Brake adjustment for sprinting

[Mcalvert]

OK, Ok, this could just as well be posted in TechTalk as here, but I'm asking the Speed fraternity...

 

One of the benefits that I have heard many people refer to when running wider front tyres (Kuhmo's in 215 profile) is that the braking is much improved, to the point that locking the front wheels is not easy to do.

 

I've unfortunately never really found this, and really noticed at Harewood yesterday that I seemed to be locking the fronts pretty much everywhere. Now I'll readily admit that this may be hamfistedness on my behalf, but it could also suggest that the front is over-braked / the rear under-braked?

 

H5 URH is fitted with Alcon 4 pots at the front, running (I THINK) RS15 pads. The rear are "standard" Caterham pads, What are my options? I'm thinking of either more aggressive pads on the rear, or a brake bias system?

 

Thoughts appreciated - Michael.

 

[Adrian Williams]

I can't remember ever locking the rears but I've locked the fronts many times

 

You're not alone if that's any help.

[Richard Price]

but it could also suggest that the front is over-braked / the rear under-braked?

---

 

Mike,

Some will tell you that the rears don't do a lot, but that's not the case!

I run dual master cylinders with an adjustable balance bar. As I wind the balance towards the rear, I can really feel the additional stopping power. Ideally, you need to use materials that have similar heat/coefficient of friction characteristics, assuming the disk and caliper sizes are well matched.

I run standard discs and calipers, and currently have Mintex 1144 material front and rear. They seem to work OK

 

 

If you were to choose a higher friction pad and a pressure reducing valve to the rears, may I draw your attention to page 328 of the 2010 blue book, and regulation S 10.7.2.

If you could adjust your brake bias as you drove the car, then, technically, your car would be illegal, which is why you'll often see them inside the engine bay, unlike a race car where they are readily available to adjust.

 

 

 

No. I have to remove my bonnet to adjust my brakes

 

Edited by - Richard Price on 9 Aug 2010 16:45:31

[Matthew Willoughby]

Richard,

 

That may be the case but the scrutineer on Sunday asked me why my brake bias adjuster is under the bonnet. He thought it was a daft place because in that position it can't be adjusted from the driver's seat. He suggested (jokingly) that I attach a piece of string to it so that I can pull it as I drive!

 

Viper blue and red Roadsport A. Speed Championship blog here

[Mark Durrant]

Richard

 

I remember the consequences of you adjusting your brake bias cat Loton Park last year

[Richard Price]

I remember the consequences of you adjusting your brake bias cat Loton Park last year

 

Ray,

So do I 😳

I knew someone would bring that up ❗

That's why I don't mess with it any more, now that i'm happy with the balance

 

 

[4ster]

Michael

I don’t know whether my experience will be of any help to you but last year at Harewood I was locking up the fronts virtually every time I braked (with far too much photographic evidence to prove it) 😳. This year, I certainly had some exciting moments but none of them involved locked brakes! I think that we can eliminate the possibility of the driver acquiring new skills, so what changed?

 

My set-up is non standard (surprise, surprise) with Alcon 4 Pot callipers, separate cylinders for front & rear and a bias bar. After picking a lot of people’s brains, – particularly Richard who was very helpful – I changed cylinder sizes and pads (they were RS15s and then RS5s) to Mintex 1144s all round. The pads made the biggest difference, with the pedal feeling much more controllable and even I can now “modulate” the braking to some extent.

 

I can now wind on a lot more to the rear as well and, although I am still rather cautious about leaving the braking late the whole setup gives much more confidence – although the real test may be how many times I disappear into the bracken at Fallow this coming weekend.

Best of luck.

 

 

Paul

Old technology - engine and driver.

 

Edited by - 4* on 10 Aug 2010 10:41:11

[Nigel Fox]

The other advantage of the Mintex pads is they appear to work just as well when fitted backwards with the friction material on piston. eh Paul 😬

 

Full time class 4 Zetec

[4ster]

Thanks Nigel, I was hoping to keep that quiet.

Mind you, if that particular mod works as well as it did at Lys y Fran, I might try it again.

 

Paul

Old technology - engine and driver.

[david nelson]

Michael

 

I have flat spoted many a fron tyre in the last 2 seasons. I was looking a the rear pad and found that they were the wrong ones (standard CC pads). I how run rs15 at teh front and 1144 at the rear. What is noticable is the rears now work. I have only done 2 events and have yet to lock up the fronts. I am sure I can if i try but before it was every time.

 

 

David