Technical > Wheels, Tyres and Brakes

Caliper brake set up

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Matt2matt2002:
Trying to adjust/ fix my son's front brake.

It's a caliper side pull. Not familiar with this one.

It was juddering so removed nut bolt and washers. No grease here so cleaned and oiled.

Put back together but not sure if washer nut bolt sequence.
Not sure it was set up correctly.

Sheldon Brown does not show an exploded diagram.

On the centre bolt front the front is;
Locking nut cap, nut , 2 washers ( one curved), the 2 arms, washer, spring and the piece the spring sets in.
The bolt passes through the fork and then rusty bolt at rear

Thoughts folks?

Diagram would be nice ! 😉

Matt at 30°
NJ USA

Danneaux:
The setup/assembly as pictured looks about right to me, Matt, complete with the thrust washer at the rear, behind the trailing caliper.

The basic problem with this sort of stamped-steel sidepull is the thin arms in the same plane as braking forces and they aren't very rigid. They clamp "okay" but judder under braking as they really can't resist the forward movement of the pads against the rim very well.

I'd say lube, adjust out any excess play, lock in the adjustment and call it done. Fitting new/uprated brake shoes can actually make braking worse with thin-armed, long-reach stamped sidepulls like these. I know...I've got a set on my 1970 Motobecane Astra U-frame Folder.

Best, Dan.

Matt2matt2002:
Thanks Dan.

Yep, it's a cheap bike with cheap components.
It gets my son to and from work.
He doesn't cycle for pleasure, ( I'm ashamed to admit ! ).
I'll give it a clean and tweak while I'm here.
My duties are looking after the cat and overseeing a new kitchen fitting.
It's been made quite clear to me that the cat comes before the $xxx,xxx kitchen!

Thanks again

Matt at 30° and covered in cat fur.

mickeg:
It can help if the part of the brake shoe that is farthest forward contacts the rim first as you apply the brakes.  Then as you tighten the brakes further, the entire brake pad grips the rim. 

If you have a stiff piece of paper like a business card, I think one or two thicknesses of that type of paper is about the right difference between the two ends of the pad for angle of the pad against the rim.  Not sure if I am being clear here.

Newer brake pads often come with some spherical type washers that make angle adjustment easy, older brakes with thin metal arms like the one cited often were simply bent for this type of adjustment since they lacked such washers.
 

Matt2matt2002:
Thanks Mick.
Your comments were quite clear and I've tweaked my own brakes in a similar way.
However on my son's bike there is no 'nose in' adjustment.

Maybe the arm could be bent but I'm not sure I'd want to take that risk.

Does the picture show the set up ok?

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