Rear calipers

[chris.richard]

I've come accross these rear calipers, which might be a good upgrade from Alfa rears if the mounting can be sorted out - it looks like radial mounting. The piston size is 54mm, giving a better rear effort than the Alfa (36mm), and much nearer a 50:50 split for a rear engined car (Alfa front piston 54mm on 12v, 57mm on 24v).
Roger Donnan used the Pro Race 4 same web page (http://www.constella.co.uk/tuning/productlist.asp?CatID=56) front and rear with good effect. (And no handbrake :o .) A bias bar or bias valve sorts out the fine tuning of balance.

Looks tempting!

[Sptwoman]

I spoke to the guy at COMPBRAKE (http://www.compbrake.co.uk/) @ Preston. Good gear and he's prepared to deal direct with "discount" for ££.. Also got my Beta ali strut mounts there :)

[Chris J]

Allen

I see Compbrake list the anodised alloy Beta strut tops.

Talking about vented disc handbrake calipers; I noticed my brother's VW Transporter has vented discs on the back with a single (handbrake) caliper.

[chris.richard]

I've spoken to Compbrake, and it turns out the piston size is 38mm, not 54 as the website above says. Bu:mad:er.

[strat6v]

RMD are just about to release a dedicated handbrake caliper that fits vented discs, see rally design's catalogue. Purely mechanical and of the sliding pin design. Cost around £ 65.00 plus vat but come with pads already.

[guy mayers]

hi John, can you post a link to the RMD caliper? I'm struggling to find something that will fit over the vented discs I've got on the back of the car and not foul the wheel!
Guy

[chris.richard]

This can take vented discsthis? (http://www.rallydesign.co.uk/product_info.php?cPath=562_588&products_id=11370)

[strat6v]

Its on page 36 of their new catalogue but not on the website yet. I asked about availability and the chap said around a months time. Its the perfect thing for us, proper size and not something designed to fit a go kart ;) will be offered to suit disc sizes 21/22mm, 24/26mm and 28/32mm.

If anybody needs more info then its best to contact Rally design or send for a catalogue.

Guy, if your rear disc has an offset something like a 164 front disc then it will fit easily. Probably no more than 25mm of caliper casting and pad on the outside of the disc.

[chris.richard]

hi John, can you post a link to the RMD caliper? I'm struggling to find something that will fit over the vented discs I've got on the back of the car and not foul the wheel!
Guy

http://cgi.ebay.co.uk/ford-sierra-granada-cosworth-rear-vented-calipers_W0QQitemZ170204492347QQihZ007QQcategoryZ2 1654QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[chris.richard]

Its on page 36 of their new catalogue but not on the website yet. I asked about availability and the chap said around a months time. Its the perfect thing for us, proper size and not something designed to fit a go kart ;) will be offered to suit disc sizes 21/22mm, 24/26mm and 28/32mm.

If anybody needs more info then its best to contact Rally design or send for a catalogue.

Guy, if your rear disc has an offset something like a 164 front disc then it will fit easily. Probably no more than 25mm of caliper casting and pad on the outside of the disc.

John, do you know the piston size?

[Sptwoman]

Chris J,
I've got the ali strut mounts, they're not anodised but naked!!! Lovely finish.. I believe the Elise has 24mm vented rear discs... (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=200211807770&ssPageName=STRK:MEWA:IT&ih=010) I'd imagine they're extra light...

Chris,
The Cosworth calipers are heavy... tried them and sold them on!!

John,
Is this just a handbrake caliper solution / a proper spot caliper? No piston or added weight involved? Are they 65 quid a side? Any idea on weight?

[strat6v]

Purely a mechanical handbrake spot caliper, a proper one and not a toy.

£ 69.50 + vat per side.

It says volume discounts available too.

No information about weights though, sorry.

