Please explain why road bikes don't have disc brakes
#101
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(along with frame clearance of course)
#102
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What in god's name are you talking about. It's the frame design that allows wide tires. I mean, unless you're on a fat bike, rims are not that wide. If you haven't noticed, various forms of rim brakes have ranges of adjustability with respect to opening for rim & tire clearance.
And the older single-pivot or cantilever brakes that allow better clearance shouldn't even be in this discussion. Their braking ability is not remotely comparable.
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#104
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Running 25mm wide tires on 20.1mm wide Shimano rims, I have to loosen the cable significantly just to open the brakes wide enough to clear. These are newer Shimano dual-pivot calipers. If I wanted to run 28mm tires, I'd have to deflate the tire.
And the older single-pivot or cantilever brakes that allow better clearance shouldn't even be in this discussion. Their braking ability is not remotely comparable.
And the older single-pivot or cantilever brakes that allow better clearance shouldn't even be in this discussion. Their braking ability is not remotely comparable.
#105
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Not trying to be argumentative, I probably misunderstood exactly what you meant but it's still not really the brakes that allow wider tires on bikes in general. Look at 90s mtbs for example... If this is specific to weight weenie bikes that top out around 23-25mm tire clearance then you may be right. Anyway, on my roadie I have 2017 Shimano 105 brakes, standard - not some weird long reach brakes or anything, and I can easily fit a 28mm tire in and out when the quick release knob is opened. I like modulation when slowing down - not a sudden jerk and easy wheel lock up when descending, so I keep my pads pretty far from the rim. Further than what I see on other bikes. I can still emergency stop just fine... It seems the fixation on keep pads super duper close to the rim is a hindrance, and brake pad material will have more of an impact on stopping power. Controlling modulation via cable tightness is going to impact wheel removal clearance significantly. I'm not sure why other rim brake designs should be excluded form this discussions since they work just fine and goes back to the OP question.
#106
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Older brake setups usually aren't. Some modern setups can be. Better pad compounds, better adjustment enabling more mechanical advantage at the brake lever, makes a big difference. Heck, setting up v-brakes for decent power is effortless.
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I might just buy a disk braked road-type bike in the future, who knows. Especially if I can get an all arounder for car traveling - one that will take 40 or so mm tires and a second set of wheels with, say 23s or 25's for strict road use. A bike that is light enough to be a fun roadie as opposed to a make do roadie.
Right now I have such a bike, or nearly so (I think it might take 40mm, but not sure... I have 32's on there now and it has a lot of additional clearance.). It has V brakes which will throw me over the handlebars in any weather or conditions I care to ride in. It will take every set of 700c wheels I have in the garage ranging from said large tires to my super light rims with 23s. Very, very versitile, and it will totally swap wheels with my wife's bike.
If we decide we need disks for the all arounders, and we can each have a second set of wheels that are totally compatable with each other and a breeze to swap out, why not. Right now, my inclination is to just get another V brake bike for my wife and call it good, since we have plenty of wheels for heavy and light tires for both.
Right now I have such a bike, or nearly so (I think it might take 40mm, but not sure... I have 32's on there now and it has a lot of additional clearance.). It has V brakes which will throw me over the handlebars in any weather or conditions I care to ride in. It will take every set of 700c wheels I have in the garage ranging from said large tires to my super light rims with 23s. Very, very versitile, and it will totally swap wheels with my wife's bike.
If we decide we need disks for the all arounders, and we can each have a second set of wheels that are totally compatable with each other and a breeze to swap out, why not. Right now, my inclination is to just get another V brake bike for my wife and call it good, since we have plenty of wheels for heavy and light tires for both.
#108
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Why don't cars have air brakes? Oh...because it would be ridiculous over-kill? (Hint, hint....)
#109
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I'm sure you're not silly enough to think that...or you simply don't own one.
#110
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Could it just possibly be that these people who complain about the performance of older braking systems simply don't know how to set up older braking systems.
