Crappy DIY $10-$20 brake cylinder brace for NC

[wleung]

Wasn't sure about the design of the BeatRush model, and I didn't want to pay that much money for just a 'feel' upgrade.
So I made a brake cylinder brace out of whatever I had lying around from my previous projects:
- 75mm M8 fully-threaded stainless steel bolt (Don't remember if I got it from Bunnings or online)
- 2x M8 stainless nut (Bunnings)
- Zenith Mending Plate 100mm with one hole drilled out to take the M8 bolt - see photo (Bunnings)
- 1x M8 Galvanised Hex Coupler 24mm (Bunnings - no stainless ones I'm afraid)
- Electrical Tape
- 1x M6 bolt washer & nut to mount other end of plate to the chassis (Randomly sourced)

Using vice grips, I stood on the plate and bent the corresponding corner of the mending plate to create a little catch between where the Nut Head would be and the bent corner. The catch is meant to mate with flat edge of the shock tower brace, and prevent the plate from sliding downwards or upwards. The idea was to keep the bolt perpendicular to the brake cylinder as much as possible, and have the part of the mending plate taking the force as close to the Nut Head as possible, so the plate is forced onto the stock tower brace edge as shown in the photo.

1st Nut is to hold the bolt onto the plate.
Put electrical tape around one end of hex coupler, and make slits at the corners of the hex so the electrical tape could be folded in neatly to cover up the end. Put on the hex coupler and tweak its position until your satisified with the amount of tension between the tower brace and the brake cylinder.
Use the 2nd nut as a locking nut on the hex coupler.

Future potential tweaks: Note that the brake cylinder face isn't perpendicular to the ground. Thus the hex coupler doesn't sit flush with the brake cylinder face, so it would apply a slight downwards force onto the brake cylinder when I mash on the brakes (which isn't ideal). Bunnings sells adjustable furniture feet with M8 threads, and if I got a shorter bolt I could use the other end of the hex coupler to attach the feet. This gives a larger surface area to hit the bottom edge of the brake cylinder face perpendicularly.
Will try experimenting with them perhaps. There was a ball socketed foot as well - but I'm unsure whether or not that would ruin the bracing effect.

NC-Brake Cylinder Brace.png

[project.r.racing]

That mending plate has zero bracing and would be weaker than the solid firewall the booster and cylinder are bolted to. So I fail to see the worth.

[Regie]

yep, sorry to say that will be doing nothing, just adding weight.

That piece of metal you have the bolt to will just flex, also where you have it attached to the guard thats pretty flimsy structure too.

10/10 points for giving it a go

Back to the drawing board you go

[RS2000]

It's not as silly as it first looks.
wleung's intension is for all the force to be directly thru' the bolt into the strut brace, with the plate just holding the bolt in position.
I think that's almost achieved.

[wleung]

Yeah it's not as well designed as the autoexec $300 solution, but It actually works well enough to notice a difference. The plate shouldn't bend under normal road use, but it probably wont' work for the 'I'm gonna die' push -> given I was able to originally bend the plate using my body weight and a massive heave of the arm. A thicker plate would probably do the trick however.
(I've never tracked, so have no idea if people use their full body weight on the brakes when braking)

I repeat: The part of the plate taking the force is the small area between the long bolt head and the shock tower brace. The rest of the plate does very little except as a safety mechanism to hold onto the bolt should it slip off.

I was just aiming to try and get something more on-centre for less than $20

That said, I've taken it off the car after today's drive.
At the traffic lights today, it hit me that the shock tower forces were just getting transferred to my master cylinder and brake booster.
Whilst the brake feel was better, I rarely have to depress the brakes as much as my old NB8A, so it wasn't as noticeable unless I intentionally braked later than usual.
I don't think I want to increase the wear and tear on my braking system just for a mild 'feel' improvement, but maybe the brake cylinder & booster are super strong, and I'm panicking about nothing? I'm guessing the brace takes a huge amount of the force away & the rest of the force is dissipated via the firewall.

I know the NC chassis is relatively strong, but it will still have a little flex I presume, e.g. when you hit a kerb or a massive pot hole on the brake cylinder side.

[wleung]

Here's a pic to clarify what I mean.

I made a mistake in my last comment.
It took a pair of vice grips AND an arm-heave (with my body weight on the plate) to bend the corner.
That had means I had a lever and an effort arm length of about 15-20 cm from the fulcrum

Given the distance between the bolt head centre and the point of contact with the shock tower brace is about 5-10mm... it could probably take my hardest leg push with very little flex?

shock2.png

[hks_kansei]

Your legs will easily put more more force into something than your arms.

Apart from generally having larger muscles, there's also the brake pedal which is a big lever (remember, the pedal assembly is hinged up behind the dash, with the master cyl rod right next to it, and your foot is then pushing a lever a good 15cm further down)



In saying that, since the plate you're using is mainly just a locator, rather than load bearing, it wont make a huge difference, since the force is going down the bolt to the strut brace.

as far as your worry about vibration etc transmitting from the strut tower to the brake master, it's not really worth worrying unless you've physically bolted the brace to both the tower, and the master.