Better brakes needed urgently

[Bedazzled]

 

I've got a VX Classic Beaulieu Seven with the standard disc brakes at the front and drums at the rear, plus Avon road tyres. I'm not at all happy with the performance of the brakes and I would appreciate some advice on the best upgrade(s) to go for. The car currently takes far too long to stop and the brakes lock up really easily (I think the rears lock up first).

 

I've read through the archives and it sounds like my options are :

1. Caterham 4-pot big brake upgrade at the front

2. Disc brakes at the rear (I read somewhere that one is available for Ital axles)

3. Better brake pads (e.g. Pagid?)

4. Better tyres

 

Which of these (or combination of the above) would give me the best improvement in braking performance for the money?

 

 

[N Longson]

I'd say you need to sort out the front to rear balance of the brakes first. Definately need your fronts to lock up first otherwise you'll be losing a lot of the braking force available - try backing off the rear adjusters a touch.

 

Also if you are running Avon CR322 then there are plenty of tyres which will give more grip - I'm currently trying to wear out my CR322 so i can justify buying some new Yokos.

 

Neill

 

 

[philwaters]

Go with Neill on this one.. new tyres... some Yoko 021's will make a HUGE difference to the braking. A lot cheaper than new calipers and discs as well. Chck out the similar braking topic for views on other kits (Alcon, Hi-Spec, AP, etc).

Tyres first though!

 

Phil Waters

Zetec is in and running

[Gary Furst]

If you rear brakes lock up first you'll definitely know it, as the car will attempt to swap ends!

 

Working in reverse order.

 

Changing the tyre might improve braking but if you have a balance problem between front and rear then this problem won't be improved.

 

Better brake pads is a definite step forward (possibly use the Pagid Blue pads), and to alter the brake bias without fitting a brake bias adjuster you could fit different grades of pads front and rear.

 

I don't know if they exist, but beware making your brake bias problem worse by having even better brakes on the rear. Also as under most (i.e. dry) conditions the front brakes do about 80% of the work stopping the car so improving the rears will not necessarily give you the biggest benefit for you money.

 

Big front brake upgrade is also a possible solution look at the AP racing (which means calipers and disk upgrade) or James Whitings Alcon brake upgrade (only the calipers change).

 

My recommendation would be to go with the brake pads first.

[Jaseb]

I've a similar problem which I tried to solve with some greenstuff on the front which started very well and are now pretty pants . When they were working well they sorted the brake balance issue out for me tho cheaply.

 

Does anyone know if Pagid do a fast road pad suitable for a 7, my old M3 has fast road pagids and they're a blinding difference over the stock items, was wondering if they might be a little less extreme than race pads - having said that ARE blues race pads ❗ 🤔 Excuse my naivety 😬

 

Edited by - jaseb on 9 Sep 2002 13:47:19

[Bedazzled]

 

Thanks for the replies. From these plus the comments posted on the separate thread from Robin C it sounds like new pads, better tyres and big front brakes are all good options, but rear discs are not worth pursuing. The car is going to Caterham for some other work this week so I might go for the big front brakes at the same time (if they will fit with my 13" minilites) and ask them to sort out the balance. Do race pads (e.g. Pagid) have any disadvantages for road use? e.g. do they only work well when hot from heavy braking or are they good for general use? Sounds like people aren't too impressed with Greenstuff pads. I think I may also invest in some Yoko 021s...

 

 

[Alex Wong1697456877]

Concurr that greenstuff is great out of the box and goes off after a few heat cycles.

 

Having driven Gordon Cardew's car on standard brakes, I suspect tyres are your biggest problem. His car stops very well indeed! As good as mine with the AP setup and EBC red stuff.

 

If you want to try Pagid's, take out a loan first (they're expensive!) and go for RS 4-2's. Graeme Finlayson (search for him on this site) can get these for you at a good price.

 

Edited by - Alex Wong on 9 Sep 2002 14:47:24

[scooby dooby doo]

You won't wear out the CR322s.

ever.

185/70R13 yoko 21Rs are only 45 quid each...

 

HOOPY R706KGU CYCLE WINGS AEROSCREEN K SERIES CUCUMBER

[ashaughnessy]

If you can lock all four wheels "really easily" then I can't see why you want to upgrade the brakes as they are already bigger than you need. You need more traction before you need more braking. However, if you can only lock one end up (especially the rear) the comments about altering the balance are reasonable. You should already have different compounds front and rear, a more aggressive one at the front and a more standard one at the rear.

