[Closed] What size rotor up front?

i run 203 at the front and 180 at the rear so you should be fine
the extra weight wont make a difference. but the increased rotor size will improve stopping power especially on longer descents where the rotor wont heat up as quickly

Crikey this indicates how gnarecoreless my riding is ..... I weigh a good deal more than you and have pretty much always run 180/160. On two bikes I'm currently running 160/160 and may change that to 160/140.

I need to ride down more hills me thinks!

For the mudfest season I changed the 200 180 combo to 180 160. I weigh abot 13 stones. More than enough power with my hated Avid Xo trail's

203's front and rear....

You can never have brakes that are too good at my skill levels.

Unless you are big or are riding a tandem no one in the UK needs 200mm rotors.

If you regularly take your bike to the Alps then fair enough

downhilldave - Member

For the mudfest season I changed the 200 180 combo to 180 160. I weigh abot 13 stones. More than enough power with my hated Avid Xo trail's

hated? how so? they are by far the best brakes ive used (ps if its the turkey gobble swap the rotors to sram centrelines and it cures it!)

no one in the UK needs 200mm rotors

LOL ridiculous, you may not need better brakes, but how can you decide I don't ?

was thinking of trying a 200mm up front

Why? Just for something to do?

If 180mm discs are not stopping you adequately and your brakes are in good working order then yes, 203mm front will probably help.

Personally I'm happy riding steep and long descents on 180mm rotors and I'm probably a touch heavier.

160/160. 1. Reasons:
1. I subscribe to the "keeps the brakes hot and burns the mud off" school of thought,
2. its not that hilly in the Surrey Hills
3. modern brakes are more powerful making larger rotors a bit less necessary.

(get changed to 200/200 for the Alps)

Note that a bigger rotor drags more than a smaller one so if there's any shing-shing going on with your brakes you'll notice it more with a bigger rotor

Unless you+bike are very heavy or extremely fast and on +5min DHs then 180 is more than good enough! Else, I would look at my brakes/bleed/change to braided hoses. Might as well save the weight (not a great deal, but its the sum of the parts)
Personally 180/160, but TBH I think 160/160 would be fine. Local hills arent very big, but I regularly race Enduro and some mini DH, plus Alps each year and Mega last year. Never had a problem with brakes overheating or not stopping me.

OW, no love on here for Avid's. Running centrelines as well. Think the 200 is overkill for the Uk. The drop down Cartworth Rd into Holmfirth is pretty long,steep and over 45mph and I can make my Magic Mary howl like a good un. More than enough power with tons of control. Where are you based? I have a rotor and adaptor you can try.

I'm 17 stone and only run a 180/160 in the UK without any issues.

I used to run 203s on other bikes but that was using older brakes that needed the extra help.

I'm 15st and run 203/180 and used to run 180/160 (both on XT's)

Not a huge amount of difference tbh but i fancied trying it because i got the slx/zee 203 disc for less than a fiver brand new.
TBH it's not necessary but i CBA to change now

14.5st and 205's front and back. Used to go with 180 on the back but when I bought a whole new setup I thought why bother going smaller to save a few grams? I've had fade with 180's so I may as well go bigger.

200/180 on my enduro bike

180/160 on my xc bike

about 90kg

I run 203/180 on my main bike, I weigh 14½ stone in my pants and ride like a massive wuss. But that's what they came with and I can't imagine the cost of buying smaller discs is worthwhile when they will make f-all difference to my ride.

OTOH, my hardtail has 160/140 because I was being a weight-weenie when I built it 🙂

180/160 on big bikes
160/160* or 160/140** on XC

That's just for me of course, personally I hate the excessive biteyness of bigger rotors, especially with current Shimano brakes, so I'm happy running the little discs, I actually downsized on a couple of bikes to 140 on the rear. You may want bigger, you may not.

*Hope X2
**Shimano SLX/XT

When I lived in the south I ran 180f 140r.

Moved to Scotland and went to a 160r, now on a 180r.

Also found the lightweight Ashima rotor quickly were found wanting, including splitting one.

Now on standard weight ones

180/160 on my bike. It seems to slow down and stop with no problems.

