Front brake option

[TonyK]

If you intend to keep it reversible (back to stock), then how about use the sleeves (10mm to 12mm) on the caliper carriers. Then use 10mm mounting bolts and not drill out the X knuckle.

By chance did you determine if there is any difference in the Abarth vs stand 500 caliper brackets, or is it the calipers themselves that are different (I'm referring to the offset)? Thanks.

You have to remember that the carriers for the pad have the threaded 12MM holes, so sleeving the one side will work for the smaller bolts, but the other side will require that the carriers possibly have a heli coil installed to reduce the bore of the threaded holes on the carrier.

For me to look at the Pop I need to take the car away from my son, so comparison between the Pop and Abarth brake components will have to wait until Sunday.

TonyK.

Grimsby Ontario Canada.

 

[Dr.Jeff]

the carriers for the pad have the threaded 12MM hole

Ahhh, that should have been obvious. Agree with the other approach you suggested.

comparison between the Pop and Abarth brake components will have to wait until Sunday

Thanks. I didn't mean to sound anxious, it's just one of those things where my thoughts are going on it and the ideas keep coming. Appreciate if you do get an opportunity to compare them.

 

[TonyK]

Ahhh, that should have been obvious. Agree with the other approach you suggested.



Thanks. I didn't mean to sound anxious, it's just one of those things where my thoughts are going on it and the ideas keep coming. Appreciate if you do get an opportunity to compare them.

Continuing on, first off all of the brake components are made of cast steel or iron. Nothing is aluminium.
Taking a look at a 500 Pop this is what you get. Different calipers that have 12MM bolts with the same bolt pattern but again they are too far towards the centre of the hub and the rotor is too big in diameter for them to work on the car. Also the brake rotor ( hat) forces the rotor too far inboard and about 3MM will have to be machined from the carrier to allow it to centre the rotor and once again the rotor diameter must be reduced. I don't see this is worth modifications when the Abarth pad carriers resolve this issue with the 500 POP rotors installed (257MM).

Brake pads from the Abarth a slightly larger as well than the 500 POP. See pictures.

TonyK
Grimsby Ontario Canada.

 

[Dr.Jeff]

Nicely done Tony, thank you very much. Really appreciate the extra effort to look into this.

As suspected, the Pop caliper/carriers are offset the same distance as the Pop rotors and therefore have the same issue as the Abarth caliper/carriers with Abarth rotors, not being centered when mounted to the X. Which makes total sense. The thing that also makes sense (but I hadn't thought about) is the Pop calipers will also be positioned closer to the centerline to match the smaller diameter of the Pop rotors. Again creating the same issue as with the Abarth components on the X. That should have been obvious but wasn't until I saw the images (thanks again for that).

So you hit it on the head; the combination of Abarth calipers/carriers and Pop rotors.

 

[lidox19]

Tony,
Could you not fit the 5mm spacer from the outside of the disc on the inside (between the hub and the disc) and use a 240mm disc?
As an added benefit this should fit under 13" wheels.
Regards
Andy

 

[Dr.Jeff]

Could you not fit the 5mm spacer from the outside of the disc on the inside (between the hub and the disc) and use a 240mm disc?

I had a similar thought, but unfortunately it won't resolve the issue:
For one thing I believe that spacer is too large diameter to fit behind the rotor, but it could be turned down. However with the smaller Pop rotor you don't need to, it already has the offset needed, when used with Abarth calipers/carriers.
But if you meant to do that with the Pop rotors and Pop calipers/carriers, then there is still the problem of the rotors being too large diameter for those caliper carriers. The Pop caliper carrier is made to fit the smaller diameter rotor, so it still fouls when mounted on the X knuckle.

 

[kmead]

A spacer could be machined/cut to go inside the hat preferably in aluminum. Would a 239mm rotor work (a common VW part dimension as I recall)?

Are the calipers actually different or just the carrier? I would presume the pistons are identical ie 54mm with a different carrier to correspond with the larger diameter disk.

How much fun was it to bleed the 500’s brakes as compared to the X? After taking it apart.

 

[Dr.Jeff]

Would a 239mm rotor work (a common VW part dimension as I recall)?

I don't think so, due to the OD of the rotor compared to the pad location. As you can see in the pic below, even with the 257mm Pop rotor, the pads are almost beyond the rotor:

So a 239mm rotor would be way short of the outer range of the pads.

Are the calipers actually different or just the carrier?

I believe the calipers are the same between the Pop and Abarth (assuming that is what you are asking). Tony did say they have the same mounting hole locations and use the same mounting bolts. Although the Abarth caliper uses different pads, so there may be some difference? Or maybe the larger Abarth pads are interchangeable with the Pop? For our application, it might be beneficial to use the smaller Pop pads, due to the calipers being a bit oversized.

 

[TonyK]

Tony,
Could you not fit the 5mm spacer from the outside of the disc on the inside (between the hub and the disc) and use a 240mm disc?
As an added benefit this should fit under 13" wheels.
Regards
Andy

Possible but we here on this side of the pond do not have access to 240MM disc's. That is the issue I have with the UNO TURBO MK1 brakes on my X1/9, I have to import the rotors and pads from the UK and the shipping is a killer.
A 3MM spacer should be all that is needed, but then the rotor again is too big in diameter.

TonyK.

Grimsby Ontario Canada.