Citroen Bx 266mm Front Caliper / Disc With Handbrake

[tomcolinjones 26]

I have noticed that Citroen BX's the 16v ones at least, have 266mm front discs, with a front handbrake like most old citroens. the bolt pattern looks the same as the rear caliper mounting. am i correct in thinking this could be a good upgrade for a 205? obviously fitted along with 283mm setup on the front. i know there is a debate about the use for uprated rear brakes for road and track, but for handbrake turns (in competition) wouldnt it be a lot easyer to lock up the back end?

 

also, i cant remember if they are vented or not, i guess off a mi16 citroen they must be?

 

any ideas? im thinking about giving it a bash.

[stuart1298 6]

dont they run on lhm fluid rather than brake fluid...

[tomcolinjones 26]

dont they run on lhm fluid rather than brake fluid...

 

good point, im guessing mineral seals are unavailabe? not a big job to change them over is it?

[stuart1298 6]

not to sure, i was looking at doing the fronts from an xm, as that was my engine doner car, but was advised against it, u might be able to buy a seal kit from the dealer, but dunno if the brake fluid would eat through it, as brake fluid is quite nasty stuff

[Ryan 99]

The 266mm discs also won't fit on the rear as the centre bore is different.

[tomcolinjones 26]

The 266mm discs also won't fit on the rear as the centre bore is different.

 

i have seen them on a xsara vts, is the hub setup not the same on these as a 205?

[Ryan 99]

Afaik the centre bore on all Pug/Citroen front discs is 66mm, and the rears are all 71mm, so the only way to fit front discs to the rear on any model is to get the centres machined out.

Edited December 9, 2010 by Ryan

[tomcolinjones 26]

i have seen them on a xsara vts, is the hub setup not the same on these as a 205?

 

i have just cheked, and the gti bore is 71mm and the bx is 66.1mm what about a s16 front disc?

 

is the 205 the only pug with 71mm rear bore?

Edited December 9, 2010 by tomcolinjones

[tomcolinjones 26]

i have just cheked, and the gti bore is 71mm and the bx is 66.1mm what about a s16 front disc?

 

is the 205 the only pug with 71mm rear bore?

 

just read this, after i posted... sorry

 

so all pug/cit is 71mm on the rear, so the xsara with 266mm discs on the back i have seen must have had them machined to fit.

does any one do this?

Edited December 9, 2010 by tomcolinjones

[Rob Thomson 6]

Why bother with the larger discs? A few extra mil on the diameter isn't going to make a significant difference but sounds like a lot of hassle. The big gains come from the larger pistons (50mm vs. 32mm IIRC) which would transform the stopping power of the rear brakes and the effectiveness of a hydraulic handbrake.

[Tom Fenton 1,536]

Afaik the centre bore on all Pug/Citroen front discs is 66mm, and the rears are all 71mm, so the only way to fit front discs to the rear on any model is to get the centres machined out.

Are you sure about this? The only reason I ask is that unless my memory fails me, both front and rear discs fit reasonably well on the "register" that the wheel spigots onto- which is obviously the same front and rear of the car.

 

Another reason that I am not sure is that I fitted a pair of 1.9 GTI front discs to the rear hubs of my car, as I have vented rear discs (for no other reason than I fancied trying it, and had the discs kicking about).

[tomcolinjones 26]

the reason i am asking is because the vts that i have just baught, 15 min ago (and i had only spoke to the owner today on the phone and he said what it had on it to me, but i hadnt seen the car yet so i couldnt see the size of the disc)it has bx calipers on it, the owner said that they are a larger piston like rob said "The big gains come from the larger pistons (50mm vs. 32mm IIRC)"

the discs look standard size to me, so i think he or i got mixed up thinking they where bx gti front discs (266mm)

so there is still a big gain for the h/brake from the caliper on the standard disc? i am not realy interested in going vented as i dont think i have ever got the backs that hot to need it, and i dont want to rely on a 'home made bracket' to help me stop!

[Tom Fenton 1,536]

If that is aimed at me, I do not use a "home made bracket".

[Ryan 99]

I had a quick look through some parts on www.brakeparts.co.uk and all the ones I checked are listed as 66mm front and 71mm rear.

