MG Midget and Sprite Technical Big Brakes for the Racer BBS discussion at MG-Cars.net

MG Midget and Sprite Technical - Big Brakes for the Racer

As the midget racers are aware I built Jason's racer over a 4 1/2 month period during the winter of 2006/07. At the time, budgetary and time constraints meant that I couldn't do what I wanted in the brake and front hubs departments. The car therefore debuted with Wolseley 1500 rear drums and stock front hubs (albeit with taper roller bearings) with modified Austin Allegro discs and Austin Princess 4-pot calipers. Unfortunately this front set up, while resulting in superb braking, is rather heavy and adds considerably to the unsprung weight. Accordingly I looked around for a lighter set up. My initial thoughts were to see whether Triumph Spitfire hubs could be modified to fit the Midget stub axles since alloy hubs are readily available here in the UK. This would also mean a greater range of options vis a vis the brake discs (rotors) and calipers because for years I had run a big vented set up on my race Spitfire and later a Ginetta G15. The trouble is that Spitfire hubs can not be modified in this way owing to the distance between the inner and outer bearing races. Accordingly, as you are aware, I manufactured my own alloy front hubs. After sourcing the vented discs that I wanted, much measuring resulted in the correct size alloy spacers being machined to adapt the disc bell to the hub:

Deborah Evans

And:

Deborah Evans

The calipers I intended using are American and produced by Wilwood in California. The reasons for using these were: 1. They are way cheaper than the equivalent AP caliper (additionally because I can source them at USA prices). 2. They are lighter than the equivalent AP caliper. 3. They have a larger pad and piston area than the equivalent AP caliper. Having set up the hub / disc arrangement a small bit of further machining was required to make up a 'carrier plate' which bolts to the front upright and to which is bolted the caliper:

Deborah Evans

Here we see the carrier plate being test fitted to the upright:

Deborah Evans

Here we see how the carrier bolts to the caliper with cap head bolts (that's socket head bolts for you American types!), before the whole thing is attached to the upright as a unit:

Deborah Evans

Some shots of the complete set up:

Deborah Evans

Caliper fitted:

Deborah Evans

The disc is just sub 10" in diameter (9.8"):

Deborah Evans

Last one (note the 'Gucci' front suspension mods). Admittedly the flexible brake hose requires a 90 degree adapter at the caliper so as to reduce kinking (which is in hand):

Deborah Evans

Nice job, heres my attempt with 9" discs & MGB calipers.

Brad (Sprite IV 1380)

You could always try this set up.

brian s

I used four pot alloy calipers made by kad (UK company)ideal if you dont want to change the disc size or do any type of conversion,just bolt on with no mods,big difference in stopping power but big price too!

Rob Newt

I managed to get 10.25 inch OD discs under 13x6j wheels but the standard rivetted steels from the early cars would touch the rivet heads. Pad area is larger than the Midget and the weight is quite a lot lighter.

rob multi-sheds thomas

As Deb said, quite expensive. I paid £50 for the whole lot. :o)

rob multi-sheds thomas

This thread was discussed between 10/02/2010 and 14/02/2010

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