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I went up and picked up my brake parts this morning and as I was loading them into the car, something occurred to me that previously hadn't:

Going from a ~10lb/side drum to a hub adapter/disc/5 wide adaptor/caliper has got to be adding 30lbs unsprung weight per side to my car. Geez, these calipers are as heavy as the ones on my Mercedes ML 500!

Anyone have some experience with this you'd like to share? Seems like, at a minimum, I'm going to have to rethink the front shocks. I'm glad I didn't throw the Bilsteins (that were way too stiff) I replaced with KYBs away. 

Original Post

That's one of the reasons I went with the Airkewld aluminum hub front brakes. They are heavy, but nowhere in the same league as the all cast-iron ones. The Wilwood calipers are light.

I compensated for the extra weight by switching to the Vintage190 aluminum wheels.

I really like the plain old non-gas adjustable Konis in the front.

Which kit did you get?

@Carlos G posted:

Do show and tell about the tank when it happens. That's one of the weak points that I want to address on my car too. 

Why hasn't someone drilled the piss out of one of those rotors yet? There is a LOT of meat on it.

I was thinking the same thing. Not just the rotors, either.  I'm thinking a 1300lb car doesn't really need a 1/2" piece of plate steel to bolt the wheels to.  These things may be going in a serious diet before I put them on. image

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We've talked about this before- this is the issue with the low budget cast iron 5x205 front brake kits.  You'll find the extra weight will give the front tires (and brakes) more bite (and even balance the car a little more), but it's all unsprung rotating weight (which is exactly what you DON'T want)!  I picked a rotor assembly up at a friend's garage and my reaction was "holy crap these things are heavy!"  As you've guessed, anything built with weight in mind (Airkeweld, Coolstop- I don't know of anything else?) is not cheap, but you get what you pay for.  Right now I'm looking at CB's aluminum hubbed (#4182) 5x130mm rotors/hubs- $189.00 a side.  I'll post here when I hear what they weigh.

  Please weigh them before you start the weight reduction program.  And you know we're gonna need pics...   Al

PS- I have drilled a few holes in a couple of things in my time, so if you need to talk about it pm me...

Last edited by ALB

There's always talk about how a Beck Spyder weighs 1300 pounds. I've never seen one that light. Did you weigh it yourself or is it just folklore? Vintage Spyders weigh around 1500, and the couple Becks I weighed were 1400 or more. This makes sense to me given the frame differences.

I ended up with the Airkewld wide5 4 piston caliper kit, and the single piston rear with e-brake. The rotors have lots of holes in them, anyway, but the aluminum bits are all solid. The brakes are occasionally noisy, squeak a little sometimes is all. The bottom line, they stop really well, repeatedly, with no fade. Even a half-hour of lapping LRP with 500 pounds of driver and passenger didn't faze them.

The front brakes do add width, according to Airkewld it's 3/8" per side, but I measured double that. It's more like 3/4". The only way to compensate for that is to put in a 2" narrowed beam, though that isn't gonna happen to ANY existing Spyder. I was lucky enough to have a second chance and get Greg to install the very first narrowed beam in a Spyder.

Last edited by DannyP
@ALB posted:

I don't know where you came up with that, Carlos, but I'm liking it...

By just picking it up.

This was an extra one with a untrue rotor. I took it to my machinist buddy so he could use it to mount up a steel wheel and check if it'll fit on his mill or CNC machine. I might get him to cut the rotor off and trim it down to use as a balancing plate.

Of course, it's easy making holes on a computer. 

Cheesy Wide 5 rotor 2

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@DannyP posted:

I'm gonna go out on a limb here, but Spyders only look right with wide5 wheels. Steel or aluminum(or both like Anand!). 

Find me a wheel that looks right(or even good) in 5 x 130. I dare you.

Technomagnesio makes a wheel that looks just like a wide five and some GTS have billet Coddington wheels that look similar. But the TM wheels are $1200/ea last I checked. I have no idea what the Coddington wheels are. 

 

I'd rather drink battery acid and broken glass than put Fuchs on a Spyder. 

Last edited by dlearl476
@Stan Galat posted:

... or you could just do modern brakes (with a modern hub) and run 5/130 Fuchs and avoid bolting barbells on the corners of your car.

Suspension issues aside, I'm coming around to the fact that adding 60# up front might not be that bad of a thing. My car is terribly light, up front, and it gets borderline terrifying 80 mph<.  I know some of that is ride height, (airflow under the pan) which I'm going to address. But knowing Ed's car has similar discs up front, I'm resigned to making them work. 

Depending how they work, I may pull them off next winter and having a machine shop lighten them up for me. 

Last edited by dlearl476

You could always lighten the rolling weight then strategically add weight to the front beam. Someone here was bolting weights on.

I'm going to check with my machine shop buddy, Brian,  and see if milling holes is something his CNC machine can do. He's already milling the ends of an old Subaru sway bar for me and looking into widening some rims. Lets see what he can do....

Would drilling out the rotors be of any benefit for stopping or cooling? or is some kind of science in the way it's drilled?

Wondering minds have got to know.

 

Dave, I have about 1.5 degrees negative camber in front, probably 3 degrees negative in the rear for proper ride height. Total toe-in is 1/16", front and rear.

