Midget/Sprite Brake Discs

Post by **ricombi** » Mon Oct 02, 2006 2:11 pm

Currently building racing minor for a pre-1960 touring car series and the regulations state that disc brakes may be used on the front of the vehicle, provided they are sourced from a car built prior to 1966.

I broached the subject with the series organiser, explaining the minor takes a marina disc setup with little probelm and that this was the easiest and I presumed oldest available. He suggested a Midget setup and I am just wondering if this is viable for the car? If not, I will bring the subject to the series organiser and fit Marian discs.

Any help much appreciated, thanks.

Post by **Kevin** » Mon Oct 02, 2006 3:19 pm

Yes the Midget setup would fit in with your requirements, the Birmingham centre sell a complete kit.

Post by **bmcecosse** » Mon Oct 02, 2006 7:38 pm

I think the Sprite conversion was 'standard' is these days - I doubt they would wear the marina conversion !! Unfortunately Sprite calipers are not the biggest in the world - are you allowed to use any caliper ?? Or must it be from the same car as the disc came from ?

Post by **ricombi** » Wed Oct 04, 2006 3:24 pm

Reading the regulations as deep as I can, and vague as they are, I gather the entire setup must be pre-66.

I'll contact the Birmingham centre and see if they can help. Thanks for the help.

Post by **bmcecosse** » Wed Oct 04, 2006 10:14 pm

Hmmmm - so when did Spridgets get front disc brakes ? The Sprite MK I was on drums - so did the MK II Sprite/MK I Midget get disc brakes - and when did they come out ??

Post by **d_harris** » Wed Oct 04, 2006 10:22 pm

I can confirm that the 1969 cars have discs - mk4 as I recall. I would assume that 1966 cars would have discs

Post by **bmcecosse** » Wed Oct 04, 2006 10:40 pm

Dunno - but I think I have seen 'C' reg 1965 MK II Sprites - presume with discs.

Post by **d_harris** » Wed Oct 04, 2006 11:43 pm

I have a funny feeling that it may only have been the frogs which had drums. Will ask matt tomorrow. he will know for sure.

Post by **moggydriver62** » Thu Oct 05, 2006 6:13 am

didnt the sebring bugeys have discs.

Post by **bmcecosse** » Thu Oct 05, 2006 7:25 am

Very probably - but certainly UK supply Sprite Mk Is only had the standard A35 drum brakes. I'm just not sure which year MK II Sprite cam out - 1964 ?? I think earliest I have seen is B certainly C reg. I remember lusting after one when I was 17 and clutching a brand new Driving Licence!!

Post by **Kevin** » Thu Oct 05, 2006 2:56 pm

Hmmmm - so when did Spridgets get front disc brakes ?

1962 according to the owners site.
What I like is the way the new engine came from the ****** *****
So it was onlt fair to get our own back with the 1275

It wasn't until 1962 that mechanical changes were to follow: The Morris Minor 1098cc engine was fitted along with a stronger gearbox, an electronic tachometer, front disc brakes and a host of other small detail changes. This model known at the time as the Sprite 1100 has come to be known as the mark II 1/2. The mark III designation was to be saved until 1964.

Post by **bmcecosse** » Thu Oct 05, 2006 7:41 pm

Pretty sure the 948 engine was retained in the first of the MK II Sprites - the 1100 not coming along until later - about 1964 when the 1100 hydrolastic car came along.

Post by **IslipMinor** » Thu Oct 05, 2006 8:29 pm

The Midget-based disc conversion comprises a 'J' shaped bracket that bolts onto the Minor swivel pin, after removing the drum, hub and backplate. The hub is replaced with a standard Midget disc wheel hub (same bearings, fits straight on to the Minor stub axle), complete with standard Midget disc (the disc is different for a wire-wheeled car). The caliper then bolts to the 'J' bracket (can need a little shimming to be central with the disc), and the pads fitted. The standard Midget brake hose is used, but needs careful routing, as there is less space between the back of the caliper on a Minor than a Midget.

That's it!

All the Sprite and Midget discs/calipers are the same, so would the exact year of the donor matter, even if you knew it?

I have this set-up, except that I am using Metro 4-pot calipers onto the solid Midget discs. Looking to change to Metro vented discs and 4-pot calipers over the winter - needs quite a bit of machining.

Post by **chrisd87** » Thu Oct 05, 2006 9:06 pm

Out of interest how much does this conversion cost? I can't find any info on it from the Birmingham MM centre.

Post by **icer** » Mon Oct 09, 2006 12:06 pm

I would be interested to know as well

Post by **Kevin** » Mon Oct 09, 2006 1:11 pm

Sorry about that it used to be listed on their site and in the ads on the back of Minor Matters, looks like you will have to give the a call.

Post by **bmcecosse** » Mon Oct 09, 2006 7:58 pm

Islip - I have a pair of vented Metro discs turned down to 7.9" if you want them. Dunno how you will fit them to the Sprite hub ? Is the Sprite caliper mounting bolt spacing the same as MG Metro 4 pot caliper ?

Post by **IslipMinor** » Wed Oct 11, 2006 4:55 pm

bmcecosse,

The standard o/d of the Metro disc is virtually identical to a Midget, that's the only bit that is!. The machining required is to open up the bore so that it fits over the Midget hub, reduce the overall length by about 6mm, and drill/tap 4 holes in the disc to match the Midget hub.

My lathe will not take the 8.4" diameter swing, so need to sort out somewhere to get it done, or allow me to do it.

The hub also needs machining to provide additional clearance for the wider caliper, but I've done one as a trial and that looks ok.

Richard

Post by **bmcecosse** » Wed Oct 11, 2006 8:11 pm

Ah ha - I thought the Spridget discs were only 7" diameter - or so. Must be larger I guess. All sounds very brave - did you make your own brackets to mount the calipers ??

Post by **paulhumphries** » Fri Oct 13, 2006 12:52 pm

I've already Midget hubs and perfect discs so am interested in this conversion.
What calipers, other than Midget, are suitable ?
Anyone a photo's of the caliper to upright mounting plate ?
I should be able to get such mounting plates laser cut via the local model engineering club contacts (a friend had has several items for his model traction engine cut - very reasonably as the company owner is a club member) so I assume there will be others interested (for cost price - no profit to me) ;-)

Paul Humphries