Front brake option

[78paesano]

My Vick Prima didn't fit in my 13 inch wheels, just a slight rubbing in my CD31 and CD39 wheels. I took it off and went back to stock brakes. I might put it back on and grind the edge of the calipers down a little, it wouldn't take much grinding for it to work, just a little bit off would do it.

 

[Dr.Jeff]

Before this thread get too side railed, I'll reprint a section from my original post:
"Please...this discussion is NOT about the merits/faults of upgraded brakes, the X's stock braking potential, unsprung weight, balancing front to rear brakes, or other such issues. I am simply curious about the ability to actually adapt the 'new 500' brakes; specifics on what is required, what fits or does not fit directly, etc. [Sorry, I don't want to sound offensive but I'd like to focus this discussion on the mechanical aspects only. Feel free to start another thread elsewhere if you are compelled to discuss other aspects.]"
Thanks for understanding.

to figure out what radius the distance was before I ordered rotors

Thanks for the extra input MotoTrooper, I'll look through your build thread as well. Per the above quote, where you mention ordering rotors in various sizes, are these all 'stock' rotor options from other models or custom items or ?? Are they a direct fit onto the hubs? And where from? I'm not certain but I think the US spec 500 rotors are something like 257mm, very close to the 260mm you chose, so that would make sense for a good fit. Looking forward to your development of the rears. Also just for thought, maybe consider an adjustable proportioning valve as a possible option to dual masters. I did that on another (non-Fiat) project with a custom brake set-up. Mounted the valve where I could access it within the cabin if adjustments were needed (however haven't needed to after getting the balance where I like it). Works well for me but it's not a track car, maybe your goals necessitate different requirements.

Beek, thanks for the excellent photos. Just judging from various images, those calipers appear to be similar (same?) as the Euro 500 / Abarth version. The Vick's kit looks to be very well done.

Actually there are other varieties of pin mounted calipers that suit the same identical spacing as the run of the mill Bendix caliper and bracket, from the early/mid 80's there are a big bunch of models that actually used the very same stub axle/ hub as the X19, and they used pin mounted calipers, so no we are not stuck with a sliding wedge caliper at all. Most models only used a solid disc, but going up to a 257mm x 12 disc makes for a worthwhile upgrade and a decent increase in stopping ability ... anything from a ritmo/regata definitely does the job, fits straight on with zero mods except using a caliper banjo bolt with the correct thread pitch.

Well stated Steve (as always). Unfortunately for those of us in the USA, options from other models are very limited due to the lack of availability. The 'new 500' is one of the few that we can easily get the components from... new parts at affordable prices from local sources.

I think my Grande Punto S has the same brakes as the European 500 Abarth (without the brembo option)... mine runs 285mm discs up front and 257 discs on the rear...next time I have the wheels off and a caliper handy I'll check the mount spacing, but from what Mototrooper says they could well be the same spacing as the X19

Sounds like a fun ride. Maybe grab some pics for us when you get the wheels off. Thanks for your input.

BTW, for those interested, have a set of Fiat Abarth 500 front brake calipers (Bosch) brackets with aero-craft spec hardware modified to fit stock exxe uprights with hosed made to fit. These were for the LeMons racer that did not work out. Will post pix if interested.

Bernice, please post pics...thanks.

My Vick Prima didn't fit in my 13 inch wheels

Interesting, I see the catalog description says "fits under most 13" wheels". I guess your CD31 and CD39 wheels aren't "most"? P.S. I think we met some time ago locally in Vegas. I'll send you a P.M.

I greatly appreciate the input from everyone. I realize the topic of brake upgrades has been discussed many times, but when searching I was not able to find much on the specific application of 'New 500' brakes on X's. That is why I'm trying to focus on that aspect here, to avoid all the redundancy of past discussions. Thanks and keep the thoughts coming.

