General Cycling Discussion - Disc vs. Pull Brakes?

I'm a city commuter and love my Jamis Coda Comp, but have a chance to upgrade to a Jamis Coda Elite. It's an '08 priced at two-thirds of the orig. MSRP. A little better components- main difference is the disc brakes on the Elite. Pros/Cons, anyone? Easy to replace or repair? Cost effective? Stop on a dime?
hmmm, I am happy now w/ Comp but, could I be happier?

disc brakes are way better at stopping on bad weather.
it makes less noise than the regular rim brakes.
the only thing you change are the brake pads, which you wont need to do for a very long time.

rotor, if you ever change your rotor (disc) is only if you get a major accident, else those things will outlast 100+ times the brake pads, i can't ever see the day rotors ever getting worn out, like the ones on cars. LOL :D

The disc brakes would be heavier. Disc brakes fall into 2 categories: mechanical and hydraulic. The mechanical ones function like regular bike brakes in that they are actuated by a cable. The hydraulic ones function like your car in that they are actuated by fluid flowing through a tube to drive a piston. From all I know, disc brakes on bikes shine in bad weather. They work much better than regular brakes in the wet and when its muddy. This is why they are popular on off road and cyclocross bikes.

The only con for a disc brake is the weight. Mechanical ones mey be easier\cheaper to maintain as opposed to hydraulic ones.

I have Avid BB7 road disks on my primary bike. I have 6500 happy miles and two winters on them. I like them.

I won't ever own another commuting rig without disks. They stop in rain and snow just the same as when dry. (Caveat: Within the adhesion limits of the tires, of course.)

The weight penalty overall is a couple of pounds.

The other potential issue is hubs. Rear hubs for disk brakes and 130mm (road) spacing are rare as hen's teeth. It limits the choice of third-party wheels.

Pads are cheap enough given how long they last. Keeping them adjusted is easy. I had some corrosion issues in the rear one towards the end of the second winter. A little TLC was all it took.

Given a choice of Good Hydraulic Disc brakes over the best Rim brakes around and I would choose discs.

But a poor set of cable operated discs- will often not give as good a braking effect as a good rim brake.

I have around 6 bikes I regularly ride. Only one has disc brakes- because it needs them. That is an offroad Tandem that is used agressively. Before fitting the disc brakes- it had Avid "V" brakes fitted and they were adequate for all my local rides up on the hills. Only problem with them was that after about 60 miles- The pilot ran out of handpower to get them to work fully. That does not happen with disc brakes.

I'm a city commuter and love my Jamis Coda Comp, but have a chance to upgrade to a Jamis Coda Elite. It's an '08 priced at two-thirds of the orig. MSRP. A little better components- main difference is the disc brakes on the Elite. Pros/Cons, anyone? Easy to replace or repair? Cost effective? Stop on a dime?
hmmm, I am happy now w/ Comp but, could I be happier?

The elite actually comes with disc brakes that are actually easy to adjust and don't suck (BB7's). If you like the bike, want to try something different go ahead and buy it.

disc brakes are way better at stopping on bad weather. it makes less noise than the regular rim brakes.:D

Ditto. Once you experience the stopping confidence that disc brakes provide in wet/sloppy conditions, you will never want to ride a bike without them.

Disk brakes will keep your rim sidewalls pristine.

Disk brakes will keep your rim sidewalls pristine.

Non-issue with disk-specific hoops--no machined and polished surface to worry about. There's no way to run rim brakes on my wheels.

The process of adjusting the mechanical discs on two of my bikes was faster and produced better results than I've had with the cantis, V-brakes, or road calipers on my other bikes.

About the only con I can think of for discs besides weight is that they can make your bike a more desirable target for thieves.

About the only con I can think of for discs besides weight is that they can make your bike a more desirable target for thieves.

word. get it? word? *sigh* Great point, though. My road bike as BB7's and got more attention from on onlooker on the rack than my buddy's pricier and better overall outfitted Giant (his is a little older and the paint scheme makes it seem a bit dated compared to my schweet looking lower level component outfitted schwinn.)

