Ted Ciamillo’s not forgotten his brakes while developing the Gravitas cranksets, and the new Negative GSL alloy brake calipers are the proof.
He teased us with some of the details when we did our factory tour, but this is our first complete look at the new brakes. They drop about 15g from the prior version in two ways. First, the quick release is now alloy, versus stainless steel. Second, by using new pad holders that are slimmer, which also improves clearance for wider wheels and tires. Claimed weight without pads is just 155g for the pair.
But weight savings isn’t all that’s new…
Feel, Modulation and adjustability is also improved. At the pads, several washers of varying thickness are included to help fit them to different rim widths. Basically mix and match, or use none at all, depending on how wide your rims are (wider rims use fewer spacers).
A new colloidal copper film bearing surface for the titanium titanium center bolt helps it roll smoother, which lends a better feel at the lever and improves fine control. Also known as modulation.
Lastly, there’s now a pressfit counter bore on the shoulder of the spring nut (the piece that the center bolt threads into to holds the spring). This prevents the front bolt from being overtightened, which could effectively seize the two arms between the bolt and nut. The benefit is that it lets riders eliminate play in the system over time, a feature not found elsewhere.
Ciamillo told us the effect is that the brakes feel like new longer, and it provides better modulation by reducing static friction as parts wear. Here’s how: Every time you brake, you’re applying force in two directions at the center bolt – sideways from the arms pushing against the wheel and upward from the wheel’s force pulling the brake as a lever. As parts wear, as all parts will, play can develop if the bolt ovalizes and/or the hole wallows out. When things aren’t perfectly round, static friction (the friction that needs to be overcome to start a part moving) increases, meaning it’ll take a bit more effort to start the calipers moving. You might not notice that during initial braking, but trying to modulate in more power once you’re already braking will require more power to overcome the static friction. But, once that static friction is overcome, that additional power will easily overcome normal dynamic friction and clamp the brakes more than intended, which can make them feel grabbier than you’d like. Basically, that’s a loss of modulation. By using the center bolt to keep tolerances tight, you can reduce the likelihood of play developing in the first place, too. The other benefit of keeping things tight is quieter performance. Lest you think it’s just a design to overcome a flawed brake, Ciamillo is talking years of regular use before requiring any real adjustments.
Retail is $369 and they’re now only available directly from Ciamillo.com. Each is handmade in their own factory.
Ciamillo says proper set up is key. The barrel adjuster isn’t intended to be a set up device, the pad spacers are. At proper set up, the cam should be at less than 50% of its stroke when it makes contact with the rims. This leaves plenty of stroke to be used for power and pad wear.