NC BBK design quality

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NC BBK design quality

Postby Tonioo » Tue Oct 20, 2020 12:37 pm

Hello,
I would like to find solutions or explanations about big brake kits for NC. Is there a reason why they are so badly designed ? The parts are strong but the adjustments are bad. I mean that the caliper is not placed correctly along the rotor and pads exceed from the contact surface.

I’ve first noticed that last year when fitting the V8R 11.75" BBK on my car. I had to find a machinist to remove about 1.5mm on the caliper braket to have the pads fitted correctly with the rotor circumference.
V8R was not helpfull to admit that the fiting was wrong. I managed myself to fit the kit correctly.

Bracket.jpg

DSC_5610.jpg

Also, the center hat chamfer was not enough to fit the hub, I had to remove a bit to have the same shape of a stock rotor.
Hat.jpg
Hat.jpg (73.22 KiB)



This year I tried to fit the GWR budget front kit on a friend’s NC. This time the hats ‘chamfer was large enough. But there is still a big problem on the pads alignment. The brackets shape is different from the V8R so it is impossible to adjust by machine them.
IMG-20200613-WA0004 - Copie.jpg

IMG-20200613-WA0005 - Copie.jpg

What solution do you have for that ?

Manufacturers claim 0.002" tolerance but in my opinion these kits are not designed seriously.
Am I the only one to notice it ?

Regards
Tonioo
 
Posts: 26
Joined: Sun Dec 06, 2009 11:09 am
Location: France

Re: NC BBK design quality

Postby Ryan @ GWR » Thu Oct 22, 2020 12:17 pm

I have a funny feeling you aren't going to like this answer, but to be frank, the pad placement on the rotor that you took issue with isn't of any concern. Without getting too bogged down in specific examples, there are even cases where a little bit of pad overhang or having the pad undercut on the rotor is an intentional part of the design of a particular big brake kit. Our Brembo rotor upgrade kit for ND is a good example; it HAS to be that way or it would not work.
Furthermore, it's not uncommon to have some variation in the placement of the friction material on the pad backing plate, or in the shape of the friction material. We've see this variation between different pad manufacturers, and even from one set of pads to the next from the same manufacturer. So one set of pads may line the friction material up with the outer radius of the rotor real nice, and the next set may be off a bit.
The point is, the pads will operate just fine in both of your pictures. You didn't need to "fix" the bracket.

As for the interior chamfer on the hats, that's something that does matter; obviously the hat must sit flat on the hub. However, most reports we get that say the hat isn't fitting on the hub, the culprit is actually that they have corrosion or debris on the hub that isn't allowing things to sit flush. I can't speak for V8R, and perhaps they had a batch of hats where the chamfer was cut wrong, I don't know. But... their hats have been fit to many NCs without issue.

The saying goes "when you have a hammer, every problem looks like a nail" and it looks like because you had access to machining abilities you went straight to "solving" things with machining to adjust, and if that got things working for you then great, but perhaps none of that was really necessary.
Ryan @ GWR
 
Posts: 389
Joined: Fri Oct 17, 2014 11:37 pm

Re: NC BBK design quality

Postby Tonioo » Sun Oct 25, 2020 9:09 am

Hi Ryan, thank you for your answer.
My hub was a brand new and the hat was not sitted flat on it because of the tiny chamfer. Hope it was just a manufacture problem. I told to V8R to check their 3D file.

For the pads I am agree that it would not be a security issue. I studied machining design and an equipment working like this is not a good thing, never seen that on stock brakes for example. And it is not a problem with the placement of the friction material as I tried different brands of pads, it is simply a bad design of the kit, and the goal of this post is also to show that it could be better adjusted.

Regarding your example on the ND rotor upgrade kit, I did not had it in hands but for sure you have the overhang on the pads, because the caliper is not designed for this rotor diameter. Isn’t it ?
Tonioo
 
Posts: 26
Joined: Sun Dec 06, 2009 11:09 am
Location: France


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