Anyone using 8" disc rotors for XC?

[gling]

To be more specific, aggressive XC/enduro oriented.

I ride trails that are are scattered with some steep and rough slopes and found that my 6" rotors (Hayes HFX 9) are not stopping me fast enough or gets very very hot. I am assuming 8" rotors will benefit me in such circumstances but wanted to get some feedback before I get them. Also, What about an 8"-front - 6"-rear combo? Anyone using this setup?

Still somewhat new to the sport.

Thanks.

[sanjuro]

3 things:

1. Hayes are not exactly the best brakes, which could be the cause of your brake fade, although an 8 inch rotor on this site is very common.
2. Not all forks can accomodate an 8 inch rotor.
3. What is your body weight?

[gling]

Thanks for the response.

I weigh 150 lbs and the brakes are fine. It's just that I really tend to plow down things at a rather fast pace and brake only when I need to. The catch is, "only when I need to". And when I do, the 6" don't really stop me in time for a quick turn or slow me down enough to evade an obstacle like a tree.

I know my fork and frame can take 8" rotors though the fact that it is a QR fork may draw some controversial comments. I am aware of the mechanical limits and possible failures of such a combination.

[johnbryanpeters]

I run 8" in front and 6" in back more for balance than for power.

[blue]

As long as you're aware of the risks (and willing to take them), I see no problem in running an 8 inch rotor in the front...I know plenty of people who do for XC.

[gling]

I run 8" in front and 6" in back more for balance than for power.


Thanks for the input.

Cheers.

[gling]

Next question is: would an 8" in the rear help much? From what I understand, the front makes the most difference.

Thanks.

[blue]

Eh, not really. You don't even need an 8 in the rear for DH...The front is what counts the most.

[Vulcan]

Thanks for the response.

I weigh 150 lbs and the brakes are fine. It's just that I really tend to plow down things at a rather fast pace and brake only when I need to. The catch is, "only when I need to". And when I do, the 6" don't really stop me in time for a quick turn or slow me down enough to evade an obstacle like a tree.

I know my fork and frame can take 8" rotors though the fact that it is a QR fork may draw some controversial comments. I am aware of the mechanical limits and possible failures of such a combination.
At 150lb there is no way you should need a 8" rotor on an XC bike. A 7" rotor might be worth considering, but 8" is total and absolute overkill. Generaly, that extra power comes at the cost of modulation, which in my opinion is very important up front.

[gling]

Vulcan,

Thanks for the heads up. I just thought a larger rotor would help and suggested the 8" as it is more common. I've heard of the 7" and will look into it a bit more. Thanks for the heads up.

Cheers.

P/s: Is that bike in your icon a Fuel?

[Vulcan]

Vulcan,

Thanks for the heads up. I just thought a larger rotor would help and suggested the 8" as it is more common. I've heard of the 7" and will look into it a bit more. Thanks for the heads up.

Cheers.

P/s: Is that bike in your icon a Fuel?
Nope its a MKIII... I used to have one.

the 7" rotor shoudl be a good balance.. Also, make sure your pads are not contaminated. I had HFX-9s with 6" rotors and I could have easily thrown myself over the bars if I grabbed a handfull of brake.

[bjanga]

I dont think 8" is overkill. Nothing wrong with 6" I would imagine, though.

[66]

Eh, not really. You don't even need an 8 in the rear for DH...The front is what counts the most.

front is 70% of the power but in DH you ride the rear much more then the front. When i get brake fade, it's in the back before the front, always.

[SkaredShtles]

I would guess that your limitation here is not the rotors - try bigger tires.

Oh - and change your style to include a little bit more preemptive braking. :D

[oldfart]

It is really terrain dependant. I can see a bigger front rotor for sure and I considered it myself. I weigh less than you at 145# and the North Shore is nothing but long steep decents. There are times when you're going into a corner a little too hot and brakes aren't strong enough. Another thing though. A larger rotor gives you better modulation because you don't have to squeeze as hard to get the same braking effect. Plus better cooling.

[BIRDMAN111]

just make sure your fork and/or frame can take the extra stress of a larger rotor

[gling]

...include a little bit more preemptive braking. :D

:D Probably a good idea. Hah!

But on another note, I guess it's just my style.

[SkaredShtles]

:D Probably a good idea. Hah!

But on another note, I guess it's just my style.
Don't blame bad habits on "style." :)

[trickten]

I run 8" rotors in the front and 6" in the back. It perfect for me.

[SkaredShtles]

I run 8" rotors in the front and 6" in the back. It perfect for me.
Dude. In Swartz Creek?!? A rigid bike would be more appropriate with cantilever brakes. :blah: