You might have heard of thicker rotors, you might also have come across finned rotors. Well now, Galfer is offering both with their new Disc Shark concept.
It differs slightly from something like the 2.3mm TRP rotors or indeed the Ice-Tech rotors from Shimano, but could be said to have traits from both. The new rotors measure just over 2mm (2.05mm by our measurement). Rotors often used to be built to be around 1.8mm width at the braking surface, but in recent years we've seen this increase. This increase is largely to help resist heat build-up, but could also help reduce flex under heavy braking load.
Galfer's rotors go even further by extending the design to include a finned aspect. The added mass of the one-piece rotors should not only help keep the high temperatures at bay but the increased surface area should also act as a heat sink, and also help the rotors lose heat by causing more airflow disruption as the wheel spins.
The pattern of the rotors features a clearing gap that alternates with blocks of 12 smaller holes along with the rotor. These smaller holes should again increase surface area and cooling. Galfer claims this design gives a 30% reduction in operating temperature compared to other high-end discs currently on the market. They also claim that these discs, with the lower running temperatures, could help increase the life of your brake pads by 25-40%.
Galfer also says that the design of the rotor means that less pressure is required in the brake line under the most fatiguing conditions, meaning less effort is required to brake. This, they say, translates into a 5-10% increase in braking power under normal conditions, although they don't stipulate exactly how.
The rotors use a laser-cut pattern that also claimed to benefit from "optimal geometry" to achieve the best possible performance. Any level of flex at the caliper or rotor will lead to a vaguer sensation at the lever. A rotor that handles load better, and is stiffer, should give a more positive feeling and a stronger initial bite to the rider.
The discs have subtle branding and a fitting to discretely hold a magnet for a speed sensor on an e-bike.
The setup has been aided in its development by a raft of the world's fastest racers, including Myriam Nicole, Amaury Pierron, Thibaut Dapréla, and Martin Maes. Galfer says the disc has already helped win World Cups, as well as the rainbow stripes under Myriam Nicole.
Initially, the discs will be available in 180, 203, and 223mm sizes but they'll also eventually be including small rotors for XC riding, too.
The new Disc Shark will be available from June 2022
in the following sizes, weights and prices:
DB0223W2 (ø180 x 2.0mm
- 127 g): €85 + VAT
DB024W (ø203 x 2.0mm
- 174 g): €90 + VAT
DB027W (ø223 x 2.0mm
- 237 g): €95 + VAT
For more infomation please visit Galfer.eu
I´ve installed these on every bike from 160mm on my road- to the 203 on the enduro bike, be it 6hole or centerlock.
Way better than any Shimano disc and still not expensive.
Are you sure? I thought they just said "Galfer Patent" for the style of wave.
When a steel is not a steal
I do have disc brakes on my road bike though
When I have seen the title I was like "cool my next rotors" but after reading the article the main bold claim is for me the price which is more than double the wave model price incredible!
1) Rotor adapters were mismachined, the face that met the hub was .025" out of spec.
2) Rotor adapters were just laughably designed, way too shallow teeth, and the pins that hold the rotor were too small.
3) I ordered MT7 pads and there was nearly .035" swing between the thickest pad and the thinnest. Zero QC.
4) After getting replacement rotor adapters, after installing everything the rotor still had a bad wobble. Upon further inspection they didn't deburr one of the 6 bolt holes.
Also; I've never had pads or rotors so susceptible to contamination. 1 drop of fluid or anything would contaminate the rotor and pads.
What could possibly justify 100+USD for a brake rotor? These are likely plain cold rolled medium carbon steel and the manufacturing technique is laser cutting. These factors are the same as the $10 rotors one can find on amazon or ebay. I've purchased several 203mm rotors new for less than $10. All have arrived flat and haven't warped over time. They are hard and don't rust readily. They outlast the Icetech rotors I replaced.
