Page 1 of 2 1 2 LastLast
Results 1 to 25 of 29
  1. #1
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    8

    Brake Rotor Size: 8"F/6"R or 7"F/7"R

    Time for me to replace my brakes and I was wondering about rotor sizes. Would an 8" front, 6" rear or a 7" front and rear serve better in terms of both stopping power and modulation? Would appreciate any input.

    Thanks.

  2. #2
    mtbr member
    Reputation: Murchman's Avatar
    Join Date
    Jan 2004
    Posts
    658
    I do a 7 front 6 back with my XTR's and love it. I tried going bigger up front but it was a little to much power. the 6 in the front would fade after a long steep downhill but moving up to 7 has solved that problem for me, a lighter ridder might not have that problem.

    I don't really see the need to go bigger in the back as the 6 does a great job and gives me pleanty of power and modulation now.

  3. #3
    EDR
    Reputation: eatdrinkride's Avatar
    Join Date
    Jun 2005
    Posts
    9,028
    I went with an 8in front and 6 in back just b/c thats what so many others have done. I've got Hayes Mags and it's worked out just fine. I ride plenty of technical stuff and the front control and stopping power when going slow is impressive. Since most of my stopping power comes from the front brake I see no reason to use a larger rear disc (in my case anyhow)

  4. #4
    mtbr member
    Reputation:
    Join Date
    Aug 2005
    Posts
    861
    I think it depends on your weight, and if your type of riding is mostly downhill, or not.
    I'm about 146 Lbs. with gear, and started with a 6F, 6R set-up, and then went to a 7F, 6R set-up.
    I noticed a performance increase in long downhill sections, but, overall, not a night and day difference. It looks good though!

  5. #5
    ride hard take risks
    Reputation: dogonfr's Avatar
    Join Date
    Jan 2005
    Posts
    25,589
    If you are concerned with weight go 6-6, if you ride agressive XC/AM go 7-6, AM/DH 8-7 or 8-8.

  6. #6
    Bike Geek
    Reputation: Rower_CPU's Avatar
    Join Date
    May 2004
    Posts
    192
    I got 7/7 with Avid BB7s and I love it - the 6/6 Hayes generics that came with my bike just couldn't hold up to slowing down 240+ pounds of rider.

  7. #7
    mtbr member
    Reputation: Davide's Avatar
    Join Date
    Jan 2004
    Posts
    1,858

    180 not enough 160 too much

    Quote Originally Posted by deoreo
    I think it depends on your weight, and if your type of riding is mostly downhill, or not.
    I'm about 146 Lbs. with gear, and started with a 6F, 6R set-up, and then went to a 7F, 6R set-up.
    I noticed a performance increase in long downhill sections, but, overall, not a night and day difference. It looks good though!
    I am 145/150 pounds and this year I went straight from V-brakes to 180/160 Marta SL just to have the extra power in front.

    The result is that I have almost too much power in the back (I miss the modularion of my V-brake) and I could use a bit more power in front. The front disc is more powerful than my excellent Vuelta Mag, but not by a huge amount. If I had to do it again I might be tempted to go bigger then 180 in front and keep 160 in the back (or be obsolete and go back to V)

    PS The weight difference for Marta SL rotors is about 20 grams, so even for a wannabe-weight-wennie like me is not an horror
    Last edited by Davide; 04-24-2006 at 07:57 PM.

  8. #8
    TNC
    TNC is offline
    noMAD man
    Reputation: TNC's Avatar
    Join Date
    Jan 2004
    Posts
    12,059
    All 4 of my setups are Hayes Mags with 8 in front and 6 in back...all 4 bikes would clearly be classified as AM setups. Like others have mentioned, a good working 6 in the back seems plenty capable for an AM bike.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Sep 2004
    Posts
    147

    7"/6"

    Juicy 7 180 front 160 rear

    More than enough brake for me.

  10. #10
    Bicyclochondriac.
    Reputation:
    Join Date
    Jan 2004
    Posts
    13,097
    Quote Originally Posted by gling
    Time for me to replace my brakes and I was wondering about rotor sizes. Would an 8" front, 6" rear or a 7" front and rear serve better in terms of both stopping power and modulation? Would appreciate any input.

    Thanks.
    Had 6/6, and then tried an 8 in the front (8/6). It was just way more power than I needed, added .3 pounds to the bike, and it locked a little too easily. I went back to 6/6. Works fine for me and my 190 lbs. I guess a 7 in the front might be nice, but I cannot see ever needing more than a 6 in the back.

  11. #11
    mtbr member
    Reputation: crank1979's Avatar
    Join Date
    Feb 2006
    Posts
    1,544
    I'm running 8" front and rear Juicy 5s. I have 6" front and rear Hayes Mags on the other bike. The Hayes were excellent when i first got them but as i got better the brakes just aren't big enough. The 8" set up at the moment is excellent on the front but a 7" might be better for the rear because i find it a bit difficult to modulate it as well as i'd like without locking the wheel up.