[Chris J]

Aren't these the ideal thing? To do both jobs that is:

http://www.hispecmotorsport.co.uk/calipers/billet_4_hb.htm

[guy mayers]

Or their spot caliper?

http://www.hispecbrake.co.uk/calipers/sva_spot.htm

I'e got to get under the car to check tolerances but I know it's tight already. Anything thicker than a Dynalite is probably going to foul!

Guy

[Sptwoman]

Brilliant find Guy.... I've been searching for ages for a solution, then these come along..

[chris.richard]

Or their spot caliper?

http://www.hispecbrake.co.uk/calipers/sva_spot.htm


Confused by this.
Disc Diameter 6mm - 36mm :confused:

It talks about hydraulic connection, but I thought a spot caliper was a mechanical handbrake only?

[Chris J]

Confused by this.
Disc Diameter 6mm - 36mm :confused:

It talks about hydraulic connection, but I thought a spot caliper was a mechanical handbrake only?

I think that's a typo Chris. It's the disc thickness from 6mm - 26mm, and it is mechanical only.

The thing is, does it work?

[Matt No VAT]

Can anyone post a pic of these beta top mounts from Compbrake?

I know its off topic slightly :rolleyes:

[guy mayers]

It's what I'll probably end up going for but I still need to get under the car to check tolerances - difficult when the 4 post lift it lives on bled to death last time I dropped the car down! Poor Spider is now living outside!
Guy

[strat6v]

The rigid type spot calipers can't move sideways as the pads wear so the mounting has to be flexible in one direction. Same problem as the wilwood spot caliper which were supplied with an earlier brake package and didn't work too well i believe.

Hi spec 4 pot would probably be ok

This problem is covered time and time again, just goes round in the same circles.The only fix is a decent seperate sliding pin type handbrake caliper thats meant to hold a car and not a go kart. Some companies do make four pots with handbrake mechanisms but have you looked at how the cable operation is arranged and how will you manage to package the cable past the gearbox and crank pulley bit???

Think about it??

[guy mayers]

John, I actually had one of the Hispec spot handbrake calipers in my grubby paws at the Stoneleigh Historic Show. Whilst the body is a rigid mounting both spot pads move towards the disc. The Wilwood spot caliper I used to have relied on very careful setting up and a slightly flexible mounting bracket but was never effective for long enough to get to the MOT station to find out if it was effective enough... Binned.
The Hispec one is very easily modified for different thickness discs due to the use of spacers between the two halves. How effective it turns out to be I have no idea yet. If I know it'll fit cleanly then I'm going to try a pair! My intention is to crawl under the car this weekend sometime somehow.
Guy

[strat6v]

looking at the drawing, the cable is at the right pull angle.

[chris.richard]

looking at the drawing, the cable is at the right pull angle. Which caliper are we talking about?

[chris.richard]

This problem is covered time and time again, just goes round in the same circles.

which indicates that there is no decent solution so far. :rolleyes:
Are we the only kitcar with these problems?

[Sptwoman]

There's lots of articles on the web covering this topic in the kit car industry... I'm going to try these brembos (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=330224203339&ssPageName=STRK:MEWA:IT&ih=014) Fingers crossed X. If they Don't work, then it's back on ebay and save a little more for the HiSpec solution!!

[strat6v]

Perfect Allen :cool:

RMD handbrake caliper is almost exactly the same design.

Looking again at the hispec unit, although it actuates both pads it still can't self centre if one pad happened to wear more than the other

[chris.richard]

There's lots of articles on the web covering this topic in the kit car industry... I'm going to try these brembos (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=330224203339&ssPageName=STRK:MEWA:IT&ih=014) Fingers crossed X. If they Don't work, then it's back on ebay and save a little more for the HiSpec solution!!

Allen, the ad says they're for 26 - 32 mm thick discs, the Alfa ones are 22, what are you using?

[strat6v]

A couple of spacers behind the pads i guess

[Sptwoman]

No flies on you John :cool: Yep, I'm using the 22mm disc Richard but will use spacers where appropriate..

