Best Brake Blocks for rim brakes

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mnichols
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Re: Best Brake Blocks for rim brakes

Post by mnichols »

I do clean the rims after each ride - I just wash spray them with a bit of Poundland Bike Wash, rinse them off and then dry them with a rag - should i be doing more?

The brakes are toed in, although I must admit I haven't checked the arc

Also need to admit to not cleaning the brake pads - do you have to remove them to do this, or do you take the wheel out and inspect them for shards?
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mjr
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Re: Best Brake Blocks for rim brakes

Post by mjr »

Sometimes opening the quick release and pushing the caliper to one side then the other is enough to inspect and clean the pads, so dropping the wheel out should be plenty.

As far as I know, typical bike wash is fine for aluminum rims.
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elPedro666
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Re: RE: Re: Best Brake Blocks for rim brakes

Post by elPedro666 »

JohnW wrote:the little bits of alu shards that come off the rims don't help with braking efficiency - especially in the wet.



Nor with rim life!
Knew it would've been said and I'd missed it in the skim-read, apologies.

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JohnW
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Re: Best Brake Blocks for rim brakes

Post by JohnW »

For me, removing the brake blocks for inspection and cleaning is a much simpler and easier job that taking the wheels off - especially the back wheel and especially if you've got gears.

Cleaning the surface of the block is one thing - removing the shards is another! - sometimes they can be embedded and hidden and sometimes I need a tool to remove them.

We all develope our own best system.
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foxyrider
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Re: Best Brake Blocks for rim brakes

Post by foxyrider »

mercalia wrote:rim brakes arent as good as discs, you will have to learn to live with them and ride differently?

I wouldnt trust any rim brakes down Porlock, I would walk: not what you want to hear :cry: You are mad to try :roll: just as mad to cycle up it :lol:

I just dont understand those people that think that bikes are suitable for any terrain and any place & any road. sign of craziness...


Feeding the brake paranoia!

Personally I wouldn't trust discs for anything where I might be over twenty mph! And a steep downhill like Porlock - yes i'd be walking!

My parents rode Porlock et al back in the 50's, they had neither hundreds of gears, lightweight (by today's standards) bikes or disc brakes. What they did was ride within their and their bikes capabilities, if that meant stopping to let rims cool - well I've done that more than once!
Convention? what's that then?
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Sweep
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Re: Best Brake Blocks for rim brakes

Post by Sweep »

foxyrider wrote:
mercalia wrote:
Personally I wouldn't trust discs for anything where I might be over twenty mph!


Care to elaborate?

declaration - I don't have any disc brakes, probably won't be getting any.

But still interested in your statement.
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reohn2
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Re: Best Brake Blocks for rim brakes

Post by reohn2 »

foxyrider wrote:
Feeding the brake paranoia!

Apparently you are :?

Personally I wouldn't trust discs for anything where I might be over twenty mph! And a steep downhill like Porlock - yes i'd be walking!

My parents rode Porlock et al back in the 50's, they had neither hundreds of gears, lightweight (by today's standards) bikes or disc brakes. What they did was ride within their and their bikes capabilities, if that meant stopping to let rims cool - well I've done that more than once!

We've toured on our tandem with discs(BB7's 203mm rotors) down some pretty steep 20%+ hills without problems just some nice bluey and straw coloured rotors on one occasional when the was three or four steep descents in a quick succession,I've ridden the same hills solo with discs(BB7's 160mm rotors) similarly without issues and frequently have ridden at 40+mph on the same bikes stopping is never a problem,wet or dry.
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To the OP I'd recommend BBB techstop pads for god dry and wet weather braking,they're a little softer than other pads so wear out quicker but they don't pick up alu shards at all IME and are far more rim friendly than other pads I've tried,and I've tried many.
Second choice would be Koolstop Salmons,not quite as good in the wet as BBB's,but they do last longer but do pick up the occassional alu shard or two especially in wet weather.

