Santa Cruz Bullit Floating Brake

This video shows how the new Santa Cruz Bullit Floating Brake Works.
You can pick it up from www.santacruzmtb.com just click on store.
I definitely think it is worth it. It makes a big difference in dealing with brake jack. It helps the bicycle track better when the brakes are applied.
If you have any questions, feel free to message me on youtube or on PinkBike.com. My name is bighit1212. Check out my website www.sierracyclesny.com.

Category:

Sports

Tags:

• Santa
• Cruz
• SantaCruz
• Bullit
• Bullet
• Floating
• Brake
• Giancarlo
• Paternoster
• Science
• Research
• Jack
• brakejack
• Sie

[1982FMJ]

Does the floating brake unit eliminate most of the brake dive.

[TissTime4Tea]

@1982FMJ

if by brake dive you mean brake jack, then yes.

brake dive is in the front and is caused by a decrease in momentum while coming to a stop.

brake jack is the inability of the rear suspension to compress when the rear brake is applied.

The floating brake only helps to eliminate brake jack. and it does so wonderfully.

[insanitylevel99]

@TissTime4Tea

no he was right single pivots get brake dive as in the suspension compresses under very hard braking. brake jack is when it pushes the suspension out as in back to where the bike sits with no rider.

[TissTime4Tea]

@insanitylevel99

I am not so sure if you completely understand what I said. I may have been a little unclear. Either way, "dive" is used to describe the forward pitch of the bicycle to do an effective mass transfer (ie. the rider). Dive has nothing to do with "jack." By the way, you are not 100% wrong in your definition of brake jack. Matter of fact you are pretty close, but the physics of it is a bit different than what you describe.

[TissTime4Tea]

@insanitylevel99

Full extension (vs. full compression, which is the bike at bottom out) is a SYMPTOM of brake jack. Brake Jack occurs when the rear brake is applied while the suspension is cycling through its travel. The wheel makes a contact point with the ground and creates an excess of angular force (into the ground in relation to the angle of the wheel/axle path) which essentially locks the swingarm in place. It actually has almost nothing to do with the shock.

[TissTime4Tea]

@insanitylevel99

There are many symptoms of brake jack.

1. a numb ride

2. a rear wheel that "locks out early"

3. a bike that "sags in the corners" (if you tend to brake in corners)

If you have any other questions regarding brake jack, squat/anti-squat, or suspension setup please don't hesitate to create a video response or shoot me a pm. I work with this kind of stuff all the time it is part of my research/job. I would love to clear up any misunderstandings anyone might have.

[anddreas2lair]

i still dont undestand why this makes any differance than using just a normal disk

[peanutaxis]

...this sets up a torque involving the point where the brake-arm is bolted to the frame, and the point where the suspension arm is bolted to the frame. In position 1 in your video this would cause jack, and in position 2 this would cause squat. So even if one could completely isolate the brake, it would still induce torque on the frame and produce interference.

Let me know what you think........

[peanutaxis]

It occurs to me that even if one could achieve a completely static brake caliper (a constant angle between the three points: the tire contact point with the ground, the rear wheel hub, and the brake pad) right the way through the suspension travel, one would STILL have brake-suspension interference:

Applying the brake would create a torque whereby the rear hub would be being pushed towards the front of the bike and the brake-arm would be being pulled towards the rear of the bike....

[peanutaxis]

It seems that in position 1 in your video, the brake caliper was moving backward (away from the front of the bike). This, it seems to me, would mean that when one applied the brake it would induce jack (suspension de-compression) in the back wheel.

The 2nd position in your video looks like the caliper is moving towards the front of the bike. When applying the brake this would induce squat.

[peanutaxis]

Hello TissTime4 Tea,

I have been thinking about brake jack for a few days now. The hardest thing to do in one's mind, I think, is to separate angular momentum conservation out from pure brake-suspension interaction ('jack').

Particularly I have been thinking about Kona's DOPE system because I recently saw a bike with two options for where to attach the brake-arm on the main frame. Your system in your video is the same except that you have infinitely many positions to attach your brake-arm.

[tomwilz15]

give it to me and i'll.... nuthing, just give it TO ME!!!