280mm brake disc upgrade

For anyone who has been admiring Clive's rear ...discs.
The seller has just put up some more kits for £150

http://cgi.ebay.co.uk/MGF-MG-TF-280mm-BIG-REAR-DISC-BRAKE-CONVERSION-KIT_W0QQitemZ220560369072QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item335a6c25b0#ht_928wt_1165

OOh - do these make breaking much better? Plus do they fit under 16" square spokes?

AdamElphick;11045 wrote: OOh - do these make breaking much better? Plus do they fit under 16" square spokes?

Clive thinks so with the 304s up front, and they even fit under 15s.

The 280mm rear disc upgrade is probably mainly of interest to those who already have the front AP setup. The rear 280mms help to restore the brake balance that was shifted frontwards by the addition of 304mm discs on the front.

What may be of more general interest, is a front 280mm disc conversion.

I have been in contact with the ebay supplier, and he hopes to have some front setups available within a couple of weeks.:yesnod:

David Aiketgate;11048 wrote: The 280mm rear disc upgrade is probably mainly of interest to those who already have the front AP setup. The rear 280mms help to restore the brake balance that was shifted frontwards by the addition of 304mm discs on the front.

What may be of more general interest, is a front 280mm disc conversion.

I have been in contact with the ebay supplier, and he hopes to have some front setups available within a couple of weeks.:yesnod:

I might be totally wrong here but wouldn't more REAR braking effect be safer? Like when you ride a push bike and you put your rear brakes on before your front to stop you flying over the handlebars in a quick stop?

AdamElphick;11050 wrote: I might be totally wrong here but wouldn't more REAR braking effect be safer? Like when you ride a push bike and you put your rear brakes on before your front to stop you flying over the handlebars in a quick stop?

At the risk of opening a can of worms, the F/TF weight balance is towards the rear - 55/45 I believe. However, when braking from speed the weight is transferred forwards and most braking needs to be done by the front brakes.

The original brake setup is pretty well-balanced but merely adequate in total effect. Meaning that the front/rear brake effect is balanced but the overall braking is not brilliant.

MGR attempted to improve the brakes by adding the AP front setup, but this, in reality, biased the brakes towards the front too much, meaning that with the AP setup the fronts tend to lockup.

The rear 280mm upgrade effectively restores the balance of the brake setup with the APs.

It is thought, by some, that a 280mm front upgrade would improve the overall braking above the standard setup, without upsetting the overall balance.

AdamElphick;11050 wrote: I might be totally wrong here but wouldn't more REAR braking effect be safer? Like when you ride a push bike and you put your rear brakes on before your front to stop you flying over the handlebars in a quick stop?

Braking should always be biased toward the front of a vehicle due to weight transfer.

I tend to brake mostly on the front wheel on motorbikes. Yes, you are right a locking front wheel is bad as the front will just slide out from under you, but a rear wheel is easier to lock as there is hardly any weight over it. Also, if you look, most big bikes have twin discs up front with only a single smaller disc at the rear.

A car is different. You still want the majority of braking at the front, but the front wheels locking is safer than the rear wheels. In a front wheel skid you will just get understeer as the car will try and go in a straight line. A rear wheel skid will most likely involve the rear overtaking the front.

David Aiketgate;11048 wrote: The 280mm rear disc upgrade is probably mainly of interest to those who already have the front AP setup. The rear 280mms help to restore the brake balance that was shifted frontwards by the addition of 304mm discs on the front.

What may be of more general interest, is a front 280mm disc conversion.

I have been in contact with the ebay supplier, and he hopes to have some front setups available within a couple of weeks.:yesnod:

Ordered my set earlier :yesnod:

So what would the differences be between these and a set for the front? Wouldn't the same kit fit both straightaway?

gotenks1321;11073 wrote: Ordered my set earlier :yesnod:

So what would the differences be between these and a set for the front? Wouldn't the same kit fit both straightaway?

Apart from the disc itself. It depends on where he sources the 280mm front ventilated disc.
It may have a different offset to the Focus rear disc he uses for the kit you have purchased. So the adapter plates and possibly the spigot rings could be different.

David Aiketgate;11077 wrote: Apart from the disc itself. It depends on where he sources the 280mm front ventilated disc.
It may have a different offset to the focus rear disc he uses for the kit you have purchased. So the adapter plates and possibly the spigot rings could be different.

Ah I see. I'll be fitting a set to the front anyway along with a set of drilled and grooved Focus discs :yesnod: Exactly the same size as the rear apart from vented obviously

David Aiketgate;11077 wrote: Apart from the disc itself. It depends on where he sources the 280mm front ventilated disc.
It may have a different offset to the Focus rear disc he uses for the kit you have purchased. So the adapter plates and possibly the spigot rings could be different.

Ok thanks Just looking around now for some 280mm discs and have a few questions. What is it that makes the F discs different? I can see that the height of the Focus disc is different to the F but what is the problem with the PCD? Is that why the Focus discs have been machined to move the stud holes? Surely there must be a 280mm vented disc out there that is identical to the Focus rears :yesnod:

gotenks1321;11097 wrote: Ok thanks Just looking around now for some 280mm discs and have a few questions. What is it that makes the F discs different? I can see that the height of the Focus disc is different to the F but what is the problem with the PCD? Is that why the Focus discs have been machined to move the stud holes? Surely there must be a 280mm vented disc out there that is identical to the Focus rears :yesnod:

280mm fronts have been available for a while from Mike Satur and MGOC but the kits are quite pricey at about £215.
Chris