Anthony

[scooby dooby doo]

two reason i can think of to upgrade brakes -

 

1) improve feel - if you can't tell what the brakes are doing - it may mean you need a stiffer peddle (different master cylinder bore size) or pehaps the brake calipers are flexing etc etc.

 

2) improve heat dissipation - even the most awful modern road car can lock its brakes these days. What it won't be able to do is brake in a controlled fashion from 70 mph to a near stop more than a few times in quick succession. this is fine on a road car, unacceptable on a track car. Bigger disks, bigger pads, venting, higher spec brake fluid are all solutions here.

 

So - to actually stop quikcer you need stickier tyres.

 

Actually -two other thoughts - if the front end is too stiff or the dampers knackered you may not be taking full advantage of the grip you have...

 

HOOPY R706KGU CYCLE WINGS AEROSCREEN K SERIES CUCUMBER

[Giles Wardle]

One further thing to consider is the rotation of the tyres.

Are your tyres rotational ?

If so, the rears should be with rotation and the fronts AGAINST.

Rear rotation with direction for traction on acceleration,

Front rotation against direction for traction on braking.

 

 

 

Edited by - Giles Wardle on 9 Sep 2002 18:56:40

[Giles Wardle]

Also, BEWARE Yoko A021R for you spec car.

I have the same spec 7 as you i.e. Morris-Ital axle.

I started with Yoko's. Great all round tyres, cheap, sticky, good in the wet, good on the road and good on the track .. BUT.......Too sticky for our axle, if you plan to do track days and drive hard.

On fast cornering, oil flows to one side and before you know it, your diff is a goner. (I did this at a private track day at Curborough)

 

However if you plan to do just road miles then Yoko 21Rs are great and unlikely to wreck your diff.

 

Track days and sprints I would recommend Bridgestone 720s (good List 1A tyre and far stickier than CR322s)

[Bedazzled]

 

There must be room for improvement because I think the current brakes are awful and friends who have driven my car quickly also comment on it. A car this light should stop on a six-pence but it doesn't. I was going to do a couple of brake tests today on a quiet bit of road to re-check which wheels are locking up first after the comments above, but it's been wet all day so maybe tomorrow!

 

Most of your comments indicate that I need to improve traction first, so I'll take a serious look into tyre options but I'm tempted to get the front brakes upgraded too. Money invested in stopping better would seem to be money well spent! It's interesting to hear the note of caution about Yokos with a live axle car but I use the car mostly for road use and I'd rather risk the diff's lifespan than continue sailing up the road every time I need to stop quickly.

 

I'll discuss the options with Caterham as well when I see them but it's great to get some input here first.

 

A couple of follow-ups :

- Is there a "Caterham-aware" garage where can I get some Yokos fitted near Woking?

- Where can I find out more about brake pad options/costs?

- Has anyone else tried the Bridgestone 720s mentioned by Giles?

 

Thanks!

 

 

[Mark H]

I run the re720 bridgestones on my early de dion and i am very impressed with them , very good in the wet and as good as the a509 yokos that they replaced if not better quite cheap too about 40 quid and they seem to last a while

 

Marc

 

the more i knock off the faster it gets !

[Chelspeed]

I can confirm that RS4-2 is the name of the compound used on pads that Pagid paint blue, therefore generally known as "blues", they are indeed the fast road pads.

 

The "next" Pagid pad is the blacks which are RS14. According to the pagid spec sheet they're pretty similar to blues in terms of mu, temp resistance etc etc but pad wear is a bit higher for blues than blacks. The only reason I think they say that the blues are more suitable to road use is that they are quieter.

 

I've got blacks on the Cat and blues ready to go on the road car.

[Bedazzled]

 

I have now done some brake tests and it's the fronts locking up first, not the rears. I spoke to Caterham earlier and they have been pretty helpfull. Unfortunately they have advised that front brake upgrades are unsuitable for live axle cars because the rears cannot be upgraded to match and they also said that Yokos are too sticky and could damage the rear axle. Therefore I cannot upgrade my brakes and I can only use a limited range of tyres. That's pretty disappointing!

 

 

[Peter Carmichael]

Have you adjusted the drums recently. You need to click the adjuster until the drum is just binding and then back off a click or two. This will improve pedal feel immensely.

 

If you have too much braking at the front, an improvement in grip will also rectify the balance. It could be any combination of camber, toe, knackered dampers or just the tyre spec as has been suggested - I don't have enough experience of this spec of Cat to give more specific answers.

[Giles Wardle]

Bedazzled,

What tyres are you running at the mo ?

Whilst braking on our spec is nothing special, it's still pretty good (or should be).