The process of adjusting the mechanical discs on two of my bikes was faster and produced better results than I've had with the cantis, V-brakes, or road calipers on my other bikes.

Very true. Avid BB7's are pretty much toolless to adjust if they've been setup properly on installation. On the flip side, I've got a cheapy disc brake on my lower end MTB that is a bugger to get right and requires an allen wrench.

Very true. Avid BB7's are pretty much toolless to adjust if they've been setup properly on installation. On the flip side, I've got a cheapy disc brake on my lower end MTB that is a bugger to get right and requires an allen wrench.

Hmm; does the cheapy brake respond to a BB5-like adjustment procedure? As in, unhook the cable, loosen the caliper mounting bolts, crank down the pad against the rotor (at least the BB5 has one adjustable pad), then retighten the bolts and reconnect the cable.

One of my bikes has BB7s, but another had BB5s, and before I sold it I took five minutes to set them up just right.

About the only con I can think of for discs besides weight is that they can make your bike a more desirable target for thieves.

FYI,my Coda Elite was 24lbs 4oz,not heavy at all. My Trek Portland is only 22lbs 14oz. Disc weight is only an issue if you're road racing.

And I've never understood the whole 'discs make thief magnets' thing. If anything,a 700cc disc bike is going to be slightly less desirable due to the fact that they are less common and will stick out.

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And I've never understood the whole 'discs make thief magnets' thing. If anything,a 700cc disc bike is going to be slightly less desirable due to the fact that they are less common and will stick out.

Wrong

FYI,my Coda Elite was 24lbs 4oz,not heavy at all. My Trek Portland is only 22lbs 14oz. Disc weight is only an issue if you're road racing.

And I've never understood the whole 'discs make thief magnets' thing. If anything,a 700cc disc bike is going to be slightly less desirable due to the fact that they are less common and will stick out.


criminals that steal bikes dont think "which one is gona be easier to resell" they just steal the one that looks the fanciest.

FYI,my Coda Elite was 24lbs 4oz,not heavy at all. My Trek Portland is only 22lbs 14oz. Disc weight is only an issue if you're road racing.

And I've never understood the whole 'discs make thief magnets' thing. If anything,a 700cc disc bike is going to be slightly less desirable due to the fact that they are less common and will stick out.

My point was not that any bike with discs is heavy, just that discs are heavy compared to rim brakes. Personally, I also feel they're well worth the weight gain. Being able to stop, and perhaps more importantly, to have full control of braking modulation outweighs the paltry few ounces given up to rim brakes. I can't feel the ounces when riding, I can certainly feel superior braking power.

Perhaps the only other downside to discs is the learning curve and specialty tools needed to service them. They require a frame with the correct tabs, special hubs and compatible levers...or even hydraulic fluid-filled lines. Hydraulics require a bleed kit for service (not typically included), all of them require very precise setup alignment to maximize power and lengthen pad life. Rotors may require truing in time, a process very difficult to get right without the jig and tools. Care must be taken to avoid squeezing hydraulic levers when the wheel is removed. Most manufacturers suggest flushing and replacing fluid once a season. Master and slave cylinders will inevitably require rebuilding in time, possibly after replacement parts are no longer available. Again, compared to relatively simple and proven rim brakes, these could all be considerable downsides to a rider wishing for the simplest cycling experience with the least amount of maintenance possible.

Considering that disc brakes drive up the price of any bicycle, yes...they are a very easy to spot sign to a thief that the bike is more valuable than average. You were attracted to them, so would any other potential buyer be looking at a stolen bike. Thieves aren't idiots. They steal what sells quickly.

Perhaps the only other downside to discs is the learning curve and specialty tools needed to service them.

Discs are easier to adjust than rim brakes. Disc pads go in and out,that's it. You don't have to adjust height,angle,or toe them in.


Rotors may require truing in time, a process very difficult to get right without the jig and tools.

