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Clio cup Rear Bias



Guys,

fitting the rear bias valve to my 182 to remove the ABS.

The "leaver bar" on the back that is connected to the spring doesn't seem to have a place to bolt to. am i missing a bracket?

Regards
 
  Pug 206 SW, 172 CUP
I would assume adjust the bias depending on what the axle is doing. The cup has very low rear braking and so is setup differently.

Exactly why someone else will have to answer.
 
  Pug 206 SW, 172 CUP
Knowing a mass car maker disconnecting the spring was probably the cheapest way to stop the rear's locking up under heavy braking and it probably came from some low spec model that needed more rear braking as most ABS systems have electronic brake force distribution and don't need bias valves. The EBD is the only bit I miss about ABS. It does a good job of giving you as much braking as possible before crappy ABS cuts in.

That's my guess anyway. I poke my leaver bar occasionally to check it hasn't seized.
 
There is a little return spring for the lever, but the lever is not connected to the suspension.

The way it works is as you press the pedal a piston in the bias valve moves out when the lever is connected to the suspension it resists the piston and increases the bias to the rear.

With it not connected you get minimum bias to the rear, which is as designed by Renault for the 172 cup.
 

McGherkin

Macca fan boiiiii
ClioSport Club Member
What does it actually do? Why is it there

When you brake, the weight of the car 'shifts' forward. The tyres at the back have less weight pushing them into the tarmac and therefore have less grip. That means they're easier to lock.

However, if you're carrying weight in the boot, or towing, more weight remains over the rear tyres so there is extra grip available, which could be used for extra braking to make up for the added weight.

The valve gauges the amount of grip available to the rear tyres judging by the height of the rear of the car. If it stands on its nose, there's probably very little weight in the rear and therefore it limits the amount of braking the back wheels can do. If the car is arse heavy, it will give extra braking to the rear in order to stop the whole lot quicker.

Simple illustration;
weighttransfer.jpg


This transfer of weight is why the front brakes do about 80% of the braking. (and the engine over the front wheels too)

The 172 cup, like all other 1*2's, isn't approved for towing and isn't likely to be carrying much weight (being the cup model it's more motorsport oriented - supposedly), so the rear braking effort is locked to minimum.
 
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Tbh thanks but not really :D .... There is four connection on the 'face' of the bias valve so assumption is rights are in and lefts are out or somthing...
 
  Pug 206 SW, 172 CUP
I did look for pictures on Google for you but they weren't much help. Not had to work on mine so the routing hasn't sunk in. If no-ones answered by the weekend I'll try get a look under my car.
 
Think i mite have got to the bottom of it by piecing together pics from google but if i dont have luck ill let you know! Thanks for your help!
 


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