# Brake rotor sizes



## solarplex (Apr 11, 2014)

I race xc on a top fuel. I had level tlms 160/160mm rotors and they sucked. Put on xts with ice techs 180/160mm.

Way more power but i feel the rear still is lacking some power. 

Do you guys over 200lbs up your rotor sizes? Seems silly to run dual 180mm on a xc rig...


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## Legbacon (Jan 20, 2004)

Seems stupid to ride with underpowered brakes.


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## stonant (Mar 11, 2016)

How often do you bleed your brakes? Make sure you're on top of your maintenance before splurging on some new parts. That being said I'm about 230 geared up and sometimes lose my confidence on my 180's on long(er) downhills (SLX brakes).


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## Ross1200 (Mar 27, 2014)

I'm on 180/180 at 205lb


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## astom22 (Aug 4, 2016)

I need to bleed my brakes, but I plan to up my setup to 203/180 ice techs with my slx's when I buy new wheels soon. I'm 240+ with gear. 

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## solarplex (Apr 11, 2014)

stonant said:


> How often do you bleed your brakes? Make sure you're on top of your maintenance before splurging on some new parts. That being said I'm about 230 geared up and sometimes lose my confidence on my 180's on long(er) downhills (SLX brakes).


Tlms didnt even have a year on them. Xts have a few ride.


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## solarplex (Apr 11, 2014)

Travis Bickle said:


> Seems stupid to ride with underpowered brakes.


Its actually made me faster downhill only using a shitty rear brake as i got use to speeds i wouldnt normally go.


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## solarplex (Apr 11, 2014)

Funny thing is ive noticed specialized putting larger rotors on their bikes. Where trek seems to stick with 160mm even on their fatbikes. 

I may just go dual 180 xc and fat, bigger rotor looks better with these large 1x cassettes


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## Bike Whisperer (Aug 7, 2012)

Full suspension 29er (Stumpjumper) I ran 203/180 and needed all that and maybe a little more.

For the casual XC riding on a hardtail I do these days, 160/160 is more than adequate. In the past my hardtail bikes usually ran 180/160 with a little more aggressive riding.


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## Mr Pig (Jun 25, 2008)

The thing about bigger rotors is that there isn't a down-side. So what's to think about?


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## Mike's MTB (Jun 12, 2017)

I'm using 180/160 on my hardtail. Haven't weighed myself in awhile, but would guess 250ish fully geared up. 

Don't have any issues, but also don't have any really long downhills around me.


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## Nubster (May 15, 2009)

260 and I don't really have any issue with 180/160. But I don't have a lot of DH stuff so heat and brake fade is rarely and issue. Even on my road bikes.


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## sfgiantsfan (Dec 20, 2010)

240-245 geared up, SS hardtail 180/160, full susp 203/180 and need it all


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## CBus660R (Jun 22, 2012)

I'm about 220 geared up, on my Trance I had 'em swap in 203/180 to replace the stock 180/160 setup before I even took delivery. I like how my brakes work for the trail riding I do. As Mr Pig said, there really is no down side to bigger rotors. The very minimal weight gain isn't worth worrying about and the bigger rotors absorb more heat before over heating and cool off quicker.


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## solarplex (Apr 11, 2014)

Mr Pig said:


> The thing about bigger rotors is that there isn't a down-side. So what's to think about?


They warp easier.


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## solarplex (Apr 11, 2014)

Bike Whisperer said:


> Full suspension 29er (Stumpjumper) I ran 203/180 and needed all that and maybe a little more.
> 
> For the casual XC riding on a hardtail I do these days, 160/160 is more than adequate. In the past my hardtail bikes usually ran 180/160 with a little more aggressive riding.


This is pretty agressive, not like could ride a cross bike on the trail xc. Very hilly, roots, rocks, blind corners and pitchy hills you boost at to momentum climb.


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## Mr Pig (Jun 25, 2008)

solarplex said:


> They warp easier.


Ok, I'll give you that, true, but it's not that big a deal and stiffer 180 rotors bend less easily than more spindly 160 ones so..


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## dirtrider76 (Sep 19, 2012)

All my bikes have 205f/180r rotor combo.


I actually recently put some Icetech rotors on my xc/light trail bike. I think they are crap. 3 rides in they are noisy, seem to grip like crap still and I can see marks in them where they aren't smooth. I used to run Avid HSX and never had issues.


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## astom22 (Aug 4, 2016)

What rotors would some of you participating here recommend? I'm not looking to break the bank, but will pay for quality. Also looking to use 203/180 combo. 

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## Nubster (May 15, 2009)

astom22 said:


> What rotors would some of you participating here recommend? I'm not looking to break the bank, but will pay for quality. Also looking to use 203/180 combo.
> 
> Sent from my LG-H918 using Tapatalk


I have Hope rotors which are good but pricey. Got them mostly for the bling. I also have some Icetechs on one of my road bikes and they are good too. I'd buy them again. Probably not the Hopes though. They aren't good enough to justify the cost. But they look nice. If you have the extra $$$ and want to add some more color to your bike...they are a solid rotor but you are paying extra for the name and the bling. Other than that...I just use the rotors that come with the brakes and I've never really had any issues.


