Disk brakes with standard drums at the back
-
- Basic 850
- Posts: 58
- Joined: Mon Jan 06, 2020 9:57 pm
Disk brakes with standard drums at the back
I'm putting 8.4" discs on the front but planning to keep standard drums at the back. Has anyone done this. How does it feel when driving? . My
reason for doing this is because the group2 arches I have wont keep the tires under the flare at the back if i use a spacered drum. The front arches are wider than the rear and accomodate the increased track width. The arches came as a set.
reason for doing this is because the group2 arches I have wont keep the tires under the flare at the back if i use a spacered drum. The front arches are wider than the rear and accomodate the increased track width. The arches came as a set.
-
- 998 Cooper
- Posts: 384
- Joined: Fri Aug 08, 2014 11:06 pm
- Location: New Zealand
- Been thanked: 13 times
Re: Disk brakes with standard drums at the back
Aside from the additional built in spacer on Cooper/GT drums they are otherwise the same internally as regular drums so will give exactly the same level of braking,
- mab01uk
- 1275 Cooper S
- Posts: 8548
- Joined: Thu Jun 24, 2010 7:08 pm
- Location: S.E. England
- Has thanked: 237 times
- Been thanked: 208 times
Re: Disk brakes with standard drums at the back
How about using standard rear drums but with separate thinner solid alloy spacers to exactly suit your rear arches/wheel offset therefore reducing the front to rear stagger to a minimum?
Minispares spacers:-
http://www.minispares.com/shop/classic/ ... spx?200104
Minispares spacers:-
http://www.minispares.com/shop/classic/ ... spx?200104
-
- 998 Cooper
- Posts: 693
- Joined: Wed Sep 09, 2015 11:22 pm
- Location: Zummerzet
- Has thanked: 2 times
- Contact:
Re: Disk brakes with standard drums at the back
The disc setup is wider than the drum setup, I found the handling was distinctly different and odd until I widened the rear track too.
Metric is for people who can't do fractions.
-
- Basic 850
- Posts: 58
- Joined: Mon Jan 06, 2020 9:57 pm
Re: Disk brakes with standard drums at the back
Unfortunately using thin spacers adds an extra layer of compliance during certifibation and those spacers wont comply as is.mab01uk wrote: ↑Mon May 23, 2022 8:18 am How about using standard rear drums but with separate thinner solid alloy spacers to exactly suit your rear arches/wheel offset therefore reducing the front to rear stagger to a minimum?
Minispares spacers:-
http://www.minispares.com/shop/classic/ ... spx?200104
-
- Basic 850
- Posts: 58
- Joined: Mon Jan 06, 2020 9:57 pm
Re: Disk brakes with standard drums at the back
Im quite annoyed that the rear arches atent as wide as the front. I might have to add fiberglass to widen them.
-
- 998 Cooper
- Posts: 384
- Joined: Fri Aug 08, 2014 11:06 pm
- Location: New Zealand
- Been thanked: 13 times
Re: Disk brakes with standard drums at the back
Are you in New Zealand by any chance? Sounds like the dumb rules applied here.btetley wrote: ↑Wed May 25, 2022 12:11 amUnfortunately using thin spacers adds an extra layer of compliance during certifibation and those spacers wont comply as is.mab01uk wrote: ↑Mon May 23, 2022 8:18 am How about using standard rear drums but with separate thinner solid alloy spacers to exactly suit your rear arches/wheel offset therefore reducing the front to rear stagger to a minimum?
Minispares spacers:-
http://www.minispares.com/shop/classic/ ... spx?200104
Most brands of arch are narrower at the rear so nothing unusual there.
How about getting cooper drums and then machining the outer spacer portion down to the appropriate width for your needs?
- mab01uk
- 1275 Cooper S
- Posts: 8548
- Joined: Thu Jun 24, 2010 7:08 pm
- Location: S.E. England
- Has thanked: 237 times
- Been thanked: 208 times
Re: Disk brakes with standard drums at the back
Another possible solution for using the correct spacered rear drums is to buy a set of Group 5 arches which are the same style as Group 2 but wider and then just use the wider rear arches from the set along with your existing Group 2 front arches.
Minispares - WORKS GP5 WHEEL ARCH SET PREMIUM QUALITY:-
http://www.minispares.com/product/Class ... |Back%20to
Minispares - WHEEL ARCH SET GROUP 2 PREMIUM BLACK:-
http://www.minispares.com/product/Class ... |Back%20to
Minispares - WORKS GP5 WHEEL ARCH SET PREMIUM QUALITY:-
http://www.minispares.com/product/Class ... |Back%20to
Minispares - WHEEL ARCH SET GROUP 2 PREMIUM BLACK:-
http://www.minispares.com/product/Class ... |Back%20to
- Peter Laidler
- 1275 Cooper S
- Posts: 6396
- Joined: Sat Jul 15, 2017 5:35 pm
- Location: Abingdon Oxfordshire
- Has thanked: 137 times
- Been thanked: 116 times
Re: Disk brakes with standard drums at the back
This is just another example of not knowing where the questioner lives, making answering the question impossible...... Where are you based Btetley?
-
- 1275 Cooper S
- Posts: 2934
- Joined: Fri Jan 15, 2016 12:22 pm
- Location: Silverstone not far away
- Has thanked: 38 times
- Been thanked: 52 times
Re: Disk brakes with standard drums at the back
Also to consider when changing to front disc set ups from oe front shoe brakes there is a need to look at what size rear brake cylinders are in use .. as the rear subframe mounted Brake Bias Valve & the Master Cylinder to be used will need to be evaluated.
Just remember that Rear Brakes must NOT Lock up
Just remember that Rear Brakes must NOT Lock up

- gs.davies
- Site Admin
- Posts: 1757
- Joined: Fri Oct 26, 2012 2:29 pm
- Location: Essex, UK
- Has thanked: 72 times
- Been thanked: 68 times
- Contact:
Re: Disk brakes with standard drums at the back
Wouldn’t it be a bit tail happy with such an exaggerated difference between front and rear track?
- AndyB72
- 1275 Cooper S
- Posts: 1385
- Joined: Thu Jun 24, 2010 12:44 pm
- Location: Wakefield, West Yorks
- Been thanked: 1 time
Re: Disk brakes with standard drums at the back
I'd be interested to know this too as I'm considering using S discs on the front of my GTM with non spacer drums on the rear to help with clearance issues.
- Peter Laidler
- 1275 Cooper S
- Posts: 6396
- Joined: Sat Jul 15, 2017 5:35 pm
- Location: Abingdon Oxfordshire
- Has thanked: 137 times
- Been thanked: 116 times
Re: Disk brakes with standard drums at the back
I thought about this while day dreaming on my drive back from Carlisle yesterday. Ignoring the braking issues, while the front and rear track is well thought out mathematically, I'm not too sure that the 1.5" (?) we're talking about here will make any real difference for a normal road car/vehicle. Chuck it about on the corners and it might get a bit skittish as they say. It's almost a convention for the F and R to be the same...... ALMOST!
You'll see no end of lorries with a narrower rear track than the front. Skinnier tyres, small dia tyres, front wheels on dual axles narrower track etc etc. It's not as if you'll be putting a set of radials on the front and cross-plies on the rear
You'll see no end of lorries with a narrower rear track than the front. Skinnier tyres, small dia tyres, front wheels on dual axles narrower track etc etc. It's not as if you'll be putting a set of radials on the front and cross-plies on the rear