Meh? The rotor on my polo bike got warped(mallet strike). I tweaked it straight with a Park Tools tuning fork jobber. You just look down at the rotor between the pads and then bend it accordingly. QED,and it's perfect.

Meh? The rotor on my polo bike got warped(mallet strike). I tweaked it straight with a Park Tools tuning fork jobber. You just look down at the rotor between the pads and then bend it accordingly. QED,and it's perfect.

Warped rotors don't render the brake useless should you be on the road/trail with one. They're cheap enough to replace as well. Non-OE rotors can be had for under $10 if you're in a budget crunch.

Discs are easier to adjust than rim brakes. Disc pads go in and out,that's it. You don't have to adjust height,angle,or toe them in.

Unless you're setting them up for the first time and have alignment issues. Disc tab facing tools are not something a home mechanic is likely to have. If you include hydraulic discs, rebuilding them can also require specialty tools.


Meh? The rotor on my polo bike got warped(mallet strike). I tweaked it straight with a Park Tools tuning fork jobber. You just look down at the rotor between the pads and then bend it accordingly. QED,and it's perfect.
It's "perfect" unless you throw it on a dial gauge jig. Granted, I'm a professional mechanic and my standards are required to be higher.

I never adjusted disc brakes before, and it took me five minutes to do both the front and rear on a set of BB5s that were on a bike I was selling.

Okay, I'm lying -- including putting the bike in a stand, it took six minutes. They ended up even better than they were when I got the bike new from the shop. So much better, actually, that I almost wanted to keep the bike instead.

I agree with the other posts already that mention how disc brakes still work well in the rain and snow. I've heard people make claims that their Koolstop Salmon brake pads worked about as well in the rain as in the dry and as well as disc brakes. However, I have not owned a pair and my Dura-Ace brake pads all well as all the other pads I've had have ever had on my bikes have always taken twice the stopping distance to stop once the wheel/rim gets wet, whereas my disc brakes just don't have this problem.

If you're doing winter biking in a place where there's snow and they salt and sand the roads and do you a lot of biking wearing out your rims can be a possibility and disc brakes are much better at dealing with that - partly it's because they don't rub against the rim so you're not wearing the rim out, partly it's because the disc is farther away from the road and doesn't get as much stuff on it.

But the disadvantage of disc brakes, in my experience (and especially if you're taking the wheels on and off your bike on a regular basis, like I sometimes remove my front wheel to get my bike in my car) is that they're very finicky to get to not rub. My dad has to readjust his disc brakes every time he takes the front wheel on and off or they'll rub. On my bike it took 3 times back to the bike shop to get them not to rub, and now that I've removed my back wheel once (switched from studded winter tires to regular tires) the back one is rubbing. I have the Shimano Alfine hydraulic discs.

I've been to 3 different bike shops asking about the problem and all 3 have tried to tell me either that's it's "normal" for disc brakes to rub, or that they can't really do anything about it. If you read around on reviews of disc brakes there's always a bunch of people who complain they can't get them to stop rubbing completely. People on this forum have tried to tell me it shouldn't be a problem, but since both mine have this problem and my dad's have this problem (he has cable disc brakes, I believe Avid 5's) and 3 different shops don't want to try to fix them, I think it's a common problem with disc brakes.

However, I'm not sure that it really slows me down much, it's mostly just annoying.

Disc rub is an issue I've experienced and is annoying. If I get rub after removing a wheel, I don't adjust the brake. I adjust the skewer. On the rare times that adjusting the skewer doesn't solve the issue, the BB7's have tooless adjustments. I've never had BB5's , but BB7's are very easy to adjust. My cheapo mtb discs are a PITA to adjust and rub out of nowhere sometimes. But again, usually I can just adjust the skewer to solve the problem.

I've been to 3 different bike shops asking about the problem and all 3 have tried to tell me either that's it's "normal" for disc brakes to rub, or that they can't really do anything about it.

Your bike shops suck. Specifically, whoever's wrenching at those shops sucks.