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## astom22 (Aug 4, 2016)

Nubster said:


> I have Hope rotors which are good but pricey. Got them mostly for the bling. I also have some Icetechs on one of my road bikes and they are good too. I'd buy them again. Probably not the Hopes though. They aren't good enough to justify the cost. But they look nice. If you have the extra $$$ and want to add some more color to your bike...they are a solid rotor but you are paying extra for the name and the bling. Other than that...I just use the rotors that come with the brakes and I've never really had any issues.


Thanks, I had looked at the Hopes too, but don't think I could justify the cost, especially when I'm picking up a new wheelset at the same time.

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## scottzg (Sep 27, 2006)

8/8 on my 6" bike
8/6 on my hardtail

220lbs.

I'd run a larger rear on the hardtail, but my past hardtails were too hard to modulate with a 7" rotor... and i forgot to build in enough chainstay clearance. 

I'm running sintered pads all around, but i don't really like them until they're warm.



solarplex said:


> Funny thing is ive noticed specialized putting larger rotors on their bikes. Where trek seems to stick with 160mm even on their fatbikes.


Makes sense, Speshy is based near mountains, trek has seen mountains in magazines.


solarplex said:


> They warp easier.


8" rotors are thicker than the smaller ones, or you're buying rotors with alu carriers so it's all the same. IMO 7" rotors are the delicate ones.


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## targnik (Jan 11, 2014)

245-ish, 203/180 on both my 29er AM HT & 650b FS Enduro steed...

I have contemplated running a 203 outback & ditching the front brake/rotor o_0

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## 2zmtnz (Apr 20, 2017)

just under 200Lbs (was 215) and I ran 203/180 (with 2 piston brakes) and they definetly added more stopping power. 

another option would be to upsize the calipers to 4 piston, my gf has them on the front of her bike (180 rotors F&R) and I feel like they have even more stopping power than mine. 

I always feel that more stopping power is never a bad thing so on my new bike I have speced 203/180 rotors with 4piston front and rear.


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## Max Gough (Apr 17, 2010)

200lbs here.

Previous bike (Nomad 3) Guide RSCs @ 200F/200R. Front was OK, rear used to fade a bit on long, demanding DH runs, even with fresh rotor/pads/bleed. Did enjoy the feel of the Guides though during 80% of riding.

New build (Carbine 29) will have Magura MT7 @ 203F/180R with the thicker 2mm Magura rotors. Word has it the heat management of the MT7s is exceptionally good, but then they are purpose-designed for downhill so you might hope so.


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## Guest (Jul 25, 2017)

I've running 180/180 on the fat and 160/160 on the fargo but swapping that to 180/160. My last XC rig ran 200/180 and that's my preference. I'm in the camp of having as much brake as your tires can handle (i.e. you don't want to lock the wheels up with every application by chucking 200s on a 40mm gravel tire, but you also need to be able to lock them up when you need to lock them up). I'm not advocating tearing trails up with rear wheel skids or anything, but I avoided an injury accident with a car three weeks ago because I can use every speck of traction my Fargo's 2" tires had available at a moment's notice.


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## solarplex (Apr 11, 2014)

Forster said:


> I've running 180/180 on the fat and 160/160 on the fargo but swapping that to 180/160. My last XC rig ran 200/180 and that's my preference. I'm in the camp of having as much brake as your tires can handle (i.e. you don't want to lock the wheels up with every application by chucking 200s on a 40mm gravel tire, but you also need to be able to lock them up when you need to lock them up). I'm not advocating tearing trails up with rear wheel skids or anything, but I avoided an injury accident with a car three weeks ago because I can use every speck of traction my Fargo's 2" tires had available at a moment's notice.


My specialized diverge i had came with a 140 rear. It wouldnt even lock up on gravel hahaha. I went dual 160s and dialed in the trps and it was way better. My new gravel bike has apex hydros, dual 160s and its awesome.

I didnt end up going 180 rear yet. I did however adjust my xt levers out a bit and seem alot better. They just seem to pull to a firmer stop, and more powerful feel. The rear will lock if i want and i have some modulation so they arnt on and off, i can for sure drag the rear brake only to speed control a hill without losing speed like using my front brake and not skidding my rear tire down it.

The 160-180 on the front went from no locking up to nose wheelies so i can imagine i would lose some modulation in the rear.


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## sgtrobo (Aug 19, 2014)

Bike Whisperer said:


> Full suspension 29er (Stumpjumper) I ran 203/180 and needed all that and maybe a little more.
> 
> For the casual XC riding on a hardtail I do these days, 160/160 is more than adequate. In the past my hardtail bikes usually ran 180/160 with a little more aggressive riding.


I'm 250 in gear, and I ran 203/180 on my Stumpy as well. I have 160/160 on my Scalpel, but I am upgrading the front to a 180, the 160 just doesn't provide enough oomph.


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## Ride_2_Fast (Jan 15, 2006)

Also trying to stick 180mm rotor on my 2017 Top fuel rear brake.
What adapter do you guys using for that? 
What is the added height of the adapter on the front post and on rear post?

(From factory the carbon frame is made for 140mm without adapter and sold with adapter and 160mm rotor)


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