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Sierra rear brake calipers - lightweight options
cosmicicecreamman - 31/12/19 at 12:59 PM

Hello all,

I'm looking to reduce the unsprung mass at the rear of my Sylva Riot. It currently runs sierra rear discs and calipers. It doesn't require any more breaking force at the rear, just looking for weight reduction.

Does anyone know of an easy and financially more favourable option for lightweight rear calipers rather than 4 pot options? Or any other ways to reduce the unsprung mass at the rear?


Many thanks


Stephen


SPYDER - 31/12/19 at 01:32 PM

Hi Stephen. There's a Golf caliper that fits. MkIV I think. I'm not sure what wheel/disc size is required. Get googling. Thinner discs is another option.


big_wasa - 31/12/19 at 01:54 PM

Mk1/2 Mx5 on little fiesta discs, they are tiny.


cosmicicecreamman - 1/1/20 at 11:44 AM

Excellent!!! Cheers chaps, will have a look at the mk4 golf options firstly. I'm running 13" wheels so maybe a bit tight. If that doesn't work I'll have a look at the MX5. At least both are readily available.

Thanks

Stephen


big_wasa - 1/1/20 at 01:20 PM

If you do a search for the user name Daf there are a few posts on a conversion he did. They easily fit under 13’s


fregis - 2/1/20 at 09:14 AM

Like said before, can change only calipers to golf, peugeot, alfa romeo, audi, or other ( they are all similar just handbrake ant pipe location different), dont need change carier, pads.

i used peugot caliper and sierra other parts. maybe i will take photo later

two things more:
Have different piston sizes, so choose.
Need make one groove in caliper for sierra pads springs

if you use all parts from golf or audi, calipers have offset +10mm for bigger diameter brakes


[Edited on 3/1/20 by fregis]


cosmicicecreamman - 8/1/20 at 12:13 PM

So...

I purchased a set of VW Golf MK4 aluminium rear brake calipers from my local scrappy and they fit the Sierra carriers. My 13" wheels fouled the callipers so a little assistance with the grinder to the calipers casting and they fit - I've not taken a huge amount of material off.

The VW Golf MK4 aluminium rear brake calipers were approx. 1 - 1.5kg lighter than the cast Ford Sierra rear brake calipers I had on already.

I've also purchased a set of these aluminium bearing carriers so hopefully lose a bit more unsprung mass at the rear of the car:

http://berrisford.co.uk/index.php/alloy-bearing-carrier-sierra.html


Thanks for the help and advice gentlemen.


Stephen


big_wasa - 8/1/20 at 12:48 PM

Are these the ones that require the hubs turning down a bit and escort discs ?


cosmicicecreamman - 8/1/20 at 06:33 PM

quote:
Originally posted by big_wasa
Are these the ones that require the hubs turning down a bit and escort discs ?


They bolted straight on, like I said the calipers needed dressed with a grinder to clear the wheel but no issue with clearing the hub or the disc.


big_wasa - 8/1/20 at 07:16 PM

Ok thanks,

RallyDesign did / do a kit that was reported to be vag calipers on Escort discs. The hubs need turning down to get the discs on.

I wondered if it was the same.


rdodger - 26/2/21 at 10:37 PM

quote:
Originally posted by cosmicicecreamman
Hello all,

I'm looking to reduce the unsprung mass at the rear of my Sylva Riot. It currently runs sierra rear discs and calipers. It doesn't require any more breaking force at the rear, just looking for weight reduction.

Does anyone know of an easy and financially more favourable option for lightweight rear calipers rather than 4 pot options? Or any other ways to reduce the unsprung mass at the rear?


Many thanks


Stephen


Hi Does your car use the Fiesta upright on the rear? With sierra 253mm disc?

[Edited on 26/2/21 by rdodger]


cosmicicecreamman - 27/2/21 at 03:59 PM

quote:
Originally posted by rdodger

Hi Does your car use the Fiesta upright on the rear? With sierra 253mm disc?

[Edited on 26/2/21 by rdodger]


My Riot doesn't use the Fiesta upright on the rear. It uses a custom made hub, with sierra bearing carriers, sierra caliper carriers and VW Golf MK4 calipers.

I use the smaller sierra bearing carrier in aluminium and the golf calipers in aluminium to reduce unsprung mass.

I've also just spherical bearing / rose jointed the back end as there was a lot of resistance in the rear suspension.

Thanks

Stephen


rdodger - 27/2/21 at 04:21 PM

Ok thanks. Good to know.


rusty nuts - 27/2/21 at 04:54 PM

quote:
Originally posted by cosmicicecreamman
quote:
Originally posted by rdodger


I've also just spherical bearing / rose jointed the back end as there was a lot of resistance in the rear suspension.

Thanks

Stephen


Crush tube issues?


cosmicicecreamman - 27/2/21 at 06:28 PM

quote:
Originally posted by rusty nuts
quote:
Originally posted by cosmicicecreamman
quote:
Originally posted by rdodger


I've also just spherical bearing / rose jointed the back end as there was a lot of resistance in the rear suspension.

Thanks

Stephen


Crush tube issues?


No, what kind of crush tube issues should I expect?


johnH20 - 27/2/21 at 07:06 PM

How do the Golf caliper pistons compare to the Sierra? From memory the Sierra is either 48 mm or 52 mm ( Cosworth ) I think the 52 mm pistons are speced on the Granada. The Golf being FWD may have substantialy smaller pistons. Suggest you check for brake balance. ( I don't have a Riot but my Cyclone is not hugely different in weight distribution. I found it a real problem to find a rear handbrake caliper that had big enough pistons. I ended up with Cosworth but like you would like something a lot lighter. )


cosmicicecreamman - 28/2/21 at 07:35 AM

quote:
Originally posted by johnH20
How do the Golf caliper pistons compare to the Sierra? From memory the Sierra is either 48 mm or 52 mm ( Cosworth ) I think the 52 mm pistons are speced on the Granada. The Golf being FWD may have substantialy smaller pistons. Suggest you check for brake balance. ( I don't have a Riot but my Cyclone is not hugely different in weight distribution. I found it a real problem to find a rear handbrake caliper that had big enough pistons. I ended up with Cosworth but like you would like something a lot lighter. )


The Golf calipers have been on the car for 1yr now and working well with the both the hydraulic mechanism and mechanical handbrake mechanism.

I sized the caliper pistons and they were the closest I could find, can't remember off the top of my head either piston size. I did need to reduce the rearward brake bias (move more to the front) but around the same time I changed all brake pads so I'm not sure if it was a function of brake pads, calipers or both.

[Edited on 28/2/21 by cosmicicecreamman]


rusty nuts - 28/2/21 at 08:59 AM

quote:
Originally posted by cosmicicecreamman
quote:
Originally posted by rusty nuts
quote:
Originally posted by cosmicicecreamman
quote:
Originally posted by rdodger


I've also just spherical bearing / rose jointed the back end as there was a lot of resistance in the rear suspension.

Thanks

Stephen


Crush tube issues?


No, what kind of crush tube issues should I expect?


If using poly bushes ,resistance when rotating suspension arms is often caused by the crush tubes not being long enough for the job, causing the suspension brackets to “clamp” the arm rather than clamping the crush tube which then allows the arm to rotate freely around the crush tube