I love how people will pay 3-10 times more for a pattern that costs roughly the same to manufacture, and one that only claims a 5-10% benefit on a part that wears over time.
Very happy with the Galfer rotor and green pads,they made my Code R brakes decent from being totally crap,no brake power at all with the sram stock rotor and metal pads.
It looks really good,but too expensive for a brake rotor.
I enjoy the Gold. According to the owner, they market them so distinctly different with the whole ‘ebike/heavier riders’ for gold and red for the rest because they got a million emails a day asking so they figured they’d try to make an easier line to differentiate with shopping. But anyways, he mentioned to me, gold is the way to go for power and handling heat. I’ve been using them and it’s actually pretty wild how much more incredible they are and noticeable compared to others such as green Galfer pros.
I’m a big fan. I’d recommend Gold
Yeah gold would have been my bet too. I’ll get some ordered.
Right on! Hope you enjoy them
this will hoover up the suckers of there cash no doubt, might have taken more interest
if they'd added teeth, if only to make the disc maintanace threads more gory : )
Happily content with my Hope rotors, they do me.
Presumably they're compatible with all braking systems?
On a side note, i did a couple of things that got the brakes feeling spot on with very little free throw:
Bought a caliper alignment block and aligned them properly. on hope brakes it's very difficult to do this properly by eye;
Also i couldn't quite get the last bit of air out of them no matter how much i bled the system, but i read somewhere that putting the bike vertical on its back wheel or in a workstand and cable tying the lever toward the bar as if you were squeezing the brake lever really hard, then leaving for a few hours at least, this forrces any trapped air to migrate up to the reservoir, then you whip the top cap off, wipe away any air bubbles, refill to the top and the brake feels perfect.
It worked for me, maybe give it a try?
And if you do the cable tie thing, make sure to do it with the wheel on the bike! Sounds obvious, but it's the kind of thing i screw up on. That, and stripping threads.
Obviously got to be careful not get oil on the pads, but it will make a difference to lever feel, particularly if your pads are significantly worn
Often times I will do a quick lever bleed with the wheel in as this serves the same purpose, ‘overfilling’ the system resulting in consistent lever feel even with old pads.@IamDave:
I never thought to do this with the wheel in and old pads - i'll give that a try.
The drilled holes in the rotor increases the cooling surface area of the rotors, like the finned head on an air cooled engine. A solid rotor would increase the pad contact area, which leads to heat build up quickly, and glazing pads/rotors.
Increase mass as @jeremy3220 noted does help to slow heat build up, but once heated you have a heavy thermal mass that also cools slowly, which is not advantageous in moderate long DH sections. I cant tell if @jeremy3220 is being sarcastic or not, but modern race car discs are incredibly complex, being made of carbon and ceramic composites that are vented and cooled.
The holes also help to clear debris, and gas buildup from the wearing pads, which actually helps the pads bite harder, I’d expect a very positive initial bite with these rotors, time after time after time, as they should effectively reduce any build up on the rotors.
I’m not sure the article explained the benefits well, whether their claims of actual numbers of increases is legit is another thing as it’s difficult to substantiate in the real world.
Car wheels, and bicycle wheels share little differences, other the basic names of the components in these cases.
A dirt bike would be a more apt example, taking a look at hard enduro bikes, they still use the cross drilled rotors to aid in all the benefits previously mentioned. No one uses a solid rotor, as it has too many drawbacks, heat build up being one, glazing, warping, etc being the unfortunate outcome.
I guess I was thinking of race cars at that level.
My limited experience with some endurance racers, had also made the shift to more exotic materials, as well as at the GT level. Different horses for different courses as they say.
For the discs you manufacture, are they vented, and drilled?
My father used to wrench on some get class Porches back in the day, and they all used vented, and drilled rotors, but that’s going back 40 years or more
The added material is there as a heat sink/strength/stability once you make those holes.
Why do you think motorcycles at the mid to high performance level would use a drilled/cutaway rotor?
