stuleah
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| posted on 12/5/10 at 10:31 PM |
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help setting up brake bias
Hi all, is there an idiots guide to setting up the brake bias bar or is it just trial and error?
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loggyboy
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| posted on 12/5/10 at 10:34 PM |
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quote:
Originally posted by stuleah
Hi all, is there an idiots guide to setting up the brake bias bar or is it just trial and error?
Trial and error or take it to a friendly MoT centre and ask them to check the balance.
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RichieHall
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| posted on 12/5/10 at 10:34 PM |
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I set mine all the way to the front, then started dialling in more and more rear bias until the rear wheels locked up before the fronts, and dialled
in quarter turn forwards.
Once I'm more used to the car I'll start dialling in more rear to get a better turn in under trail braking.
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BenB
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| posted on 12/5/10 at 10:36 PM |
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This is a good description of the process I've always heard of
"Throw on some old tires (the same type you will be racing) and ask a friend to help. Find somewhere that you can safely test your brakes. Have
your friend stand where they can safely observe the operation of your brakes. Drive at a decent speed, but not too fast. Slam on the brakes and lock
them up. If you can't lock up the brakes at a moderate speed you may not have enough brakes. Have your friend observe whether the front or rear
brakes lock up first. You can tell which tires are locked up by the smoke billowing up from them. Adjust your brakes until the front tires lock up
just before the rear tires. Record this set-up as your starting point. The bias may need adjustment from time to time as factors change."
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britishtrident
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| posted on 13/5/10 at 06:58 AM |
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quote:
Originally posted by loggyboy
quote:
Originally posted by stuleah
Hi all, is there an idiots guide to setting up the brake bias bar or is it just trial and error?
Trial and error or take it to a friendly MoT centre and ask them to check the balance.
MOT rollers are not of any use for setting front/rear bias.
Only way is road test on a good dry tatmac surface starting from too much front brakes, puttting on one turn towards the rear at a time to
find the balance point then winding back a couple of turns.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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britishtrident
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| posted on 13/5/10 at 07:05 AM |
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quote:
Originally posted by BenB
This is a good description of the process I've always heard of
"Throw on some old tires (the same type you will be racing) and ask a friend to help. Find somewhere that you can safely test your brakes. Have
your friend stand where they can safely observe the operation of your brakes. Drive at a decent speed, but not too fast. Slam on the brakes and lock
them up. If you can't lock up the brakes at a moderate speed you may not have enough brakes. Have your friend observe whether the front or rear
brakes lock up first. You can tell which tires are locked up by the smoke billowing up from them. Adjust your brakes until the front tires lock up
just before the rear tires. Record this set-up as your starting point. The bias may need adjustment from time to time as factors change."
You have just described a great way to have a massive accident. Slamming on the brakes with too much rear bias will result in an instantaneous almost
un-catchable spin.
Setting bias up for the first time on a car demands a great deal of caution always starting from a setting with too much front bias. If the
hydraulics are sized correctly the balance point should be somewhere near the centre position and one turn either way makes the difference bewteen
wet and dry race settings.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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blakep82
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| posted on 13/5/10 at 08:09 AM |
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quote:
Originally posted by britishtrident
quote:
Originally posted by BenB
This is a good description of the process I've always heard of
"Throw on some old tires (the same type you will be racing) and ask a friend to help. Find somewhere that you can safely test your brakes. Have
your friend stand where they can safely observe the operation of your brakes. Drive at a decent speed, but not too fast. Slam on the brakes and lock
them up. If you can't lock up the brakes at a moderate speed you may not have enough brakes. Have your friend observe whether the front or rear
brakes lock up first. You can tell which tires are locked up by the smoke billowing up from them. Adjust your brakes until the front tires lock up
just before the rear tires. Record this set-up as your starting point. The bias may need adjustment from time to time as factors change."
You have just described a great way to have a massive accident. Slamming on the brakes with too much rear bias will result in an instantaneous almost
un-catchable spin.
"Find somewhere that you can safely test your brakes" was they key bit to that
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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bi22le
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| posted on 13/5/10 at 10:52 AM |
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This is an interesting read for me as my Striker has a bias bar and Im to scared to touch it!
Im doing a track day on sat so ill see what happens then. Ill take it in small steps and mark the original set up.
Whats the difference between wet and dry set ups?
I take it wet has alot more front bias.
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
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Fred W B
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| posted on 13/5/10 at 11:06 AM |
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I've never tried it, but Smith recons you can get it somewhere close (as a starting point, before the track testing) in the garage on stands by
putting a little load on the brake pedal and trying to turn the wheels by hand. Adjust until you have them feel about the same, with a bit more to the
front.
Cheers
Fred W B
You can do it quickly. You can do it cheap. You can do it right. – Pick any two.
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02GF74
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| posted on 13/5/10 at 12:38 PM |
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.... quick hijack - how do these bias valves work? is it matter of chaing size of an orrifice to restrict fluid flow to the rear?
asking 'coz on a cylcing forum, a one armed cyclist is looking to be able to operate front and rear brakes with one hand and a bias valve would
be a good solution (ignroting the fact that the lever would tavelt further since it operates 2 sets of brakes)
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Staple balls
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| posted on 13/5/10 at 12:49 PM |
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quote:
Originally posted by 02GF74
.... quick hijack - how do these bias valves work? is it matter of chaing size of an orrifice to restrict fluid flow to the rear?
asking 'coz on a cylcing forum, a one armed cyclist is looking to be able to operate front and rear brakes with one hand and a bias valve would
be a good solution (ignroting the fact that the lever would tavelt further since it operates 2 sets of brakes)
I did something like that once with some Magura HS33s, balanced the brakes using harder pads on the rear, and front/rear spaced differently, so fronts
gripped first.
It worked fine, but difficult to control, no idea how it'd work with one arm.
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stuleah
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| posted on 13/5/10 at 06:06 PM |
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Thanks for the info guys, sounds like what i thought, mainly trial and error until its somewhere close.
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prawnabie
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| posted on 13/5/10 at 08:51 PM |
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quote:
Originally posted by 02GF74
.... quick hijack - how do these bias valves work? is it matter of chaing size of an orrifice to restrict fluid flow to the rear?
asking 'coz on a cylcing forum, a one armed cyclist is looking to be able to operate front and rear brakes with one hand and a bias valve would
be a good solution (ignroting the fact that the lever would tavelt further since it operates 2 sets of brakes)
They are talking about bias bars not valves. Valves are banned under IVA rules
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RichieHall
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| posted on 14/5/10 at 08:09 PM |
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A bias bar works my moving the fulcrum between the front and rear master cylinders, transmitting more force, therefore more braking pressure to one
than the other.
This link explains it much better!
Rust is lighter than Carbon Fibre!
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Antnicuk
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| posted on 15/5/10 at 08:09 PM |
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thats a very good link but the key bit of information that i always forget is 'which way do i screw the bias bar to move bias to the front or
the rear?' is it the closer the pivot point is to the front m/c the more braking is appled to the front?
Its probably very obvious but i can never remember.
600 BHP per ton, Stylus Brought back from the dead! Turbo Rotary Powered!
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