14 replies to this topic

[Badger360]

Hi

 

I have a 93 Mayfair 1275, I have brought vented disc's for the front do these fit straight on or do I need to modify - I have the standard calipers - 8.4" disc's

[Cooperman]

Vented discs really are entirely unnecessary for a road Mini.
They may be helpful for long distance racing with race pads, but for the road, the 8.4" solid discs are fine.

[johnR]

The size of the tyre contact area is more likely to be the limiting factor in braking force on a well maintained Mini.

[Badger360]

Vented discs really are entirely unnecessary for a road Mini.
They may be helpful for long distance racing with race pads, but for the road, the 8.4" solid discs are fine.

thanks for the advise, I don't have a problem with the current solid disks but was going to put a new set on as am restoring and saw the vented ones so i brought them - and i questioned it after weather the caliper will even over the wider disc's

I guess I can send them back and get some standard ones 

[KTS]

usually, vented discs, which are considerably wider than a standard solid disc, require the use of a special caliper

 

do you have a part number or link to the discs that you have bought ?

[imack]

You'll need discs, calipers and drive flanges.

[Badger360]

http://www.minispare...96.aspx|Back to

 

usually, vented discs, which are considerably wider than a standard solid disc, require the use of a special caliper

 

do you have a part number or link to the discs that you have bought ?

[cal844]

Just send the vented discs back, or sell them and buy solid discs. Solid discs and a Mintex 1144 pad will be fine on the road.

[Badger360]

will do, seems like the best option 

 

thanks for all your help

 

Just send the vented discs back, or sell them and buy solid discs. Solid discs and a Mintex 1144 pad will be fine on the road.

[Ethel]

They originally came from Metros, so you'd need Metro calipers & drive flanges to accommodate the extra width. You can get alloy calipers from the Mini specialists, or spacers to convert some solid disc versions.

 

As above, the solid discs offer identical performance (with identical pads), except for better cooling which can be a mixed blessing. If your pads are below optimum temperature they'll take longer to heat up & cool quicker, that's more likely going from A to B on a road than round a race track as fast as possible.

[Cooperman]

+1 for the Mintex 1144 pads. Ideal for road use, although they do fade if used for competition in any 'meaningful' way.

[Tornado99]

I'd think vented rotors could be recommended if driving a lot in mountains etc. where you'd need good heat control. 

 

There are also solid disc/rotors with cross drillings and/or grooves in the friction surfaces. These help by primarily allowing the heated gases coming off the pads to escape more efficiently. 

Edited by Tornado99, 18 February 2022 - 08:20 PM.

[Cooperman]

The only time you might find vented discs a benefit in mountain road driving is on a closed road special stage, downhill, driving absolutely on the limit on tarmac racing tyres

[Tornado99]

The only time you might find vented discs a benefit in mountain road driving is on a closed road special stage, downhill, driving absolutely on the limit on tarmac racing tyres

We've got extremely large mountains here in Western Canada. You can be winding down a steep slope for 15-20 minutes. Having a brake overheat could mean a trip over the guard rail and into a canyon. 

[Cooperman]

Unless you are driving absolutely on the limit, you won't have a problem using solid discs and M1144 pads. If in doubt, fit Mintex 1166 or 1177 pads, which are 'full-race or -rally' pads. If you are getting the brakes that hot you might consider using a high-boiling-point brake fluid such as AP600 or equivalent.

However, if you do drive down the mountains at those sorts of speeds, as in flat out and full throttle between corners and brake as late and as hard as possible, it seems likely that on an open public road there could be issues with the police.

The only Minis which had a lack of braking were the original 850 and 1000 with drum brakes all-round and the 997/998 Cooper which had the 7" x 1/4" thick discs. In fact, the 998, which had the larger LDB19 size pads were not too bad when the old Ferodo DS11 pads were used with a comp brake fluid. The advent of the Cooper 'S' with the super 7.5" x 3/8" thick solved the problem and with the right pads for the appropriate application, there has never been any problem since. Of course, the 8.4" discs should be a bit better, but I can't say I have noticed any difference.

On my 1964 full-on rally Cooper 'S' I have to use the 7.5" brakes and I fit Carbon-Metallic pads and AP600 fluid. I have seen the discs actually glowing red after a long hard stage, but they never fade nor does the fluid boil. On my 1990 Cooper road-rally car I have used 8.4 discs with M1166 pads which were absolutely fine, but I have switched to 10" wheels, so now have the same set-up as my 1964 car.

Actually for going fast downhill on twisty roads, it is not the braking which is the problem, it is the ability to make the car 'turn-in' and carry the speed through the corner without spinning whilst getting back on the power as early as possible. That is down to accurate suspension set-up. In fact, to ge really fast in a Mini, don't over brake.

Edited by Cooperman, 19 February 2022 - 01:00 PM.