BTW I'm convinced it's grit from wet roads that's picked up by some pads more than others,which then begins to slice of bits of alu rim whilstt pushing the grit further into the pad and the alu picking up more alu every time the brake is applied.
Strangely the softer BBB pads don't pick up grit though logic says they'd pick up more :?
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elPedro666
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Re: Best Brake Blocks for rim brakes

Post by elPedro666 »

Amazing how often experience trumps logic!

Haven't tried BBB, will give them a go next time...

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RickH
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Re: Best Brake Blocks for rim brakes

Post by RickH »

reohn2 wrote:BTW I'm convinced it's grit from wet roads that's picked up by some pads more than others,which then begins to slice of bits of alu rim whilstt pushing the grit further into the pad and the alu picking up more alu every time the brake is applied.
Strangely the softer BBB pads don't pick up grit though logic says they'd pick up more :?

I think the grit may also vary depending on local geology.

Up on the hills here there is, at least in part, millstone grit (used to make, unsurprisingly, millstones. Millstones made in Whittle-le-Woods, south of Preston were shipped all over the world via the Leeds Liverpool Canal). Coming down steep West Pennine hills in the wet running Mavic Open Pros & the original Shimano blocks you could practically see the front rim wearing (plus the associated grinding noises & grey "rim soup" running down the frame)! I reckoned a lifespan about 4000 miles out of an Open Pro round here, although that did improve somewhat after I switched to different pads (but I've forgotten what off the top of my head).
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Brucey
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Re: Best Brake Blocks for rim brakes

Post by Brucey »

If you have grit or whatever embedded in a brake block you can usually hear it because the sound is very different from normal.

A tip; if you hear this noise, try going on and off the brakes a few times, eg 2s on, 1s off, 1s on etc. Very often the embedded crud will loosen itself in the brake block (in part though melting I think) and can come out when the brakes are reapplied. IME this won't happen if you just drag the brakes. I also think that slots in the brake block can help both to clear debris as well as help to prevent it from becoming embedded in the first place.

Note that with new rims (with machined braking surfaces) it is odds-on that you will get some swarf coming off the rims and getting into the brake blocks. This means that almost any replacement pad is likely to do better than an original one

Another tip; it is a good idea to alternate between brakes (any brakes) during a descent; this gives you one cool brake ready at all times. If both rim brakes get hot enough, the brake blocks will start to wear about x10 faster and there will be more noise and less retardation than normal. This situation is to be avoided because when this happens you are never that far away from the heat getting into the tyres and that can cause a whole new range of problems. When the hill gets so steep that you must use both brakes to even hold your (modest) speed, you have three choices;

1) carry on as you are and (almost inevitably) overheat both brakes
2) stop and let the brakes cool
3) let the bike run for a few seconds to let the brakes cool.

Option 3 isn't really an option on a steep and twisty descent. Even on a typical Alpine descent (with long straights between hairpins) it takes guts and commitment because you might soon be approaching the next corner at 50mph or so if you do this. In this situation failure of either brake will mean an appointment in hospital or a cosy new home in a wooden box.

It is as well to note that the best way to overheat brakes is to ride slowly and drag them all the way down the hill; cooling is less efficient at low speeds and the net work done by the brakes is also greater; at speed the aero drag dissipates a lot of energy which then isn't dumped into the brakes. This effect is not insubstantial; a lithe racer needs ~0.5kW to do 30mph and a touring rider (with panniers, sat up etc) will need half as much again or more at similar speeds.

Dragging brakes slowly down even a 500' descent will overheat very many disc brakes (discs turn blue, organic pads start to smoke etc etc) and a similar 1000' descent is very likely to melt the plastic parts on the caliper body and/or boil the fluid in quite a few hydraulic systems. IME to avoid overheating issues with disc brakes is often just as difficult as with rim brakes.

You will hear claims that 'brand-X hydraulic brakes' were tested by having a professional bike rider drag the brakes down some descent or other and you may assume that this means they will work for you in the same way when touring.

Don't believe it.

Mr Professional bike rider may be twice as brave, go twice as fast, weigh half as much (as you and your touring bike), and furthermore be riding a descent that may be 1/3 the gradient of some of the more vicious UK descents.

