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I think that Spider Chris did some too.

mk1 wrote: ↑Mon Jan 09, 2023 2:30 pm Can someone post a link to the original article giving details on modifying drive flanges, cos I'm buggered if I can find it.

M

Think this is it Mark http://mk1-forum.net/viewtopic.php?p=122525#p122525

That's the one........ The only hard bit is the drive flange material. But a decent lathe (I did a couple on my Myford following Dermotts article) using tipped cutters.

Following on from what D said, I turned the spacers down from the old knackered 998 flange

Like I said at the time. Every 998 Cooper owner should download the article AND get hold of a pair of decent 850 flanges for a rainy day. They ain't makin' no more.

gs.davies wrote: ↑Mon Jan 09, 2023 12:18 pm

Peter Laidler wrote: ↑Mon Jan 09, 2023 11:51 am Can anyone on the forum point me in the direction of an authoritative article based on verifiable data that states quite clearly, mechanically and scientifically proves that well/properly set-up TLS brakes are more efficient, thermally greater or superior, more worthy, an improvement or in any way better than an equivalent, well/properly set-up set of 7" Cooper discs?

I have NEVER seen an authoritative article to substantiate this claim in my very few years of mini cooper ownership. I have asked the same question MANY times. They're not as thermally efficient as the bigger and later Cooper brakes but they're certainly superior to TLS's in every mechanical and thermal way.

Steel helmet on of course and hope that my forthright view/engineering opinion here doesn't rattle the moderators. If you are a 7" properly set-up Cooper user and happy with your lot, feel free to chip in

I’ve wondered this too. Maybe there’s some contemporary detailed road tests that show braking distances and pedal effort for the Cooper 997/998 and the Mini 850..

One reason there isn’t much direct comparison is that the 7.0” discs were a marked improvement over the single cylinder drums of the time, and the 997 brakes weren’t available at the same time as twin cylinder drums? Then there was also the change from 997 to 998 when the pad size was upsized

Perhaps the scale goes something like this:
Single cylinder drums
997 7.0”
Twin cylinder drums
998 7.0”
Cooper S 7.5”

My experience only goes as far as twin cylinder drums and unboosted 7.5” discs. When my twin cylinder drums were maintained and adjusted correctly they had a good pedal feel and would lock up the front brakes under emergency braking - they can’t really function much better than that from a braking power perspective. I never pushed them to the point of fading on the road. One thing in their advantage over 997 brakes is the larger friction area of the shoes compared to brake pads. 7.0” discs are also only 1/4” thick when new so they don’t have a large amount of mass from a cooling perspective (although similar to a drum)

I suggest at the next Mk1 performance day at Blyton you have a braking test, 5 stops from 50mph to zero and see who goes the best

Now I had the single cylinder drums on my car and I thought the brakes were superb (compared to other minis I drove on TLS set ups).

But I do like the idea of a test of the 7’s to see what happens

Definitely this:

Single cylinder drums
997 7.0”
Twin cylinder drums
998 7.0”
Cooper S 7.5”

My 998 disks with yellowstuff pads are way better than TLS .. I'd love to prove it at Blyton but I'm bringing the other one (unless i break it beforehand )

You want to Test Brake Efficiency ?.. you will probably remember the "Tapley Meter " .. today on UK ebay they are about £50 or less.

Peter Laidler wrote: ↑Mon Jan 09, 2023 6:35 pm That's the one........ The only hard bit is the drive flange material. But a decent lathe (I did a couple on my Myford following Dermotts article) using tipped cutters.

Following on from what D said, I turned the spacers down from the old knackered 998 flange

Like I said at the time. Every 998 Cooper owner should download the article AND get hold of a pair of decent 850 flanges for a rainy day. They ain't makin' no more.

Right Peter.....thought I'd add a procedure to do the job.