I've found that rear toe of zero or positive in any way makes the Spyder VERY twitchy.

My car is solid and stable up to 125, I haven't gone any higher, that was enough of a pucker(what if anything at all goes wrong in the back of your head) factor. The car felt stable, I just thought why do I need to go faster?

So it turns out I flew off half-cocked so to speak. The Hub is actually aluminum. Not cast iron as I originally thought (I looked at them for about 10 seconds when I unloaded the car)

I took my scale down to the storage unit today and it’s not as bad as I thought. 

Drum and two shoes weighs 14.5lbs

Disc and hub weigh 14.5lbs, caliper weighs 6.5lbs. 

I imagine the backing plate and slave cylinder weigh a pound or two so I’m probably only adding about 5lbs/side unsprung weight. Vintage 190’s will probably lop off another pound or two. 

But I have bigger fish to fry. I started examining the pieces and parts and found this:

3F8875BD-8156-4849-84AD-B94CCF75BC3E
4EF46DE7-FBF2-44DC-B8B2-ABFF131AE4AA
AD08C16A-EF51-4B7F-8E37-4AAF49C5D7EF

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  • 3F8875BD-8156-4849-84AD-B94CCF75BC3E
  • 4EF46DE7-FBF2-44DC-B8B2-ABFF131AE4AA
  • AD08C16A-EF51-4B7F-8E37-4AAF49C5D7EF

I believe the Vintage 190s save 40 pounds on the entire car, 10 lbs. a corner difference from steel is a fantastic savings.

I have a rear backing plate with wheel cylinder in the garage. Now to find that old postal scale......

No bearings and seals included with the kit? There is always a hammer/brass drift and a bearing repack.

Last edited by DannyP

Measured on the back side, the thickness to the bearing is .515 on the thick side and .460 on the thin side. So the hub appears to be machined .055 off center.

Based on my experience as a machinist in another life I guessing they attached the disc to the hub, slapped it in the chuck, then machined the hub, rather than machining the hub, then attaching the disc and balancing it.

I wracking my brain to try an imagine a reality where this won’t result in horribly out of balance wheels/tires and a resultant vibration.  I hope you guys can before I call and raise hell tomorrow. 

Last edited by dlearl476
@DannyP posted:

I believe the Vintage 190s save 40 pounds on the entire car, 10 lbs. a corner difference from steel is a fantastic savings.

I have a rear backing plate with wheel cylinder in the garage. Now to find that old postal scale......

No bearings and seals included with the kit? There is always a hammer/brass drift and a bearing repack.

Re: bearings and seals. Yeah, I didn’t bother with them as they’re the same from drum to disc. 

RE: 190’s. That’s good news. That will more than make up for the weight of the calipers. 

Last edited by dlearl476

Wow, that's bad. I couldn't see what you were talking about before. I'd raise hell tomorrow, Dave. I guess there isn't an interference fit of the rotor to the hub?

FYI, I had to machine my Airkewld hubs. The outer snout for the grease cap was too large, and I didn't want to ruin the face of the hub prying the cap off. I machine it down so the cap just slid on, and secure it with a bead of silicone.

And then on the inside, the seal opening was too small, so I machined that to the right size and made sure it was a rough finish so the seal would grab.

So the moral is, even when you pay good money for what you think is a superior product, it may not be. And then I go back to the usual statement: nothing bolts right on these cars. Almost ever.

I wouldn’t mind if I could fit this. There’s no way anyone can make this right, save “reinventing the wheel” machining it round and taking a larger OD bearing. 

I’ll talk to John tomorrow and see what he says. Unbeknownst to me, these are CB brakes I ordered from aircooled.net, so I imagine that puts John in a bit of a bind. He bent over backwards to hold my hand in this stuff that I knew next to nothing about. Had I known they were CB  I’d have just ordered from them in the first place. 

Now that I’ve had a big stinky cheeseburger and an ice cream cone, I’m in a little better frame of mind to send him an email.

Another thing that chaps my ass is the cheap Chinese hardware holding the disc in the hub isn’t even close to any tolerance. You can see in the top pic that there’s 1/8” slop in the washers.

It does seem like there’s an interference fit in the center of the disc. Obviously it’s just within .575” tolerance, which, given the mass of these things, I’m sure translates to at least 3-4 grams out of balance  

All this would be much less of a PITA if they hadn’t been back ordered for two months. 

Last edited by dlearl476

I left my bathroom scales down at my storage so I checked when I went back. There’s about half of the space (.055/2) between the ID of the disc and the OD of the hub.  I imagne this all started by machining to OD of the back of the hub ~.025 too small to center the disc properly. I guess our definition of “interference fit” is different from the machinists.

I guess the silver lining is the fact that it was off enough to be noticeable, and I didn't spend the next two years tracing a vibration that couldn't be cured with tire balancing. 

Last edited by dlearl476

Dave, I went out to the garage and weighed a swing axle backing plate with wheel cylinder: 3 pounds, 2 ounces. You have a ~3 pound weight gain that is offset quite nicely by the lighter wheels, and then some.

John is a great guy, I'm sure he'll take care of you. It just may take a bit of time with the backorder situation.

Speaking of the backorders, it could be virus-driven. Or maybe the old supplier went by the wayside and they've changed production to a new place. Who knows?

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