Disc Brake Conversion - Midget Brakes onto a Minor?

Post by **WillST** » Sun Oct 26, 2008 12:02 am

I have a line on either a 1970 or a 1974 Midget for very cheap. Haven't found any info on converting a 1960 Minor Traveller to front disc brakes using a later disc brake Midget donor. If it is possible to do, I'd be most grateful if someone could tell me where I might find more info on doing that? Thanks.

Post by **IslipMinor** » Sun Oct 26, 2008 8:27 am

Will,

Yes it used to be quite popular conversion.

You need a pair of 'J' brackets - they used to be available from Mini Mania in the USA, but don't know of anywhere else now. Here is the link to Mini Mania for the brackets:

http://www.minimania.com/web/Item/DSK100/InvDetail.cfm

I have a drawing of the required dimensions if you can get them made?

For the basic conversion you will need a pair of the 'J' brackets, Midget calipers, hoses, steel wheel front hubs and discs (wire wheel hubs and discs are different). In addition to that you will need the standard Midget caliper mounting bolts (2 per side), 6 spacers (have the dimensions, but could use washers) and 6 button head socket screws (5/16" or 8mm) + Nyloc nuts to fit the mounting bracket to the Minor front swivel pin.

This link gives you all the detailed fitting instructions:

http://www.minimania.com/ArticleV.cfm?DisplayID=80

One final thing is that if you fit any disc conversion to a MInor, you will need to dismantle the master cylinder to remove the 'residual pressure valve', otherwise the pads will rub and create a lot of heat and unnecessary wear (ask me how I know, I forgot to do it!!!)

As with most of the disc brake conversions, the pedal pressure can be quite high, and fitting a servo makes the whole conversion very pleasant to use.

Post by **bmcecosse** » Sun Oct 26, 2008 11:53 am

Not the best disc brakes - but one of the easier conversions and allows you to keep the standard wheels. You may also want the differential from that Spridget - may be a higher ratio (lower numerically) for easier cruising.

Post by **WillST** » Sun Oct 26, 2008 4:31 pm

IslipMinor wrote:Will,
Yes it used to be quite popular conversion.
As with most of the disc brake conversions, the pedal pressure can be quite high, and fitting a servo makes the whole conversion very pleasant to use.

Richard, thanks much for the links and further info on the conversion! Yesterday I came across eBay Seller "billmister1" who sells Minor front/rear tube shock conversion kits, as well as a Midget disc brake conversion kit using the J-Brackets--cheaper than MiniMania's Brackets. They look to be of the same or better quality too. I bought a set of the brackets from him and will let the list know how it goes when I get a chance to put them on.

How come it used to be a popular conversion? What faults does it have? And do you have any further info on what servo to use and how to fit it?

Thanks again, Wil

Post by **WillST** » Sun Oct 26, 2008 4:39 pm

bmcecosse wrote:Not the best disc brakes - but one of the easier conversions and allows you to keep the standard wheels. You may also want the differential from that Spridget - may be a higher ratio (lower numerically) for easier cruising.

Bmcecosse, yes, I did keep the 3.9 diff as I plan on installing a 1275. Seems it would be a little bit tall for just a 948cc Traveller wouldn't it?

Also, please tell me why they are not the best disc brakes for a Minor?

Thanks, Wil

Post by **bmcecosse** » Sun Oct 26, 2008 5:33 pm

The discs are a bit on the small side - other conversions use larger/thicker/vented discs - but involve a good bit more 'fitting' with special hubs to take the wheels - or use of non-standard wheels. Of course - regulars on here will be amazed to see me talking of discs - since I am a great believer in fitting the larger 9" drum brakes from a Wolsley 1500. These bolt straight on and require no servo or master cylinder modification. But I appreciate they may be a bit thin on the ground where you are (but Nash - Metropolitan probably has the same brakes !!) and you seem to have the Spridget brakes already in stock! The 3.9 will give a fine flat ground cruising ratio - but of course will not be great at hauling up hills! It will of course be fine with a 1275 engine - although I'm hoping my 3.7 diff will be even better in that role!

Post by **WillST** » Sun Oct 26, 2008 6:18 pm

bmcecosse wrote:The discs are a bit on the small side - other conversions use larger/thicker/vented discs - but involve a good bit more 'fitting' with special hubs to take the wheels - or use of non-standard wheels. Of course - regulars on here will be amazed to see me talking of discs - since I am a great believer in fitting the larger 9" drum brakes from a Wolsley 1500.