 

[rocco79/138]

Oh great cat herder... Not to confuse or confound but I had the bearings replaced all four corners and remember Jonathan commenting that the bearings for the new 500 and the nearer X were very similar... There may be a way to shift hubs or carriers or both or a mixture of all the parts but you would need to get of the pieces and get to measuring. Just a WAG and thinking outside of the box...
If you could switch the carrier you could use the stock 500 caliper mounts.
Wildwood sells a remote proportioning set up just FYI.
Regards

 

[Dr.Jeff]

Just a WAG and thinking outside of the box...

I love any thoughts that are outside the box...pretty much where I live, that is when I'm not in the box that is my home.
I believe (but haven't confirmed) the 500 rotors are a direct fit onto the X hubs, which is half the battle. But you are right, if the entire carrier can be swapped then the calipers will be properly located to match the rotors. However it poses other hurdles with strut mounting, steering bits, etc. I'll see if I can find a decent diagram of the 500's front hub assembly for reference. So far I'm finding most of the info on the US spec 500 mainly focuses on the Abarth edition, which appears to be much the same as the Euro 500 (in regard to brakes anyway).

A long time age we were discussing coil-over suspension ideas for the X (long before any of the aftermarket guys offered decent options). And Pete W mentioned the idea of transplanting VW Mk1 (Rabbit/Golf) strut assemblies into the X. That would allow not only many excellent coil-over choices, but also loads of brake options and a 100mm bolt pattern for endless wheel options. Pete, I know you always have lots of great projects going, but did that thought ever get off the ground?

 

[motoTrooper]

So I received the front brake pads this morning and it looks like the 260mm rotor will work just fine(probably 257mm would work too). I was looking into various custom options, mulling a 257mm front rotor when I happened upon one of the moderators on Lancisti.com getting rid of multiple sets 260mm rotors he had made for brake upgrades that he didn't want to support anymore. For the 12mm solid rears I followed the rabbit's hole googling 4x98 brake rotors and the largest diameter I found (257mm diameter) were for the europe only Alfa Romeo 145/146. They have solid 12mm thick rotors as well as 22mm vented rotors made by several aftermarket producers (brembo, tarox, ebc, black diamond). Since the rear calipers on the Fiat 500 require the solid 12mm style I went for the largest diameter I could find (went for the black diamonds).

Indeed I was/am considering proportioning valve(s) as well. All options are on the table at this point.

We'll see if I'm nuts and taking a long walk off a short pier while I am keeping as tight a rein on costs as I can. I have nothing but respect for Bernice's racing development and overall technical expertise but I started walking this path way before all this and enjoy the process of experimenting. I hope to offer some evidence either way before too long. But I am doing something fairly kooky with my Scorpion with the engine swap so the whole thing is really a big experiment.

 

[fiatfactory]

Discs are the easy part... 240mm/257mm /284mm/300mm in ventilated discs with 4x98 bolt pattern, and in 257/284 there are several different offset values available.

Solid discs...251/257 are very common sizes across many Fiat/Lancia models.

SteveC

 

[fiatfactory]

Another possibility for available (in the USA) calipers and carriers would possibly be Fiat Freemont/dodge journey nitro wrangler compass... just a guess but I can see Fiat making a lot of stuff suitable cross platform.

SteveC

 

[Dr.Jeff]

dodge journey nitro wrangler compass

Good suggestion Steve, I'd forgotten about the clones. I believe those US variants are the same as the US 4-door 500 (500L or 500X), so they likely have the same brake components as the standard 500. But I will see what I can find out. Even if they have the same brakes, they offer additional search options when sourcing the components (i.e. more models to look for on suppliers' listings).
For the most part the 500 brake components are not only readily available but also relatively inexpensive here (not to mention new), so perhaps for us they are a better option than trying to find components from non-US models. For comparison I posted a couple current "U.S. eBay" listings for Uno Turbo brake parts (very surprised to find any) on Dan's rear brake discussion. I assume there is much more of it available in Europe and therefore better prices? Especially when shipping costs are added (when I buy from US suppliers I often get free shipping).