That your tyres are locking up, suggests that the brakes are working fine it's your traction that needs looking at. As PC suggests this needs a combined look at tyres, suspension and toe/camber etc.

Hope it works out OK. At least being near Woking you are near Caterham.

 

[C7JFM]

i dont really understand why caterham dont recommend the AP upgrade for a live axle, especially as the fronts provide most of the braking. As regards sticky tyres you could always swap your axle for ford (lots of us have)... then you will need more horses...aeroscreens....carbon fibre..........

[Graham Sewell]

Caterham recommended the AP setup for my live axle. The only caveat that they placed was that they couldn't upgrade the rear brakes to suit. I guess this might lead to over-braking at the front although nifty use of brake shoes/ larger rear slave cylinders may help.

 

The only problem I had that may be car specific was the the clearance to the wheel rim is so tight that the balance weights need to be between the spokes.

 

If anything, the live axle cars seem to be more heavily braked at the rear than the de-dions which I don't understand as they only have puny drums.

 

 

 

Low tech luddite - xflow and proud!

[Peter Carmichael]

Uprating the fronts won't help. Bedazzled already has the fronts locking up prematurely. The problem is too much front bias on the brakes.

 

FWIW, at Brooklands I was getting a lot of front lock up until I changed the damper settings... at the rear two clicks stiffer ❗

[buroz]

Most of the Grads (basically your spec car), use GreenStuff pads. These help a lot.

 

I can't believe that you are locking your rear wheels up. I've had my rear brakes bind on (twice) and it made very little difference. I pretty much use the rear brake adjustment to fine tune my pedal position.

 

Going to 21's will be a helluva difference. You'll be able to corner and brake soooooo much better. However the CR322's are a lot of fun on the track, I reckon... especially in the wet. Not very fast, but a whole lot of fun.

[Graham Sewell]

If you are locking your wheels when braking, then you braking capability already exceeds your grip, so improving the braking with 4pot et al will not stop you any quicker (in my case, the rears always locked first so I quickly learned where the limit was and never went near). The only way to stop quicker will be sticky rubber as that is the only way to increase the level of friction with the road. After all, brakes slow the wheels and tyres stop the car.

 

I have been running Yoko's for about 10,000 miles and the only damage to the rear axle has been the need to get the bearings shimmed. But this could have happened on the Michelins anyway as it is quite common for Scholarship cars to suffer the same problem.

 

Also, just because a car is light does not make it stop quicker. Friction is a funtion of applied force (as in mass of car * gravity) and the coefficient of friction. Therefore, if all things remain the same a 3 ton car will stop in the same distance as a caterham provided it has the same tyres and the wheels are locked.

 

Low tech luddite - xflow and proud!

[scooby dooby doo]

Slight technical aside: the friction law is not quite linear with weight so doubling the weight doesn't quite get you double the grip. but factors like unsprung versus sprung weight and the ability of the dampers/springs to keep the tyre in contact with the road will probably outweigh this.

 

Anyway

I'd suggest going to Yoko21Rs as a first step and keep the rear axle topped with oil for peace of mind.

 

HOOPY R706KGU CYCLE WINGS AEROSCREEN K SERIES CUCUMBER

[ashaughnessy]

Second attempt at posting this - apologies if it comes out twice!

 

Your brakes are likely to be hugely better when really warm than when cold. When cold they will feel like they are rubbish. This obviously depends on the pad material but I reckon most pads likely to be used on a Caterham will feel this way. Mine need a fair amount of warming up before they feel really good. Once warm, they are hugely better. On my live axle car with Mintex 1144 pads at the front (pretty standard stuff) and Yokohama A032R tyres, I can make the free ends of my seatbelt straps stick out almost horizontally. Unless you drive like a lunatic, it's hard to get the brakes really hot on the public road (though I imagine a lot of drivers on this forum do drive like lunatics )

 

Saying that you shouldn't use sticky tyres with a live axle is rubbish. Any upgrades you make will put increased stress on the car but you just have to live with that. Putting Yokohamas on won't immediately make your car collapse, it just means you may or may not get less mileage before something breaks. If you're unhappy with grip, get better tyres! I've had A021Rs and they were good (in the dry), the A032Rs are even better (in the dry).

 

Most things on the seven work better when you're going fast. The brakes get up to temperature. The tyres get up to working pressure. The rubber on the tyres gets to working temperature. This all helps. When you're driving slowly (like you have to on the public road) they don't work well. Also, hard suspension settings (overly stiff dampers) that work well on a smooth race track don't work well on a typically bumpy public road.

 

Finally, make sure the rear brakes are working properly. These can give up the ghost without you really noticing.

Anthony