At twice the speed the cooling on the brakes is up to four times more effective (and at least twice as good in relation the rate of heat generation), and the other factors may mean that you are dumping heat into the brakes up to six times faster.

cheers
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MikeDee
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Re: Best Brake Blocks for rim brakes

Post by MikeDee »

I've used Shimano, Kool Stop, and Tektro pads. Kool Stops are the best in terms of needing the lightest hand force at the lever. Shimanos are not quite as good in term of braking power, but wear longer and squeal less. Tektros have poor braking power. I did a tour last year in Humboldt County, CA, which had very steep and poor roads including dirt, so I had to do a lot of braking. The Kool Stop pads were excellent.
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RickH
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Re: Best Brake Blocks for rim brakes

Post by RickH »

Brucey wrote:...Even on a typical Alpine descent (with long straights between hairpins) it takes guts and commitment because you might soon be approaching the next corner at 50mph or so if you do this. In this situation failure of either brake will mean an appointment in hospital or a cosy new home in a wooden box.

Of course you don't have to let the bike run ever faster until you get to a corner. You can always brake for a few seconds to scrub off a bit of speed once you reach the edge of your comfort zone. Rinse & repeat... but look ahead for signs of a corner looming to try to avoid going straight into "braking for the corner" without a gap to let things cool after "scrub your speed" braking &, if in doubt about whether your brakes are overcooking, err on the side of caution and give you & the brakes a break.

On steep twisty stuff it is maybe an advantage on a tandem that, although the overall weight is higher, the rear brake is pretty much as good as the front so it is easier to keep things in check by alternating brakes where you might find it hard to do so on a solo. Having said that, even on the worst descents there are usually spots where there is somewhere to at least let one brake off at a time for a few seconds.
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foxyrider
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Re: Best Brake Blocks for rim brakes

Post by foxyrider »

Sweep wrote:
foxyrider wrote:
mercalia wrote:
Personally I wouldn't trust discs for anything where I might be over twenty mph!


Care to elaborate?

declaration - I don't have any disc brakes, probably won't be getting any.

But still interested in your statement.


I ride in the Peak District for a lot of the time, long 10km descents, shorter steeper stuff, twisty bumpy lanes. I have a CX bike with discs that covers a lot of miles in that terrain alongside my various rim braked machines. The only bike I have brake problems with is the CX which reduces my confidence in it.

Compared to all the hype I get through more pads than rim blocks/per mile, I spend more time adjusting brakes on it and without dragging the brakes often get to 'burnt clutch' smells from overheating pads and the quickly wearing and heat warping rotors. If I could i'd swap the bike to rim brakes tomorrow.

Even on the flat they are no better than adequate - I even went through a set of pads over three weeks in Holland and Frisia!

Maybe my expectations are higher than others on here, maybe I descend faster, ride closer to the limits but this is my experience.

By comparison i've never had significant fade on rim braking even on long technical alpine descents, I am much more confident that they'll work when I need them to.

Others may have different experience and comparing a tandem to a solo isn't exactly relevant as different dynamics come into play - I have ridden and raced the things before even DP brakes were an option!
Convention? what's that then?
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Keezx
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Re: Best Brake Blocks for rim brakes

Post by Keezx »

mnichols wrote:I do clean the rims after each ride - I just wash spray them with a bit of Poundland Bike Wash, rinse them off and then dry them with a rag - should i be doing more?



Water+Soap is IMO pretty useless for cleaning rims and pads.
I always use brake cleaner (which is likely a strong sovent) on a cloth and take the wheel out to get good access to the pads.
1 Wipe and the cloth is black , proves that it's working.
Like Brucey said, you can HEAR when it's necessary.
Brucey
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Re: Best Brake Blocks for rim brakes

Post by Brucey »

quite a lot of 'bike wash' sprays are (I think) a strong acid or alkali. They are usually quite effective at cleaning rims, and will happily tarnish many forms of finish on aluminium parts if the cleaner isn't rinsed off.

However given the choice of cleaning rims and cleaning brake blocks, I'd choose the latter in most cases; IME the worst rim wear happens when grit and/or swarf is trapped in the brake block. In many instances it is important to regularly check the brake blocks and to pry out any rubbish of this sort.

cheers
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