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MG Midget and Sprite Technical - Brake shoes for hard use

Anyone have any experience and recommendations for a hard, slow wearing brake shoe?

Thrashing the car yesterday at Curborough, the brake pedal was getting noticeably longer even after a handful of runs and I had to wind the rear adjusters up three flats (!) at lunch time.

Can't remember what shoes are in there, but they seem to wear VERY quickly and thus the pedal feel is never particularly consistent and thus not very confidence inspiring.

Cheers,
Malc.


Malcolm

The recommended lining for competition use at the rear was Ferodo VG95.I used them in my race car and they lasted very well. Its no longer manufactured. Mintex or EBC brakes may be able to offer an equivalent.
Bob Beaumont

Malc

Think the main choice would be between standard Mintex rear shoes or harder fast road or race spec Mintex rear shoes combined with a similar spec for the front pads (i.e. standard road spec rear shoes with standard road spec front pads; fast road/race spec rear shoes with fast road/race spec front pads).

Magic midget seem to be out of the uprated Mintex rear shoes but still probably worth a call: https://www.magicmidget.co.uk/shop?Collection=Brakes

Peter May Engineering might have stock: https://www.petermayengineering.com/product/mg-midget-and-austin-healey-sprite-mintex-competition-rear-brake-shoes/

Guess it shows you were trying hard enough!

I would want advice on bedding them in as well as wanting to know what they would be like on the road when doing an emergency stop when cold. Pity there is not more choice of linings as fast road is probably a good compromise for short track sprint and hillclimb use - not that many dabs plus needed from cold, for a car that is used on the road too. If you were circuit racing then different with something harder that could last the distance and be great for huge stops from great speed albeit at the expense of the first corner being a bit interesting on cold front brakes!

Daniel Stapletons book has some info and advice (perhaps you should offer to write a section on home-brewed fuel injection for the 1500 engine in a next edition?): https://www.veloce.co.uk/authors/authors.html#!/The-MG-Midget-&-Austin-Healey-Sprite-High-Performance-Manual/p/135968760 If you want to know what Midget Challenge racers did in the 1980s see:

Cheers
Mike
M Wood

Malc

Ran out of time - info on MG Midget Challenge car prepn in the 1980s see: http://austinhealeyspritemk2.blogspot.com/2015/06/mg-midget-race-preparation-30-years-ago.html either Ferodo DS11 front pads with VG95 rear shoes or Mintex M171 front pads with M20 rear shoes. Not sure if either are available now, last time I looked the Mintex pads were M1171 and cannot remember what the uprated Mintex shoes were.

There is the EBC green stuff option as Bob mentions. I know for front pads there are enthusiasts of Green Stuff and those not so keen in relation to perhaps dust or disc wear or something? (cannot quite remember the concerns)

Hopefully David Smith, Rob Armstrong and other ardent racers will be along with some practical advice based on experience.

I reckon for regular hillclimbs you might be OK on good quality (Mintex) road pads and shoes with new fluid and careful adjustment including checking on the event. Sounds like you got many runs at Curborough so perhaps plan to change your shoes (and pads?) at lunchtime (and hopefully not pants!). Mr Armstrong apparently reported his freshened up (new build?) K Series powered car had a good view through the side window when going sideways at this MASC Curborough event.

Cheers
Mike
M Wood

Front brakes are fine. I know there are a lot of EBC haters, but I have had a set of Yellowstuff pads in there for years and they have worked well. I plan to try the Mintex M1144 pads as and when I need to change them, but not because I haven't got on with the EBC, but because everyone raves about the Mintex and I want to try them out and see what all the hype is about!

So it's just the rears that are troubling me.

I managed 16 runs yesterday and the car held up pretty well all in all.

Cheers,
Malc.
Malcolm

Mintex 1144 are OK for fast road and some track use, but 1155 were always better for racing.

M20 shoes were always the favourite in my time, but I don't know about availability these days. I used to get mine from my local Min specialist.

The other option, as mentioned in another thread, is to reduce the size of the rear wheel cylinder. My M20s used to get very hot, even with 1500 wheel cylinders, so I changed to Cooper S.
Dave O'Neill 2

I’ve recently swapped to the Mintex race shoes due to going through a standard set virtually every race. They’ve held up pretty well after 4 races. The friction material is bonded and riveted (although only a couple of rivets).
Fairly expensive at around £100 but worth it.

Strange really because I’ve done years and years of sprinting and hillclimbing and only used a couple of sets of standard shoes in that time. I even did a couple of seasons of racing on one set of standards. Maybe the newer standard friction materials are softer, though I did try several makes.
John Payne

Mintex 1144 on mine. Front and rear. I set fire to a set of shoes and then turned my drums purple, got rid and fitted rear discs. Question is where's the long pedal coming from? The biggest issue I had was the original disc overheating. Go bigger, and/or vented.

