cant center brakes
#1
30mi/day commuter
Thread Starter
Join Date: Apr 2008
Location: Toronto, Canada
Posts: 797
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
cant center brakes
hi i have these brakes.
I cant figure out how to centre them... what i do is release the quick release clamp the pads onto the rims and hold the front bolt (left most in picture) and tighten the rear bolt, standard nut behind the crown (not in picture).
but as soon as i pull the brakes it just goes back to the way it was... Ive watched videos but nothing seems to work.
I cant figure out how to centre them... what i do is release the quick release clamp the pads onto the rims and hold the front bolt (left most in picture) and tighten the rear bolt, standard nut behind the crown (not in picture).
but as soon as i pull the brakes it just goes back to the way it was... Ive watched videos but nothing seems to work.
#2
Guest
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
Make sure your front wheel is centered properly. Is your wheel in the dropouts? Does the rim/tire have the same clearance on either side of the fork blades?
There are flats on the 'nut' that the brake spring passes through. A 13 or 15mm (or whatever size it is) cone wrench should fit on those flats.
You should be able to center the brake caliper by just moving it with the cone wrench. It is probably not necessary to release the QR, clamp pads on rims and etc. That seems too complex for what you need to do.
if you have been doing that, the brake arms may need to be re adjusted so they are not too loose or too tight. is there any side to side play in the brake arms?
There are flats on the 'nut' that the brake spring passes through. A 13 or 15mm (or whatever size it is) cone wrench should fit on those flats.
You should be able to center the brake caliper by just moving it with the cone wrench. It is probably not necessary to release the QR, clamp pads on rims and etc. That seems too complex for what you need to do.
if you have been doing that, the brake arms may need to be re adjusted so they are not too loose or too tight. is there any side to side play in the brake arms?
#5
Insane Bicycle Mechanic
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,842
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 808 Post(s)
Liked 711 Times
in
379 Posts
hi i have these brakes.
I cant figure out how to centre them... what i do is release the quick release clamp the pads onto the rims and hold the front bolt (left most in picture) and tighten the rear bolt, standard nut behind the crown (not in picture).
but as soon as i pull the brakes it just goes back to the way it was... Ive watched videos but nothing seems to work.
I cant figure out how to centre them... what i do is release the quick release clamp the pads onto the rims and hold the front bolt (left most in picture) and tighten the rear bolt, standard nut behind the crown (not in picture).
but as soon as i pull the brakes it just goes back to the way it was... Ive watched videos but nothing seems to work.
What you're doing isn't going to work because you're not turning the spring mount after the brake is tightened down. The spring mount is between the caliper arms and fork crown in your photo. As Mr. Orange says- you can reach the hex on the spring mount with a cone wrench and turn it, but only after you've got the center bolt snugged down. Turn it until the brake shoes are centered on the rim, squeeze the brake a couple times, center again, and keep going until it stays where you put it.
If you can't reach the brake mount with a cone wrench, you can sometimes turn the bolt by putting a wrench on both ends of the bolt and turning the whole assembly. This works sometimes, other times the caliper adjustment tightens down and the caliper binds up. Annoying. The last ditch method is to take a round punch and hammer on the return spring to get the spring mount to move. This usually works, but it also tends to damage the return spring.
__________________
Jeff Wills
Comcast nuked my web page. It will return soon..
Jeff Wills
Comcast nuked my web page. It will return soon..
#6
Banned
need a wrench holding on the side the brake is on ,
while you tighten the nut holding the brake on the fork on the opposite side.
while you tighten the nut holding the brake on the fork on the opposite side.