FWIW, I haven't had to adjust mine much, if at all, when taking the wheel in and out. And, like I said in my previous post, doing a full adjustment front & rear takes less than ten minutes, at least for an Avid BB5 or BB7 setup. Your hydraulic brakes should be even better.

You should know how to do this; if you don't already, you need to learn. Scroll down to just above "Brake pad removal and replacement" to see how to align the calipers:
http://www.parktool.com/repair/readhowto.asp?id=126

Truing rotors:
http://www.parktool.com/repair/readhowto.asp?id=125
BTW, you don't need a wheel stand with a micrometer. Just listen for the "zing-zing" sound as the warped rotor touches the pads (if that's the problem) and make it go away.

Also, at the bottom of the first link, there's "Resetting brake pads"; do this after you've exhausted your options aligning the calipers and truing the rotors.

Disc rub is an issue I've experienced and is annoying. If I get rub after removing a wheel, I don't adjust the brake. I adjust the skewer.

Oh yeah -- even easier. :thumb:

Really, I'm not being sarcastic. It's rare when a wheel can be slapped back into the dropouts and be perfectly aligned, even with regular rim brakes.

What about dry stopping power of disc compared to non disc? I'm wondering if there will be advantages when pulling a kid trailer, a couple of big hills I get pushed hard and the brakes squeal a lot more than normal and of course all heads turn on the MUP when they hear the loud noise.

What about dry stopping power of disc compared to non disc?

Overheating issues aside (and that in itself started a big debate over in the Road forum, talking about extended downhill runs -- meaning 30+ mph down mountain roads), they all clamp onto the wheels hard enough to lock up and skid the tires. Both disc and non-disc systems, then, work well enough that the limiting factor is really the tires and how well they grip the pavement (or dirt).

Your bike shops suck. Specifically, whoever's wrenching at those shops sucks.


^^^This.

I've purchased several bikes new from shops that needed the brakes adjusted properly. It amazes me that this seems to be a common problem. Building a wheel or initial install of a front derailleur are way more complicated than setting up disc brakes,and most shops seem to handle these tasks no prob. As for rubbing,the only probs I've ever had were with lower end,single adjustment units or hydros,and both could be fixed with just a little extra TLC.

Your bike shops suck. Specifically, whoever's wrenching at those shops sucks.

FWIW, I haven't had to adjust mine much, if at all, when taking the wheel in and out. And, like I said in my previous post, doing a full adjustment front & rear takes less than ten minutes, at least for an Avid BB5 or BB7 setup. Your hydraulic brakes should be even better.

You should know how to do this; if you don't already, you need to learn. Scroll down to just above "Brake pad removal and replacement" to see how to align the calipers:
http://www.parktool.com/repair/readhowto.asp?id=126

Truing rotors:
http://www.parktool.com/repair/readhowto.asp?id=125
BTW, you don't need a wheel stand with a micrometer. Just listen for the "zing-zing" sound as the warped rotor touches the pads (if that's the problem) and make it go away.

Also, at the bottom of the first link, there's "Resetting brake pads"; do this after you've exhausted your options aligning the calipers and truing the rotors.

I appreciate your links and I'll look into them for my bike.

However, my point (disagree as you may) is that when I walk into a bike shop and tell them my rim brakes are rubbing, they say "We can fix that" and that's that. Maybe they have to true the wheel (which is something that takes some skill to do), maybe they just have to reseat the wheel in the dropouts, maybe they need to reposition the brake pads. Worst case maybe the brakes or wheel needs to be replaced, but they're always like "we can fix that, it's just going to cost money".

But when I walk in with the same issue with disc brakes, instead of a confident "we can fix that" attitude they get a grimace and immediately start trying to convince me that it's normal, or that it can't be fixed, or that they'll take a look but there's no promises. I mean, I'm offering to pay them money to fix the problem and they're still trying to talk me out of it.

So I think it's completely reasonable to say that it's a real possibility your disc brakes will rub and you won't be able to get it fixed.