[Ian Gear]

Hi all
I have been driving 2 years with Hispec breaks for a Beta Hawk.
They have all the dimensions to fit a Hawk strato's.http://www.stratossupersite.com/forum/newreply.php#
Ian Gear

[mudhut]

Hi Ian.

The link you've posted looks incomplete. Do you have bigger images of those brakes? I think I'm getting old and the eyes are not eying as well as they used to.

[guy mayers]

Ian - did you resolve your mastercylinder problem? I saw a listing on Ebay for a 124 M/C that described it as 131 as well. I think I have a spare 124 Spider one that may have suffered heat/fire damage somewhere is you want to dismantle that for comparison.

Went into the garage to check the clearances, battery flat this morning and the brakes seized on - hasn't been out since October.... Maybe later!

Guy

[chris.richard]

Flexi pipe looks a bit stretched on full droop Ian - is it OK?

[Ian Gear]

Yes I got a master cylinder for a fiat 131 from the US for $24.00 and $24.00pap New!
The HiSpec brakes are Billet 4 caliper. Same size all round. With a limiter to the rear.
Ian Gear

[Ian Gear]

Yes the Flexi pipe OK. Looks a bit stretched as its was replaced later.

[mudhut]

Thanks for the pics Ian.

[guy mayers]

Ho hum - there's a lot to be said for regular use... Charged the battery but no go. Looks like no spark at the moment so I've got some checking to do when I get a nice day. Managed to crack the brakes off and move the car forward enough to get underneath to check the gap I have to work with - 21mm. I've fired off an email to Hispec but I suspect that the SVA Spot Caliper they have developed needs more than that!
Guy

[strat6v]

Is that behind a coffin spoke wheel? Seems strange, i can fit a big four pot down there. What is your disc offset?

[Ian Gear]

All the offsets were done by HiSpec with alloy bells, and are fitted behind the old 15" compermotive split rims that most early Transformers had with a Beta set-up. The rear caliper mount is on the inside face of the strut hub, and therefore had to be made parallel with the outside.
Ian Gear

[guy mayers]

The offset ain't the problem John. The diameter of the disc on the back is 309mm and the internal diameter of the coffin spoke is 330mm. Kinda tight down there!

Guy

[Ian Gear]

Some more pick's of the hand brake set-up.
Ian Gear

[strat6v]

Wrong diameter disc then. I have the 284mm alfa discs with brembo 4 pots all round. Plenty clearance.

[mudhut]

This is the h/brake cable pulling downwards, right Ian?

Wil you be able to bend the cable sufficiently on a reasonably large radius to get to the horseshoe comfortably (presuming you are using this part)? Where will you secure the outer cable between calliper and horseshoe?

So many questions I know but I think I can get a great deal more braking force out of the rear and can then will get more weight transfer to the front to work harder too.

[strat fan]

Just a quick note with regard to the high spec rears.
The rear calipers shown in Ians Pics are the old style HI spec units & they work really well, they are however not very popular with the SVA people because they are not completely mechanical which is why Hi Spec now do the other type of caliper (SVA billet 4) with the seperate handbrake pads. These work but not aswell as the old style. They are a lot more critical on the set up & need the correct handbrake lever ratio otherwise it is difficult to meet the percentage of the design weights required on the test.
The RMD caliper looks like a direct rip off of the Brembo caliper which Tim has fitted (see pic below) & these do really work well but are an expensive option as they are purely handbrake & you still need a seperate brake caliper.
John as far as I can tell with the HiSpec unit you shouldn't get uneven pad wear & if you do the way the mechanism works it wouldn't affect the centering of the pads relative to the disc as they are both on pivoting levers & one pad pulls against the disk then the other (I can take some pics of the hispec units if any body requires them)

[Ian Gear]

The hand brake is a downwards pull using a ford scorpio cable shortened by about 18". I went for this so I cleared the splash guards. HiSpec have not made a tangental pull lever.http://www.stratossupersite.com/forum/newreply.php#

Ian Gear

[strat6v]

Cable looks a little low. Probably too low for the rally boys, but ok for the road.

