Is 200mm rotor over...
 

[Closed] Is 200mm rotor overkill on the back of a DH bike?

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Bike came with a 200mm rotor on the front and back - the front I can understand but the back wheel I find just locks up.

The brakes it came with are Avid Juicy 3's which I know aren't the best anyway, so I'm wondering if reducing the rotor size may be a better option than spunking out for a new set of brakes.

At the end of the day I want just a little let on-off'ness on the back.


 
Posted : 12/01/2012 10:45 am
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the back wheel I find just locks up.

don't squeeze the lever as hard?

but after the mockery; big discs are a little better on long descents, where heat build up can be a problem.

so i don't bother with big discs unless i'm in the alps.


 
Posted : 12/01/2012 10:46 am
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I wish it was that easy - the brakes just have that switch like tendancy. It really is nothing... nothing... nothing... Anchors away!!! There is no in between.

Edit now that you've edited - I'm thinking maybe a 160 on the back


 
Posted : 12/01/2012 10:48 am
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"Power is nothing without control"

I run 203s each end, and quite like the 'single finger braking'...


 
Posted : 12/01/2012 10:51 am
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I've got 185mm on the pitch and its more than enough, I've been thinking of putting 180/160 on it as modern brakes have so much more power than those of 5-6years ago.

Also, light rotors like aligator aries can shed 1/2lb off the bike but lose some power (but you can go up a rotor size and still save weight).


 
Posted : 12/01/2012 10:53 am
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Xiphon - what brakes?


 
Posted : 12/01/2012 10:54 am
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peaty used to run a 140 on the back didn't he?

didn't seem to slow him down much.


 
Posted : 12/01/2012 10:56 am
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Yeah, good point - most of the braking is done on the front anyway.


 
Posted : 12/01/2012 10:59 am
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Although bear in mind people tend to drag the back more to regulate speed, so heat build up is greater. A few of the quick guys run a bigger rotor on the back than the front to combat this.

I've run a 185 on the back of my DH bike for years & never really felt the need for more. But then i'm no Minnaar...


 
Posted : 12/01/2012 11:06 am
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Although bear in mind people tend to drag the back more to regulate speed, so heat build up is greater. A few of the quick guys run a bigger rotor on the back than the front to combat this.

Pallindrome? The quick guys wont be the ones dragging their brakes!


 
Posted : 12/01/2012 11:15 am
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More weight over the back.

I run Code 7s (Juicy lever, code Caliper) with 200mm rotors at each end. Back only locks up when I want it to.

Try and get your back nice and flat so you've got an even weight distribution on both wheels, but still plenty over the back, that will increase the traction and make locking up harder. It will also give you more grip to play with full stop.

And do one-finger like Xiphon said.


 
Posted : 12/01/2012 11:16 am
 IHN
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Keep it on, everyone knows that skidz are cool.


 
Posted : 12/01/2012 11:18 am
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Juicy 3s are a bit grabby IME.

Bigger rotor = more modulation I thought.


 
Posted : 12/01/2012 11:21 am
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doublepost


 
Posted : 12/01/2012 11:21 am
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peaty used to run a 140 on the back didn't he?

didn't seem to slow him down much.

I like that ๐Ÿ™‚


 
Posted : 12/01/2012 11:24 am
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Quite like the 200mm Elixirs on my FR bike. I drag the back quite a bit on the descents and it works well.

Great for scrubbing off speed without actually braking IYKWIM


 
Posted : 12/01/2012 11:26 am
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As said above, pro's don't brake much! Can't say I have ever wished for less power, you don't have to use it all the time.


 
Posted : 12/01/2012 11:32 am
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My DH bike has 203mm rotors each end. I don't really like them though (apart from the heat thing), they feel a bit rubbish compared to 160s. Must be a modulation thing.


 
Posted : 12/01/2012 11:34 am
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I found my Juicys very on/off with any sized rotors. There are some bargain brake deals out there at the moment. Get some Shimano or Maguras. You know it makes sense.


 
Posted : 12/01/2012 11:50 am
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I'm with you nonsense. I used to run a 185 when I ran Juicys on the dh bike, now running Shimanos with a 205 without any issues


 
Posted : 12/01/2012 12:00 pm
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203s + Juicy 3s = plenty of power and control
225/205 + Hope M6/M4 = masses of power, yet control

Would rather have the power available - albeit with a *slight* weight penalty (in the grand scheme of things) - than too little power.

I can do one-finger stoppies with both the Juicy3s and M4s... ๐Ÿ˜€

Plus, big rotors look cool!

[img] [/img]

[img] [/img]


 
Posted : 12/01/2012 12:08 pm
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I've had a big heavy DH bike with 200mm rotors F/R before, I'd say it is overkill if it's a proper race bike, the intention is to go as fast as possible and the brake setup should reflect this, the front brake will be doing most of the proper deceleration while the rear is for "scrubbing" (that's the theory) , 200mm Front for sure, 170/180mm Rear is more sensible IMO...

That said I can see the benefits of anything that allows you to reduce the input rider effort even if it's just a bit of pressure on a brake lever, learn to live with it or try a smaller rotor, up to you really...


 
Posted : 12/01/2012 12:11 pm
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might try 185 out back initially, if that don't work it@ll be selling them for something better. Like the look of the new Shims


 
Posted : 12/01/2012 1:15 pm
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Go retro and fit V-Brakes ๐Ÿ˜‰


 
Posted : 12/01/2012 4:24 pm
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Juicy 3s are all well and good until you need to a) change the pads, or b) bleed them.

When that point arrives, throw them away and get something (anything!) else.

Current preference is shimano's fine new offerings.

Bushwacked, you already tried the new SLXs (200/180) on my Covert, I've got new XTs (180/160) on my 575 now which you can try too if you like, they are crazy good ๐Ÿ™‚

Dave


 
Posted : 12/01/2012 5:02 pm
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Juicy 3s have been exceptionally reliable for me - still on factory bleed, and 3rd set of pads - since March 2008...

Just as much bite as they did rolling out of the bike shop brand new.


 
Posted : 12/01/2012 5:15 pm
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Are the pads sintered ? If so try resin, may offer a bit less initial bite.


 
Posted : 12/01/2012 5:18 pm
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still on factory bleed

you've done well changing the pads, but you have yet to experience true hatred.

Once you (attempt to) bleed them, you will see the light and rid yourself of them - or you will attempt to live with them, deny the truth and enter a masochistic spiral of self flaggelation as you lose the will to live.

Good luck with that ๐Ÿ™‚

Dave


 
Posted : 12/01/2012 5:21 pm
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Dave - wondering what the difference is between the XT and SLX - like the feel of Shimano's - been a Hope man until recently but the Big S is getting some good reviews.


 
Posted : 12/01/2012 7:35 pm
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still on factory bleed
you've done well changing the pads, but you have yet to experience true hatred.

Once you (attempt to) bleed them, you will see the light and rid yourself of them - or you will attempt to live with them, deny the truth and enter a masochistic spiral of self flaggelation as you lose the will to live.

Good luck with that

Dave

@alfabus

its really not that difficult either change disc pads, or to bleed Juicy's or even Elixir's if you actually know what you are doing?

been using different sets of Avid brakes since 2005, and sold / maintained 100s of pairs to paying customers, no real problems to speak of, just the odd pair sent back for 'warranty' due to a manufacturing fault which is understandable when you are manufacturing on the huge scale that the SRAM conglomerate does


 
Posted : 12/01/2012 8:01 pm