I also run our ECER90 test program, which is quite demanding on discs. Plain rotors ALWAYS pass, most the time cross drilled crack (same rotor just drilled) and that’s deemed a failure. SBS patented dimples in the outer diameter of their discs for this exact reason, you still get the look but they don’t crack as much
Here’s a typical race rotor we produce
I've debated with coworkers why they are cross drilled when race cars are not and our conclusion seems to be looks. Brakes look way cooler cross drilled.
This was an interesting article a few years back where they analyze why the high performance brakes on a nissan failed in a really bad crash. After a fair bit of testing, their main conclusion is that insufficient air flow to the brakes is a major contributor to the failure.
Note that it had nothing to do with cross drilled cooling or flat rotors in this case. In this case, you have to consider the whole system, not just the rotor shape.
The holes have to be pretty small when you're talking about rotors that are about 2mm thick. The radius of the hole can't be bigger than the rotor thickness to break even on surface area. You're talking about relatively small gains in surface area.
Also, you misunderstand what the effect heat capacity has. A higher heat capacity doesn't need more cooling because it won't be as hot in the first place. Ultimately it's about finding the right balance between cooling and capacity. On a mountain bike rotor the holes are primarily for clearing debris and saving weight, the gains in cooling are minimal at best.
The first mention of "Nissan's official opinion" was "the brake pads are not designed for racing" so they started by testing brake pads. Further things were later tested with the motive if being thorough.
The OEM probably thought that the car is not being used as intended so it is not out problem. It is designed to look like a race car but not designed to race like one. Not worth the effort to resolve.
Now maybe I’m incorrect, but I’m cool with that, as I’m learning. If we are discussing increased surface area by drilling holes.
If said hole drilled is 2mm, (I’m just picking random numbers here, as I don’t know the actual hole size)
A= 3.14 x r squared
3.14 x 1 squared
3.14 x 1
=3.14 x 2 (rotor has two sides)
Now the new surface area after hole drilled is essentially a rectangle that is the circumference of the circle x the 2mm rotor thickness
Circumference is 6.28 (2 x 3.14 x r)
Area of rectangle = l x w
6.28 (l) x 2 (w- rotor thickness)
Now subtract the original 6.24 (original surface area of both sides of the hole you drilled, and your left with 6.32.
By drilling the 2mm hole, have you effectively doubled the cooling surface area (not contact area), while clearing, water, dirt, etc?
I’m just taking a stab at this, I’m not standing on a milk crate professing I right. I’m sure I’ve missed something, so I’m open to learning, so go easy if I’ve fooked it up.
Your calculation looks correct but what is that increased area as a percentage of the total rotor surface area? You also have to include the lost heat capacity. I don't know what size holes they drilled. Some are obviously much bigger than 2mm.
You need something to clear debris and I'm not sure how feasible slotting mtb rotors would be.
If that’s the case they have increased cooling surface area from 4200ish mm from 2100ism mm.
I’m not sure on the total surface area, but if that’s the case, they have effectively doubled the area by drilling the holes.
True there are several larger holes, not sure on the size, but I’m making the assumption they’re accounted for.
So if we are debating the effectiveness of “adding” drilling holes, then I think they have made a good choice.
The capacity of the rotor to absorb heat has, as you mentioned been diminished by drilling the holes, but the bump in thickness might account for that.
Realistically, for heavier, fast riders, these might make a significant difference in heat management as a whole, and potentially much more durable.
I might buy one, just to check it out now.
Really appreciate your polite, educated responses.
a set of verniers should probably cost £40-50 to be trustworthy. these look to be the £8 variety.
We use a lot of mitutoyo at work because they don’t bend or get mangled as much as cheap callipers, but that’s the main reason. The other reason is the quality of the battery compartments and screw holes is shit and often gets damaged replacing batteries. Our in house metrologist is a big fan of the cheap callipers and micrometers you get from big box stores and eBay/AliExpress.