Side Pull Caliper double nut brake

[BSA]

I am having a nightmare adjusting the above. I have followed the park tools wenbsite tutorial and It doesnt seem to matter how loose I have it one of the brake pads just pulls across and sticks on once applied.

Its an old bike and I think the springs have gone. I have no I would like to source some off ebay because this is a cheap commuter but Im not sure where to measure the depth (start and end points). Also im not sure if a modern brake will fit and give me better performance/less hassle.

Can anyone help?

 

[02GF74]

without seeing a picture, I can only guess but if you say the "sprongs have gone", then the pads would never clear the rims. In any case, is there not one spring?

With the caliper brakes I am familiar with, I just rotate the bolt that the brakes pivot on by moving the caliper (shimano ultegra/105) but on cheaper models I've had to put a spanner on the nut and turn that in unison with the caliper otherwise the spring will just bring the caliper back to its previous position.

hope that makes sense.

 

[BSA]

hope that makes sense.

I will have a look and try to rotate the caliper. If I remember (Im currently at work) the caliper attaches via bolt that is threaded at both ends. One end has a nut behind the frame and the front has the caliper then 2 nuts (one with a closed end lock nut?)

I will get a picture today for reference it is driving me mad!

 

[ASC1951]

My first bikes were all like this. I remember coming down the Tourmalet with piddly little Weinmann sidepulls, thinking "someone has to invent a better system than this!"

It could be the springs (usually one, sometimes two half springs) but those were very durable items and didn't break or lose their springiness in normal use, although corrosion could be a problem with cheap ones. The most likely causes were:-
- front nut too tight (which you have checked)
- frame nut too loose, so the whole assembly moves
- sticky muck and rubbish on the bit at the outer end of the spring, which on some models has the spring sliding across it as the brake opens and closes
- ditto on the inner faces of the two halves of the brake.

Take it all completely to bits, clean it thoroughly (WD40 is good), reassemble and adjust. They are such simple mechanisms that if it still doesn't work something must be bent or broken. I always found that dirt was the cause.

Modern dual-pivot brakes are much much better.

 

[tyred]

I have a bike with these. What you need to make sure is that the nut in front of the caliper isn't too tight. It should allow the whole caliper to move from side to side with gentle hand pressure but shouldn't be loose enough for the caliper to move around by itslef. This will cause juddering when you brake as the caliper arms vibrate. Put a spot of oil on the pivot and work the caliper to work it in. Also make sure your cable is moving freely.