#7
Senior Member
Yeah, you cannot hold the brake by hand when tightening the nut, because you're only holding the arms, which will still let the centrebolt spin. You can hold the centrebolt with a 13mm cone-wrench. In most cases, you will still need to re-adjust the centering after you've tightened down the back nut. Insert 13mm cone-wrench and twist the centrebolt:
#8
30mi/day commuter
Thread Starter
Join Date: Apr 2008
Location: Toronto, Canada
Posts: 797
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
wow that was easy, i've always just clamped down the pads and everything was peachy... oh well... lesson learned
#9
Senior Member
Join Date: Oct 2004
Location: NYC
Posts: 2,124
Bikes: All 70s and 80s, only steel.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
I've got the Park tools offset wrench, but I've found the old-school method more reliable for centering single-pivot calipers. It also works on all brakes of such type (the Park tools wrench doesn't always fit on the spring mount well enough):
(1) Tighten the mounting bolt nut on the back of the fork as tight as possible with the brake centered as well as you can get it as you tighten the nut;
(2) immobilize the front wheel by straddling it and holding it between your legs so that you're facing the front of the bike head tube;
(2) hold a flathead screwdriver or punch against the top of the spring on the side of the brake furthest from center. Hold it at an angle pointing down and slightly inwards, on or near the spring's coil;
(3) keeping the punch in contact with the spring, take a sharp whack at the top of the punch/screwdriver with a hammer.
This should shift the brake a bit more towards center. If it doesn't move, try the above procedure again. Repeat until the brake has swiveled a bit closer to center. Test the brake by pulling on the lever after every move to see if it remains centered. You may have to whack the brake so it actually moves past center, but then returns to center after pulling on the lever.
Two things to note when doing this: (a) take care to hit only the spring of the brake caliper. This part is steel and under tension at the coil, so the impact from the punch won't damage it, but if you hit the brake arm by accident, its soft metal will most certainly get dented or injured by the harder steel of a punch or screwdriver; (b) the pads do not need to be perfectly centered around the rim to be effective: the most important thing is that they are not rubbing against either side of the rim when the wheel is spinning freely. (Once one pad hits the rim, continued pressure from the cable will cause the other arm to swing to the rim faster, thus leading to an equalization of the brake pressure from both sides).
(1) Tighten the mounting bolt nut on the back of the fork as tight as possible with the brake centered as well as you can get it as you tighten the nut;
(2) immobilize the front wheel by straddling it and holding it between your legs so that you're facing the front of the bike head tube;
(2) hold a flathead screwdriver or punch against the top of the spring on the side of the brake furthest from center. Hold it at an angle pointing down and slightly inwards, on or near the spring's coil;
(3) keeping the punch in contact with the spring, take a sharp whack at the top of the punch/screwdriver with a hammer.
This should shift the brake a bit more towards center. If it doesn't move, try the above procedure again. Repeat until the brake has swiveled a bit closer to center. Test the brake by pulling on the lever after every move to see if it remains centered. You may have to whack the brake so it actually moves past center, but then returns to center after pulling on the lever.
Two things to note when doing this: (a) take care to hit only the spring of the brake caliper. This part is steel and under tension at the coil, so the impact from the punch won't damage it, but if you hit the brake arm by accident, its soft metal will most certainly get dented or injured by the harder steel of a punch or screwdriver; (b) the pads do not need to be perfectly centered around the rim to be effective: the most important thing is that they are not rubbing against either side of the rim when the wheel is spinning freely. (Once one pad hits the rim, continued pressure from the cable will cause the other arm to swing to the rim faster, thus leading to an equalization of the brake pressure from both sides).
#11
aka Tom Reingold
Join Date: Jan 2009
Location: New York, NY, and High Falls, NY, USA
Posts: 40,503
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
Mentioned: 511 Post(s)
Tagged: 0 Thread(s)
Quoted: 7348 Post(s)
Liked 2,474 Times
in
1,437 Posts
Clever. I've never heard of that. I'll try it next time.
Meanwhile, I've been tapping the stronger side with a hammer and punch, and it has worked reliably for me for many years.
Meanwhile, I've been tapping the stronger side with a hammer and punch, and it has worked reliably for me for many years.
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
#12
Old fart
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,790
Bikes: Several, mostly not name brands.
Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3590 Post(s)
Liked 3,400 Times
in
1,934 Posts
If you have clearance problems with the cup, remove the brake and add a washer to move the flats further out to where you can grab them with the cone wrench. Once you're at that point the rest is easy.
Last edited by JohnDThompson; 10-18-10 at 05:48 PM.