[Ian Gear]

Yes its lower than I wanted but its Ok for the road. Rally boys would go a top pull but then how do you clear the splash guards?

Ian Gear

[SUSIT]

Yes its lower than I wanted but its Ok for the road. Rally boys would go a top pull but then how do you clear the splash guards?

Ian Gear



Is your calliper mounted leading or trailing edge Ian, was thinking of ordering these to go with my hi spec fronts, had bought compbrake racing 4 for the rear but not happy with the fit as they are lug mounted and not radial.
The only downside is the hi spec is not designed for rally or racing use with the mechanical hand brake although they did tell me there is no reason that they could not fit it to there racing 4 pot but have no plans to do so :( :(
Would I get the cable in with a sump guard in place?

[Ian Gear]

Are you going to the National Kit Car Show, as you will be able to see my setup? the rear is mounted to the existing Hawk mount but on the revise side that will need to be
made parallel with the outside. They do the same calliper without hand-brake too, so one could mount the SVA hand-brake on the other side?!

Ian Gear

[SUSIT]

Are you going to the National Kit Car Show, as you will be able to see my setup? the rear is mounted to the existing Hawk mount but on the revise side that will need to be
made parallel with the outside. They do the same calliper without hand-brake too, so one could mount the SVA hand-brake on the other side?!

Ian Gear


Yup you could if it was a Hawk upright however being a poor nurse not to mention a tight fisted scot then sadly I have an Allora using modified Beta front uprights/hubs on the rear of the car so only one calliper mount.
Wont make Stoneleigh but will be at Chatsworth if your going.

thanks for the info
Stephen

[chris.richard]

Wrong diameter disc then. I have the 284mm alfa discs with brembo 4 pots all round. Plenty clearance.

So what adapters have you needed to mount these John? And what are you using for a handbrake?
I've just acquired a parir of Brembo 4-pots, should I get more?

[strat6v]

166 four pot brembo's all round. Front brackets are with the cnc man at the moment, four sets being made, two for me and a pair each for two others here ;) Still got the rear adaptors to do, much easier than the front ones so i'm gonna do them on my mill.
I'm going for some of those rmd or brembo jobbies like allen boughtfor the handbrake. The more i look at that hi spec handbrake caliper, the more puzzled i am. Yes both pads move on a linkage but i still can't see how they will centre themselves, ie if one pad wears more then they won't work. Does anybody have a better pic of the linkage?

[chris.richard]

What size wheels are you using John? I don't want to go above 15", partly looks, and partly having shelled out for 10 Revolutions!

[strat6v]

They are Hawk's 15" coffin spokes.

[strat fan]

Hope this helps a bit John, you can just make out the linkages (poor photography on my part)
Also added a pic of the original Hispec caliper.
With regard to the Brembo option it does come with the wheel which brings the cable out toward the centre of the car which helps with clearing the wheel rims etc which I haven't seen on the RMD version/copy.

[strat6v]

Thanks Craig

Still looks to me like they don't self centre. Both certainly move but both by a fixed equal amount :confused: I need to have a play with one.

You are right on the RMD/brembo cable routing. I could machine a pivot wheel without too much hassle. I'm on the hunt for some of the Brembo's.

[guy mayers]

You are right on the RMD/brembo cable routing. I could machine a pivot wheel without too much hassle. I'm on the hunt for some of the Brembo's.

That makes two of us John! I've not had any reply from Hispec about thier SVA spot caliper - great customer relations management! If you find a source please let me know, perhaps we can get a discount for more than one set?

Guy

[strat fan]

I know what you mean about Hispec they are terrible to deal with.
John I have a pair of Brembos here if you want to look at them (I am passing through your area on Saturday) & I have a contact who can supply them but would need to check price tomorrow.

[strat6v]

Call in if you are this way, you are most welcome :) Kettle is always on, just watch out for all the junk on the driveway :D

Be good to have a look at the options. Any prices would be good too.

