Trouble aligning brake pads on Modolo Corsas.
01-19-22, 09:52 PM
#1
Senior Member
Thread Starter
Trouble aligning brake pads on Modolo Corsas.
Hopefully this isn't too much of a dumb question. I'm having a hard time adjusting the brake blocks on the front bike of my bike. It is a vintage bike equipped with modolo corsas, but the brake blocks have been replaced by a previous owners (shimano). I just can't gets them to be correctly aligned. The left stands 2-3mm further out, as you can maybe see in the picture. I was just wondering if this was a normal phenomenon with vintage calipers. It does seem to me that the cause of the problem is the position of the arms themselves. Also, could there be any way to improve the situation? It is quite hard to adjust the toe-in factor as well. The right pad is fine but the left one "toes out".
Thanks a lot!
Thanks a lot!
01-19-22, 10:13 PM
#2
Senior Member
Join Date: May 2010
Location: Bastrop Texas
Posts: 3,004
Bikes: Univega, Peu P6, Peu PR-10, Ted Williams, Peu UO-8, Peu UO-18 Mixte, Peu Dolomites
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 409 Post(s)
Liked 580 Times
in
397 Posts
You most likely already know this but I would mention that those little cupped washers are more than just spacers. When setting up modern day pads on my vintage calipers I have often had to double up or change what would be the normal position of the washers to change the angle on the pad. Also when putting on new pads I have to make small adjustments to them over the first few rides...
__________________
No matter where your at... There you are... Δf:=f(1/2)-f(-1/2)
01-20-22, 01:21 PM
#3
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 16,106
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3362 Post(s)
Liked 2,000 Times
in
1,311 Posts
I wonder if the down tube has an impact scar where the caliper's cable adjuster/QR hit it. This type of booboo can bend the arm and/or the center bolt to an angle like your photo shows.
If this is what happened it would seem that bending the arms would re establish the pad alignment. However some caliper arms have been made of an Al alloy that doesn't like being bent and might snap off (Universal and Berilla are two I know of as examples).
Looking closer at the image it looks like the center bolt might be bent. Being made of steel this could be straightened w/o concerns (taking the usual care that bending stuff takes). I have straightened many center bolts over the years and it goes a long ways to ending up with better pad/rim alignment. Remove the center bolt and roll it on a flat surface to see where the bend is, mark it with a Sharpie and hold the bolt in the jaws of a bench vice (a rag wrapped around the portion in the jaws protect the threads) and I like to use a drift punch to better locate where I am focusing the hammer blow. Tap/hammer as needed with checking the bolt's straightness with each blow. For an experienced wrench this might take all of 10 minutes including the reassembly of the caliper. Andy
If this is what happened it would seem that bending the arms would re establish the pad alignment. However some caliper arms have been made of an Al alloy that doesn't like being bent and might snap off (Universal and Berilla are two I know of as examples).
Looking closer at the image it looks like the center bolt might be bent. Being made of steel this could be straightened w/o concerns (taking the usual care that bending stuff takes). I have straightened many center bolts over the years and it goes a long ways to ending up with better pad/rim alignment. Remove the center bolt and roll it on a flat surface to see where the bend is, mark it with a Sharpie and hold the bolt in the jaws of a bench vice (a rag wrapped around the portion in the jaws protect the threads) and I like to use a drift punch to better locate where I am focusing the hammer blow. Tap/hammer as needed with checking the bolt's straightness with each blow. For an experienced wrench this might take all of 10 minutes including the reassembly of the caliper. Andy
__________________
AndrewRStewart
AndrewRStewart
01-20-22, 01:50 PM
#4
Senior Member
Thread Starter
Andy, your advice is always on the spot. Thank you very much. There is indeed a clear paint chip on the DT, exactly where the brake hits it.