I've had issues where I/someone put the front wheel on a bike with rim brakes and the brakes rub because the wheel wasn't quite on straight. I mean it's happened so many times I've found myself in a routine - if someone is going slower than everyone else, the first thing I do is check that their rim brakes aren't rubbing. And disc brakes rubbing apparently don't slow you down nearly as much as a rim brake rubbing. But as I said, I've never seen a mechanic look at a rubbing rim brake and turn down money to fix it saying "they're supposed to be that way".

Overheating issues aside (and that in itself started a big debate over in the Road forum, talking about extended downhill runs -- meaning 30+ mph down mountain roads), they all clamp onto the wheels hard enough to lock up and skid the tires. Both disc and non-disc systems, then, work well enough that the limiting factor is really the tires and how well they grip the pavement (or dirt).

I found it interesting that last year my model (Giant Cypress DX) was sold with disc brakes and this year its sold without. I wonder why the change, if they decided that it wasn't worth the extra cost or something. If I could find a surplus place that had parts from last year I could probably swap everything easily :)

Overheating issues aside (and that in itself started a big debate over in the Road forum, talking about extended downhill runs -- meaning 30+ mph down mountain roads), they all clamp onto the wheels hard enough to lock up and skid the tires. Both disc and non-disc systems, then, work well enough that the limiting factor is really the tires and how well they grip the pavement (or dirt).

Even towing an additional 50 pounds behind the bike? (That's a question, I'm really not sure)

So I think it's completely reasonable to say that it's a real possibility your disc brakes will rub and you won't be able to get it fixed.

I think it's completely reasonable to say that those shops suck. And I mean that in the kindest way possible, that they're not your fault.

I kinda dealt with my disc-equipped bikes exhibiting less-than-stellar braking until Ben at CHB (not sure if you'd know him, dynaryder) got his hands on my DBX's BB7 brakes and totally revamped them without breaking a sweat. I watched him and thought, "Hell, I could do that," so I readjusted my Bad Boy's BB5 brakes not long afterwards.

Seriously, it's easy -- stop typing here and do it yourself... well, unless the bike's not at your side at the moment. ;)

I found it interesting that last year my model (Giant Cypress DX) was sold with disc brakes and this year its sold without. I wonder why the change, if they decided that it wasn't worth the extra cost or something. If I could find a surplus place that had parts from last year I could probably swap everything easily :)

Almost every bike model from every manufacturer either dropped in specs or got more expensive. Giant chose to spend less on parts in that case.

Even towing an additional 50 pounds behind the bike? (That's a question, I'm really not sure)

Yup. You're not the first to tow large loads.

I think it's completely reasonable to say that those shops suck. And I mean that in the kindest way possible, that they're not your fault.

I kinda dealt with my disc-equipped bikes exhibiting less-than-stellar braking until Ben at CHB (not sure if you'd know him, dynaryder) got his hands on my DBX's BB7 brakes and totally revamped them without breaking a sweat. I watched him and thought, "Hell, I could do that," so I readjusted my Bad Boy's BB5 brakes not long afterwards.

Seriously, it's easy -- stop typing here and do it yourself... well, unless the bike's not at your side at the moment. ;)

What's CHB?

CHB = Capitol Hill Bikes, my neighborhood shop. Between Ben and Bernie they're building some good knowledge on the mechanics side.

Yup. You're not the first to tow large loads.

The 50lbs is just the kids, then there is the weight of the trailer and the toolkit and snacks/water I carry as well as the rear seat.

But its more that I like to modify/upgrade anything and everything :)

Heh... Well, you'll be fine. However, if you insist on bombing down Pike's Peak with a full load and both kids, ... well, you ain't right in the head anyway. :D

Yea, I know, its more about upgrading something just for the sake of upgrading :)

But when I walk in with the same issue with disc brakes, instead of a confident "we can fix that" attitude they get a grimace and immediately start trying to convince me that it's normal, or that it can't be fixed, or that they'll take a look but there's no promises. I mean, I'm offering to pay them money to fix the problem and they're still trying to talk me out of it.

Find a new shop. Or learn to do it yourself.

