CAT7RDR

New bike upgrades?
Sounds like you did not purchase the bike you wanted.
Why not put about 20K miles on it then change out consumables when they are worn?

BlazingPedals

His comment SHOULD help. He's telling you, you are worrying about stuff that isn't a problem yet, and may never be. Are you an ultra-clyde, going down long and steep descents? On a tandem? I think you're probably worrying about nothing and you should save your money for when you discover an actual problem.

Jon_g2 

I agree but look a the way PeteHski wrote to tell me not to upgrade things yet vs "you make no sense" like the other guy pretty much said. It's the way people say things that is like, if you have nothing nice to say don't say anything you know? Anyway, I do appreciate all input

Jon_g2 

I appreciate your help in more than 1 post I've had questions about.

I guess I didn't quite explain that I love to descend at high speeds and I do so very often so I wanted something better from the get-go if 105 wasn't good enough. I only asked if 105 wasn't good but people got mad lol. If 105 is good enough than I'm absolutely fine with it, but I wasn't clear about that I guess.

I should further add that I live in a very, very high traffic area and therefore I have to ride early in the morning because later in the day it's happened plenty of times where I have had to hit the brakes hard to avoid getting it by a car since there's so many cars in the road. Not ideal for high speed descends I guess but it's the way things are.

Anyway I repeat, I appreciate everyone's help.

Shadco 

Not a fan of Ice Techs, just saying.




.

Jon_g2 

I've read very good things about these as far as weight and braking performance. Have you had any issues with warping?

Shadco 

With the RT CL900s yes since installing these no more issues.

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t2p

I believe the RT70 rotor is an Ice Tech rotor - but might be mistaken

if so - that is a good rotor and will accept many types of pads and the construction (aluminum sandwiched between steel) is said to dissipate heat better

I believe the CL800 rotor is an Ice Tech Freeza rotor - also a good rotor with similar construction and with a slight upgrade over the standard Ice Tech rotor

I have Ice Tech rotors on three Shimano disc brake bikes - they work very well … they replaced Shimano low end rotors

If I rode at higher speeds I would have been tempted to go with Ice Tech Freeza rotors


There is nothing wrong with your inquiry on the braking system of your bike - regardless if you’ve never ridden the bike or if you‘ve logged 5K miles

Jon_g2 

Thanks for the information.

And yes, I never meant to sound like these rotors I have don't work or. I do believe in trying stuff out before replacing but I did mention that if the RT70s weren't good enough for steep descends I'd rather not have to find that out during a ride. I believe my braking technique is pretty good too. On top of that, it's my first brand new bike and I don't plan on buying another road bike for many years to come so I want to upgrade it where needed.

squirtdad

105 is far from bottom end for shimano

SoSmellyAir

You are going from (105 or SLX) SM-RT70: SHIMANO CENTER LOCK Disc Brake Rotor ICE TECHNOLOGIES 203/180/160/140 mm | SHIMANO BIKE-EU

... to (Ultegra) RT-CL800: SHIMANO CENTER LOCK Disc Brake Rotor ICE TECHNOLOGIES FREEZA 203/180/160/140 mm | SHIMANO BIKE-US

Yes, the cooling fins on the latter do help heat dissipation from the disc, although (as others above have suggested) heat dissipation from the pads may play a bigger role to reduce brake fade.

But it seems that most Ultegra (and GRX) bikes are now equipped with (XT) RT-MT800: SHIMANO CENTER LOCK Disc Brake Rotor ICE TECHNOLOGIES FREEZA 203/180/160/140 mm | SHIMANO BIKE-EU

Jon_g2 

Thanks for the link to those. I am definitely learning a lot.

veganbikes

Good rotors and pads make a big difference in braking but brand new equipment that you haven't ridden should be ridden for a bit before you start making changes like that. The only thing I would probably change on a brand new bike is pedals but a road bike shouldn't come with pedals in fact really no bikes from a shop come with pedals anything on it is just a test ride pedal. Maybe saddle if there is one I know that works super well.

On a flat bar bike I would replace grips if they aren't Ergon but beyond that I would ride the bike first always. Though I build my bikes from the frame up so I never really have these problems so I put the components I want or at least the components I want within my price range. If I got everything I want it would be Sturdy Cycles and Firefly with Di2 or Rohloff and a ton of really high end ti components and such. So I have to be semi reasonable.

