Rear brake locking

[Lotelan]

I am new to 7's having owned a Zetec converted de-dion for just two weeks. Went out for a play with the handling yesterday (brilliant!) and discovered that the rear brakes lock up early under heavy braking. Is this normal or is it possible that I have the wrong pads fitted or something?

 

Thanks in advance.

Martin.

[StewartG]

Mine used to do this but I tried two modifications(this assumes you have stndard brakes).The first was to remove about a third of the rear brake pad area, this stopped the back locking up before the front, unfortunately it does so by reducing rear braking effort, far better to increase front braking effort. This is expensive and means either a big brake kit from Caterham or Alcon calipers from James Whiting. The second remedy was new tyres - Yoko 32R's, 185 on the front and 205 on the back on standard 13 inch wheels. Less oversteer, more traction out of corners, a more compliant ride and better rear arch filling aesthetics. Must be why some racers use this set up.

[Graham Perry]

James whiting used to offer an upgrade using Austin Embassador/Princess calipers that I went for because I had a similar problem, except my car used to swap ends under extreme braking ! Despite their modest provenance they are an excellent AP unit that many people use in all forms of motorsport and are much cheaper than a £ 600

upgrade like Caterhams factory one. He may still have this system available. It is very effective.

[Stopher-Walker]

I am getting ready to purchase a caterham and was wondering about their braking properties. I recently had an interesting time with my current car (not a caterham), when someone pulled out on me whilst I was doing 60mph+ on a country road and then proceeded to turn right. I slammed on my brakes and locked up all my wheels, with great plumes of smoke behind me. Luckily after much swerving, I managed to stop the car, whilst the other driver just carried on, oblivious to the accident he nearly caused. Apart from me now getting round to improving my driving skills and practising braking properly - skid-pans, etc., can any one tell me whether anyone has ever put ABS on a caterham - I know it's against the whole ethos of the seven - but after this incident, I'm a little bit paranoid.

[V7 SLR]

You don't want ABS for God's sake. A Se7en will stop sooo quickly, you'll pull up in 1/3 of the distance of any other car. People who have driven mine brake for T junctions and end up stopping way short of the line.

 

If someone pulls out on you whilst you are driving a Se7en you'll either pull up easily, or you'll have the control and ability-of-the-car to avoid an accident. Often this is quoted as pro-active safety, rather than the passive, Nanny-state, safety requirements of ABS and airbags. These passive safety requirements are fine for those who don't care about their driving, or drive something with as much control as a Volvo but they are way-off for a Se7en.

[mark.hall]

Not sure how ABS will prevent people from pulling out in front of you. Also those people who do that are even less likely to see a Seven, so drive defensively, and paint your car in LOUD colours!

[Dave H]

2 options. Learn to drive properly, IAM, RoSPA or if you've got loadsa money HPC will all help. Or drive something REALLY big and solid (try Beryl), then flatten the blind b****ds. They'll only do it the once then.

 

 

[Lotelan]

Looks like I've found the problem. On removing the front pads I found some fair sized chunks missing from the friction material, looks like they've been overheating?? One of the wheel bearings is also Knackered so I'll mail order a new one from those helpful people at Redline Components. While I've got it all dismantled does anyone know if it would be worthwhile fitting a pair of grooved/drilled disks or are the standard ones up to the job?

[StewartG]

Whilst you've got it in bits try fitting some HAWK brake pads from Cambridge motorsport tel 01767 677969 If I'd got this much improvement in bite and stopping power from a big brake kit I'd have said it was money well spent but the new pads only cost about £40

[Lotelan]

Thanks Stewart.

Unfortunately I've already bought a set of standard pads! If these don't sort it I may try your suggestion.

 

[Geoff Johnson]

I was talking to James Whiting about this a couple of months ago & at his suggestion changed the front pads, he sells some much grippier ones, I think about £24 total for both sides. As he pointed out looking at the car there is always much more brake dust on the rear wheels that the front (I do clean it sometimes ...honest). It's certainly a cheaper way to go than going to the Alcon calipers etc. I now have a bright yellow nose & roll bar, but they still pull out in front of me, something to do with line of sight I guess. Next move is to paint my head yellow I 'spose

 

Geoff

[Andrew Russell]

If you want some super soft, ultra grippy, fast acting, front brake pads contact Roy Lane at TechCraft in Warwick. He supplies Mintex pads M1122 compound for about £55.00.

 

If the name is familiar, Roy is a multi British National Hillclimb Champion.

 

They are a competition pad used for sprints and hillclimbs and have full braking efficiency from cold, unlike many performance pads which require heat generation before being trully effective.

 

I use these pads on my 2.0 XE engined Seven with AP four pots and the stopping power is incredible.

 

One word of warning, they do leave your front wheels VERY dirty, after even the shortest of blasts.I suspect that they won't last for ever but in a Seven with limited use, that shouldn't be a problem. OK that's more than one word! Sorry!

[mark.hall]

Surf in to Dave Andrews Homepage and check out his idea of modifying a Mini pressure compensator. You'll find it at

http://hometown.aol.com/dvandrews/index.htm

[Darren Smith]

I agree with Graham Perry's comments, Its not unheard of for the car to swap ends due to rear braking being more effective than standard front brakes. Rather than reducing the rear braking efficiency improve the fronts with AP four pots (or as Graham suggested go to JW who I beleive has an alternative to the princess set up now) Alternatively, someone has been trying to sell a boxed set of AP fronts since before xmas. Check out the for sale forum?

 

 

Darren

[Lotelan]

Well I've now fitted the new (standard) front pads and guess what - the rears still lock up first! A mate of mine said he'd heard that if the front and rear circuits are connected the wrong way round at the master cylinder this could be the problem. Does anyone know what is the correct way round so I can check it?

I really find in hard to believe that Caterham would produce a set up that's so out of balance.

 

[StewartG]

I've just had a brilliant idea, if you drive everywhere in reverse your brake bias would be correct. Problem solved.

[StewartG]

There's more to this rear brake locking than meets the eye. I've fitted uprated springs and this stops the front end diving under braking,less weight is transfered off of the rear wheels and they can't lock. You also get more front end bite/less understeer, which I didn't realize it was doing before.

[Tim Seipel]

So what sring rates did you fit and which base engine do you use?

[StewartG]

The springs are the Juno ones advertised in these pages recently fitted to a 2L 16v Vauxhall car.

[Pierre Gillet]

Stewart,

I am very much interested by your idea, and looked into the YOKO 032R tyres charter( 01/2000) and could not find 185 and 205 on 13 inch wheels. Instead I found 175/60 and 215/50.

Also what is actually the width of the 13 inch wheels you are using?

 

 

[StewartG]

For Yoko tyre sizes try www.yokohama.co.uk or George Polly Tyres on 0143 586 3679. I'm using 13x6 wheels