GuineaFowl

My first real post here, unfortunately it's a tale of woe. Wasn't sure whether to put this here or in the Bicycle Mechanics forum.

My fiance rides a Specialized Dolce Sport which we bought a few months ago. She has been complaining about not being able to brake effectively from the day she first rode it. I decided to try it out myself and compare to my Allez Sport and sure enough her brakes sucked compared to mine.

At first we thought it was just that her brakes weren't adjusted properly so I adjusted them as close as they could go to her rims but that didn't help.

Then we compared flex in the cantilevers between her generic Promax cantilevers and my Shimano Sora's. Hers seemed to flex slightly more but not enough to make much difference in my opinion. They're both hot forged and quite flexible as a result in any case.

As an experiment I decided to swap her front brake blocks with my rear brake blocks allowing us both to have Shimano Sora blocks up front and Promax blocks in the rear brake.

That gave her some level of improvement and we've been cycling like that for quite some time now. We recently went out cycling with a friend who just got himself an Ultegra equipped bike and I straight away noticed that compared to his brakes ours were making a dry scraping sound whenever we applied them. The sound describes quite well how they
feel too, there doesn't seem to be much gripping, just a scraping. The Shimano Sora pads are much better in this respect than the Promax but still not anywhere as quiet and grippy as my friend's ultegra blocks. At least they are not as bad as what I'm about to unveil to you about the Promax blocks ...

This morning I decided to take my brake blocks off and try and get to the bottom of what felt like a near total loss of braking ability on the rear brakes whilst I was descending a steep and winding road yesterday. The following photos show the state of the Promax blocks and my rear rim where they were mounted. I haven't taken any pictures of the front rim and Sora blocks but I assure you they still look factory new.

Overview..jpg Block Closeup..jpg Rim Closeup..jpg

What you can see in these pictures is shards of metal embedded into the Promax rubber and also on my rear rim. To me it seems as if these shards are baked into the Promax blocks since the Soras are completely clean and free of anything like this. Looking closely at my rear rim with a magnifying glass - I'd like to know what you think from the picture but to me they look almost melted into the grooves. My front rim is not affected in this way and being the only rim never to have had the Promax blocks applied to it, again, I can only assume this has been caused by the Promax blocks.

I must admit to having seen some shards on the Promax blocks once before but I assumed they had been picked up from the road and so I just removed them with an awl and reinstalled the blocks. This was done at the same time I swapped the brake blocks between bikes.

These things actually come standard from the factory on a Dolce Sport. I complained when my fiance said she wanted the Dolce because you get a lot less bike but have to pay more for it if you compare it to the equivalent Allez, but even with that I was not expecting this to happen.


Time for new blocks methinks,

Guinea Fowl

ptle

Cheap brake pads will look like that if you don't clean them. I recommend cleaning the aluminum rim too, and if that happens sand the brake pads so they're flat/even.

If you are getting new pads, I recommend Kool Stops.

gsteinb

Brake blocks?

lazerzxr

The metal is alloy that has been picked up as the rim wears. It happens. Kool Stop pads are good...

GuineaFowl

gsteinb, shame, you only have 7535 posts, I guess you want me to tell you they're also known as brake pads. Also I recommend you pedal at a cadence of around 90 rpm. Please stop trolling this newbie. *motions hand toward the mace his momma gave him for using in the big wide interwebz*

gsteinb

The ability for some folks to infer non existent tonality and meaning is pretty amazing. I never heard the expression before. Calm down.

GuineaFowl

Sorry, gsteinb, was expecting to be attacked for being a newbie. I am likewise pretty amazed you've never heard of the term brake blocks before.

Wanderer

"Brake Blocks" was common terminology, before "roadies" came into existence....... All that really matters, is that the poster gets his/her point across.

Maybe we should have a "Proper English & Terminology" sig for those that want to debate that stuff.

merlinextraligh

The term arose back in the day when the pads were just pretty much basic rectangles blocks of rubber:



You can see why pads like that could be described as blocks

gsteinb

I don't think I was debating anything. I posted the term and a question mark, as I pointed out I never heard it before. If that's debate to you I think you're a bit misguided and simply pitching for an argument that doesn't exisit

billyymc

Try these: https://www.pricepoint.com/detail/111...Brake-Pads.htm

I know it says MTB pads, but I use them on my TriCross and they work really well. Even so, you need to clean your rims once in a while.

ptle

Those are cantilever type brake pads. Even though the OP mentions cantilever brakes, his picture shows road brakes.

If I'm not mistaken, the Dolce uses road brakes. I don't think there are mounts for cantilever brakes.

https://www.bikepedia.com/QuickBike/B...9256&Type=bike

Menel

Just get some Ultegra pads.
I replaced mine at the beginning of the year, Ultegra Pads from REI were $11 for a set. Far from costly...
And my brake arms themselves are some Tektro something another, I'm pretty sure they're not special, but stops my bike real good.

Psimet2001 

Common for many types of brake pads - BTW g - the other English speaking sections of the world use a lot of different terminology for cycling products - brake block continues to be one. Tyres instead of tires, rear mech instead of derail, etc... They are used to Americans acting all ethnocentric about these small variations and occasionally react like Canadians do - as though they have a big chip on their American hating shoulder....

Dig out the aluminum bits and de-glaze the pads with some sandpaper. When getting new pads go with something someone recommends for your locale and conditions. In general I recommend Kool Stop Salmons for alloy rims in our area.

Wanderer

Just get some Kool Stop Salmon pads, with the Kool Stop pad holders. After that, replacement is easy and cheap - just slide in new pads.

And, the Kool Stop Salmons, will really improve your braking.....

colombo357

I think he meant break blox.

GuineaFowl

Nicely picked up on ptle - I did indeed intend to write callipers not cantilevers. I should have also mentioned that all of this damage occured on one single 20 mile ride as that would give you a better idea of just why I think this is abnormal. It seems to only happen if we need to brake really hard as happened on my last ride. I am teh fail of the century today.

Apologies again to gsteinb for biting at him. Today I learned that a person's post count does not mean that person knows that pads and blocks are interchangeable terms for the same parts of a bike, however, I am sure his knowledge would dwarf mine on most other aspects of this sport!

Cheers to all for the suggestions. I'll try and remember to come back and update as to what I decided.

coasting 

something similar happened to my shimano 105 brakes. i had to dig out more than one lumps of aluminium from them and there were a couple of very deep score lines on the rim.

RaleighComp

Wet weather or puddles often exacerbates this problem. Road grit thrown up with the water gets caught between the pad and the rim which then micro-gouges the rim and the gouged out aluminum bits become embedded in the pad only to become semi-permanent implements of further destruction.

ryder0182

Had the same problem with the stock pads on my Bianchi, just swapped them out with some DA pads and haven't thought about it since.

e2py

+1

A cheap set of dental tools is great for picking out these bits until you get a better set of pads. I use a diluted solution of SimpleGreen on a worn out ScotchBrite pad to gently clean off the braking surface of the rims. Good pads on clean rims brake better and, because we're on BF, they look better. Good luck.

DScott

Embedded bits or no, brakes either work well as is, or they don't. The embedded bits don't change that. They can wreak havoc on the rims, but they'll still stop the bike.

My Campy record pads pick those up all the time, and they're decent brakes. Clean them out during your regular maintenance, and move on. Or stop, as needed.