Brake drag reduction clips

[Ecky]

Originally Posted by cbaber

Did you spin the wheel before and after installation to see if there was any improvement that you could feel? I'm also skeptical of a spring that you can be bent with your fingers. The force needed to separate the brake pads is probably more than the spring can provide. I'm curious if cleaning and lubing the caliper would help the little spring out. Did the instructions mention anything about applying the springs to a brake caliper with 200k+ miles on it and how that brake dust buildup might effect the parts performance?

Originally Posted by California98Civic

I think you have a better fit, most likely. Looking forward to your results.

A test suggestion: Since the improvement if there is one will be too small to measure in FE and since ABA is a bit too tough, how about before and after video of the wheel spinning up on jack stands. Get the wheel to 15 or 20 MPH, hold it, let it glide to a stop. Video the wheel. See if the clips help the wheel spin even half a second longer.

Just a thought.

-james

Good idea James, but I don't actually have a set of jack stands, just a beefy hydraulic jack and the crappy one that came with the car.

When I was putting the new brake pads on, I noticed that even pressing very lightly with one finger on the caliper greatly increased the resistance to spinning the wheel. Also, they are stronger than their appearance would suggest (definitely a lot more force than a bent paperclip would provide), though definitely less than I expected. I have no data yet, but if pressing lightly on the caliper has that effect, perhaps pushing outward lightly is all that's necessary.

@cbaber, I'm not sure if it's supposed to be this way but there's some resistance from the transmission when I attempt to spin the front wheels, so it's not easy to judge. When I do the rears it make be more telling. I'm still breaking in my brake pads anyway.

[RedDevil]

Even with the (extra in my case) clips I can feel and hear (window down) the brake pads scrape the disk. Apparently they stick a bit.
A sharp tap on the brake cures it, and so does the occasional dent in the road. Another benefit of running high tire pressure; the bumps get through

[Ecky]

Got back from my trip, and as I expected, any gas mileage changes were small enough as to be indistinguishable from noise. However, I *have* noticed a change when sitting at stoplights - specifically, I tend to roll backward or forward now from something as small as stopping at the edge of a painted white line.

I believe I'll be getting a set for my rear brakes, they're certainly not hurting.

[Piwoslaw]

Originally Posted by Ecky

However, I *have* noticed a change when sitting at stoplights - specifically, I tend to roll backward or forward now from something as small as stopping at the edge of a painted white line.

That's proof that they are working

[IsaacCarlson]

Originally Posted by Ecky

Got back from my trip, and as I expected, any gas mileage changes were small enough as to be indistinguishable from noise. However, I *have* noticed a change when sitting at stoplights - specifically, I tend to roll backward or forward now from something as small as stopping at the edge of a painted white line.

I believe I'll be getting a set for my rear brakes, they're certainly not hurting.

How much air do you have in your tires?!

[BHarvey]

Just put them on the rear of the car and spun the wheels before/after and there is a big difference. The wheels go twice the revs with the clips vs before. Too bad they don't make them for the front calipers....

[Tesla]

Originally Posted by t vago

It'll be very interesting to see the results of any A-B-A testing for these clips. Been considering getting a set.

Originally Posted by California98Civic

A test suggestion: Since the improvement if there is one will be too small to measure in FE and since ABA is a bit too tough, how about before and after video of the wheel spinning up on jack stands. Get the wheel to 15 or 20 MPH, hold it, let it glide to a stop. Video the wheel. See if the clips help the wheel spin even half a second longer.

Just a thought.

-james

A couple of comments,
I read an older thread recently about modified air intake with OP reporting 2mpg improvement from one summer to the next and there were numerous denigrating posts, suggesting the thread be thrown in with the Unicorns, am curious why this thread isn't given the same treatment, there is no verifiable repeatable results under controlled conditions reported here either, just seat of the pants claims.

I also question safety considerations, as I understand the clips, if working correctly pull the caliper back to a fully open position, this would result in a delayed braking response from brake pedal activation to the actual time pads make contact with discs. This becomes even greater as pads wear down and some vehicles may not even have enough volume in master cylinder pump to fill all 4 calipers enough to begin braking in a single stroke of the pedal, not a good situation in an emergency situation. Disc brakes are designed to keep pads close to discs as the pads wear down so breaking response is as quick as possible. There is also the question of whether Insurance would be voided by this type of modification.

