Rotor size advice please

starbuck

I'm about to upgrade my deore hydraulics to XT M785 servo wave brakes (prob from rosebikes, although will have to swap levers round).

I have an Orange EVO2 and currently, I have 160mm rotors front and rear. I'm thinking of changing my rotors to the ice tech ones to get the best braking I can.

I have a reba RLT TI fork which can take up to a 210mm rotor, so was looking at getting the 203mm rotor up front. I don't know what the maximum size is I can have on the back, but was possibly looking at either a 160mm or 180mm.

I ride mainly XC and singletrack and also road riding. Would 203mm on the front be overkill? How do I tell what the maximum size I can go to on the rear is?

A larger rotor will give me better braking (from what I've read), any cons to this?

is there anything to be said for having same size front and rear?

stubs

203 mm is a big jump from 160 especially with the new brakes. Unless you are doing Downhill racing or weigh more than about 20 stone its more than most people need. You wont need any more than 160mm on the back unless you like doing skids all the time.

I am a big bloke and never needed any more than 180 fr 160 r even in the Alps though the discs did go a pretty blue colour.

rockmonkeysc

203 is a bit big for XC riding. They will have a lot of bite and not a lot of control. I'm 16 stone & I only use 185 rotors on my downhill bike with a single finger braking set up.
Try 160 with the XT's to start with they will be more powerful than the old Deore's.

stubs

starbuck wrote:

(prob from rosebikes, although will have to swap levers round).

Why will you need to swap levers. :? All you need to do is fit them to your bike front right back left. You dont need to undo anything as far as I know.

Chunkers1980

They come euro stylee

stubs

Chunkers1980 wrote:

They come euro stylee

I was forgetting XT brakes arent flip flop. Ignore me.

nicklouse

Kep the rotors as is or maybe go 180 front. No need for more.

starbuck

Thanks for the advice guys, looks like I'll be going 180 fronts then. Would there be much difference between 180 and 160 on the rear( as there's only £3-4 difference between 180 and 160)?

BTW, anyone know the cheapest place to get ice tech rotors? CRC have them for £32(160) or £36(180), anywhere cheaper?

bazza333

I have 160's on the back of my bikes and I can lock the wheels on ANY surface...why would you want more?
Weight transfer means you don't need the same size rotors back and front.
Bazza

Chunkers1980

Just 160 rears saves weight too, in the rotor and bracket. On the front it's mostly a price worth paying, not the rear.

YeehaaMcgee

I don't get all the naysayers saying that 203 is too big. It's down to personal taste. I happen to love the way big brakes respond, so "nuh" to you all.

Thewaylander

kinda with Yee, though i use 180's all round, as long as a brake has good modulation just means you got more power to spare

But 180's should be plenty

The Rookie

160's both ends here, the back locks up easily enough, so why add weight (and larger discs make it easier to scratch the stay as well!) I also run just a 160mm on the front as most my usage is flattish XC, I can still lift the back wheel with the front but it needs a heavy squeeze, but I really don't need that much braking that often so accept the compromise, as my forks are PM staying 160mm saves even more weight as no adaptor or second pair of bolts is needed.

supersonic

How much do you weigh? 'Best' braking is not always the most powerful, it depends on the person - are you struggling with the brakes?

steelie600

Look at motorbikes for an example, 2 farking hoooooj rotors on the front and 1 weedy one at the back. Like Yeehaa said its all about weight transfer, you can do a shed load more braking with the front wheel than the rear.

Yes a 203.. will create more braking torque than a 180 but it will also dissipate more heat than a 180 due to larger surface areas. Double edged sword here, better cooling but more powerful possibly a bit grabby brakes.

Now im a fat fook so Ive got a 203 and a 160 and should be fine for some big ass rolling stoppies!! Woop

matt@theforce

I couldn't agree more with it being down to personal taste.

I went from a 203/180 Hayes Stroker Trail setup to a 180/160 xt (M785) with Ice Tek rotors and the Shimano's seem much more powerfull yet smoother/lighter (single finger braking)/easier to use, Couldn't imagine what they would be like with a 203mm front rotor :twisted:

YeehaaMcgee

matt@theforce wrote:

I couldn't agree more with it being down to personal taste.

I went from a 203/180 Hayes Stroker Trail setup to a 180/160 xt (M785) with Ice Tek rotors and the Shimano's seem much more powerfull yet smoother/lighter (single finger braking)/easier to use, Couldn't imagine what they would be like with a 203mm front rotor :twisted:

In a word, awesome

nicklouse

steelie600 wrote:

Look at motorbikes for an example, 2 farking hoooooj rotors on the front and 1 weedy one at the back. Like Yeehaa said its all about weight transfer, you can do a shed load more braking with the front wheel than the rear.

Yes a 203.. will create more braking torque than a 180 but it will also dissipate more heat than a 180 due to larger surface areas. Double edged sword here, better cooling but more powerful possibly a bit grabby brakes.

Now im a fat fook so Ive got a 203 and a 160 and should be fine for some big ass rolling stoppies!! Woop

So what are you going to do when you find some real hills?

steelie600

Probably go arse over tit when I grab a handfull of front brakes!! :LOL:

Thats a while in my future yet boss, need to get fit and lose some poundage first. Baby runs for this puppy for another 2 stone or so atleast!

Gotta have goals, and ill cross the brake issue when I get to it!

YeehaaMcgee

nicklouse wrote:

steelie600 wrote:

Look at motorbikes for an example, 2 farking hoooooj rotors on the front and 1 weedy one at the back. Like Yeehaa said its all about weight transfer, you can do a shed load more braking with the front wheel than the rear.

Yes a 203.. will create more braking torque than a 180 but it will also dissipate more heat than a 180 due to larger surface areas. Double edged sword here, better cooling but more powerful possibly a bit grabby brakes.

Now im a fat fook so Ive got a 203 and a 160 and should be fine for some big ass rolling stoppies!! Woop

So what are you going to do when you find some real hills?

I don't understand the question.

steelie600

Is it because you is black?