Caliper brakes, overhaul and correct setup advice please

[retro-rich]

On my RRA I have Weinmann 500 side pull caliper brakes.

When I stripped the bike and rebuilt, I shied away from fully stripping down the brakes.

But, they are not set up right, when releasing the lever it leaves one pad on the rim. Last night I stripped the rear, polished all the surfaces as the bit in between the arms I couldn't reach before was covered with corrosion of some sort. I also found that the washers were corroded, cleaned as best I could and think I've managed to lose one, doh. Can these washers be purchased separately anywhere or does anyone have spares they wish to sell?

Also, does anyone have a link to a diagram for these? Would like to be sure I'm re-assembling them right.

What about grease? should that go anywhere near these brakes and where abouts?

Would also appreciate any advice for centering these correctly. It's the type with a double nut at the front (furthest from frame). Doesn't seem to matter which way I twist or tighten they always pull away uneven.

Thanks

 

[Midlife]

I'm sure there will be a pic somewhere of how they go together

As for adjustment the double nuts are to "lock" the callipers together, just tight enough so that they move and spring apart.

As for one pad hitting first, try the single nut that holds the brakes to the frame, undo and then bodily move the calliper a bit as tightening the nut can twist the calliper round, failing that with the brakes on the frame pick the spring that is on the side of the pad against the rim, pick it off with some fine nosed pliars and pull it towards you and then tuck it back onto the calliper, this will unilaterally tighten the spring and even out the pads.

Finally before you do that ensure the spring top is horizontal as tightening the holding bolt can twist the calliper (as mentioned). It's acceped that you can take a "drift" and smack the spring just as it exits the centre of the brake to level it off...allegedly.

Anything on Sheldon Brown.

Shaun

PS I run Weinmann 500's on my Jackson, they were light, and dirt cheap and Weinmann did all the spares. There must be millions of them kicking around if you have lost something

 

[Old Ned]

Basically what Shaun says plus I always have a very light smear of grease on the centre pivot pin, on the washers, on the spring retainers on the arms and on the mating faces of the caliper arms. It can be a bit awkward getting them centred using the fixing nut and a tap on the spring with a drift of some sort often does work. I find that 500's work very well once they are sorted.

 

[gregs656]

You might get a good idea of how it goes together by looking at the front - that is how I worked out how to put mine back together :roll:

Always take pictures before you start taking things apart
Always take pictures before you start taking things apart
Always take pictures before you start taking things apart
Always take pictures before you start taking things apart
etc
etc

One day I will remember

 

[Midlife]

We used to use a variety of "drifts" for removing locking rings, headsets, adjust brakes etc but in this instance a drift can be any flat ended bit of metal...........a very large screwdriver with a flat end will do. Don't use a thin ended screwdriver or you will make a dent.

Weinmann 500's worked well because of the mechanical advantage (leverage) associated with the short drop of the stirrups

Shaun

 

[Johnsqual]

Hope this doesn't sound daft, but could it also be corrosion in the brake cable?
I once spent a while trying to centre a set of cantis before I realised that the inner cable was rusty and that was why the brake was staying stuck against the rim.

Johnny

 

[retro-rich]

Good tip gregs, lol, also another tip is to go have another look in proper daylight, I managed to find the washer! I really do need to get some kind of work surface near the shed, I keep dropping stuff.

Shaun and old ned, some excellent advice thank you.

I stripped it again and reassembled, pretty sure all the washers in the right place. I greased all the surfaces, was a bit unsure about this before getting grease near the brakes but I wiped it all down afterwards and I'm sure if any is on the pads it will rub off quick enough.

I clamped down the inner nut just enough to hold it together, then tightened up the frame fixing nut as tight as it seemed it needed. Then tightened the inner nut right up, until the braking action was too tight then backed off a touch, and bingo the both sides release properly. I did find one tip online about using a spanner at both ends, frame nut and inner nut and turning both same direction to centre the arms, seemed to work ok.

Only thing is that the double lock nuts feel just a tad too loose with the spanner, but any tighter and the brake action is too tight, this normal?

Really pleased so far though, something else I've learned.

Thanks for the help

 

[retro-rich]

Hope this doesn't sound daft, but could it also be corrosion in the brake cable?
I once spent a while trying to centre a set of cantis before I realised that the inner cable was rusty and that was why the brake was staying stuck against the rim.

Johnny

Good point johnny but cables and outers replaced end of last year and condition looks ok. Canti's I've tackled before and they are difficult wotsits also

 

[Midlife]

The double lock nuts should't be loose.... tighten down the inner flat nut to a very tight finger pressure and the callipers will just bind together.

Then tighten down the domed nut on to again to a very tight finger pressure and the callipers will bind....

Get a spanner (usually a ring spanner) and hold the domed nut still and use a flat spanner to "undo" the flat nut a tad which will release the callipers. when they feel right then use the ring spanner to lock the domed nut against the flat nut..

sorted

Shaun

 

[retro-rich]

Thanks shaun

The lock nuts on these ones don't haven't a domed nut. There is instead two rather narrow nuts of the same size, way too narrow to get the inner one with the spanners I have as it covers both nuts.

I've had another go at tightening them but think I need to get some kind of narrow spanner to fit the inner nut, kind of cone wrench type thickness.

Also, the end of the stud has a square shape, from reading another thread I think this may be to assist centering the arms?

Both front and back done now and much better than they was, although only tested on the stand stll needs a test ride.

Thanks for the advice