[tomcolinjones 26]

If that is aimed at me, I do not use a "home made bracket".

no, it wasnt, and not as an insult either, sorry you read it wrong or i wrote it incorrectly. just meant that i dont fancy using an aftermarket braket. no offence intended.

[Guest renolarsen]

I did the mod, and had to make some "Homemade Bracket"

 

i took the wheel hub in a lathe to take the corner of, so it fits standard 266 discs.

 

the handbrake arms on the calibers are on the top and not the button, so i extend the cables about 20mm and made a new nut to adjust it

 

here is some pics.

 

 

http://www.facebook.com/photo.php?pid=9555...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=9555...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=9555...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=1149...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=1294...p;id=1176185495

[Rob Thomson 6]

so there is still a big gain for the h/brake from the caliper on the standard disc? i am not realy interested in going vented as i dont think i have ever got the backs that hot to need it, and i dont want to rely on a 'home made bracket' to help me stop!

If you can resolve the LHM problem, then yes. The standard rear calipers aren't big enough to work well with a hydraulic handbrake with a standard 0.625" master cylinder. Either you need a tiny master cylinder or larger slave cylinders. The 50mm pistons in the BX calipers will provide about 2.5 times as much braking effort as the standard 32mm pistons, assuming the same pull on the lever.

 

If or when I get another rally car this is top of the list of modifications.

[tomcolinjones 26]

If you can resolve the LHM problem, then yes. The standard rear calipers aren't big enough to work well with a hydraulic handbrake with a standard 0.625" master cylinder. Either you need a tiny master cylinder or larger slave cylinders. The 50mm pistons in the BX calipers will provide about 2.5 times as much braking effort as the standard 32mm pistons, assuming the same pull on the lever.

 

If or when I get another rally car this is top of the list of modifications.

 

cheers rob. im picking up the xsara friday, so i will be swaping these over asap, and sorting out the bias. im guessing you can fit 1.9 rear pads in the caliper, as i think they are the same shape, just thinner?? i have ebc bluestuff pads, would make sense to use them!

[tomcolinjones 26]

I did the mod, and had to make some "Homemade Bracket"

 

i took the wheel hub in a lathe to take the corner of, so it fits standard 266 discs.

 

the handbrake arms on the calibers are on the top and not the button, so i extend the cables about 20mm and made a new nut to adjust it

 

here is some pics.

 

 

http://www.facebook.com/photo.php?pid=9555...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=9555...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=9555...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=1149...p;id=1176185495

 

http://www.facebook.com/photo.php?pid=1294...p;id=1176185495

Nice job my friend, nice 205 aswell!

[matyasg 0]

also, i cant remember if they are vented or not, i guess off a mi16 citroen they must be?

Yes, they are vented.

[tomcolinjones 26]

Rite, Its to cold to do anything properly, but now the Xsara is in the barn, i decided to take of the BX calipers it has on the rear, and see if i could make a direct fit vented rear disc setup using 1.9 front discs.

The pads in the citroen caliper are the same as 1.6 gti fronts by the looks, and the slider is wide enough to cater for vented discs, so using gti rear pads that are quite a bit thiner it will give me a bit more room and hopefuly not having to offset the caliper, there should be plenty of movement in the slider.

this is what i just knocked together.

obviously its not a 266mm setup as the title says, but it does use the 50mm piston from the citroen bx front calipers, and still has the cable mec for the handbrake, and if all i have to do is expand the centre of the discs so it will fit on the rear hubs, i think it will be something different, although i wont be getting the brakes hot enough to warrent using vented, at least it is possible.

Edited December 19, 2010 by tomcolinjones

[welshpug 1,646]

I'd be inclined to just fit the pad carrier to suit non vented discs then you'll have less issues with uprated pads being too cold.

[tomcolinjones 26]

I'd be inclined to just fit the pad carrier to suit non vented discs then you'll have less issues with uprated pads being too cold.

 

would a xs one fit?

[welshpug 1,646]

I don't know, but that's the only type there is so if you have one I'd certainly try it, saves messing with grinding out vented discs to make them fit.

[tomcolinjones 26]

good stuff, ill get on it in the moning, and get them mounted at least, see whats goin on. they where on a dot fluid car, and the fluid from out of the caliper didnt look discoloured, so i can only assume that the seals have been changed over from LHM.