Front brake discs - size

[DavidL]

Idly gazing at my car today, it occurred to me that there's a good half to three quarters of an inch clearance radially between the caliper and the wheel. I remember the original Metro used 12" wheels, which would have dictated the original disc diameter. Has anyone fitted larger front discs to take advantage of the extra space afforded by 13" wheels?

Did the Rover 100 use bigger discs, or did it continue to use 12" wheels?

It may just be an inefficiency somewhere on my car, but the brakes on my VW van are significantly more powerful than the Midas's.

[manifold]

Might need to check the mechanism to ensure there's no play between servo and pedal ala what Hans has done.

My brakes work perfectly...but they are different to standard setup and don't need a servo....just a heavier foot.

[DavidL]

I can stop, but I do need a considerably heavier foot than in my van, or indeed, just about any modern BMW or MINI (I have to drive those at work). Hadn't realised there could be play between servo and pedal, I'll have to have a look for that on here and see what Hans had to do.

I'm still thinking about the idea that it could be a brake imbalance, just not sure where to start with investigating that...

[Moneypit]

The pedal on my convertible gets drawn down quite a bit when you start the car up, so doesn't leave a lot of travel for braking .I disconnected the servo pipe and got a hard pedal almost instantly but required Herculean effort to stop the car!! So I've opted for the servo assistance 'till I can have a better look. It is difficult to lock all wheels up on mine in the dry I must admit!

[Stuart]

I can stop, but I do need a considerably heavier foot than in my van, or indeed, just about any modern BMW or MINI (I have to drive those at work).

That reminds me of the day the new Mini was launched, I'd gone down to the dealers in my mk3 the only car I had at the time. I went for a short test drive in a Mini, at the first junction I nearly put the bloke sat in with me through the windscreen I don't think it helped his confidence when I said sorry this is the first time I've driven a car

I believe the Metro servo only doubles the assistance, and new cars have something like 5 times the assistance. I found some cheap EBC pads helped a lot compared to the pads I had fitted.

[manifold]

....dont forget to check your metro pedals have been shortened and re-welded on the pedal box the 'required' 2 inches on the vertical crank.....

....especially on the convertible due to the raising of the foam sandwich floor.

It definitely makes a difference, both for bleeding and for brake performance.

[DavidL]

I can stop, but I do need a considerably heavier foot than in my van, or indeed, just about any modern BMW or MINI (I have to drive those at work).

That reminds me of the day the new Mini was launched, I'd gone down to the dealers in my mk3 the only car I had at the time. I went for a short test drive in a Mini, at the first junction I nearly put the bloke sat in with me through the windscreen I don't think it helped his confidence when I said sorry this is the first time I've driven a car

Brilliant!

I believe the Metro servo only doubles the assistance, and new cars have something like 5 times the assistance. I found some cheap EBC pads helped a lot compared to the pads I had fitted.

Interesting info about servo assistance being more on newer cars there. I'd also realised that I have no idea what the pads are like, so I might give a new set of EBCs a go and see what happens. Thanks for the idea!

[DavidL]

....dont forget to check your metro pedals have been shortened and re-welded on the pedal box the 'required' 2 inches on the vertical crank.....

....especially on the convertible due to the raising of the foam sandwich floor.

It definitely makes a difference, both for bleeding and for brake performance.

The pedals have definitely been shortened, although since I didn't do it, I have no idea whether the correct length was removed...

[DavidL]

I believe the Metro servo only doubles the assistance, and new cars have something like 5 times the assistance.

From a Google search, I found discussion about replacing a 2:1 ratio servo on a Sunbeam Tiger with a 2.75:1 ratio servo. http://www.sunbeamtiger.co.uk/tech%20tips/brake.htm

Which makes me wonder if I could find a replacement servo for the Midas offering a better ratio; although given that you don't often get something for nothing, I'm wondering; if I do find one, where would the extra assistance come from? The article mentions a bigger diameter, but this has to be fed from the available vacuum, obviously. Would the available vacuum be sufficient?

[Stuart]

As you say I believe diameter plays the biggest part in assistance gain, I'm sure there will be more than enough vacuum to run a bigger servo.

I don't think being sat on the floor in the Midas helps,pushing downwards in a Metro I'm sure generates more braking power.