FYI,take an gear hub into any of the DC shops and they'll freak. General consensis is that they can't be user serviced. But Sheldon Brown has the Shimano Nexus manual on his website,and a friend of mine actually enjoys playing with them. Shops are not always the be-all and end-all of knowledge.

Find a new shop. Or learn to do it yourself.

FYI,take an gear hub into any of the DC shops and they'll freak. General consensis is that they can't be user serviced. But Sheldon Brown has the Shimano Nexus manual on his website,and a friend of mine actually enjoys playing with them. Shops are not always the be-all and end-all of knowledge.

The real issue with those is time. At shop rates of $60/hr and up...many customers would balk at the repair bill, and I can understand shops avoiding them, even if they do have the knowledge to service them. The repair bill could quickly approach replacement cost.

I'm having disc rub issues with the front and rear of a bike that's less than a year old (Novara Fusion). I have tried adjusting them myself, but the only way I can get them to not rub is to have them too loose. The mechanics from REI say it is normal. I used to have a mountain bike with a disk in the front, and whenever a LBS adjusted it, it would always rub a little and I would fiddle with it, but only able to make it have more play than ideal to stop the rub. I've got the "they just rub sometimes" routine from multiple places. Two of you in this thread are from the DC area, so maybe you have an idea of a shop that can help. I can try the CHB place, though if anyone knows a decent place closer to me that would be great.

I've looked carefully through the thread, and there's one issue with disc brakes that nobody seems to have mentioned. Isn't it the case that, if disc brakes are fitted to a bike with quick-release wheels, the torque resulting from the application of the brake can cause the quick-release to pop open, with predictable consequences? I'm sure I read that somewhere and didn't imagine it. May explain why some manufacturers have gone back to rim brakes.

Dunno.

I know that quick releases can cause your wheels to disappear when your bike is locked outside work or a store. So I use bolt-ons.

I've looked carefully through the thread, and there's one issue with disc brakes that nobody seems to have mentioned. Isn't it the case that, if disc brakes are fitted to a bike with quick-release wheels, the torque resulting from the application of the brake can cause the quick-release to pop open, with predictable consequences? I'm sure I read that somewhere and didn't imagine it. May explain why some manufacturers have gone back to rim brakes.

Yes, you read it, and no, you won't have a problem as long as you set your quick release properly tight.

If you're still worried, there are a few manufacturers who use a fork that has the caliper tabs on the front, which is supposed to help push the axle into the dropouts under braking. A side benefit is that it makes mounting a fender really easy.

Dunno.

I know that quick releases can cause your wheels to disappear when your bike is locked outside work or a store. So I use bolt-ons.

Well yes, if you don't run a cable or lock through them...

Disk brakes will keep your rim sidewalls pristine.

Non-issue with disk-specific hoops--no machined and polished surface to worry about. There's no way to run rim brakes on my wheels.

Exactly. Disc brakes will never wear out your rims like rim brakes will. In fact, you don't even need a braking surface on your rims. Mine, too, are disc-specific, with no machined braking surfaces. They're about 5 years old and still look like new.

yoder: which REI? I've had good luck with both the Rockville and College Park locations;I'd be surprised if either had said that. From what I saw on REI's site,it looks like your brakes only have single pad adjustment. If that's the case,do this:

1) Turn the inner pad in until it stops the wheel from turning. Then back it out slightly. Spin the wheel and listen for drag. Adjust the pad out until it just stops dragging.

2) Tighten the brake cable up at the lever until there's only like 2 threads showing(and remember to have the cable slot pointing down). Loosen the cable down at the caliper. When you spin the wheel,there should be no drag(if you set the inner pad properly as above). Now spin the wheel and manually move the caliper arm until it just starts to drag,then back it off a touch. Tighten the cable so the arm stays at that spot. The wheel should spin free,and the brake action should be tight.

3) If the outer pad drags when the cable is loose,check your skewer to see if it's too loose. If that doesn't fix it,then the caliper may not be mounted properly(I've had this happen once). Have the shop take a look at it,or pull up the installation instructions on Tektro's site to see how to center it.