Or, make it go round corners better so you don't need to brake as much.
Rob Armstrong

That second point is a very valid one! More work to be done there for sure.

Malc.
Malcolm

Drums expanding significantly as they get well hot will make the pedal longer.
Paul Walbran

Good point Paul.

Maybe time I dug my minifin drums out again! :-)

Malc.
Malcolm

Badge of honour Malc that you have driven hard enough for that to happen!

I once had the whole lining fry up and the pistons pop out far enough to lose the lot. A brief tarmac section in the middle of an otherwise gravel special stage had 4 long straights and tight 90deg corners between. The last corner got it.
With a co-driver, spare wheel and toolbox, coupled with bias set heavily to the rear to get the tail out on gravel, the rear brakes were working harder than the front and didn't have a chance.
Now it has discs....
Paul Walbran

John, ref the sprints and hill climb experience, there is often not enough distance for the brakes to get hot enough to be a problem. At our entry level track sprint day we keep to 3 lap sprints because we have found that in a 4th lap the hard chargers in their daily drivers can run out of std brakes.
Paul Walbran

Paul, yes you’re right, even the longest of sprints here in the UK doesn’t really tax the brakes too much, well not on my car anyway. But moving to racing usually shows up any weakness and it did with mine! I had exactly the same experience as you with the shoes completely gone and pistons popped out with total loss of brakes.
I’ve now upgraded the fronts to 4 pots and the Mintex race rear shoes and it seems a lot better - but still not amazing.
Other racers I know have no problems at all, even using standard shoes. I must stop using the brakes!

It’s been a while since I’ve seen your car at Silverstone, I remember you doing the sprint, must have been 2007 ish. No sprint there now, not even the one on the Stowe circuit.
John Payne

Is it actually cooking the rear brakes or just wearing them down---two different issues--no use fixing one if it's the other
The usual cause of rear brakes overworking is the mismatch front/rear
If you have harder pads in the front then they need more pedal pressure to make them work and the poor old rears cop that extra pressure----If you feel you have enough braking power, then maybe just go smaller wheel cylinders in the rear--you only need enough rear brake to hold the rear in line under brakes
If it's just a heat/material issue causing overheating---lots and lots of vent holes in the backing plates and some in the face of the drums maybe

looking at your pic--that poor old front tyre's copping it, I'd be whacking some more wind in that before you flip it off the rim
suspension--I see about 5deg lean there which roughly means 5deg. pos camber-----first step of going faster would be to address that

willy
William Revit

On the first visit to the track in 2003 with standard drum brakes, these were fading within 2 laps due to boiling brake fluid and the brake shoes turned out to be vitrified (melted) upon returning home. It was also clear that the rear braked too hard.
It took me a lot of time (reading and a lot of experimenting) to solve the problem. Daniel's book was very helpful with this.
One of the causes of the wrong bias is that tires have gained much more grip in half a century and the asphalt on the track is very rough. This puts more weight on the front and less weight on the rear tires when braking.
Standard front disc brakes and small rear wheel cylinders in the latter type of drum brakes together with Mintex 1144 just didn't help enough to achieve a perfect bias. Finally I mounted a bias valve. Now I am satisfied.
Flip Brühl

This has sent me down a bit of a rabbit hole... and I think I already have the 11/16ths bore cylinders. I haven't been able to measure them, but looking at old pictures I am pretty sure the pin locations that I can see are for the smaller cylinders. There is a vague flicker of a memory of buying the wrong parts at one point too.

Also, yes Willy, more pump required! Although those tyres aren't fit for the job anyway. I put them on because I thought it was going to rain and so I was ready to go home when it did... but it didn't! ha ha. 8 year old, 155 section junky Firestone road tyres on the front there. Hilarious to throw about, but not fast!!

And thanks Flip. I am now considering a complete do over of the brakes this winter and might do as you suggest.

Cheers,
Malc.
Malcolm

Hang on... being thick. 11/16ths is right for a 1500.
Malcolm

Not thick, just thinking
Can you find some 5/8" cylinders that fit or get yours sleeved maybe
William Revit

Yep. Part no. GWC1101 is 5/8" bore. They are on the list! :-)

Malc.
Malcolm

just double check what you have already though, you might have that size already and just getting the same again--
William Revit

Well...

Track day at Anglesey on Monday was the final nail in the coffin! :-D Double pumping the brakes to get them to work wasn't very confidence inspiring!

New rear bits ordered, with 5/8" bore cylinders, Mintex shoes and new "genuine" adjusters and wedges.

Fronts seemed to cope OK-ish with standard discs and yellowstuff pads. Albeit getting very hot and smelly after 20 mins of track time. I will ponder some upgrades in due course.

Malc.
Malcolm

This thread was discussed between 11/07/2023 and 09/08/2023

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