat rounded. Andy