Classic & Vintage - Problem With My Vintage Dia-Compe Brake Levers

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Briareos
02-04-07, 05:04 AM
Hello, I've been building a fixed-gear bicycle recently, and being the wise person I think I am I have decided to put brakes on it (front and rear). I nabbed a pair of Dia-Compe "Aero Gran Compe" brake levers. They're beautiful, white hoods with white levers!
Anyway...I have some 6.5 mm white cabling as well, and I used the wire that came with my cheapo Tektro brake calipers. The problem I have is, I can't get the brakes to stay tight, even after I put them together. They work great at first, but then something happens and they stop braking as well. But the most annoying part of all this is that my front brake lever will make this grating sound when I pull back on them as well as having an uneven pull that feels rough and abrasive.
I figured it was the cable rubbing against the inside of the brake lever, and at first I was right. I could see the black metal of the inside had marks all over it. So I put some metal thingy that came with my brakes (eek I know, I'm a nub) inside and it eliminated the problem at first.
I'm left with brakes that are abrasive and make a horrible grating sound and their brake functions decrease after a few uses.
Can anyone help me out?
I actually have a pair of white Dia-Compe GC levers in my parts bin that I have not used. Looking at them from the back, I can see that I am missing a piece that threads into the cable entry hole and provides a positive stop for the cable. Without this threaded insert, no way are the levers working properly. Maybe that's the piece you're talking about. It looks like it might thread in from inside or outside - I'm not sure which is right - but my guess is outside. You may want to try the other way if possible. Next - your cables - Modern road bike brake cable housing is 5mm OD and made for cable that is 1.6mm. If your housing is 6.5mm the hole in it is probably much too large. Your Tektro cable is probably 1.6mm, and if it rubbed much, could now be fraying inside your lever and housing. Sounds like to me you need new cables, housing, and use a housing end. Good luck and good braking.
nlerner
02-04-07, 06:53 AM
Sounds like a couple of things might be going on: The uneven pull and grating sound when you apply the brake could be an issue with your brake pads. The cheap Tektro calipers likely have cheap pads, which aren't settling evenly on your rims when you apply the brakes. Try swapping in some different pads and see what happens. Second problem you seem to have figured out--the need for a metal cable stop at the end of the housing that goes in the brake lever. If that hasn't solved the problem, you might have a kinked cable, so try a known fresh one. Also, make sure the ends of your cable housing are cleanly cut without any stray pieces of coiled steel interfering with the movement of the cable. Finally, it's important that you cut the cable housing to the right length; there needs to be enough slack for the movement of the caliper when you apply the brake, but not too much!
Neal
well biked
02-04-07, 07:46 AM
If the grating and grinding is coming from the brake pads when they contact the rims, I highly recommend getting some Kool Stop pads, preferably in the salmon color. They have the best pad compound currently made, in my opinion, and are the best cure you can find for grinding and grating sounds coming from your brakes-
Briareos
02-04-07, 04:23 PM
I actually have a pair of white Dia-Compe GC levers in my parts bin that I have not used. Looking at them from the back, I can see that I am missing a piece that threads into the cable entry hole and provides a positive stop for the cable. Without this threaded insert, no way are the levers working properly. Maybe that's the piece you're talking about. It looks like it might thread in from inside or outside - I'm not sure which is right - but my guess is outside. You may want to try the other way if possible. Next - your cables - Modern road bike brake cable housing is 5mm OD and made for cable that is 1.6mm. If your housing is 6.5mm the hole in it is probably much too large. Your Tektro cable is probably 1.6mm, and if it rubbed much, could now be fraying inside your lever and housing. Sounds like to me you need new cables, housing, and use a housing end. Good luck and good braking.
Hm, I DO see the threads inside where the cable goes through, but my brakes didn't come with anything to screw in there. They were NOS in the box and even the levers were still in sealed plastic. They gave me some ferrules to use but I don't think that they will solve my problem, as they do not have threads.
As far as brake pads go, that isn't the problem. I hear the crunchy noises when I use the brakes when not moving. Slack with the cabling is fine from what I can tell, the front brake cable has enough extra bend so that when I brake, the housing isn't stretching out.
I think my problem is those threaded inserts. I've pretty much concluded the sounds and feel come from the cable in the inside of the levers, rubbing against the metal. The rear brakes work fine, I don't think it's cabling or housing.
Perhaps I should extend the front brake house all the way into the brake lever (but not too far obviously); putting the housing where the cable rubs against the inside of the levers.
I'll try tonight!:rolleyes:
Thanks for the responses! :o
There's a Dia Compe domed ferrule that was used inside many of their early aero levers. Make sure you're using it.
http://www.loosescrews.com/index.cgi?d=single&c=Cable/Casing&sc=Ferrules&tc=&item_id=DC-B95&id=682138216021
Are the threads inside basically useless and this ferrule provides the cable stop - or does this ferrule fit inside another threaded insert?
coelcanth
02-04-07, 09:24 PM
i have a pair of similar dia-compe levers.. i think they're called 'ax' or something.. but there are no threads.
for some reason they didn't mold a cable stop into the lever body so you'd just have to jam somekind of ferrule or cable stop inside.
apparently they designed a specific domed ferrule but i think pretty much anything that fits will work
If the grating and grinding is coming from the brake pads when they contact the rims, I highly recommend getting some Kool Stop pads, preferably in the salmon color. They have the best pad compound currently made, in my opinion, and are the best cure you can find for grinding and grating sounds coming from your brakes-
Concur.
I also concur with those who wrote about ferrules.
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