# Mountain Biking - Reguler brakes vs. Disk brakes

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View Full Version : Reguler brakes vs. Disk brakes

Rudso
09-29-05, 11:00 PM
Im looking to buy a Specialized Hardrock Sport. Nothing to fancy just something i can go out with and have a lil fun. Im a first time mountain biker and was wondering if there is a big difference between a regular brakes over disk brakes. I think the difference between them on a Hardrock Sport is about \$70. Is it worth the extra \$?

Raiyn
09-29-05, 11:14 PM
Im looking to buy a Specialized Hardrock Sport. Nothing to fancy just something i can go out with and have a lil fun. Im a first time mountain biker and was wondering if there is a big difference between a regular brakes over disk brakes. I think the difference between them on a Hardrock Sport is about \$70. Is it worth the extra \$?
Don't they teach newbies to search?

The following has been reprinted more times than the Bible here

Why are discs better than rim brakes?

The difference is friction. Friction is of course the force acting against the momentum. Friction under all circumstances will be greater in a disc system than a rim system. Not even ceramic rims and their pads can compare to the sustainable friction of a disc system. Not to mention the effects of inclement conditions on rim brakes.

Let's start by taking a look at the physics involved. There's a law of physics that states how an object in motion has a certain amount of energy due to its momentum. This energy is called kinetic energy. In order for this object in motion to stop or slow down, it must lose some or all of its kinetic energy. It does this by converting the kinetic energy to heat.

It's pretty simple. At your wheel you have a metal disc and a set of friction pads. The pads squeeze or push onto the metal. When this happens, you create friction. Friction generates heat, of course. Since the wheel is turning, then the kinetic energy of your momentum is converted to heat at this point and discharged harmlessly into the atmosphere (with a slight loss of pad material), and your bike slows down. The faster it is going, the more heat is needed to stop it. The more pressure you apply to the pads, the faster it can discharge the kinetic energy. The disc aids in the discharge of the heat generated. The surface area of the rotor allows heat to dissipate more quickly.
Rim brakes work well, but they have a hard time shedding heat well enough to prevent fade when used really hard. Brake fade occurs when the brake overheats dramatically; braking power is vastly reduced. The fact that rubber compound rim brake pads can only sustain so much heat and pressure before they break loose is another key point as is the fact that disc pads, being made of a more durable substance, are not prone to the same failures.
Facts
Disc brakes handle heat load and dissipation better than calipers.
They don't transfer the heat generated directly to the rim, like calipers.
Disc rotors are MUCH cheaper to replace than an entire rim (as low as \$15). As far as being able to lock a wheel: yes you can lock a wheel much easier with a disc than you can a caliper of any type, however if your brakes are PROPERLY setup, you also have greater modulation with less effort than any caliper system ever invented.

Do I have V brakes on my road only commuter? Yes, due in no small part, to the fact that both my frame and fork are not disc compatible. As I plan on eventually (after my shock upgrade on the trail bike) swapping out the fork on my commuter for a rigid model that has disc tabs I will not be without the added all conditions stopping power of discs for much longer. It is also possible that I may even just get a fork with V-brake bosses as the current setup is adequate for most everything I encounter while commuting in Florida, but it's funny how things can change.

Having said that the Tektro Discs on the current Hardrock sport aren't worth crossing the street for. Save your sheckels and get some Avid BB7's and a decent wheelset. You won't find decent discs on a Hardrock until you hit the Hardrock PRO disc with the Avid BB5's

the wonginator
09-30-05, 05:06 AM
actually, once the tektros break in, they're not that bad... and i ride them quite a bit. maybe i'm just lucky.

and for the record, i have ridden HFX-9's and BB7's so i know what real discs feel like.

cod3man
09-30-05, 07:01 AM
I will second that top end v-brakes works very well.

Callaway
09-30-05, 07:09 AM
I would agree that disc brakes are cool looking and that higher end disc brakes do work better than v-brakes in certain conditions, but not the disc brakes at that level. So, no, it is not worth the extra money.

actually, once the tektros break in, they're not that bad...
Just to be clear, I am not saying the low end discs are bad... just not any better than the v's, hence not worth the extra money.

10010011
09-30-05, 02:04 PM
Personally I would take a hard tail with disk brakes over a full suspention with rim brakes.

Even a cheap set of cable pull disks will out perform rim brakes specially under wet or muddy conditions.

Also figure in ths cost of replaceing rims ever year or two over disk pads and rotors.

cod3man
09-30-05, 04:41 PM
yeah, hey Rudso- where do you live??

if you do live in a wet climate- west coast- get discs.

Raiyn
09-30-05, 04:44 PM
I'll say it again the Tektro discs are godawful. He'd be better off getting a set of Avid BB7's aftermarket

Namenda
09-30-05, 04:59 PM
I'll say it again the Tektro discs are godawful. He'd be better off getting a set of Avid BB7's aftermarket

Got to agree. The difference is like braking a '78 Monte Carlo vs. an '05 Corvette. No comparison.

Callaway
09-30-05, 05:26 PM
The stumpjumper that I have on layaway comes with Avid BB7's but for an extra \$200 bucks. Well, I can get the lower model with V's (other than that identical bike, even the same hubs) and then upgrade to the aftermarket BB7's- save money and have a back up/extra pair of V's... win-win :D

Namenda
09-30-05, 05:30 PM
That's what I did. Don't know what I'll ever do with the leftover v-brakes, though.

Raiyn
09-30-05, 05:32 PM
That's what I did. Don't know what I'll ever do with the leftover v-brakes, though.
http://img304.imageshack.us/img304/9164/ebay6sy.jpg

Callaway
09-30-05, 05:34 PM
...or save em for a rainy day (well not literally, you would ideally want your discs) or for another bike-

Namenda
09-30-05, 05:35 PM
Point made. Maybe I'll do a group sale of all the bits and pieces I have laying around.

Raiyn
09-30-05, 05:43 PM
There's also this as well

Namenda
09-30-05, 05:50 PM
Charity begins at home, right? Although I wouldn't mind passing some of these items along gratis, some of the stuff just isn't worth using anymore. Wouldn't want to stick someone with a bike part that is possibly in poor condition.

Raiyn
09-30-05, 06:06 PM
. Wouldn't want to stick someone with a bike part that is possibly in poor condition.
Then use it for Arts and Crafts or something. Heck I'm planning on making a lamp out of an old fork

Callaway
09-30-05, 06:08 PM
Agreed, don't be afraid to get crafty... as specialized says "innovate or die"

Drunken Chicken
10-01-05, 02:07 AM
Then use it for Arts and Crafts or something. Heck I'm planning on making a lamp out of an old fork
Sounds fun, post some pics when you're done. :)

Raiyn
10-04-05, 10:36 PM
Sounds fun, post some pics when you're done. :)
I'll see what I can do. I've got a lot of "irons in the the fire" so to speak at the moment.