Athena brake centering problem - suggestions?

[54ny77]

Can't for the life of me get my Athena brakes to center. Just the driveside caliper goes through the clamping motion. Cable's tight, bolts snug, wheel centered perfectly, there's a correct amount of housing going from seat cluster to caliper (i.e., not a sharp bend), etc.

Note: these calipers don't have the centering adjust screw.

It's on a vintage frame, for whatever that's worth, and the top tube has housing clamps. On a whim, I held the housing in place right in front of the seat cluster so as to provide more clamping force, and that seemed to work. Does that make sense? It's almost as thought the housing is flexing just a tiny bit, but enough to "push" the non-drive side caliper against the rim.

Got any ideas?

[steamer]

Sounds like the bolt that mounts the brake to the frame is not actually tight, and therefore not providing the needed friction. Is the nut bottomed out on the threads before making contact with the frame?

[54ny77]

^^the nut seems to be plenty snug, i hit 5Nm easily on torque.

[PacNW2Ford]

According to Park Tool, the bolt should be 90 in-lbs = ~10.2 Nm...
https://www.parktool.com/blog/repair...s-and-concepts

[54ny77]

steamer yeah you're right, I took out the barrel nut and the washer is getting crushed. Will dig around for bigger washer diameter. Thanks!

Pacnw2ford: def. getting more than 4, it's a steel frame so I'm tightening till it's "tight.". Am sure it's at or near 10. With new washer, I'll break out a different torque wrench, I was using a 5Nm clicker.

[Joxster]

You also centre the brake with a cone spanner, I think it's a 13mm and use the Campag serrated washer.

[purplecu22]

Also check your brake cable housing length, My single record brakes are very sensitive to brake housing length. If it is perfect it will push or pull the caliper and move it over time. Just my experience.

[Ralph]

If it doesn't have the 15MM nut (on Campy's) to off center it with before you snug up the attachment bolt, I would take a brake block off, off center the brakes (to twist the spring), put brake block back on (at this point caliper is off to one side), then as you finish tightening the attachment nut let it kinda untwist as you tighten. To get brake blocks to hit rim same time, you may not get them to be even both sides when you're not using them. No need to over tighten the brake recessed nut.

Kinda hard to explain....sorta an art....but it's how we always had to center old side pulls. (although usually could just push off to one side with brake block on)

[Black Dog]

Originally Posted by 54ny77

steamer yeah you're right, I took out the barrel nut and the washer is getting crushed. Will dig around for bigger washer diameter. Thanks!

Pacnw2ford: def. getting more than 4, it's a steel frame so I'm tightening till it's "tight.". Am sure it's at or near 10. With new washer, I'll break out a different torque wrench, I was using a 5Nm clicker.

Can you post a pic of the setup? It would really help.

[AngryScientist]

put an extra one of these on there:

[ultraman6970]

What angrey says. sometimes you have to put extra ones so they bite at the frame side and the caliper side, if you are using a flat or a spacer.

No idea what generation of athena are you using, looks like is the old one? Check out the lenght of the nut you are using becausep robably too long aswell, if too long and dont have the right size you can dremel it a little bit and call it a day. A way to find out is to put an extra washer tho.

The other detail, sometimes the springs are in the wrong place and you have to actually youo have to move them using the center pivot with a cone wrench. When i say in the wrong place i mean that the left and the right spring arent set in the middle, so one spring will slide more than the other one.

Hope this helps.

Of you are using skeleton athena, pretty much the same plus the centering screw thingy.

[54ny77]

Purplecu22 and Ralph, those are very good ideas I will tinker with them.

You're right about housing length and sidepulls. I was just checking out the length and positioning on an older vintage bike with Campy Nuovo Record brakes and it's a longer gentle slope of housing, with two top tube clamps (vs. my 3, the last of which I installed at the tip of the seat cluster lug point).



edit: purplecu22: you nailed it, it was housing length, which has the tendency to "push" or "pull" the caliper alignment as you mentioned. I took off about 1.5" of housing and relocated the top tube housing clamp about 1.5" farther (towards the middle of the tube). Presto, centered.