Troul 

from the random brands i've tried with rotors & pads, I've noticed poor stopping performance & usually they'll squeal with the slightest splash of muck water. More noticeable when using resin pads. I prefer the metallic pads, even though they'll wear faster & lunch the rotor faster. Affordable metallic pads have been harder to find lately too.

Jon_g2 

I read metallic pads are quite loud. But you can't have it all I guess lol.

BlazingPedals

Well, I'm not exactly typical. My lowracers both have one disc in front and a caliper in back. Air resistance to help with braking is basically non-existent. Put me on a straight downhill and nothing short of a tandem team with a 70-tooth chainring can touch me. My home range is pretty flat, but I've had both lowracers in the mountains of Tennessee, with 8-12% grades and hairpins. What rotors do I use? Right now this one has a little sawtooth one that weighs 85g. The other one has just an OEM one from Avid. Unless you're running heavily loaded down big twisty hills, I think agonizing over whether Ultegra brakes better than 105 is kind of funny. But it's your money.

Jon_g2 

I do stress over the little things unfortunately. But it helps me learn lol. Nice looking ride 😁

CrimsonEclipse

The proper answer is: "kinda"

Here's the problem:
Is there a standardized heat dissipation rating?
Probably not.

And like all engineering, what is the compromise?

Is it "high end" because of the name? model number? material? shape?
Now add the other components: Calipers, pads, actuators, and levers.

So probably, yes, higher end rotors might dissipate heat better.
Now the question is: will you notice?

If heat dissipation is a primary concern, then I suggest a larger rotor.
More surface area = better heat dissipation.
Consider a system designed for cargo bikes or tandems.

Remember: in the world of engineering, ALL cycling components are low end.

Alan K

Sounds like a reasonable plan… so why not determine if an upgrade is really needed. Try a lower grade hill first and see how it feels and work from there to steeper grades.

There have been times when I have upgraded my bicycle components to the best available before trying, but it was never due to a concern that 105 or ultega will not stop my bicycle compared to DA set of brakes. On one of my steel bikes, I still have 105 brakes and they work perfectly well, as they are designed to do.

Jon_g2 

Yeah I guess I just like to swap out the things that don't work from the get-go. Or not necessarily that they don't work well, but that may not last very long because they're not of good quality like it happens many times because manufacturers want to save a few pennies. So my reasoning is that if things could be changed for not a whole lot of money, and on top of that you can sell the removed parts then why not do so? But you guys all post very valid points. I came onto this forum to learn and I'm definitely getting an earful from some people but I'm sure most mean well lol
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mpetry912 

to better dissipate heat, use finned pads perhaps ? that's where the heat build up is

rotors have lots of air passing over them

I like a "center lock" front hub over ISO. feels much more solid.

/markp

Alan K

You only need to be sensitive in assessing how well your brakes are working.
Various people have different style of interacting with each other but to be candid, in this thread I’ve not encountered any post I would consider offensive.

Enjoy your new bike, use it and don’t overthink.

[If you are really terribly keen about heat dissipation from rotors, as a few participants already suggested, use larger rotors.
If that isn’t possible, there’s always the DA rotors with Al layer shaped to dissipate more heat, specially at faster speed. All else inadequate, find someone to custom design rotors for you where instead of Al, a Cu layer is used - with better coefficient of thermal conductivity (a bit heavier though).
Here’s another option, use a wheel set that can use rim as well as disc brakes - combine the two together - it’s quite doable! ]

PeteHski

For reference I’ve ridden stock 105 brakes down twisty 20%+ descents many times on my Giant Defy and it has the small 140 mm rotors front and rear. Not a hint of brake fade or lack of power. I’m an 80 kg rider with reasonable technique. I’m a confident descender, but fairly conservative. I’ve done some big climbing/descending days (4000 m) on this bike and never even felt the need to fit a larger 160 mm front rotor. The standard pads are quiet too and have good wear life.

ofajen

Are you actually brake-limited very much? In many circumstances you will be traction-limited so the rotors don’t matter so much.

Otto

The Chemist

I use Jagwire rotors on my road bike and cheapo no-name brand rotors on my gravel/commuter bike, and honestly I don't notice any really performance difference between them.

The Jagwire rotors look better, though. 😂