Are there any disad...
 

[Closed] Are there any disadvantages to running 200mm rotors?

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As above. Currently running 180mm with my Avid Guide brakes.


 
Posted : 04/05/2016 4:48 pm
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depends on your weight really, they can be quite grabby.

what size are you running out back?


 
Posted : 04/05/2016 4:50 pm
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I was told once, by an LBS, that because I was a fat lad I should run smaller rotors as using big rotor will cause spokes to snap.

Charming eh? I'm not even that fat.

I thought he was talking total pony anyway mind. I don't see an issue with big rotors, you just need to pull the lever a bit less, no?


 
Posted : 04/05/2016 4:51 pm
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Don't crash in the peleton with 200mm rotors would be my advice.


 
Posted : 04/05/2016 4:52 pm
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Check your forks, some have a maximum rotor size, mainly xc and trail ones (32mm stanchions or thereabouts).


 
Posted : 04/05/2016 4:55 pm
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Purely hypothetical here - I wonder if on massive rotors, at everyday speeds, you'd end up glazing pads as you wouldn't really generate enough heat when slowing down...?


 
Posted : 04/05/2016 5:00 pm
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They aren't light.

Most 200mm rotors are 190-200g

Most 160mm rotors are ~100-110g (I've got some 50g ones!).

That's 1/3 lb saved between 203mm rotors and 160mm before you start looking at fancy designs.


 
Posted : 04/05/2016 5:07 pm
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6-7 years ago I built a bike with BB7's and the only sets I could get for a decent price came with 200mm rotors fore and aft.

They fit in the back of a 456 fine.

They are still there and still fine, they are very responsive, that might equate to grabby I guess.

My pads have never glazed.

I'm 100kg dripping wet and I've not snapped a spoke on that bike (the bike is 33lb too).

I have never crashed in the peleton.

The Pace RC40xcam forks are fine for 200mm, but the bushing on the RC41 wore out a bit quicker (ie I've had to change them once) no idea if that is down to the brakes though.


 
Posted : 04/05/2016 5:35 pm
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From my experience, the positives of increased stopping power and resistance to brake fade from 200 front/180 rear outweighs the additional weight and risk of bending them in transit. But (..there's always a but! :)), I think it depends on your weight and how and where you ride- also the make and model of brake and state of their fluid. FWIW, I'm just under 90kg in full gear and have a weird preference for riding trials-type super steep technical natural descents, where the brakes are on and off constantly - and I normally go over to the Alps, Spain or Dolomites once a year to get my 'big mountain' fix.

In the UK, and with decent brakes, I've only occasionally felt the need for anything bigger than 180/160 or 180/180 - and for trail centres, 180/160 is absolutely fine. However, in the Alps, even with fresh brake fluid and a decent bleed, I've experienced various degrees of brake fade with Avid, Formula, Hope and Shimano when running 180/160 rotors. I've given up with fancy bling multi piston brakes now and just run standard XT and SLX with ice-tech rotors on my 'big' bike.
After almost boiling my XT brakes in Italy, a local guide recommended bigger rotors, and they work a treat - noticeably more power and no fade on long descents, but still not too grabby for general pootling around in the UK.

I guess with brakes, theyre one of those things where it's maybe be better to have some spare capacity and put up with the additional weight (unless you're a XC racer....in which case, you need therapy!....hee hee)


 
Posted : 04/05/2016 5:42 pm
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Vacations to Canada (whistler and north shore) always 200/200 or similar (203) large size rotors

For the UK, typically 180/160, perhaps 200 on the front for dh racing.

Noticeable difference in leverage/modulation and heat management between each rotor size,especially on the front brake which has the real stopping power


 
Posted : 04/05/2016 8:55 pm