    So i think 8" front and 7" rear is probably the ideal set up with the technology at the moment, but having said that, i also think that you can never have too much brake.

  12. #12
    SLX
    SLX is offline
    mtbr member
    Reputation:
    Join Date
    Aug 2005
    Posts
    657
    I have 8 front 6 rear Hayes HFX 9 HD works well. I had 6 front and v brake rear for awhile but the front was cooking.

  13. #13
    banned
    Reputation: gonzostrike's Avatar
    Join Date
    Jan 2004
    Posts
    11,258
    you forgot

    7" front 6" rear

    6" front 6" rear

    what will work for you? depends on your riding style, your braking style, your typical terrain, your weight, you abilities.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Feb 2005
    Posts
    135
    I am running 8/8 on mine - with Aztec clean-sweep rotors (which are lighter than XT's anyway).

    You can never have too much braking power - you just have to learn to be more gentle when you don't want to tear your tyres to bits. But when I ran a 6/6 and an 8/7 on my enduro, both times the rear would get cooked even though the front was fine with the 8. So, 8/8 it is then, and these cope with the Alps no probs.

    Weight difference is negligable with the lighter rotors. Control is everything.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    8
    Just an update.

    Based on my riding style, braking style, terrain, and et cetera, I have decided to go with the 8"-front - 6"-rear combination. The 6"-front/rear was the benchmark but I wasn't too crazy about it. At 150 lbs., I am somewhat on the light side and 8 inches in the front may seem overkill but after trying them out, I liked the feel of it - a lot. It's not so much about stopping power; the 7" had just about the right power I was looking for by the way. It's more about the feel and how much I have to pull on the lever to get a certain amount of stoppage(?). I don't really care about weight as long as it is not an extra bike I am carrying around so the 8" made my day. As for the rear, I would have put an 8" rotor on too but felt little to gain - touche to those who brought up the lack-of-need of a rotor larger than 6 inches in the rear.

    I am still relatively new to this and appreciate all the input thus far; I am not discounting any additional input though. I also won't deny that I am still rather wet behind the ears compared to many others and having said that, hope to learn whatever I can to save me a few bucks, headaches, and some skin while riding.

    Cheers.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    8
    ChamMTB,

    Not denying that an 8" in the rear helps/adds but the cash I saved bought me an 8-pack of Guinness instead . I felt that a 6" was good enough so I stuck with it. Thanks for the post though.

    Cheers.

    Quote Originally Posted by ChamMTB
    I am running 8/8 on mine - with Aztec clean-sweep rotors (which are lighter than XT's anyway).

    You can never have too much braking power - you just have to learn to be more gentle when you don't want to tear your tyres to bits. But when I ran a 6/6 and an 8/7 on my enduro, both times the rear would get cooked even though the front was fine with the 8. So, 8/8 it is then, and these cope with the Alps no probs.

    Weight difference is negligable with the lighter rotors. Control is everything.

  17. #17
    29 some of the time...
    Reputation: AL29er's Avatar
    Join Date
    Jan 2004
    Posts
    4,945
    At 240lb with a full camelbak I swapped to 7x7 setup 2 years ago and have been loving it since. Personally I find the 8" rotor a bit grippy for all but steep/fast dh. And the 6" rotor in back gets really worked on longer runs with my weight. My 6in rotors were always discolored and very hot. Since swapping to 7in I have little to no discoloration/oxidation and heat is dissapated much better. I have run a 8frx7r and liked it for aggressive riding, but do admit that the weight is a bit much for just trail riding.

  18. #18
    mtbr member
    Reputation: hiccup's Avatar
    Join Date
    Oct 2005
    Posts
    127
    Here's a related question I've been facing on my Heckler build...
    Hydro in front and mech in the rear? As others testify, there is not much power required in the rear, so I was thinking 6" bb7 back there to save money. Another plus to that is it'd allow me a more expensive brake in front... Hope M4? Very likely overkill for me, another 150lb. rider. But I do go plenty fast for extended amounts of time and would love the fade resistance and superior modultion of those beauties. Any thoughts?
    The more pedestrian option is to go with Juicy 5's or Mono Minis front and rear. At least then I'd have matching levers! I'm sure that would be a fine solution for me, but if I can have bb7 in back and M4 in front for the same price... why not?

  19. #19
    VooDoo user.
    Reputation: TIMBERRR's Avatar
    Join Date
    Feb 2006
    Posts
    2,394
    8" fr / 6" rr

    been working for me.

  20. #20
    ride hard take risks
    Reputation: dogonfr's Avatar
    Join Date
    Jan 2005
    Posts
    25,589
    Quote Originally Posted by hiccup
    Here's a related question I've been facing on my Heckler build...
    Hydro in front and mech in the rear? As others testify, there is not much power required in the rear, so I was thinking 6" bb7 back there to save money. Another plus to that is it'd allow me a more expensive brake in front... Hope M4? Very likely overkill for me, another 150lb. rider. But I do go plenty fast for extended amounts of time and would love the fade resistance and superior modultion of those beauties. Any thoughts?
    The more pedestrian option is to go with Juicy 5's or Mono Minis front and rear. At least then I'd have matching levers! I'm sure that would be a fine solution for me, but if I can have bb7 in back and M4 in front for the same price... why not?
    Stick with hydro fr & rr if you ride, if your cruising then do your mech rr hydro fr. If you ride i would go with the Hayes HFX-Mag for power & El Camino for XC.

