brake cable installation, what am i doing wrong?



mattlavallee

New Member
Oct 7, 2007
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the bike is a '95 cannondale t400 with drop bars. i just got a new set of IRD cantilever brakes, and new bar & stem. the brakes are installed with the tension spring set in the middle of the 3 holes on the frame, newly greased mounts. the levers are the original dia-compe ones, and the problem is that when i put on the new cables, no matter how i mount it on the bar, there's a ton of drag on the cable, so much that when i do hook up the calipers, there's not enough tension to completely disengage the brake. it seems like the alignment isn't right where the ferrule on the outer cable goes in against the cable stop, and the ferrule is too wide to fit in the hollow spot on the cable stop. there's not enough room in there to really adjust the alignment of the outer cable. has the ferrule size changed since the mid 90's? the cables are lubed and move freely when not installed or when the ferrule is not up against the cable stop. i've tried routing the cables under and on the front of the handlebars, but that didn't have an effect on the resistance.

i guess i could just start upping the tensions screws on the calipers and move the spring into the higher tension hole, but it seems like the cable is giving more resistance than it should to returning.
 
mattlavallee said:
the bike is a '95 cannondale t400 with drop bars. i just got a new set of IRD cantilever brakes, and new bar & stem. the brakes are installed with the tension spring set in the middle of the 3 holes on the frame, newly greased mounts. the levers are the original dia-compe ones, and the problem is that when i put on the new cables, no matter how i mount it on the bar, there's a ton of drag on the cable, so much that when i do hook up the calipers, there's not enough tension to completely disengage the brake. it seems like the alignment isn't right where the ferrule on the outer cable goes in against the cable stop, and the ferrule is too wide to fit in the hollow spot on the cable stop. there's not enough room in there to really adjust the alignment of the outer cable. has the ferrule size changed since the mid 90's? the cables are lubed and move freely when not installed or when the ferrule is not up against the cable stop. i've tried routing the cables under and on the front of the handlebars, but that didn't have an effect on the resistance.

i guess i could just start upping the tensions screws on the calipers and move the spring into the higher tension hole, but it seems like the cable is giving more resistance than it should to returning.
Ferrule size and/or alignment is likely the issue. The cable is probably dragging in the stops.
 
mattlavallee said:
the bike is a '95 cannondale t400 with drop bars. i just got a new set of IRD cantilever brakes, and new bar & stem. the brakes are installed with the tension spring set in the middle of the 3 holes on the frame, newly greased mounts. the levers are the original dia-compe ones, and the problem is that when i put on the new cables, no matter how i mount it on the bar, there's a ton of drag on the cable, so much that when i do hook up the calipers, there's not enough tension to completely disengage the brake. it seems like the alignment isn't right where the ferrule on the outer cable goes in against the cable stop, and the ferrule is too wide to fit in the hollow spot on the cable stop. there's not enough room in there to really adjust the alignment of the outer cable. has the ferrule size changed since the mid 90's? the cables are lubed and move freely when not installed or when the ferrule is not up against the cable stop. i've tried routing the cables under and on the front of the handlebars, but that didn't have an effect on the resistance.

i guess i could just start upping the tensions screws on the calipers and move the spring into the higher tension hole, but it seems like the cable is giving more resistance than it should to returning.
You need to assess the situation at each point of contact.

FIRST, disengage the brake cable from the caliper ...

Now, how much resistance do you feel when you SIMPLY pull the cable to-and-fro inside the cable housing (one hand on the bare end & your other hand on the "barrel" at the other end of the cable)? There really should be NONE to speak of ...

Did you LUBE the cable? A thin coat of almost ANY grease (including VASELINE -- aka "Petroleum Jelly") will do.

Is there a kink in the cable housing at any point (particularly, where the cable enters the brake lever's housing)?

Is the housing inserted all the way into the brake lever body, but properly stopped by the lever body so you only see bare cable when you pull on the lever?

Does the problem exist with BOTH the front-and-rear brake?

Is there a chance (!?!) that you are using derailleur housing for the brake line?

As far as the ferrule at the end of the cable housing, remove it and/or (more importantly) be certain the OLD ferrule isn't lodged inside your cable hanger OR insert the cable housing end with the ferrule into the brake lever body.
 
thanks for the suggestions--

the cables are lubed with a light oil. with the brake disconnected, there is very little resistance in pulling the cable through UNLESS i push the ferrule all the way up to the cable stop. the ferrule will not fit into the hollow on the cable stop, and i just checked to make sure there were no old ferrules stuck in there. i wasn't aware that there are different ferrule sizes. there are no kinks in the housing, they are new and i haven't messed them up yet. this problem is happening with both front & rear brakes. i'm pretty sure this is brake housing and not derailleur housing, it had the standard brake nubs at the ends of the cable.

i had thought about trying to reverse the cable so that the non-ferrule end went to the brake lever, but i thought it might be important to have that reinforcement in there where it is pulled tight up against the cable stop. i take it that not something i should worry about?

thanks
 
ok, i flipped around the outer cables so that the non-ferrule end is in the lever. much less resistance now, the bare end of the outer cable fits into the hollow on the cable stop easily. i went ahead and repositioned all the caliper springs to the higher tension hole and everything seems to be working as it should. braking force all around is much better than with the old calipers, i can easily skid the rear. thanks for all the suggestions!
 
mattlavallee said:
ok, i flipped around the outer cables so that the non-ferrule end is in the lever. much less resistance now, the bare end of the outer cable fits into the hollow on the cable stop easily. i went ahead and repositioned all the caliper springs to the higher tension hole and everything seems to be working as it should. braking force all around is much better than with the old calipers, i can easily skid the rear. thanks for all the suggestions!
Good solution. I never worry if I'm missing a ferrule. Before reading this post, I was going to suggest that you chop them off.