1. Old 850 flange...they may need some 'truing' up on the lathe before you start.
2. Turn the front of the flange down for a good fit in the chuck when you reverse the flange. This piece will be surplus and will be removed later...
3. I used an angle grinder to remove the high spots on the inside of the flange where the studs go through....this makes it so much gentler on the lathe.
4. Turn the inside of the flange down the same thickness of the old Cooper flange... and check the face of the flange for trueness.
5. Make a new wider collar for the front oil seal.
6. Make a spacer that will go between the flange shaft and the CV joint shoulder....approx. 1/4" wide....Peter suggested using a piece from the old Cooper flange.
7. Final step is to remove the piece on the front of the flange that was used in step 2.
8. New locating holes to be drilled for the set screws that attach the flange to the disc. Two would be fine.
9. Trial fit the whole assembly to ensure the disc is centered in the caliper...some minor machining may be required to get this perfect
*********NOTE It is important to get the spacers correct as these will determine the position of the disc.**********

Thanks for finding the original page, I spent ages looking.

Although this is certainly "a way to do it", it doesn't really surprise me that no one has done it commercially. the spacer bit to extend the splined shaft is (in my opinion) a 1st order bodge, something that may well be safe, but not something a commercial company could possibly contemplate offering for sale.

For my money, getting an original pair metal sprayed would be a better option, but having said that, only one of my cars has small disks & I have a spare set of flanges "just in case" (These are NOT for sale).

From a pure engineering point of view, I think that the addition of the splined 1/4" approx spacer is academic to the strength of the modified flange (apart from the fact that it acts as a spacer and you can adjust to a accurately set the disc in the centre of the caliper of course).
Any mechanical 'loading' onto that spacer and eventually onto the CV shoulder is linear, caused by the very tight nut onto the washer, down the flange shaft, spacer and directly onto the CV shoulder.

The only reason for using an old piece of used splined shaft is that a) it's already sized for its outside dia and b) the splines prevent the spacer from ANY independent rotation that might cause wear if it were to become even slightly loose in the future, by fair wear and tear.

The alternative options, such as metal spraying might be cheaper (just joking of course....) but metal spraying is a pointless exercise if the splines are knackered.

I'm minded to suggest that the reason why this modification isn't commercially viable is due to the small scale required.

Peter, all of the flanges I have seen that are deemed useless is due to the outer shaft surface worn beyond repair.
Wide grooves etc.
Regarding the inner spacer...it doesn't have to be splined...just a plain spacer....the splines on the CV joint do not extend all the way in.

Making the spacers is the easy job....cutting the flange takes time and patience....nice fine cuts.
I have done 4 sets in total and just completed another set for a client here.
It's been 8 years since I made the first set and they are still on the road.

Cheers
D

Hi all.
Had a '64 997 Cooper way back. Xlnt fun car, trialled rallied, sprinted, gymkhaned, hillclimbed etc. Useless discs, even after a 850! Fitted cometition pads, fixed it. Local garage in NZ version of MOT replaced with standard (they didn't ask!). Could tell right away. Queried - 'pads worn out' they said - weren't! Told them to put back, refused, claimed std were fine. I demanded boss drive car on road, off we went 60mph I said 'do emergency stop'. He braked lightly, claimed they fine. I demanded repeat, full braking. He did, faded right out by 30mph, he went white!
Much later in life I bought another std Mk1 850 (my last min of four). Mate had a min 1000, blew gears,fitted 998 Cooper motor and box. I got old motor and bust cooper box. Put my cogs and 3.44 diff (recalibrated speedo) and 998 in mine. Went well, nice Cooper remote! Later found 1100 donk in bits. rebuilt it, planed head, ported, pocketed. Used 1100 cam (hottest std?) bored inlet manifold to 1 3/4, made adapter to fit Maxi SU (its std needle worked fine). Topped off by freeflow. Nice. would top 90mph uphill and scared off lots of competition! (4th place in NZ Gymkhana Nationals, missed 3rd by 0.7 secs over whole day competition!).
Some of you would have seen the NZ movie 'Goodbye Pork Pie', if haven't should, its a Min hoot. My boot was painted 'Steak Pie'.
Would love another but not practical for me these days! Or a Moke, dream on...
Keep up the good work.

This modification of standard mini flanges to Cooper spec seems to be a regular feature on the forum. Thanks to Dermott and his detail, his photos - and experience (that I admit to copying successfully a couple of times now) - maybe the conversion part of this thread ought to feature in 'THE KNACK.

Even if you haven't got a lathe, a small Myford did mine, any local machine shop would be able to do the job if you give them th accompanying photos

What about it.....?'