  21. #21
    SLX
    SLX is offline
    mtbr member
    Reputation:
    Join Date
    Aug 2005
    Posts
    657
    Quote Originally Posted by hiccup
    Here's a related question I've been facing on my Heckler build...
    Hydro in front and mech in the rear? As others testify, there is not much power required in the rear, so I was thinking 6" bb7 back there to save money. Another plus to that is it'd allow me a more expensive brake in front... Hope M4? Very likely overkill for me, another 150lb. rider. But I do go plenty fast for extended amounts of time and would love the fade resistance and superior modultion of those beauties. Any thoughts?
    The more pedestrian option is to go with Juicy 5's or Mono Minis front and rear. At least then I'd have matching levers! I'm sure that would be a fine solution for me, but if I can have bb7 in back and M4 in front for the same price... why not?
    You weirdo..m4 are made for downhill freeride type ridding pair that up with a bb7 and thats like Hillary clinton hooking up with Arnold Swarz for presidental election of 2008. However wierder things have happened.

    Your right forarm is going to be alot bigger than your left and your going to have to tell your buddies that its cus of your 'brake lever" :blush2:

    J/K it will work fine. I used to ride hydro front and vee rear. however now 8 F 6 R hydro hayes HD because I was heating it enough to vaporize snow. Using a mech and a hydro would be a hassle, you would have to have 2 mantaince scheemas: bleed a hydro and consistantly adjust the mech for pad adjustment.

    Id go Jucy 5 8" front and 6" rear. or the bomb setup would be m4/m6 front hope mono rear.

    My current setups:
    FSR XC with hayes hd hfx 8" and 6" <----more power (comfortable 45-0 mph stop in 3-4 car-lengths on road)
    Enduro with saint 8" and 8" <---more modulation (still breakin in who knows)
    Last edited by SLX; 05-02-2006 at 09:16 PM.

  22. #22
    mtbr member
    Reputation: hiccup's Avatar
    Join Date
    Oct 2005
    Posts
    127
    Thanks fellas! Always some good opinions on these boards.
    I'll probably end up with Juicy's front and rear, but DAMN don't those golden 4 pot M4's look sexy as hell! Maybe I'll scrape together some more dough and go M4 front/mono rear.
    I can dream, can't I?

    Thread hijack over.

  23. #23
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    68
    I run Hope Mono M4 8" front and rear on my AM bike and Hope Mono mini 6" on my single speed xc bike. The Hopes are sooo much nicer than the Hayes HFX's I was running. There are lots of great brakes out there but none give me wood like the CNC machined Hopes. I'm still struggling to figure out why everyone is running the larger front rotor. I have to it admit it looks cool (moto style) but, it just doesn't make sence to me. I ride with an expert downhill racer and we both dis-color our rear rotors but never the front. Maybe different riding areas have something to do with it. I doubt it though. We've both rode Big Bear, Moab, Fruita, etc, etc. Of course I use the front brake hard while going in a strait line but, I use the rear all the way into corners. Especialy when pushing really hard. By dragging the rear brake into a corner it sets the rear end up to slide before the front tire lets go. It makes the bike much easier to control mid corner that way. I do notice the rougher the trail gets the less I use the rear brake. It upsets the suspension too bad. When the trail turns real ugly I do all my braking in a strait line. Does any one else see this or ride this way?

  24. #24
    Fort Valley = Gnarl Fest
    Reputation: Jekyll_Jockey's Avatar
    Join Date
    Aug 2004
    Posts
    605

    physics

    OK a larger rotor is going to give you more stopping power and modulation. But of course how fast you can ultimately stop is limited by the amount of traction you have with your tires.

    The larger rotor is like using a larger lever; the force applied at the end of the rotor is going to get multiplied by the radius of the brake rotor. The difference between a 6 and an 8 rotor is not going to be extreme but it will be noticeable.

    The larger rotor up front is going to help stopping power a lot also, because most of your stopping power comes from your front wheel. So an 8 rotor up front will provide more breaking force than a 7 rotor up front.

    Now the your weight, ridding style, terrain, and many other variables are going to influence what rotor combination be optimum for you.

    I run a 160mm (6.5) rotor in the rear because that is the biggest I can fit. I also run a 185mm (7.4) rotor up front because I wanted a large rotor up font than my old 160mm and that was the adapter size Price-Point had in stock at the time.

  25. #25
    mtbr member
    Reputation: mtnpat's Avatar
    Join Date
    Jan 2004
    Posts
    654
    If your gonna go big, go BIG!

    I'd rather have it and not need it, then need it and not have it.

    Them be 8 inchers.
    Attached Images Attached Images

Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •