R1200rt Rear brake rotor recommendations?

[Plasterman]

Any good choices for a replacement rear brake rotor for my 2009 1200 RT?

 

What is a wave rotor , is there any benefit to it?

 

Tom

[Guest Kakugo]

Wave rotors were originally made for dirt bikes because of the "swiping" effect. Then somebody noticed they also have the advantage of less weight, meaning less unsprung mass, and hence found their way on road bikes as well.

There's a long going controversy if they are really worth the trouble over conventional round rotors.

 

Some maintain the edges of the wave rotors provide additional contact area for the pads and hence perform better but, to be completely honest, I installed wave rotors on one of the wheel sets on my last sportsbike and found zero difference with regular rotors despite using brake pads designed for wave rotors. I am under the distinct impression had I not used wave rotor specific pads they would have been worse than regular rotors.

 

In my experience they are more of a "cool factor" than anything else: sure, they help shave off a little unsprung weight (which is always good) but apart from that they are nowhere near a wizardly as advertised.

 

As for your question about which choices there for a rear brake there are four brands I am aware of which offer rotors for the RT: Brembo (aftermarket), ABM, EBC and Braking.

ABM only offers the wave pattern, Brembo and EBC only the round pattern while Braking offers both.

Braking has been my go-to aftermarket supplier for over fifteen years. Cannot really fault them and they wear much more slowly than equivalent Brembo units without losing anything in stopping power.

My experience with EBC rotors is quite negative: they only work well with their own brake pads. Anything else means literally seeing the rotor wear under your very eyes.

I remember fitting EBC rotors to my brother's Honda and he literally went through them, prompting me to ask if they were made of cheese. Once I installed Braking rotors, no more issue. In facte he said those were the best rotors he ever had on any car or bike (and he goes through quite a few).

[MikeB60]

Don't think the Braking brand is available in the states.

 

I've used the ABM wave rotors available from Beemer Boneyard on my 2006 RT and have several friends who have them on their bikes as well. No issues and much better price point than stock.

[Guest Kakugo]

Don't think the Braking brand is available in the states.

 

Braking has three distributors in the US:

 

Western Power Sports

Tucker Rocky Distributing

Lemans Corporation (Parts Unlimited)

 

Now, I am not sure if the whole line is available in the US and how much time would something not on stock take to be delivered, but it's worth a shot.

 

I was actually tempted by ABM rotors, but the local Braking dealer was able to beat their best price by a fair margin... proving once again the cheapest part on a BMW is the rider.

[racer7]

In track use, may things are justifiable that make no sense for the street. Wave rotors, race pads and similar are either not sensible for street use or stretching into the experimental zone.

 

For street use on any kind of vehicle it is unwise to get too far from OEM unless you have the engineering skill (know all the relevant math and can source all the needed materials). Any changes made should be done on solid info and designed to eliminate whatever defects might exist in the OEM stuff that are perceived by the user.

 

For example, stock pads may dust too much for owners taste, not have the desired modulated feel, etc. Or maybe the owner wants to get one bike in his fleet to match the braking feel of a different one. In such cases, pad substitutes that are proven to reduce dusting, alter friction coefficient in the desired direction, etc may all make sense.

 

Similarly, for rotors- if they wear out too fast, warp (note that whats called warping is most often erratic pad deposition) or don't work well with the chosen pad, a rotor change might be helpful. But it is much harder to predict what type of result will happen when a rotor is changed compared to a pad. The effects of rotor surface finish (rarely stated in a quantitative way for other than very expensive race rotors) are substantial to wear, break in, and behavior. Whether or not rotors are burnished and how matters. Material matters because it impacts deposition, a key factor in how well pads break in and work. Weight matters because lighter rotors will reach higher surface temps in extreme use- that can shorten pad life and rotor life.

 

So I would always suggest staying as close to OEM as possible unless you have solid info that anything different is truly going to be an improvement. The chance of an unwanted result is too high- especially for bikes with linked systems where the rider uses mostly the front brake.

 

For me, balanced, solid braking performance always outweighs a few $ so economics are never the driving force in what I use.

[dirtrider]

clip---

 

What is a wave rotor , is there any benefit to it?

 

 

Afternoon Tom

 

Wavy brake rotors have some advantages & some disadvantages.

 

Their biggest advantage is: the petals of the brake rotor have spaces between them & that allows the rotor petals to sweep dirt, mud, & large amounts of water out from between the brake pads. (this is very desirable for dirt bikes & off road bikes but not a big deal for street bikes).

 

The other advantage is: the outer diameter has a larger convoluted surface showing so they can cool just a bit better & warp a bit less. (your BMW really doesn't have much of a problem with either).

 

The other advantage is: the wavy rotors usually weigh less, so less unsprung weight. (not a big gain here on a BMW street bike, but can be noticeable on a light weight dirt bike riding off-road in the deep sand)

 

The other advantage is: they just look cool (but with bags on the BMW motorcycle not much gain with this on the rear)

 

The down side to both road bikes & dirt bikes is: while the wavy rotors allow excess water to be spun out it also allows water in while riding at lower speeds so the wet braking can be diminished for the early part of a braking event.

 

If you are looking for gain without much cost then holes drilled in the rotor surface give better cooling, usually less warping, a place for some water to go, but can sing under some light braking, especially when wet.

 

The stock BMW RT already has enough rear braking to lock a wheel up (with ABS disconnected) so you really don't need much more braking enhancement on the rear.

 

For my performance bikes I usually change out the stock stainless steel brake rotors for some nice dead cast rotors as that allows better brake modulation & more precise braking, but this really seems unneeded on the large BMW RT's & the cast rotors do tend to rust if pads & rotors are not completely dried out before parking the bike.

 

[Plasterman]

Thanks for all the advise. Purchased to rotor from BeemerBoneyard. Looks like good quality at a good price

[Bernie]

Thanks for all the advise. Purchased to rotor from BeemerBoneyard. Looks like good quality at a good price

 

That is what I used for the rear and front.