Golf rear Calipers - Update

[Graham Perry]

I know some of you were hoping that these could be made to fit a Caterham and that we were a little bit disapointed when Norman drew a blank with these when he tried to fit them to a car with 13 inch wheels.

 

Just a quick note to let you know that I have obtained what I think are the right calipers and that after a brief session playing with them I think that they may work with 13 inch wheels after all in some circumstances, so there is cause for optimism. Area's that will need attention are the handbrake cables, hydraulic lines and most importantly the fouling of the calipers with the wheels as Norman discovered.However, I do have access to the resources of friends fabrication/engineering company so this will make things a little easier, but we would rather do it without cutting metal if possible.

 

We will be looking into trying to install them on my 1990 De-dion in the next month or so and I will report back. I am however at the busiest part of the year workwise and won't be able to dedicate too much time to it, hence the conservative timeline.

 

Just a quick thank you to Norman Verona for taking this as far as he did and doing all the legwork *thumbup*

 

Edited by - Graham Perry on 18 Feb 2005 16:14:44

[Normans_Ghost]

Graham, I can machine the calliper to fit, make the pipes and the clevis pin for the handbrake. problem was I didn't need these callipers and couldn't get hold of anyone who would commit to buy. They haven't gone back yet but will be next week.

 

If you need any help just email me.

 

Norman Verona, 1989 BDR 220bhp, Mem No 2166, the full story here

[John Howe]

Norman, if you can machine them to fit I'll happily buy them - if this offer is of any use phone me (01444 892127)

 

JH

Deliveries by Saffron, the yellow 222bhp Sausage delivery machine

[Graham Perry]

Norman, Thanks for the offer, I will let you know if we need any help

 

Graham

[MorganMan]

I don't know which model Golf the calipers come from but you might like to check out German, Swedish and French Car Parts. They have Mk 4 rear calipers on their website @ £52.50 per side.

 

www.gsfcarparts.com

 

Mike

[Luke Beaumont]

Graham, you wouldn't by any chance be coming to the Duratec Clinic this weekend? I've got a shaft/hub/wheel rigged up and would like to see the clearance myself.

[Graham Perry]

Luke, Sadly not, I have a long standing commitment. Calipers are away at the moment being cleaned up and checked anyway.

 

Edited by - Graham Perry on 12 Jan 2005 07:06:23

[Luke Beaumont]

Ah well. Might have to grab some myself then. I will be asking HiSpec about the handbrake Ultralite tomorrow, fully expecting the answer "they'll be available this year", just like the last two years.

[Graham Perry]

😬 but really ☹️

 

Edited by - Graham Perry on 13 Jan 2005 06:48:31

[Luke Beaumont]

Hmm, well, that was the answer I got. The caliper looks quite different than it used to. It now looks production ready, and even Martin Bell was assuring people that it would be coming out in the next few months. We shall see. I'd like to know how the handbrake mech works inside the caliper but they weren't for telling.

 

If this caliper does become available and works as intended I think for me it will be the caliper of choice. It's 1kg without pads, so will probably be about half the weight of the golf setup as well as being a proper 2-pot.

 

To anybody going on Sunday - ask them about the mounting orientation of the cable. As they have it on display, it looks to me like it would foul a De Dion ear.

[Graham Perry]

Well we have been having a little play, and the news is that they will fit my car, but sadly they won't fit everyones.

 

As Norman discovered the issue is the 13 inch wheels. I have two 13 inch sets, one set of which fit with the calipers with 4mm to spare and one set that don't fit by a big margin. I have done a few measurements and the restriction is the internal diameter across the inside faces of the rim . The problem you have to take account of is the trough that is cast into the rim to help change the tyres. For the calipers to fit you need a very shallow trough that doesn't go too far into the area occupied by the caliper and disc and reduce the internal diameter. To see if they might fit take your spare off and measure across the inner diameter of the rim. We reckon that if this dimension at the narrowest point is more than 12 1/4 inches then the wheels may fit. Any less and I don't think they will. One other thing to consider is how close the wheel spokes are to the hub mating face on the wheel. The back side of the spokes need to be at least about 10mm outboard of the wheel face that mates onto the hub. The reason for this is that the Golf mk IV Caliper is physically larger than the Sierra one and overhangs the hub face when viewed from above and so could foul the wheel spokes. Overall this is less of a problem than rim size, as I checked 4 different wheels including 15 inch and all the spokes cleared the caliper easily, but one was only by about 3 mm so it is worth checking.

 

I guess it could be possible to remove metal from the caliper but we decided against that, as the amount we would need to remove to make my second set of 13 inch wheels fit, was about 6mm which we felt was too much for safety.

 

The next issue may be a problem for some and that is the pad swept area. The golf pads are slightly too big for the Caterham discs (The pads cover a larger area than the Ford ones) and the top 2-3mm falls outside the disc area. We think there are two solutions to this. One remove the pad material (it represents approx 5% of the pad area) or fit new discs. I am told the Caterham rear discs are the same as the fronts. If that is so then the slightly larger & thicker GT6 / Vitesse disc should fit (I have them on the front of my car) , but these are heavier and may negate any weight saving on the calipers. We are going to remove some pad material and give it a try. If it doesn't work then we will use the larger discs and turn them down to the same thickness as the standard rears.

 

The handbrake we think can be made to fit easily without cutting the current mechanism in any way or changing the Caterham handbrake. We haven't yet finalised how to do this but it should be simple as the mechanisms and mountings are similar.

 

The bolts that hold on the caliper through the de-dion ear are different thread to the Sierra ones so you would need those with a thread similar to the Golf ones to make it fit, you do need a spacer of about 4/5mm on each bolt to move the caliper outboard by this amount to centre the disc in the caliper.

 

The pipework should be easy, but you need to have them made specially as the Golf caliper has a Banjo style connection to the inlet that is different to the Ford. Bleeding will not be as easy (was it ever though) as the bleed screws are not located at the highest point. We will need to see how this goes, but we may bleed them off of their mounting at about a 9 o'clock position

rather than 12 o'clock, but we will see.

 

Brake balance may also be an issue as the cylinders are different sizes. My car has a balance adjuster so I doubt this will be a problem

 

So in summary, the issues are;

 

1/ Wheel size (possible show stopper for some)

2/ Pad swept area (the fix might not suit everyone)

3/ Pipes & Bleeding (do-able)

4/ Mounting bolts and spacers (easy to get)

5/ Handbrake (Easy)

6/ Brake balance - depends on your car

 

I don't have any photo's yet and they are not yet fitted or test driven, but they should be at some stage in the next month and I will report back then. I have discovered that I have a driveshaft gaiter split so that needs to be fixed first ☹️ For some the work involved may not justify the weight saving (about a kilo) but I am going to give it a go. The Golf calipers do have cooling fins though so they may respond better to the rear overheating problems that some of us have on our cars.

 

Edited by - Graham Perry on 18 Feb 2005 16:48:17

[Normans_Ghost]

Well done Graham, If there's anything I can do, just shout.

 

I must get around to making the prop brake. What with Blue Lights, jacks, Le Mans, I havn't had much time.

 

Norman Verona, 1989 BDR 220bhp, Mem No 2166, the full story here

[Graham Perry]

Bringing this back for an update. Everything has now been fitted on my car and gently tested and it works fine. I will be running it in anger next Sunday in a sprint although I doubt they will get hot there. We did a few emergency stops from low speed to test them and it didn't show any underlying brake balance problem even though the Golf caliper has larger pistons than the old Sierra ones. I don't have any decent photo's yet, something I hope to address soon.