New life into old brake blocks?

[michael franks]

We all fiddle around with old bikes and old bits and pieces of bikes and there are some remarkable instances of members renovating all kinds of parts. I've got a couple of pairs of STX RC and LX 537 canti brakes which have the silver cartridge type of shoe which takes a slide in pad. The pads have hardened to the point that they are unusable and even the lightest touch of the blocks on the rime elicits an awful sound similar to sandpaper on metal. There's plenty of life left in the blocks and I wonder if there's any way of
returning them to a usable condition. Thanks.

 

[MR OX]

We all fiddle around with old bikes and old bits and pieces of bikes and there are some remarkable instances of members renovating all kinds of parts. I've got a couple of pairs of STX RC and LX 537 canti brakes which have the silver cartridge type of shoe which takes a slide in pad. The pads have hardened to the point that they are unusable and even the lightest touch of the blocks on the rime elicits an awful sound similar to sandpaper on metal. There's plenty of life left in the blocks and I wonder if there's any way of
returning them to a usable condition. Thanks.

I've filed blocks down in the past with varying levels of success

 

[BrushedAluminium]

yeah try sanding them down on a curb stone removing any shine or residue

 

[weeman_mtb]

I've took the top hardened part of the rubber off on a surface grinder with perfect results. I realise most people don't have access to a surface grinder so maybe a belt sander or just sandpaper and a block or as above a curb stone would achieve similar results with some care.

 

[michael franks]

That's brilliant guys! Both methods sound do-able and nice'n'easy too!
Thanks to both of you for taking the time to reply.

 

[captaincowelly]

I've used a piece of abrasive paper (400/600 grit) laid on a sheet of glass and rubbed them that way.Easier to maintain a nice,flat,even surface on the pad.Or in situ just use the same paper on a rubbing block.
If there's a lip,I just trim with a sharp blade.Worth checking for any grit embedded in the pad first,often had that happen.If it can't be picked out,best replacing the pad to save rim wear.
Another possible cause is pad type.Those type of replaceable pad inserts were produced for alloy or ceramic rims.Would be unusual,but is there any possibility they're for ceramic rims?Usually marked on the pad,but ceramic pads do grind when used on alloy.Made that mistake myself!
Old pads do feel very hard,but I have a couple of sets over 25 years old that work just fine (and quietly!).

 

[michael franks]

Marvellous! A bit sandpaper and a little elbow grease and now the brakes are working beautifully and quietly.
Not a hint of the dreaded grinding noise! Thanks again guys.

 

[prezza]

Although I have never tried it… I’m wondering whether a heat gun may also supple up the rubber? Seems to work on car bumper mouldings etc on YouTube?