In the story about the Tucson Motorcycles racer, you may have noticed the front brakes in the various images and they looked a bit small. Those brakes are only 230mm compared to a more normal 320mm disc. But if you look more closely, you’ll see something else, there’s 2 of them on each side of the wheel for a total of 4 discs.
Why 4 small discs? According to Beringer, the advantages include:
* Power Increase of 20% compared to a single 320mm cast iron disc which allows to the riders to shorten their braking distances significantly. Some comparative tests have shown evidence of this gain as well as a lower temperature of the discs.
* Weight saving is significant compared to the standard systems Cast Iron 320 weight: 1950 g Quadruple Disc 230 weight 1460 g The 980 g saved in unsprung weight improves the grip of the front wheel.
* Reduce the gyroscopic inertia to make turning easier: “The gyroscopic inertia of the Quadruple Disc is 3 times less than the inertia of 320 discs and 30% less the inertia of carbon discs”
The Beringer quadruple discs use a fixed center pad with caliper operated outer pads.
If you’ve been reading The Kneeslider for a while, you may remember another front brake design intended to reduce gyroscopic inertia, the reverse rotating brake rotors from designer Rob Kasten. How well any of these work in practice to reduce steering forces isn’t clear, though anecdotal reports from racers seem to be positive.
I’m not sure how long this Beringer design has been around but it’s available for a number of current sportbikes. Interesting.
Link: Beringer Brakes
Hugo says
make them out of a CMC (Carbon Ceramic ) and it’s even more interesting. There was a guy who raced in the French SBK with this system. probably the cost doesn’t justify the system compared to a normal one…
hoyt says
The cost justification could be short-term if a higher production volume would bring the cost down within a closer range to justify.
This is cool. It shows off more of the wheel (which seems to be in vogue) while offering what appears to be improved performance.
Is it lighter than a perimeter brake setup? Easy to change a wheel for endurance racing?
GAMBLER says
lighter? lower MOI?
pabsy says
i like it, a much better directon than the muddle headed perimeter systems
modern equipment works better than the riders ability to use it but for racing it could make a difference and doesnt add much complexity
the biggest advantage is reduced gyroscopic effect
very neat as a performance add on
Spaceweasel says
I saw some of these years ago on some streetfighters in England. Couldn’t find the blokes who owned them to ask any questions. I was looking to install a set on my Speed Triple, but couldn’t ever find any info here in the states.
It seems that the quad discs are made of iron. How much lighter might they be if they went to carbon…
Any word on pricing? Their web site isn’t very helpful.
trojanhorse says
Ok, could someone explain to me how the brake rotors are not pushed towards each other and deformed as the center, double-sided brake pad wears down? Looking at the picture I don’t see how the system can auto-adjust for pad wear, like a traditional setup does.
B.Case says
trojan, my guess would be that the semi-floating discs take care of that.
Ry says
Why not add more discs that are even smaller diameter like a clutch assembly? 100mm discs?
Blair says
someone has got the math wrong, 1950 – 1480 = 470 not 980 stated above. Unless they are referring to the weight of each side which isn’t made clear, in any case 2 x 470 is 940 anyway.
Dave says
What about bolting another set of calipers and discs in front of the fork? Quadruple the braking power.
kneeslider says
Blair,
Check your numbers, 1460 not 1480. 1950 – 1460 = 490 for each side, times 2 is 980.
FREEMAN says
If it’s all a matter of weight then the perimeter system is the way to go. Less parts to fix, maintain, and replace, too.
trojanhorse says
Thanks B.Case, I think you must be right. Seems like the rotors must be able to float quite a bit to compensate, if the drawing is even remotely to scale.
christopher says
FREEMAN- unfortunately it is not all a matter of weight. it’s more about the placement of weight. take a regular 26in bicycle wheel in your hands (imagine you’ve got a rod through the middle to hold onto) start it spinning and then try to turn it. now do the same with a 20in wheel. assuming they’re roughly the same weight, the smaller wheel is easier to turn. perimeters look great, but placing as much of the rotational weight of the brakes towards the center of the wheel will ALWAYS be the better performing option. btw, i love this idea. seems obvious now i’ve seen it.
Azzy says
I think another set of calipers would heat up the rotors too fast, and cause them to warp pretty easily.
B.Case says
I think Buell would argue that the placement of their perimeter rotors is ideal, actually. The design of the perimeter system allows the structure of the wheel to be highly optimized, and therefore lighter, due to the reduced load at the wheel hub. And, there’s only a need for one rotor and one caliper. Overall, if it’s not lighter than a conventional setup, then it’s at least comparable.
Last month at the MOTO-ST at Barber, I noticed Buell was doing quite well with the perimeter setup. Ultimately, it was the conventional rear brake that caused problems. Granted, most riders don’t use the rear brake, but it was actually the extra seconds in pit lane that cost them the lead.
All this jibber-jabber about which alternative technology is better, really makes very little difference in my opinion. Every time I want to know just how good we’ve got it these days, I pull the cover off my 27 year old Yamaha and drop-kick her to life. Shimmying and shaking down the road, with cast iron platters and single-pot grippers, I must remind myself to anticipate stopping at least a block before I need to.
hoyt says
Using the rotating bicycle wheel example….
when trying to stop the rotation of the wheel, which is easier: stopping the wheel by grabbing the outer edge of the wheel or stopping the wheel by grabbing the smaller, rotating device around the hub?
I think you would find stopping the rotation by grabbing the outside of the larger rim would be easier (in that example).
Both the perimeter and this design have advantages….it depends on the application. It is curious why no other race bike besides Ghezzi-Brian and Buell have used perimeter brakes while racing….that is not to say, the perimeter is not better for street use (or even racing at the level the 1125R is racing).
RE: the comments above about carbon brakes…..you are referring to racing applications right? I thought carbon brakes do not work on the street due to not getting warmed up enough.
Sean says
I’ve seen these on streetfighters before, too. The perimeter vs hub mounted or even halfway up the rim mounted as in the BMWs is really just a tradeoff of maneuverability, weight, and stopping power. I’m more into former than the latter two, but the Beringers are very cool.
Hugo says
Tony Foale built a perimeter brake system, I think in the seventies or so…
FREEMAN says
The reverse rotating brake rotors are an interesting concept, but perhaps why not stick to whatever brake system floats your boat and just have a cylindrical weight hidden inside a solid wheel rotate in the reverse direction to counteract the gyro, if that makes sense? Then both systems are independent.
Alex says
Because then unsprung mass will be increased even more.
jp says
Beringer’s had these at least since 2000 or thereabouts. I had one of their brake systems on my 2001 CR250 supermoto. VERY very strong brakes, and used the same pads as a then-current GSXR-600. Was checking into a set of these for my VFR streetfighter project, but they were almost $3000US then.
Ry_Trapp0 says
very cool, i love these original and creative ideas! i still think perimeter is cooler though.
george tandrias says
if i am not wrong ,replacing 2 single discs with 2 dual and nothing else,the stroke(distanche)of brake cylinder(pump),should be increased twice,because of the double pads that will have to be pushed.a 0.25 mm grip tolerance for each pad.