#112
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Cantis are by far the most difficult to deal with, especially with somewhat peculiar pad shapes (Kool stop). Only good for rear brakes and the only sensible all road rim brake you can use with brifters.
Vee brakes don't work with brifters so they're out (tried mini vees with travel agents, not a good idea) and vee brakes, while powerful, lack modulation ie. are grabby.
Caliper brakes are easiest to deal with most of the time but they force you up against an unpleasant choice. If you want braking power you need to use a small tire so gravel and all road's out (and I don't mean smooth groomed hard packed quasi asphalt gravel, I mean rocks the size of your big toe, loose sand and washboards). If you want tire clearance you also lose all braking power and with big rubber you kinda want more power as well.
And then there are discs which are, not counting duds, fire and forget, immune to tire size consideration, have adjustable braking power (disc size and pad material), have better modulation than any rim brake (ie. have tons of power, yet are not grabby) and best of all, don't wear down rims.
A disc can be a dud as in a hydro leaks or a mech... well, all mech disc issues are fixable. But if you don't have a dud you slap them on once and you never touch the caliper position again (if you do it correctly the first time). Like all parts on a bicycle, discs too require maintenance so you need to swap pads, bleed or swap cables or housings every few years or so.
Also rim wear may not be an issue in sunny california but live where I live and you'll be swapping rims every couple of years. Rain and slush are bad for rims.
Also, I like discs because they give me freedom in my setup. I can use brifters and 37mm tires but don't have to deal with the cancer that is cantis (much, my rear is canti, front is disc but I very rarely use the rear brake, it's more of a backup). If you haven't ridden good 37mm tires, you should. A little slower (aerodynamically) than 25's or 28's but a lot more comfy, more puncture resistant and best of all, allow you to ride almost any road imaginable
#114
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Air brakes use compressed air as an actuating booster. They can be drum or discs ... but when trying to stop a semi-trailer (42 tons loaded) you simply cannot get enough power out of a human thigh.
Most road cars use hydraulic brakes, but when weight and space is not an issue, but reliability and simplicity is ... compressed air (stored at each wheel) gives the kind of power a 42-ton load needs ... and a leak doesn't dump 32 gallons of highly toxic and very expensive liquid onto the road.
Bikes don't need that much stopping power ... well, mine don't. Maybe you ride a 40-ton bike, I don't know.
Drum brakes were replaced by discs on cars because discs gave more swept area for much less weight and were easier to cool and replace. They were developed for racing, so all those things mattered.
Also, there is a limit on maximum pad size on internal-expansion drums ... of course there is a limit for disc size as well but the disc can be almost as big as the inside of the wheel ... and more pistons for more power, and pads longer than are needed.
Thing there is the brakes cars were using (drums at the time) couldn't handle the increased speed that cars were achieving. Discs provided more braking power----When more power was needed.
Not really a situation where bikes Needed more braking power .... once you can lock the tires, you have passed maximum usable braking force
In fact ... some folks might think Stucky was saying Discs provide more power and weight and complexity than are needed for a bike .... a Little different that the interpretation to made.
Just an alternate view.
#115
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OK so you are fairly new at this. I have about 25 years on you.
True
Caliper brakes are not safe for serious off road IMO
No question a disc brake is superior but that doesn't mean that the other types set up properly are not suitable FOR A BICYCLE
Umm, no, where I live we had 12 feet of snow this winter. I don't go to Cali the DOT is hard on Canadian truck drivers. . . OK all truck drivers.
Yes disc brakes are very easy to set up, makes the inept seem like they are doing a great job, everyone get a participation medal.
Plus at the temperatures brakes on a semi get to, it would boil brake fluid.
Nail hit squarely on head
Any given braking system suited to the purpose and application to which it was designed regardless of the type of vehicle, set up properly and in good mechanical condition will give more than adequate braking power.
