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  1. #1
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    Benefit of Larger rotors?

    Currently running Avid Juicy brakes 160mm rotors. Question #1 Can I run larger rotors?
    Question #2 What is the benefit? Question #3 What brand of rotors can I run (aftermarket)?

    Thanks in advance!

    Woody

  2. #2
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    The search is your friend, as this has been asked to death, sometimes several times a week or even in a day:

    "Larger Rotors"
    http://forums.mtbr.com/search.php?searchid=7411400

    Also try "bigger rotors". The first one returned several hundred hits, many with the same subject in the title.

  3. #3
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    Hi, yes, you can run larger rotors, you will just need to purchase the correct adapters (cheap) to correspond with your rotor size. You should be able to go up to 8" on the front, the rear maybe limited by your frame though. Any of the avid rotors should work. A larger rotor has more leverage and more material to absorb heat.

  4. #4
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    Quote Originally Posted by jager7
    Hi, yes, you can run larger rotors, you will just need to purchase the correct adapters (cheap) to correspond with your rotor size. You should be able to go up to 8" on the front, the rear maybe limited by your frame though. Any of the avid rotors should work. A larger rotor has more leverage and more material to absorb heat.
    And this type of simplification and "yes you can!" is why one shouldn't trust the internet to give them advice on safety equipment.

    First thing is many forks have size limits, especially with QR's. Why? Such things as mounts not being made for extra forces, legs not being made for forces beyond a certain point, dropouts not being rated for the forces applied to them, QR's not being able to cope with said forces...

  5. #5
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    Quote Originally Posted by Jerk_Chicken
    And this type of simplification and "yes you can!" is why one shouldn't trust the internet to give them advice on safety equipment.

    First thing is many forks have size limits, especially with QR's. Why? Such things as mounts not being made for extra forces, legs not being made for forces beyond a certain point, dropouts not being rated for the forces applied to them, QR's not being able to cope with said forces...
    good point, i had forgotten about that, my bikes are all thru axle and bolt on hubs so it's not something id considered

  6. #6
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    Here is a copy/paste of my reply to a similar thread I posted in yesterday.

    "Something to keep in mind about rotor size is if you have more than you need it isn't really a good thing.
    Size depends on what type of riding you will be doing, and how much you weigh, and how big of rotors will your frame and fork handle. Some forks will only handle a 185mm rotor.......some older forks will only handle a 160mm. Most forks designed for AM/DH/FR will handle the big rotors no problem, where a lightweight XC fork may only handle a 160 or 185 max. Also, will the larger rotor clear the chainstays of the frame?.
    If the rotors are too big you will have an "on/off" feel, meaning no modulation.
    If you weigh under 200lbs and are doing agressive XC or AM type of riding a 7" front and 6 or 7" rear should work good. If you are a bigger person like I am you need the larger rotors otherwise your brakes will heat up too fast and will fade easy.
    I'm almost 300lbs and I run a 203mm front and a 185mm rear. I ride agressive XC leaning more toward the AM side of things and this combo works great.
    On my commuter bike I run 160mm BB7's and can toss myself over the bars no problem if I wanted with 2 finger braking.
    My point is, don't get too much brake, as you will lose all feel."

    What frame and fork are you running?
    Look, whatever happens, don't fight the mountain.

  7. #7
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    A larger rotor has more leverage which I like for a lighter pull using single finger braking.
    A larger rotor will run cooler.

    I run an 8" front and 7" rear. I weigh 215 without gear.
    Some say you can lose feel with bigger rotors. I think this is pretty dependent on brake/pad combo. My Hayes HFX-9 is somewhat like this. My Shimano, no way.

    Some say a larger rotor might generate too much braking force for a fork. Hmmm, a 6" rotor can generate just as much force as an 8" rotor. You just have to squeeze the 6" harder. The real limit to absolute braking force is the traction of the tire.

  8. #8
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    Quote Originally Posted by NormanPCN
    Some say a larger rotor might generate too much braking force for a fork. Hmmm, a 6" rotor can generate just as much force as an 8" rotor. You just have to squeeze the 6" harder. The real limit to absolute braking force is the traction of the tire.
    "Some say"? How about the fork manufacturer?

  9. #9
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    Quote Originally Posted by NormanPCN

    Some say a larger rotor might generate too much braking force for a fork. Hmmm, a 6" rotor can generate just as much force as an 8" rotor. You just have to squeeze the 6" harder. The real limit to absolute braking force is the traction of the tire.
    good point if anyone was concerned they were gonna stop so fast it'd tuck the fork under the frame and snap it... the concern is the amount of leverage the longer caliper bracket puts on the disk mount and lowers.
    .

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