By the way Steve, while researching related topics in old Xweb threads, I came across this picture (with an interesting story to match):

I love the truck. Here are a couple of others I like:

 

[kmead]

Good suggestion Steve, I'd forgotten about the clones. I believe those US variants are the same as the US 4-door 500 (500L or 500X), so they likely have the same brake components as the standard 500. But I will see what I can find out. Even if they have the same brakes, they offer additional search options when sourcing the components (i.e. more models to look for on suppliers' listings).
For the most part the 500 brake components are not only readily available but also relatively inexpensive here (not to mention new), so perhaps for us they are a better option than trying to find components from non-US models. For comparison I posted a couple current "U.S. eBay" listings for Uno Turbo brake parts (very surprised to find any) on Dan's rear brake discussion. I assume there is much more of it available in Europe and therefore better prices? Especially when shipping costs are added (when I buy from US suppliers I often get free shipping).

By the way Steve, while researching related topics in old Xweb threads, I came across this picture (with an interesting story to match):
View attachment 3403

I love the truck. Here are a couple of others I like:

View attachment 3404
View attachment 3405

Some cat herder you are...squirrel!

 

[kmead]

Another way to think about it might be to combine Fiat based rotors with some other mass market car's calipers.

The reality is a new intermediary bracket is going to be needed to go from the holes we have on our steering knuckles to the holes on brake caliper mounts. So going from what we have to something else is a reality in any case so does it matter if what we are going to is a "Fiat" part?

Another thing to consider is the material the caliper is made from, preferably aluminum. Not all are. Unsprung weight is the enemy here given that you are adding weight with a larger likely thicker rotor plus bracketry.

The big draw for the Uno Turbo caliper set up is that the mount for the caliper bolts directly to the our existing knuckle with no intermediary bracket. This is a big advantage as secondary motion of the caliper assembly can have a big effect on the pedal feel and modulation of threshold braking as distortion of the mount can cause the caliper release to be delayed.

 

[kmead]

The attached pdf is an interesting document with a variety of piston sizes across a wide variety of cars old and new. Piston diameter is going to be critical to maintain pedal feel, motion and overall balance of the braking system.

As we look at choices for the whole system we may wish to break up the functions at the rear, a separate caliper for e brake and another separate caliper with the right diameter pistons to achieve the desired brake balancing.

 

[Dr.Jeff]

The reality is a new intermediary bracket is going to be needed to go from the holes we have on our steering knuckles to the holes on brake caliper mounts. So going from what we have to something else is a reality in any case so does it matter if what we are going to is a "Fiat" part?

The original hope was that a caliper from another model Fiat would have the same mounting dimensions as the X. Therefore able to be mounted without need for a intermediary bracket. If you will, a modern version of the Uno Turbo upgrade, but with components readily available here (eg. 500). As I understand MotoTrooper was able to do that on his Scorpion with 500 calipers (still in progress). If this 'direct fit' can be done on the X, then naturally the diameter of the rotors would need to correspond with the location of the new caliper (like he did). However as you say, we could also begin with the 500 rotors and then find other calipers to adapt. "Ideally" both (500 caliper and rotor) could be made to work as a matched set. Really what's needed is some sample parts on hand to play with. At the moment I'm still trying to sort out all of the new-500 caliper options and their derivatives (base vs Abarth, US vs Euro, Fiat vs clones, etc). I thought the 500 'clones' (per Steve's suggestion) would all use the same components as the 500, but it appears not (I'm finding lots of different part numbers). So there are even more options to consider.

One of my main reasons for starting this discussion was the hope that someone has already experimented with the use of 500 calipers on the X [still hoping to hear more on that, I could not find anything on this when 'searching' Xweb or the net]. If the concept works, the thought process would be to then address the rear brakes to balance these in front. However Dan's discussion on 38mm rear calipers is a good one that may offer a great companion to this. I suppose the rear 500 calipers could also be considered?

 

[kmead]

In modern cars there are not a lot of 48mm piston front calipers. One of the few I could find was the Citroen C2/C3 which uses a Bosch type front caliper which is the full floating type. Clearly there are others as Vicks uses a Bosch caliper so they are out there to be found.

