By Jeff Cobb
This is the street portion of the review. We have not track tested them yet.
When it comes to safety and control of your motorcycle, arguable one of the most critical components is your brakes.
About a month ago we began evaluating GOLDfren S33 compound high-performance brake pads which we substituted for well-regarded EBC HH compound pads in the front and rear of a Yamaha R1.
So far we have been pleasantly surprised, but before we get into that, we’ll tell you a little bit about GOLDfren.
The Czech-based company began making sintered disc brake pads 20 years ago in 1991. It has since broadened its line to include products for small aircraft, industrial, automotive, mountain bike, and of course, on- and off-road powersports applications.
GOLDfren sponsors several world-class motorcycle racers, supplying them not just with brake pads, but also products from its range of brake rotors, over-size rotors and adapters, braided-steel-wrapped brake lines, and high-performance calipers.
For street purposes, GOLDfren’s products are certified by the strict German testing institute TÜV.
Frankly, learning that GOLDfren brake pads were TÜV-certified was one of the reasons why we agreed to test them. The German government standards are a reassuring sign of quality.
GOLDfren’s sintered metal brake pads come in a wide array of compounds from OE-replacement to racing, and the company says it spends a significant portion of its operating budget on research and development.
About GOLDfren S33 compound
The S33 series is one of a few race-worthy GOLDfren brake pad compounds that are good for track or street duty.
Interestingly enough, the S33 compound started life as an off-road application, but GOLDfren began using it for road-going bikes and found in this case what works in the dirt also works well on pavement.
The S33 compound is still being used by motocross and enduro riders at the world championship level, and is suitable also for aggressive road and track use.
The friction materials are engineered to stand up to intense heat, are self-cleaning, and environmentally friendly – with no asbestos or lead in them. They also shed very little brake dust.
GOLDfren says they offer a long service life which we have not been able to evaluate because that takes a lot of miles or severe conditions (like racing) to find out.
The S33 compound is also supposed to be not so hard on the rotor, and that would make sense. A softer compound pad that grips will wear faster than the rotor.
As is the case with tires, this is a trade-off. If you want ultimate stopping performance, you need ultimate friction, which comes from the brake pad being softer than a touring bike’s pad would likely be, for example.
Because a high friction coefficient is a safety and control factor, our personal preference is always for ultimate grip, so this suits us fine.
Setup and Conditions
The ’98 R1 we used is mildly modified with fresh RaceTech suspension upgrades and fresh Michelin Pilot Pure 2CT tires. Curb weight is around 440 pounds, and it has been dyno’d at 148.4 rear wheel horsepower.
Brake lines are stock, but the fluid is clean, and stock 4-pot Brembos and stock 310mm rotors up front work well.
Weather conditions were mostly ideal with ambient temperatures between 70-100 degrees F. We did not rain test, but GOLDfren says the S33s are suitable for wet conditions, and we have no reason to doubt it.
As mentioned, until we swapped in the GOLDfren S33s, we had a club racer and track-day enthusiast’s favorite in the R1 – EBC HH-compound pads – so this was a tough benchmark for GOLDfren to test against.
We cleaned, then mildly abraded the rotors with sandpaper, daubed a little bit of Permatex Disc Brake Quiet (goop) between the stainless backing plates and rear of pads to prevent resonance and squeal, and the pads dropped in as easily as OE.
Ideally, you would want a new rotor surface to interface with new pads, but we did what a lot of riders do, and just slapped them in after mildly scuffing the surfaces and taking care not to contaminate the new pads.
On the road
Immediately upon installation, the S33s worked pretty well, and I got a good sense that these would bed in to the existing minor grooves in the used rotors.
I spent the next 75 miles or more giving them only moderate use to prevent them from overheating or glazing, and to give them the chance to mate up.
Focusing on the critical front brake operation, after not too long, I began using them more aggressively, and they did not disappoint.
Taking the GOLDfrens up to speed on a variety of primary and secondary roads, they hauled the 440-pound bike and my 200 pounds (with gear) down as hard as could be desired.
Feedback at the lever is predictable, and initial stopping action is immediate. They are not grabby, but work very similarly to the way the benchmark EBCs did.
Doing hard stopping drills on a variety of road surfaces, the GOLDfren S33s were up to and beyond the task – depending on the adhesion capabilities of the road.
On moderately grippy roads, a two-finger squeeze will dive the front end and hum the front brake up to the point of lock-up – and this is with a properly setup suspension not prone to excessive dive.
On more grippy roads, I could easily have flipped the bike on its nose.
Not wanting to get too reckless, more often it was just a matter of modulating them at the edge. I noticed no fading on the street.
The rear brakes are far less critical and frankly, stock may be good enough for solo sport riding. If you have a passenger or carry a heavier load, rear brakes become more important. All I had to do was press my right foot with moderate pressure to see a tuft of expensive tire smoke in my mirrors.
The rear brake works fine as well, modulates predictably, and as is typical, can easily be locked up with moderate lever pressure.
The GOLDfren S33s have never squealed.
Human anti-lock brakes
Brake testing can be fun, and sometimes kind of sketchy. Last weekend on a country road where farmers drive their tractors, the pavement looked about average, but grip was actually slick.
At about 50 mph, I locked up the front a couple times inducing tire squeal and the front slid sideways before I let off a micro-second later.
Good stuff. Always nice to ride away from those and be able to tell about it. Trying front wheel slides on an off-camber road can put you down right quick and we do not recommend it.
Good enough for stunters too
The S33s have power to go beyond ordinary hard braking. Basically, I had all I needed, and assuming road grip was there for my fairly sticky Michelins, I could lift the back wheel at highway speeds if I wanted. A couple times I did lift the back wheel below 50 mph just to probe boundaries.
While I was not going for big stoppies, several times just for fun – after making sure no one was following me – I would nail the brakes on good pavement and skim the back tire off the ground at speeds below 20 mph.
Without needing to position my body weight too far forward, it was fun to hear the rear suspension linkage and tire unload and hit back down as I came to a stop.
That is about as hard as you can brake, and the S33s will let you do it consistently.
We also don’t recommend this unless you are already experienced.
We are calling this a street test because track use heats brakes beyond what you can achieve on the street.
As far as street duty goes, these are definitely better stoppers than OE, and will reliably haul you down as well as you are able.
GOLDfren says they are suitable for cruisers, sport-tourers, and other kinds of street bikes.
Even though they are high-performance oriented, they may be worth considering for other street bikes because strong brakes are important no matter what you ride.
Because GOLDfren already races with this compound, we are sure they will work well on the track, but we aim to find out as soon as possible how they work at ten-tenths pace.
In the mean time, we would recommend them as long as they fit your application.