Cable bolt torque on campag brakes - stick with 5Nm?

[neeb]

Campagnolo specify a torque of 5Nm / 44 in. lbs for the cable bolt on their skeleton brakes.

This seems pretty low, and I know a lot of people say to just do it up by feel and ignore the recommendation, in which case you will almost certainly be exceeding 5Nm.

However, I have noticed that in used brakes the little textured washer that presses the cable often gets a groove in it, and that once this happens you tend to need to do the bolt up tighter to get a secure fix. So what I am wondering is whether if you stick to the recommended 5Nm you will avoid this problem and still get a secure grip on the cable.

Brand new set of SR brakes, and I want to get this right from the outset... Might seem like a pedantic point, but there's nothing worse than not being sure that the cable won't slip when you really crank on the brakes!

[Valbrona]

If you tighten up the bolt so tight that it damages the cable, then it is too tight.

[neeb]

That's pretty much what I was thinking.

Time-honoured as it is, the whole idea of the cable being secured by a friction bolt seems pretty primitive to me, given the importance of the brakes on a bike.

[PoorCyclist]

I just do around 3-4nm. I turn the hex wrench end snug without arm strength and it is usually good.
I have taken the bolts apart built by mechanics and it is not 5nm either, the cable is barely pinched at all.

My brake set calls for 6nm but I am pretty sure it is a pain to tighten and more to loosen (the bolt is on the end of external cam arm.. tiny TI bolt and pincher) without knocking it off alignment.

If not tight enough, it probably slipped 1mm and you might not even notice it.
If the bike is for stunts where it needs to skid and do stoppies, then make sure it is tighter.

[Calnago]

5Nm has been working fine for me. I think that's pretty tight actually. Never had a cable slip. Too tight and the cable gets all squashed making it more difficult to adjust properly if you need to.

[Calnago]

5Nm has been working fine for me. I think that's pretty tight actually. Never had a cable slip. Too tight and the cable gets all squashed making it more difficult to adjust properly if you need to.

[neeb]

Ok, torque wrench set to somewhere just over 4.5 Nm...

While I'm at it, another thing that's bugging me - Campagnolo front brakes come with two of those serrated washers, while the rear brakes only have one. The washers can only go in front (i.e. the brake side rather than the bolt side), but are you really supposed to use two on the front, and if so, why?

[Valbrona]

The Campag serrated brake washers have been around for years now - my old Record Colbalto brakes had the exact same ones - and they have quite sharp edges. For this reason, I have heard of some people dispensing with their use in the case of carbon frames - too sharp. However, I have found the brakes work best with them (stay centrally aligned) and they are currently installed on my SR brakes + CF frame.

You use as few washers at the front and back as needed - usually just one. Multiple washers can come in handy in the case of deep seatstays/fork blades and when the inner edge of the brake pad holders would otherwise contact with the seatstays/fork blades.

[Butcher]

but are you really supposed to use two on the front, and if so, why?

Because on my fork, one is not enough and the brake would hit against the fork. I am certain there are others that would not hit with only one but not mine.

[neeb]

One washer works fine for me, so one it is then..

Brakes installed, working nicely, happy!

<edit - someone will be along shortly to argue for the aerodynamic advantages of having the brake 2mm closer or further way from the fork... >