Nearly all VWs use a 38mm piston rear caliper which is aluminum. I can attest to their quality as mine ran 15 years in Michigan salt before one of the adjustment mechanisms started to stick. They would make a fine basis for an updated rear disk set up. You would need to reengineer the actuation mechanism for the hand brake but I don't see that as too big a hurdle.

 

[Dr.Jeff]

Regarding 48mm floating Bosch front calipers, I found a earlier thread discussing the ones used in a vendor's upgrade kit. That discussion identified a couple vehicles that came with those calipers. So yes, there are sources.
Agreed, VW calipers work very well. I've utilized a few of them over the years on various VW projects (have a couple spare sets in storage). And they can be purchased new for great prices. Therefore they are a good option indeed.

However I'm not necessarily locked into the 48mm front, 38mm rear criteria. My thinking is to first find the most suitable front arrangement (however that is defined*), and then find a rear size that balances what is on the front; it may be 48/38, or they both may be larger. An adjustable bias valve should also be part of the mix. Finally the correct master cylinder size can be determined to work with whatever calipers are chosen. As you can see, I'm keeping all ideas open for consideration and I'm not opposed to replacing the entire system with suitable upgrades. For no real reason I kind of like the idea of finding components for the front, rear, master, whatever, all from a common source. This helps assure compatibility of individual parts to some extent. Plus it should help in finding a donor vehicle/supply source. And future servicing may be a little easier if everything has a common denominator.

So we might consider using the front calipers from a VW as well as the rears. But this still leaves the choice of suitable rotors unanswered. I keep thinking back to something that was mentioned on Xweb a long time ago; the possibility of swapping the entire strut assemblies from a VW (eg. Mk1 Golf) onto the X. This opens up tons of possibilities for coil-overs, brakes, wheels, etc. But that would be a very large project.

My initial attraction to the use of 'New 500' front brakes is their relative fitment on the X (especially the rotors). It still needs further investigation, but the possibility of using the rear 500 calipers is worth further thought. And they match many of the desired criteria (see below).

*What defines the "most suitable" brake system for this exercise will differ depending on the intended use and several other criteria. But my initial concept was to identify components that offer the following (as much as possible):
1) Fairly simple fitment. For example no machining of hubs or rotors required, no cutting and welding of carriers needed, no alterations to the suspension or body needed, etc (see the PBS brake up-grade for an example of NOT this). In other words, as much of a "bolt-on" kit as is feasible (like I described earlier, a modern version of the Uno Turbo brakes).
2) Components that are easily obtained, modern design, and affordable (unlike the Uno Turbo brakes have become). The "modern design" element would include things like floating calipers, vented rotors, and having service parts readily available.
3) Ability to make the total package work on the X: front brakes, rear brakes, master cylinder, all connections, E-brake, whatever. So not only components that are compatible with each other but also with the vehicle.
Naturally it is not likely that all of this can be achieved, but these criteria should be considered as much as possible. Please feel free to add or subtract from this list.

And to answer the question in advance, no the stock X does not need all that braking upgrade for normal street driving. But how about a K20 X or a track day X, or ??? To me this is an exercise in identifying options, all options, and not a question of need.

 

[Eastep]

I believe those US variants are the same as the US 4-door 500 (500L or 500X), so they likely have the same brake components as the standard 500.

Nope. I have an L Trekking, a 500 "pop" and an X1/9. All are different.
Ill try to mount the rotors from the pop to the X, this weekend. The L is more like a Jeep Compass. Same sizes, same bolt pattern, and 5 lug. Ill double check the PN on the calipers abd pads. The L braking stuff is much larger then the Pop.

 

[Dr.Jeff]

Ill try to mount the rotors from the pop to the X, this weekend.

Ill double check the PN on the calipers abd pads.

Thank you for checking these out, it will be a huge help!

Ya, I realized the other 500 variants and their clones all have different brake components when I started checking part numbers and comparing images. Turns out there are a large variety of components used, but its difficult to know just how different they are without having them in hand to compare. Surfing on-line parts catalogs only gets you so far. That's where your access to these will be a real benefit.

