Disk Brakes ?

[Eduardo]

This has been puzzling me for weeks, a disk brake is basically a larger version of a rim brake and the brake is the caliper and the rim is the rotor ? so surely a rim brake is better than a disk brake due to it being a "20 or "26 rotor? i asumed this due to people saying a larger rotor=more braking power.

If this is true the surely a rim brake on a "26 is more powerful than it would be on a "20 due to the "26 rim( rotor) being larger? or has it all got something to do with the fact that a disk brake is closer to the hub ??? Hopefully someone understands thuis as its about as simple as i can put it

Thanks for reading

[mfereborn]

the theorys there but its not quite right, i am 100% disc brakes after years of downhill... basically the direct pressure onto the disc, and the sheer size of the disc pad give you amazing stopping power, couple this with a decent hydraulic system and you have a brake system that will compete with any other typical 'horse shoe' style brakes, even the fancy hydraulic ones found on these new fangled trials bikes. also, the centre of the wheel where the rotor of a disc is found spins faster than the rim, therefore the speed increases/decreases alot faster, ebing another reason discs are so powerful.

just stay clear of poor brakes with the normal cable set up, on discs its far too easy to lock them up

[Eduardo]

  mfereborn said:

the theorys there but its not quite right, i am 100% disc brakes after years of downhill... basically the direct pressure onto the disc, and the sheer size of the disc pad give you amazing stopping power, couple this with a decent hydraulic system and you have a brake system that will compete with any other typical 'horse shoe' style brakes, even the fancy hydraulic ones found on these new fangled trials bikes. also, the centre of the wheel where the rotor of a disc is found spins faster than the rim, therefore the speed increases/decreases alot faster, ebing another reason discs are so powerful.

just stay clear of poor brakes with the normal cable set up, on discs its far too easy to lock them up

How can that be right ? they spin at exactly the same speed, how can the hub spin at a different speed to the rim?

Edit: cable disc's and cable rim brakes can be an advantage over hydraulic and vice verser (spelling)

Edited October 25, 2007 by lazyboi

[mfereborn]

  lazyboi said:

How can that be right ? they spin at exactly the same speed, how can the hub spin at a different speed to the rim?

Edit: cable disc's and cable rim brakes can be an advantage over hydraulic and vice verser (spelling)

its not speed as such more, i donmt know how to explain it, the outside of an object will always make fewer rotatations than the centre, well actually thats not right either... the hub of a wheels alot smaller than the diametre of the wheel itself, therefore one is travels round the given point more than the other...

i dinanr i cant explain it but the general idea is the centre rotates faster than the wheel.

and i hate cables, they stretch, wear, snap, and slide far tooe asily for my liking... i dont see any advantage of a cable over a disc unless you want to hold an endo without having to hold the brake lever

[chrisbikefix]

i think disc personal are alot better than a v brkae. apart from braking advantages they also help if you get a buckle as the brake will not catch and also for mud clearance. I actually run a v-brake as i side hop to my left hand side, and i always seem to fall straigh onto discs all the time, which can get annoying. A disc is more powerful though, even though a v brakes on a bigger leverage ratio, the power of the two hydrolic pistons is greater than a v brake offers. The compound of the pads also works better ...