Beta Techno 250 Brake Squeak

[peter_fazio]

   Hi,

 

  I have a '97 Techno 250 that makes an annoying squeak from the front disc brake.  It does not squeak or squeal while riding or braking.  It only makes the sound when just slowing moving the bike or if you slightly rotate the front wheel while the bike is up on the workstand.  I have pulled the caliper (Grimeca) off, removed the pads (pads have plenty of thickness), sanded and cleaned the pad material.  I have also applied disc brake "anti-squeak" compound to the back of the pads.  I have cleaned and used emery paper on the disc to remove any stray rust or high spots.  That process gets rid of the noise until after I spend some time riding the bike.  After a ride the noise is back as usual.  Not real bad, but just annoying.  Any thoughts on Techno brake noises ?

 

                                              thanks,

 

                                                          Pete

 

[imbeta]

It sounds like your pads are contaminated. If you've already tried sanding them down and had no success then you will probably have to just get some new pads. One more thing you could try is to give the pads another sand down and also give the disc a blast with with a blow torch to burn off any oil / dirt on them.

[goudrons]

Disc brakes can often creak or knock due to the way they are attached to the wheel hub.

 

The discs aren't bolted directly on, but use "top hat" spacers between the bolts and discs to limit the heat transfer between disc and hub.

You always get a little back and forth "float" in them, many replace the spacers, but it's often the holes in the disc where the spacers fit have gone oval as well after years of slapping back and forth.

This can cause the disc to skimmy a little when braking.

 

Contaminates are the biggest cause, cleaning fluids, WD40, brake fluid and suspension fluid (from leaks) getting onto the pads and/or discs.

You need to bin the friction material and replace if you've anything on them, but I find you can clean the discs off by riding up and down with the brakes on, so the discs are feckin' mad hot (thats a technical term in case you didn't know) then pour clean water on them.

You know when you've done it right because the water sizzles and turns to steam.

 

The steering bearings can creak too, particularly when braking heavy, down hills, so worth checking, regreasing and tightening them as it can sound like the brakes.

Edited May 5, 2015 by goudrons

[lineaway]

If it does not squeak while riding, not much to worry about. You either have a slightly warped disc or as said before bad wheel bearings.

[peter_fazio]

   Thanks for the suggestions.  Maybe I'll just replace the pads and see what happens.  Like I said earlier, its not really that bad, since it does not make the noise while riding, only while moving the front wheel very slowly.

 

                                thanks,

 

                                       Pete