180f 160r on the Shan, I'm 75kg in all my gear and only occassionally have a 'moment' (but that's probably me rather than the brakes) Tyres and technique has just as much effect as rotor size IMO

downhilldave - Member

OW, no love on here for Avid's. Running centrelines as well. Think the 200 is overkill for the Uk. The drop down Cartworth Rd into Holmfirth is pretty long,steep and over 45mph and I can make my Magic Mary howl like a good un. More than enough power with tons of control. Where are you based? I have a rotor and adaptor you can try.

sorry dave I read it as you hated them 😆 I think they are brilliant brakes tbh

only reason I was wanting to swap, was id seen a rotor cheap and the mount for the 200mm rotor doesn't use the stupd CPS washers, ive converted my rear tp none CPS using a avid mount, but sadly the front can only use the CPS washer system with a 180mm rotor

there are ways around it using other brands etc, but wanted to use the same mounts, so was going thinking of trying the 203 up front

probably overkill though we do a lot of steep descents I guess (ride peaks etc), and its certainly not flat

16 stone . 203,180

I think you get more feel by not working the brakes so hard.

11.5 stone kitted up and use a 203 front. Mainly Cannock but we do Stile Cop (DH/Mini DH) quite a bit so I leave em on for everything.

Also, I go through a set of sintered pads once every other year. Works for me.

Unless you are big or are riding a tandem no one in the UK needs 200mm rotors.

Have you seen me go downhill?

[img] [/img]

I've got my own gravitational pull! So I need all the help I can get!

203/180. Only because that's all I had left as spares.

I had been running 180 F&R which was fine. I did go up to 203's for Canada last year & still cooked the brakes after a few weeks of bikepark action.

I'll probably just leave them as they are this year & learn to brake less/crash more.

203/180. with 2014 Deore brakes.

16.5 stone with all the finesse of a hippo in a ballet skirt.

I don't see any advantages in going smaller.

Currently on Deores with 160 at both ends, been fine all winter.

In the spring when I build up my FS again I'll run 180 each end with Zee's although I can't think why I'd ever need that level of braking....it's very much a vanity thing on a new build!

Had the Deores on 160s at BPW this winter, Rogate, Surrey Hills etc....they can lock the wheels with my 90kg on the bike so they're more than enough.

I've got my own gravitational pull! So I need all the help I can get!

stay off the pasties then Binners!! 😉

I run 203 on the front and 160 on the back.

Works good. When descending I can lock up the rear easy, so no need to go bigger, 203 means you need less force to lock up the front, which reduces fatigue.

I use a 203 on the big bike even though I don't need it- never a drop of fade in the alps or racing so, it's more than adequate for normal use. But I figure it gives me a bunch of margin for error and the weight penalty's not big.

160s on the back usually.

203mm front/180mm rear for me, because i have an xfusion slant fork that only allows a rotor of that size (the lowers were cast with fixed mounts when they first came out).

stay off the pasties then Binners!!

what a ridiculous proposition.

12 stone, 200mm / 180mm rotors Hope E4s, allows me to ride faster than my smaller rotor brethen as I can brake later, depends if you're a Strava'soul like me 😈

Got M4 on the inbred and XT (2014s) on my fs. I have the same 203 / 180 on each.

I have arthritic fingers and find the extra rotor size does !make a difference. As well as that, the
Larger rotors seem to give a bit more feel as opposed to on / off with smaller sizes.

I've never had brake fade. The brakes always feel as sharp at the bottom of the hill as the top. I know that rotational weight means more that sprung weight in how a bike feels, but, it's gram . I say go big!

what a ridiculous proposition.

he's had a fatwa placed on him banning him from Greggs for a month

180f/160r, 120kg, never needed any more.
Maybe I need to ride somewhere a bit steeper 😕

About 90kg. XTs with 203/180 on both 'main' bikes. The braking equivalent of nuking the site from orbit...

203/180 on the "AM" bike
203/160 on the XC hardtail

I like stopping.

Big Bike Hope V2s 203 and 183
XC Bike Shimano XT 775s 180 and 160
Commuter Shimano Deore 525s 180 and 160
Weight 100kg

I have 183/160 on the hardtail, 183/183 on the full-sus. Started out with a 160 rear on the full-sus but it felt a bit underpowered with the grip the rear tyre had compared to on the hardtail.

There's plenty of heavier riders than me so I can see why they'd be using 200+ rotors - look at the size of the brakes on a Bentley or Rolls. 1/2mv^2 and all that...

I like max braking with min effort so it's 203/180 for me. It'd be 203 both ends but the 180 is all I had spare when I built it up. It is a 180/170mm bike right enough.

Big rotors are great for some bonkers trails that require late hard braking

im gonna try it - sod it - rotor is an incredible 11.99 on wiggle at the mo, and the new mount will get rid of CPS washers so all in all its win win!