If well maintained and correctly operating, the pads should open enough through vibration and normal variations in the disc surface such that they will just skim over the highest point in the disc and friction will be negligable overall.

I also thought about what effects may be occuring with airflow between the disc and pads, if flipped to a horizontal plane pad travel over the disc simulates a vehicle travelling over a flat road, so is there greater air resistance by forcing air under the pad or directing air around the pad, not really sure, but it is worth considering as a possible counter effect to any surface friction benefits.

[cbaber]

That is a good point Tesla. Everything about these products scream scam, yet we haven't been as skeptical as with other products. It could be that I have never seen these marketed, unlike other magic products. They don't immediately claim to offer MPG gains, but rather softly say it will improve brake pad life, noise, and fuel economy. If you do try to buy them you probably have to look hard to find the right set for your car. Magic products tend to be universal application, and can be found in all the big box stores.

[RedDevil]

It is not in the unicorn corral because these clips are used by several car companies and their function is well understood.
Honda puts 2 clips on each front brake of a Civic and 1 on the 2nd gen Insights.
It is no snake oil.

They solve a problem that should not be there in the first place.
When you apply the brakes the fluid pushes the pistons against the brake pads, which make contact with the disk and slow it down by friction.
When you release the brakes the brake fluid recedes and pulls the pistons back in. But the pads stay where they are; against the disk. If the pads slide freely to and fro the disk that is no problem, as the slightest touch against the disk will make them move back. But often they do not move that freely and keep stuck against the disk, heating and prematurely wearing themselves.

The springs put a relatively minor force on the pads to make them stay in contact with the pistons. Once there the brake fluid prevents further regression.
There is no such thing as pushing back the master cylinder and needing to pump before they can be fully applied. If that were so the system would be leaking, and leaking badly as the force on the brakes when applied is so much greater than the spring action.

What makes it hard to quantify the effectiveness is that the excess friction on brakes without them is not constant. It will be there after breaking, but recede over time as stresses on the axle and bumps in the road allow the pads to move back. Nonetheless there are statistics and they unmistakenly show the effectiveness of the springs.

The same erratic behaviour of brakes that miss these springs can be felt in a stock Insight, like mine was, when you gently brake to a stop. At first it will use only regenerative braking, but as the speed gets too low for that the disk brakes will apply.
The transition between those two phases was always a bit unpredictable; suddenly breaking harder one time, while hardly braking at all the next time.
Although that behaviour is not yet completely gone, it is much less annoying than without the extra springs. I'm in control instead of on edge.

When I had them mounted we turned the hubs by hand. That was hard without them and noticeably easier once they were on.
Now when I put my car in neutral I can push it forth and back with two fingers. I did just that a week ago.

[Tesla]

Originally Posted by RedDevil

It is not in the unicorn corral because these clips are used by several car companies and their function is well understood.
Honda puts 2 clips on each front brake of a Civic and 1 on the 2nd gen Insights.
It is no snake oil.

They solve a problem that should not be there in the first place.

So they are a standard maintenence item on a couple of vehicle models because of (poor?) design.

The use on other vehicles would be questionable.

All the vehicles I have worked on, the piston does not retract, hydraulic pressure is just removed and then disc movement then pushes the pad back slightly so there is just the slightest gap between disc and pad, this ensures the pad grabs as soon as brake pedal is pressed.

I know on my vehicle if the pads, just one wheel, have been retracted manually it takes significant pedal travel before the pads even touch the disc.

I assume the springs act on the backing plate of pads, how do they account for pad wear, i.e. springs would need to open more for new pads and less for worn pads.

Just think people should be aware of what they are actually doing and what implications there may be.

As part of ABA testing, maybe an ABA braking response should also be tested, particularly with worn pads, tenth's of a second make all the difference when it comes to emergency braking and if the first half of pedal travel is just dedicated to making contact with the discs, then this may be a serious problem in those situations when you want to stop like right now.

I don't know if this is an actual problem with these springs, just putting it out there as something to consider, maybe someone with these springs could actually report back on gapping on new and worn springs as well as pedal travel before disc contact is made by the pads.