From what I can tell so far the 500's front rotors should directly fit the X. And its been mentioned that the 500 Abarth edition's front calipers fit the Scorpion although the caliper mounting bolts for the Scorpion are smaller diameter than those for the 500, so the Scorpion's holes had to be drilled out....otherwise they had the same mounting pattern. I've never had a Scorpion but aren't they the same as the X in this aspect? And although the Pop and Abarth 500's use different calipers, I think they have the same mount pattern. Therefore the most likely match will be your Pop's rotors and calipers on the X.

Please let us know what you find. Thanks.

 

[dcioccarelli]

I came across this listing on German eBay recently for some Brembo calipers:

http://www.ebay.de/itm/181063084560

The listing says that it is for a Fiat Regata (138) 75 i.e. 1.5 which should be the same as an X1/9. That said, looking at the photo, I can't see how it could fit. On the other hand, it is only 30 Euros...

Dom.

 

[lookforjoe]

From what I can tell so far the 500's front rotors should directly fit the X. And its been mentioned that the 500 Abarth edition's front calipers fit the Scorpion although the caliper mounting bolts for the Scorpion are smaller diameter than those for the 500, so the Scorpion's holes had to be drilled out....otherwise they had the same mounting pattern.

Good luck with this project! Looking forward to pics of your progress.

Haven't seen any posted specs to corroborate this? Hub and disc offset & ID/OD are the same? From my experience playing around with Volvo brakes, I wouldn't make any assumptions as to what will or won't fit without the parts on hand to physically test fit on an X1/9.

As already mentioned, I would expect that you will be making adapter brackets at an absolute minimum to get any of this to work

 

[Eastep]

As already mentioned, I would expect that you will be making adapter brackets at an absolute minimum to get any of this to work

^^ this. Or at very least (and mostly insignificant) a bit of grinding, spacing with washers/custom spacers, and enlarging/ relocating of mounting holes.

 

[Dr.Jeff]

I came across this listing on German eBay recently for some Brembo calipers

But unfortunately "no shipping to the United States of America".

Just for fun I pulled out a spare set of front and rear disk brakes from a water cooled VW (Mk2-Mk4 era) and tried them on the X.

The front calipers can easily be adapted to the X with a simple adapter bracket (took me less than a hour to measure, design and build a set of test brackets...really don't see what all the fuss is about). The VW calipers have 48mm pistons and are intended for 240mm vented (or solid) rotors. In order to maximize the caliper's benefit on the X, a larger diameter vented rotor should be used; although the stock X rotors are perfectly centered with the VW caliper and could work (the VW calipers can be run with either solid or vented rotors, depending which pads are fitted). The VW rotors might also work on the X if hub-centric rings were added to keep them true, however the X's hubs would need to be re-drilled for the 4X100 bolt pattern (which opens up a ton of wheel options). This combination would give the X a better design caliper and vented rotor (both are cheap and easy to get), but not necessarily a huge upgrade overall; pistons are the same 48mm, and rotors go from 227mm solid to 240mm vented. And not sure it is worth changing the hubs over to 100mm bolt pattern. Perhaps use a vented 240mm rotor from another model Fiat/etc [Per Steve C: "Discs are the easy part... 240mm/257mm /284mm/300mm in ventilated discs with 4x98 bolt pattern, and in 257/284 there are several different offset values available"]. Or as stated, the calipers could be run with the stock X rotors. However I still think the "New 500" rotor/caliper option is a better approach.

The rear VW calipers have 38mm pistons and could work but are not as easy as the fronts. Due to the mounting bolt locations the adapter bracket will move the caliper further out (radially) from the center-point. So larger diameter rotors would be needed. And the park brake cable approaches from the opposite direction (bottom to top vs top to bottom). I did not try mounting the cable so I'm not sure what's involved. At this time I am more focused on front applications; after they are determined then the rears can be designed to match the requirements dictated by the fronts.

MotoTrooper, any new progress on the New 500 brake application for your Scorpion?