Recently upgraded my son's bike to something with hand operated brakes. Its a hand me down special, but seems to be relatively solid except for the brakes. It has these side pull brakes and I have 2 issues with them:
1) They wont stop. I have pretty good grip strength and I am squeezing these things with all I've got and I can barely get it to slow down. The pads are contacting as they should. I took them off and sanded them to get the old layer of crud out the way. Wheel rim in that area is clean. Cable doesnt feel like its binding or anything. Just need new pads? If so, recommendations?
2) The adjustment of these is wonky. They always pull one side more than the other. Is there any way to adjust the 'balance' L/R on them?
Those brakes generally suck and don't do much.
Is the rim painted? I haven't had good luck with any pads on a painted rim.
From my experience, they are a bit like a sliding caliper and WILL contact one side before the other. There is a centering spring, but it just holds the entire assembly centered while the brakes are NOT being applied.
Also, I *think* the front tire is on backwards. Not a big deal and might not make any difference at all! Just an ocd thing.
No, rim isn't painted. You are right I think the tire is backward, but probably not worth turning around (coincidentally, this has footpegs on it and I'm not sure what size/shape the nut is way down in there)
So let me rephrase, one side will contact before the other, but when released, that side has most of the travel. For example in the pic, the RH side* will move a ton, the LH will move maybe 1/16" before touching, but on release will only move out 1/16", while the RH moves way more than that. Is that normal behavior?
*left if you are riding the bike
I don't think it should matter as far as brake pressure, but I've never seen one where the cable comes in the bottom. That encourages dirt and water to accumulate in the bottom of the curve. I would flip that so the cable enters the top arm and pulls on the bottom.
Make sure the center bolt isn't too tight. The pivot needs to be pretty free, almost to the point of sloppy. Any binding there will cause all kinds of issues.
With the brakes released, you should only have about 1/8" clearance between the pad and the wheel, assuming the wheel is straight.
Toyman! said:
I don't think it should matter as far as brake pressure, but I've never seen one where the cable comes in the bottom. That encourages dirt and water to accumulate in the bottom of the curve. I would flip that so the cable enters the top arm and pulls on the bottom.
Its a BMX bike where the front steering can spin 360 degrees, so the cable runs though the center of the pivot and has different routing:
In reply to ProDarwin :
Interesting. My kids must not have had front brakes on their BMX style bikes. They did have detanglers for the rears. Those were always fun to adjust.
Pads are inexpensive and easy to replace, try the softest ones you can find to see how much difference they make. A lot of the reviewers on Amazon are saying that the brake sets come with crappy pads, so you are not out anything even if you decide to replace more parts later.
That 180deg loop has to do wonderful things for friction, esp. if the housing and cable are less than the highest quality.
The center pivot should not be a simple bolt thru everything. It should be a double-ended stud with the spring-holding piece fixed in the middle. That way you can center the brake and lock the adjustment with the nylock on the back side of the fork. The acorn + locknut on the front side will cause problems if they are overtightened, as Toyman! notes.
+1 for new/better brake pads. That's almost certainly the root of the problem.
Are the pads making full contact with the rim?
Sometimes only a corner of the pad grips the rim. You may have to sand them to ensure they make full contact.
Side pull brakes have sucked since I bought my first Schwinn back in 1974.
Side-pull brakes are old-school, but they should work just fine.
Don't worry about one side engaging first. The brake calipers on your car do the same thing. The piston pushes the inner pad against the rotor which then slides the caliper on the pin to apply equal pressure on the other pad. The caliper on your bike is floating on that top bolt the same way.
Sanding the shoes does next to nothing. The cheap rubber in those gets punky the whole way through. You might have improved it a bit, but not enough to fix it. New shoes are cheap.
A properly-operating brake just like that one should eject you over the handlebars if you squeeze hard enough. I still have a bike with cheap old school brakes like that and it will lock up the rear in a heartbeat and stop on a dime. They'll never be new hydraulic discs, but they're perfectly fine.
I have never had a bike with the cable running through the hollow stem where the front brake worked worth a darn.
According to the bike magazines in the 80s, a chrome rim gave superior brake action, but my mountain biking experience says a machined aluminum rim is best. No matter what, brake pad choice is really important. Cheap pads may as well be a piece of plywood screwed to the caliper.
At least you don't have plastic mags. Those, you may as well just learn to drag your shoes on the tires to slow down 
FWIW, not big on the arrangement of having the cable come up from the bottom. Anyway, to fix the centering issue, lock it down, carefully, from the backside of the fork. Also, they make a tool that holds the pads against the rim. Makes the process a lot easier.
I got some new pads, - $6 for a full set lol. I was talking to the guy at the bike shop and he said "unless there is a need to spin the bars 360 degrees, just run straight cables". That seems to mirror Knurled's comment about this particular cable routing not working well.
So I'll try the pads, if not I'll run straight cable.
Put new pads on, it's every bit as terrible as before. Got to be cables I guess.
Could be, but don't neglect the pivot action at both the hand lever and the brake arms at the wheel. When they're crudy and dry, they can eat up a lot of your hand effort.
I didn't see it mentioned above, but you can rotate the spring perch to better balance the outward pushing of the pads. A little fiddly, but perfectly doable.
Regarding the “reversed” cable setup, that’s the Potts Mod.
Now there's a term I have not heard in a long time.