No question a disc brake is superior but that doesn't mean that the other types set up properly are not suitable FOR A BICYCLE
Also, I like discs because they give me freedom in my setup. I can use brifters and 37mm tires but don't have to deal with the cancer that is cantis (much, my rear is canti, front is disc but I very rarely use the rear brake, it's more of a backup). If you haven't ridden good 37mm tires, you should. A little slower (aerodynamically) than 25's or 28's but a lot more comfy, more puncture resistant and best of all, allow you to ride almost any road imaginable
Most road cars use hydraulic brakes, but when weight and space is not an issue, but reliability and simplicity is ... compressed air (stored at each wheel) gives the kind of power a 42-ton load needs ... and a leak doesn't dump 32 gallons of highly toxic and very expensive liquid onto the road.
Nail hit squarely on head
Any given braking system suited to the purpose and application to which it was designed regardless of the type of vehicle, set up properly and in good mechanical condition will give more than adequate braking power.
#116
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That's nice but that only tells me you're probably better at older tech while we're probably pretty equal at more modern stuff.
I'm not talking about offroad, I'm talking bad roads to gravel where people usually prefer wider tires. The other rim brake option for brifters is cantilever. So the option one has is either
A) big tires and crappy braking or
B) small tires with ok braking (the power is there with calipers, but in my experience all powerful rim brakes also tend to be grabby as heck)
Or you can use disc and get great braking and wider tires. Now that wide tires are proven to be fast, there really is no more reasons to use narrow ones except on track and when chasing the absolute fastest TT times (not because of rolling resistance but aero)
Bicycle is a pretty broad term and depending what you want to do with it the issues I've mentioned above may or may not apply.
But you live in continental climates right? Cold in itself is not harmful for rims. What we have is slush, sand, road grit, water and salt, all of which combined make a pretty great sanding compound.
Don't take this the wrong way but I have a feeling you might be among the majority who does it wrong. Do you follow the Hope tech method or avid method? 'Cause one of them is wrong. I'll let you ponder which.
And while rim brake users tend to brag about how they can easily throw themselves over the bars, I've always thought that one would want to avoid going over the bars. Putting a steel rod in your front wheel is the most powerful brake out there but you can't really call that a good brake. Discs offer modulation, rim brakes are either weak or grabby. Or at least that has been my experience.
Caliper brakes are not safe for serious off road IMO
A) big tires and crappy braking or
B) small tires with ok braking (the power is there with calipers, but in my experience all powerful rim brakes also tend to be grabby as heck)
Or you can use disc and get great braking and wider tires. Now that wide tires are proven to be fast, there really is no more reasons to use narrow ones except on track and when chasing the absolute fastest TT times (not because of rolling resistance but aero)
No question a disc brake is superior but that doesn't mean that the other types set up properly are not suitable FOR A BICYCLE
Umm, no, where I live we had 12 feet of snow this winter. I don't go to Cali the DOT is hard on Canadian truck drivers. . . OK all truck drivers.
Yes disc brakes are very easy to set up, makes the inept seem like they are doing a great job, everyone get a participation medal.
Any given braking system suited to the purpose and application to which it was designed regardless of the type of vehicle, set up properly and in good mechanical condition will give more than adequate braking power.
#117
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Disc brakes are what allow big tires. With the focus on wider tires across the spectrum, you're rim brakes put severe and un-necessary constraints on brake geometry.
If you're running 23mm wide tires on 23mm wide rims then modern dual-pivot calipers are awesome. If you want 28mm tires on standard rims, you basically need disc brakes or it's a major headache.
If you're running 23mm wide tires on 23mm wide rims then modern dual-pivot calipers are awesome. If you want 28mm tires on standard rims, you basically need disc brakes or it's a major headache.
There are a bunch of rim brakes you can buy that will allow up to 42mm tire.
The problem has never been the brake, it's that bike manufactures didn't design a bike that could fit the tire. The fork and brake bridges were too low.