Ok, I see. I bought the Midget for its 1275 & ribcase, only recently found out I can install the brakes as well--nice bonus

! Yes, Wolseleys are very thin on the ground over here--never seen one in fact--and precious few Metropolitans as well!

The fellow I bought the J-brackets from is also mucking about with a better master cylinder for the conversion, it'll be interesting to see what he comes up with.....

It will be interesting to hear what you think about the 3.7 diff when you get 'er running!

Regards,
Wil<br>

<br>

Post by **bmcecosse** » Sun Oct 26, 2008 6:50 pm

Very smart Traveller - the tyres (tires) look to be quite large for those rims !

Post by **WillST** » Mon Oct 27, 2008 3:23 pm

Thanks for the good word! I hadn't looked closely at the tires, good point to bring up. They are 175R14 88S tires. I only recently bought the car, still sorting out the electrics and what I hope isn't a compression miss (gonna put a 1275 in it anyhow). Do you think that is too big a tire for the rims?

Post by **Onne** » Mon Oct 27, 2008 4:10 pm

Yes, I would not go past 155, 165 at a stretch

Post by **d_harris** » Mon Oct 27, 2008 7:13 pm

I'd say 155 at a stretch on standard rims!!!

Post by **bmcecosse** » Mon Oct 27, 2008 11:47 pm

Yes - even the 155 tyres generally available here are really too wide for these narrow rims, so 175 will wobble all over the place. You can of course have the wheels widened to suit the tyres, or buy it a nice set of alloy wheels!

Post by **Bazzalucas** » Tue Oct 28, 2008 2:25 am

I have 175 radials on standard rims, and find them to be great! The car came to me fitted with them, so I have nothing to compare them to, but I certainly wouldn't have thought there was anything wrong with them until this thread!

Post by **WillST** » Tue Oct 28, 2008 6:07 am

Hmmm, one opinion after actual use that 175s work well, several opinions that they don't, though these haven't actually tried them? Has anybody else besides bazzalucas actually run 175s? Do they peel off the rims under hard cornering, do they actually wobble? What are the actual problems with running 175s?

Post by **bmcecosse** » Tue Oct 28, 2008 2:46 pm

Well - the rims are only 3.5" wide, and 175 tyres are alomost 7" wide - so figure it out for yourself! The correct width wheel for a 175 tyre will be 5.5"/6" wide!

Post by **WillST** » Wed Oct 29, 2008 4:46 am

bmcecosse wrote:Well - the rims are only 3.5" wide, and 175 tyres are alomost 7" wide - so figure it out for yourself! The correct width wheel for a 175 tyre will be 5.5"/6" wide!

Ok, so what! As far as I can see, you are just repeating conventional wisdom, which often in my experience is a bunch of useless blather. What is your--or anyone's--ACTUAL experience using 175s?--THAT is what I am asking about.

We have a person who has reported good results ACTUALLY using 175s, and several others who to the best of my knowledge (including you) are just repeating "conventional wisdom" with no actual experience themselves. I tend to think that the ones who have actually experienced something might know a bit more about it. Have you used them yourself or know of someone who has used them with unsatisfactory results? If not, maybe you should not be quite so self-righteous in your comments? Bloody hell, I might be a newbie, but you got me up on my hind legs.....

Post by **d_harris** » Wed Oct 29, 2008 8:35 am

I run 175s and find them to be brilliant however, I have 6" Rims.

Post by **bmcecosse** » Wed Oct 29, 2008 11:18 am

The results can't possibly be 'good' using 175 tyres on 3.5" rims!! I would go as far as to say it's actually dangerous to run tyres that wide on narrow rims - very high risk of them rolling off the rims on brisk cornering.
But - if you are happy with that - good luck to you!

Post by **IslipMinor** » Wed Oct 29, 2008 11:53 am

The tyre manufacturers recommended minimum rim width today for a 175 '80' section tyre is 5" - I can only assume there is a very good reason for this?

There has been a move over the years to increase the minimum width for a given tyre size, to reduce the risk of the tyre rolling off the rim under severe conditions. Just when you need the car to help you the most is not the time to find out that the rim was too narrow!

Post by **WillST** » Wed Oct 29, 2008 3:53 pm

Bazzalucas has been running 175s on standard rims with good results. The PO of my car ran the 175s on my car for almost 5 years with no adverse issues at all, other than the speedo reading low.

I agree that under hard cornering the car could roll off a tire. The car does not wobble now. I will keep the 175s on there and not corner hard until I can afford a set of alloys, or widen my standard rims.

Across the pond here Morris cars are experiencing a resurgence, deservedly so because of their gas mileage, ease of maintenance, and low parts cost--I just wish alloys weren't so dear

!!