Disk brakes

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MM50sracer
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Disk brakes

Postby MM50sracer » Sun Mar 29, 2015 6:37 pm

Being new to the MM owners Club and living in the USA I realize that I'm at a disadvantage. I am restoring a late 1950s H-Mod car that is based on a MM. I have already replaced the rear and front axles. The rear and fronts have Sprite/MG Midget wire wheel hubs mounted. I would very much like to use the Sprite disk brakes in front but have issues because there is no mounting for the calipers. If there is someone with a design, I can make the parts myself. Also would like to have disks at the rear; any info there?

Regards,

Phil Z

IslipMinor
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Re: Disk brakes

Postby IslipMinor » Sun Mar 29, 2015 7:25 pm

Phil,

This is the bracket that you need to fit a Spridget caliper to a Minor upright.
[frame]Image[/frame]
They are available from Mini Mania in the USA (Mini Mania, 870 Gold Flat Rd., Nevada City, CA 95959 USA. Tel: 800.946-2642) and this link:

http://www.morrismania.com/part/DSK100A ... dapter-Kit

If you have the standard wire wheels then you will need to get both a pair of disc brake hubs for wire wheels and the disc (rotor) for wire wheels (both are different to the steel wheel versions).

No need for rear discs as most of the work is done by the front brakes.

You may find that a servo is a good idea to give an easy pedal pressure. If you do fit one, remember to re-route the supply to the rear axle from the standard connection at the back of the master cylinder to the outlet of the servo. Without this you will only servo the front wheels!

It's a very good upgrade and with Mintex 1144 or 1155 pads gives good 'feel' and fade resistance.

You may find that the higher brake line pressure needed for the discs results in rear wheel lock up under heavy braking. If so then one solution is to fit a modified 'Classic' Mini rear pressure limiting valve in the supply to the rear brakes - ours is fitted under the bonnet and once set up has not needed any adjustment for about 10 years!

This drawing shows what to do to modify the standard 'fixed' valve into an 'adjustable' one:
[frame]Image[/frame]
With only a single outlet to the rear brakes, the second outlet needs to be blocked off.
Last edited by IslipMinor on Mon Mar 30, 2015 12:04 pm, edited 1 time in total.
Richard



bmcecosse
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Re: Disk brakes

Postby bmcecosse » Sun Mar 29, 2015 7:31 pm

Avoid discs at the rear! There are drawings for the Spridget caliper mounts on the king pins - someone will be along with it in a few minutes. However the tiny Spridget discs are not any better than a set of the later Minor 8" drum brakes ! There are ways to upgrade them of course, if you feel you will need more stopping power... Slightly puzzled when you say you have replaced the front 'axle'.....a Morris Minor doesn't have a front 'axle' ??
ImageImage
Image

MM50sracer
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Re: Disk brakes

Postby MM50sracer » Mon Mar 30, 2015 3:26 pm

Thank you for your reply to my wire wheel application.

I received this morning, Monday, a response from Mini Mania.
They indicated that their kit will not work with wire wheels; only works with steel wheels.

Per your suggestion, I'll use drums at the rear.

The only fitting to mount calipers I found was from Australia.
The fitting/caliper mounting plate is bolted to the rear of the axle. They use Marina calipers.

I have measured the clearance between the inner wire wheel hub and the rotor; there is less than the required space needed, about 2 ". The stock MG Midget caliper is 2.5 inches thick; measured for the caliper center line.

I did notice yesterday that stock MG Midget calipers has an indent in them for wire wheels? Do not know if this will work?

Regards,

Phil Z

IslipMinor
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Re: Disk brakes

Postby IslipMinor » Mon Mar 30, 2015 4:21 pm

Phil,

Moss has the same part number for steel/wire wheel caliper, so I do not immediately understand why the 'J' bracket will not suit wire wheels? Are they 'original' fit, i.e. directly to the hub or a bolt-on to the steel wheeled hub?

The disc/rotor is different for wire wheels (less offset), but that is because the wire wheel hub places the disc mounting face closer to the upright than the steel wheel hub. The caliper is in the same place for both wheel versions.
Richard



MM50sracer
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Re: Disk brakes

Postby MM50sracer » Wed Apr 01, 2015 2:33 pm

Richard,

Thank you again for your reply.
I am using the MG Midget wire wheel hub that carries the bearings and the correct rotors; not the bolt on wire wheel adapters.