[guy mayers]

Says they are full floating.. (http://www.ipsco.org/Custom%20Services/Parking%20Brake.htm)

No idea on price/shipping though!

[strat6v]

They look to have a sliding pin arrangement, looking at the flats on the pin/bolts. Good find Guy.

[guy mayers]

Says they are full floating.. (http://www.ipsco.org/Custom%20Services/Parking%20Brake.htm)

No idea on price/shipping though!

Found a US supplier of the Brembos - $1050 per pair plus shipping and duty. I don't think so.

Also had some details from the Ipsco people. Thier caliper comes out at $300 per pair including a "general mounting plate", weight is 3lbs per caliper with a pad area ot 4sq" per side giving 8sq" per disc so this one is sounding promising. I'm waiting now for the critical dimension for my application and I'll let you know when I hear more.
Guy

[chris.richard]

I've come accross these rear calipers, which might be a good upgrade from Alfa rears if the mounting can be sorted out - it looks like radial mounting. The piston size is 54mm, giving a better rear effort than the Alfa (36mm), and much nearer a 50:50 split for a rear engined car (Alfa front piston 54mm on 12v, 57mm on 24v).
Roger Donnan used the Pro Race 4 same web page (http://www.constella.co.uk/tuning/productlist.asp?CatID=56) front and rear with good effect. (And no handbrake :o .) A bias bar or bias valve sorts out the fine tuning of balance.

Looks tempting!
Some more data on these. Pity the 54mm piston is a lie!
Mounting hole distance 90mm

Maximum thickness of disc 14mm,

Piston size 38mm,

Overall width 135mm,

Overall depth of Caliper from furthest outboard point to furthest inboard point 165mm

[guy mayers]

Found a US supplier of the Brembos - $1050 per pair plus shipping and duty. I don't think so.

Also had some details from the Ipsco people. Thier caliper comes out at $300 per pair including a "general mounting plate", weight is 3lbs per caliper with a pad area ot 4sq" per side giving 8sq" per disc so this one is sounding promising. I'm waiting now for the critical dimension for my application and I'll let you know when I hear more.
Guy

The critical dimension for me is the gap between the outer edge of the disc and the inner surface of the wheel.
They've just replied to my queries and the thickness of this part of the caliper is .75" which is going to be tight but it will go. They've also confirmed that the caliper is designed for use inside a 15" rim so things just got better!
I am in the process of ordering a pair and hope to have them on for Stoneleigh. Or at least in a box with me!
Guy

[guy mayers]

Just had a reply from Mark at Ipsco - following the placement of the order on Saturday the calipers are built, attached to the generic mounting plate and on the way by airmail at a total cost of just under $350. Hispec haven't even replied to a question I sent them by email 10 days ago...
The reply included a few pictures of the calipers, I suspect that I'll have to make another mounting plate that will include the cable mount but the caliper lever appears to take a spherical cable end so the Beta one ought to fit straight in.
Guy

[chris.richard]

Another possibility? - Brera calipers:
3.2 JTS 24v rear 292x22 ventilated combined 41mm piston and floating caliper. Retail price is £182.84 each plus vat
2.2 JTS rear 278x12 solid combined 38mm diameter piston and floating caliper

[Sptwoman]

Guy, All looks to be good news as handbrake calipers have been a real pain to source. My Brembos arrived last week and I have a mounting plate design with Crabb's of Flint. £40 a pair made of HE30 (They supplied) @ 15mm thick.. If you need any help in this area let me know.

[strat6v]

I have aquired a pair of the brembo handbrake calipers. Can they do a second pair of mounts?

Do you have a copy of the drawing you could email?

It would save me a job designing a mount then an age machining it. I'll still have to get a mount welded on the hub carrier though :o

[guy mayers]

Callipers have arrived today but our nice Customs people got thier pound of flesh out of me. Unfortunately this doesn't give me time to get them installed but I'll bring them to Stoneleigh in case anyone wants to have a look!
Guy