New brake blocks don't release - spring tension?

[Bowthy]

Hello,
Wonder if a bike expert can help me out here. I recently bought some new brake blocks for my dual caliper Tektro brakes (they're Tektro 510As on a Halfords Virtuoso)

The new blocks are a few millimetres wider than the old, so I adjusted the cable.

Now, after applying the brake-lever, the blocks don't release from the rim.

Think I need to increase the spring tension, but I'm not sure how to do this.

Anyone know if it's even possible with dual caliper Tektro 510As ?

Thanks in advance for any help.

All the best.

 

[totallyfixed]

Extremely unlikely it's anything to do with the spring tension, the cause of brakes not releasing is usually friction between inner and outer cables. It's one of those things like the headset on a bike that never gets serviced, out of sight out of mind. Winter, especially this winter is favourite for brake cables to get all sorts of crap inside them. release the cable, unscrew from the adjuster and pull the outer off. to be safe as you can't see the inside of the outer I would replace it, dead cheap from your LBS.

 

[Bowthy]

Thanks for the info, I'll try that out.

But, the thing is, if I put the old pads back on, adjusting the tension so the calipers are closer to the rim, the blocks spring back after application.

 

[colinr]

Is this any use? https://www.cyclechat.net/

 

[Bowthy]

Thanks, it was useful. I'd pretty much done that (Shouldn't "turn lever F..." actually be "turn lever A..." ?)

Brakes are fine until I use them, then they don't spring back, so short-term answer is just not using the brakes.

I'm fitting a new cable and outer as soon as they arrive...will let you know how I get on.

 

[colinr]

You're right about F and A. I auto-corrected it in my head. Apparently the small hex bolt (C) affects tension but it's mostly likely filthed up like totallyfixed says.

 

[fossyant]

With new pads you will have to back off the cable - mainly at the calliper clamp (brake bit at the wheel) - i.e. undo the cable clamp, let a bit more brake wire through and re-tighten.............. the new pad will be a good few mm's thicker..... hence being closer to the rim......... (sorry if this sounds simple but it's a mistake folk make)

You'll also possibly need to fine tune with the adjuster (the finger nut thing where the cable goes into the calliper)

Just a quick suggestion before you think it's a major fail, this is in basic bike talk.

As above - lots of issues about cable issues..........

 

[Midnight]

Extremely unlikely it's anything to do with the spring tension, the cause of brakes not releasing is usually friction between inner and outer cables...

+1.

Here's a link to caliper servicing on Tektro's site... http://www.tektro.com/04support/pdf/000907RX40-1.pdf
This will give you an idea how calipers work. Hex nut C is actually for centering the pads and has nothing to do with tension. Nut D will affect tension, but unless you've adjusted this already it is unlikely to be the cause.

I'm no expert, but I hope this helps.

 

[Bowthy]

Problem solved...

I replaced the inner and outer cables and still had the problem, so went to LBS where they pointed out the caliper was a bit gunky so I unscrewed nut "D" (as in the previously mentioned thread ), and gave it all a good clean and put it back together. Brake's are working great now.

Thanks for everyone's help, it's all very useful.

 

[Bill Gates]

I was going to say that...... I recently changed my brake blocks and had the same problem. I took them apart and dug out the oil lubricating hole on the sleeve connecting the two parts of the calipers with a paper clip and applied WD40 and then applied some oil and hey presto.