It seems to me that the only to use the "J" flange would be to bolt it on the back side of the axle.

There is about 1/8" between the rotor back side and the axle flange where the drum backing plate mounts.

Since this week is Easter time, I will be revisiting this setup next week. What I'm going to try is to see if the Midget calipers will fit because it looks like they have an indent to accommodate the wire wheel inner hub.

Regards,

Phil Z

IslipMinor
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Re: Disk brakes

Postby IslipMinor » Wed Apr 01, 2015 3:53 pm

Phil,

The picture below shows the 'J' bracket in place with a steel wheel hub and disc. The wire wheel hub and disc should put the disc itself in the same place relative to the 'J' bracket. The 'J' bracket is one for the Metro calipers, but the Midget bracket is very similar and mounts in the same place.
[frame]Image[/frame][frame]Image[/frame]
Does this help you?

That was the first version of the disc brake conversion and it used Metro 4-pot calipers with the Midget solid disc, and this is the latest version with Metro vented discs and 4-pot calipers:
[frame]Image[/frame]
With the Midget disc there is no machining required to use them, but with the Metro vented discs they have to be machined and 4 new mounting holes drilled and tapped, and the hubs machined slightly to provide clearance with the caliper. Well worth it as the results are superb!
Last edited by IslipMinor on Mon Apr 06, 2015 8:49 am, edited 1 time in total.
Richard



MM50sracer
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Re: Disk brakes

Postby MM50sracer » Sat Apr 04, 2015 3:54 pm

Richard,

YES and Yes; the pics are great and are all that I'll need to build my own brackets. Thank you for taking the pictures.

The only issue is to actually build the brackets for wire wheel hubs that have less inner hub offset/back space.
Since my H-Mod racer weights about 850 pounds or less the Midget rotors and calipers should be fine.

I also saw how you added a front sway bar. Did you have one made or is it from some other car?

I'll also have to figure out how to send pics.

Have a Happy Easter.

Regards,

Phil Z

IslipMinor
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Re: Disk brakes

Postby IslipMinor » Sat Apr 04, 2015 6:32 pm

Phil,
wire wheel hubs that have less inner hub offset/back space
Yes, but the wire wheel rotor has less offset as well, so the actual brake rotor is in the same position as a steel wheeled one.

The sway or anti-roll bar came from a now defunct company called Owen Burton and they are now available from ESM - this is the link to the item:

http://morrisminorspares.co.uk/shop/pro ... c0a209f6ad

I didn't like the way the front brackets are attached to the chassis leg by drilling horizontally through the leg, so made up 2 x 5/16" plates and welded them to the front of the chassis leg. Drilled and tapped 2 x 6mm ISO Coarse threads in each plate to accept the screws supplied with the kit. By welding all round the plates, it made sure that no corrosion can get in between the plate and the chassis leg.

P.S. To add pictures, there is an 'Upload Picture' box at the bottom left-hand corner of the text editing box, and to the right of that a 'Browse' button. Click on the 'Browse' button to select the picture(s) to upload. If they are too big, it appears to upload them, but in fact does nothing! Use something like Photoshop to reduce the image size and try again.
Richard



MM50sracer
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Re: Disk brakes

Postby MM50sracer » Mon Apr 06, 2015 1:03 am

Richard,

Thank you for your reply on Sway bar. I'll have to build chassis attachment points as the car currently does not have a sway bar.

I did revisit the disk brake info and went over the drawing you sent. And Yes the setup is/will be very close to what you provided.

Will follow later this week with at least one/two pics, will take some small size pics. The car is currently on a work platform.

Regards,

Phil Z

MM50sracer
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Posts: 6
Joined: Sun Mar 29, 2015 6:03 pm
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Re: Disk brakes

Postby MM50sracer » Wed May 27, 2015 3:32 pm

To Richard, All that helped with the disk brakes.

I do very much appreciate your pics and advice helping me to get my racer put back together.

Some welding and ... are the next steps.

Hopefully, the file with pics will be posted.

Regards,

PHil Z[frame]Image[/frame]


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