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What I have is The Best. Always.
I have bikes with different braking systems. The Best is whichever one I am riding.
And I mean The Best---the universal,same for everyone, no exceptions, can't get anything anywhere any better ever--The Best.
If I ride a fixie with no brakes--No brakes are The Best brakes.
What I have is The Best. Always.
Five pages when the matter is so simple.
I have bikes with different braking systems. The Best is whichever one I am riding.
And I mean The Best---the universal,same for everyone, no exceptions, can't get anything anywhere any better ever--The Best.
If I ride a fixie with no brakes--No brakes are The Best brakes.
What I have is The Best. Always.
Five pages when the matter is so simple.
#119
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Doesn't have to be Specialized...
22 of 2017's hottest disc-brake-equipped road bikes ? the bikes in the vanguard of the disc revolution | road.cc
22 of 2017's hottest disc-brake-equipped road bikes ? the bikes in the vanguard of the disc revolution | road.cc
#120
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It is so facinating to watch road bikers re-hash the same disc-rim debate that mountain bikers went through 15 or so years ago. Pretty much all the same arguments as well.
#121
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Umm sounds like off road to me.
And while rim brake users tend to brag about how they can easily throw themselves over the bars, I've always thought that one would want to avoid going over the bars. Putting a steel rod in your front wheel is the most powerful brake out there but you can't really call that a good brake. Discs offer modulation, rim brakes are either weak or grabby. Or at least that has been my experience.
I think it is wonderful that you can set up disc brakes you are the bestest on the planet but . . .
What I have is The Best. Always.
I have bikes with different braking systems. The Best is whichever one I am riding.
And I mean The Best---the universal,same for everyone, no exceptions, can't get anything anywhere any better ever--The Best.
If I ride a fixie with no brakes--No brakes are The Best brakes.
What I have is The Best. Always.
Five pages when the matter is so simple.
I have bikes with different braking systems. The Best is whichever one I am riding.
And I mean The Best---the universal,same for everyone, no exceptions, can't get anything anywhere any better ever--The Best.
If I ride a fixie with no brakes--No brakes are The Best brakes.
What I have is The Best. Always.
Five pages when the matter is so simple.
#122
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I have brand new Spyre mech discs ... so far, not impressed. Good stopping in the wet, but not particularly better than good rim brakes. I hear they need to bed in before they hit full power. if this is as good as they get ... go hydro or stay rim. Mech discs are simple but not sure they are anything but heavier.
Also, compressionless brake housing is a must for mechanical disc ESPECIALLY for road bike brakes.
#123
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What I have is The Best. Always.
I have bikes with different braking systems. The Best is whichever one I am riding.
And I mean The Best---the universal,same for everyone, no exceptions, can't get anything anywhere any better ever--The Best.
If I ride a fixie with no brakes--No brakes are The Best brakes.
What I have is The Best. Always.
Five pages when the matter is so simple.
I have bikes with different braking systems. The Best is whichever one I am riding.
And I mean The Best---the universal,same for everyone, no exceptions, can't get anything anywhere any better ever--The Best.
If I ride a fixie with no brakes--No brakes are The Best brakes.
What I have is The Best. Always.
Five pages when the matter is so simple.
#124
Banned
All discs need to bed in. It takes a few long hard stops to get there. With mountain biking that usually happens pretty fast, but with a road bike you may need to be more intentional about doing it.
Also, compressionless brake housing is a must for mechanical disc ESPECIALLY for road bike brakes.
Also, compressionless brake housing is a must for mechanical disc ESPECIALLY for road bike brakes.
Opposite land.. new disc brakes , replaced pads, need a few easy modulated stops to bed in pad to disc,
later you can do your aggressive down hill stops.. after bedding them in.
....
#125
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Sure you don't have to do hard stops to get full bedding in, but it is going to take longer.
Last edited by Kapusta; 06-19-17 at 10:49 AM.