master cylinders

[the captain]

can someone explain (or clarify what little i think i already know) about the bore and ratio of a master cylinder (brake)

Im going to put a radial master cylinder on the R1 but theres a few different options fo me to choose from

now...am i right in thinking the bigger the bore the better the braking is but its harder to pull? if im right cool......i still need to know what this ratio business is all about though!

lateshift? whats the score!:grin2

[Jetski]

Mick isn't around the pc today. He's on location with Robson Green and Mark Benton, filming the next series to ITV's 'Northern Lights' named 'City Lights' :laugh1

I have just spoken to him and he does know the answer to this, but it was a bit tricky over the phone, so will reply later.

He also confirms, that Robson Green is extremely short :D

[the captain]

He also confirms, that Robson Green is extremely short :D

i feel it is only right that he be "spamed" then!!:laugh1

robson green that is!

[harriebird]

i think the bigger bore, harder to pull thing is correct shane.

i replaced the piston on my clutch slave cylinder on my 748, the idea is that it is meant to be easier to pull but the lever seems to need to be further out to get enough pressure to move the piston....work that one out :confused:

it feels lighter and everything but it's no good coz now i have to stretch more :grin2

[DoodleBug]

The bigger the bore of the master, the more fluid is pushed into the braking system when you pull the lever, the harder the brakes work.

Now that will mean a little more pressure on the fingers. However, if you get an ajustable one you can change the amount of lever travel. More travel = less leverage on the cylinder per mm of lever travel = lighter controls but equals slightly less pressure on the system.

In a nutshell an adjustable setup allows you to decide how much travel on the lever produces the same amount of pressure on the brake caliper, so longer travel for a lighter feel at the lever, shorter travel for a firm lever. Its all about how you want them to feel.

[the captain]

so out of these options which would provide the best bracking and which would be the harder to pull on ......just so i can clear it all up in me head!
i want it to be quite firm with little lever travel but i dont want to be using two hands to apply the brake!!!

16bore X 18ratio
19 X 18
19 X 20

[Perilous]

A 20 ratio lever gives less travel and will be harder
18 gives more travel & is easier to pull
16 is the easiest to pull and has the most feel and travel

(More or less a direct quote from PDQ)


Most people I know use the Brembo 19 X 20.


I use one on both ZXRs. One has rebuilt early H model calipers on it (As used on ZZR 600, ZX6R F model as well) and the #1 bike has ZZR1200 4 pot calipers on it.


I never need to use more than two fingers on the lever even when braking as late as possible from a flat out straight into a 1st or 2nd gear hairpin but theres enough feel from them to carry the brakes up to the apex of a corner in the wet.


My friend who races Forza Extreme (Last years SS400 championship winner) also uses the same M/C on a Gixer 1000. He currently had his best race result (2nd) this season in the wet so there's obviously enough feed back for a tuned Gixxer in the wet.



One thing to watch though if you're going to put a radial M/C on. Be carefull not to knock the lever in the wrong direction if you're putting the bike in the garage or anything. They have a little ali disc inside the cylinder that's designed to break in a crash so the innards don't get pulled out of the cylinder and it's really easy to break if you knock the lever the wrong way. It's cheap enough to get repaired or you can do it yourself if you have lathe you can make the disc on but it's still a major pain in the butt.
Also if you buy the Brembo one it's a good idea to put a bit of lockwire through the main pivot pin (Even on a road bike) as although it's rare, they've been known to occasionaly come out. (Shane Byrne being the most famous example)

[Lateshift]

Cant really add anything to that, and am probably too knackered to try after being up since 3.30 this morning and having only just got in :D

But the 19x20 seems to be the one that most go for as far as brake performance goes, its expensive but worth it :)

But bear in mind with harder braking from these comes more wear on the rotors and the pads ;)

[the captain]

sweet..cheers dude...so the 19X20 is gonna give nice solid braking.
Id rather it be a little hard coz im just one of these people who like the minimum of travel in a lever.....i hated the ones on the gixer coz they felt so spongey!!

[Lateshift]

They wont be any harder to pull for the average person, they will however require less travel (which gives the impression you are really pulling on them).

This is why its becomes effortless nearly to use two finger braking because whilst you may seem to think you are putting extra effort into using them, the levers isnt actually travelling very far because the bigger bore is able to push more fluid in one go ;)

[Perilous]

sweet..cheers dude...so the 19X20 is gonna give nice solid braking.
Id rather it be a little hard coz im just one of these people who like the minimum of travel in a lever.....i hated the ones on the gixer coz they felt so spongey!!

On the Gixxer 1000, changing the master cylinder is the first thing most racers do with them for that very reason.
Same with the ZXR 400s now we're allowed. By the end of a race with the standard 14mm cylinders the lever was on the handle bar.
I did use the 5/8 cylinder as used on most 600s which is a cheaper upgrade for the 400 than the Brembo but IMO the Brembo gives a much better feel and is worth the extra money.
Another bonus is that with the layout of the cylinder and the bleed nipple on it they make the brakes really easy to bleed.
Replacement levers are dear though, although I've yet to break one in a crash but I keep trying.:laugh1 :laugh1

[the captain]

excellent....i should be sorting myself out with one end of the month then hopefully!!!

sweet feet!!!!:rockon

[Perilous]

This is why its becomes effortless nearly to use two finger braking because whilst you may seem to think you are putting extra effort into using them, the levers isnt actually travelling very far because the bigger bore is able to push more fluid in one go ;)

Which is one of the main reasons I like them as I like the lever as close to the handlebar as possible.

After racing Brands GP last year with a broken fifth metacarpal in my left hand and a broken third finger on the right, effortless is what we like.:laugh1 :laugh1

Now go to bed or you'll be all grouchy tomorrow.:grin2

[Lateshift]

Yaaaaarrrrrr, (quick scratch of nads, arse and obligatory rub of the eyes :D ) dont feel like i have slept :D

DHM of all people are now doing the "fold-up" levers for radial M/C's now, they look pretty nice and are supposed to work well as far as saving the levers go :)

I think i saw them at Intobikes.

Not too sure about the one on mine but i think its a Brembo with 18mm bore, the lever travel seems to be minimum but then again the brakes on the RSVR are pretty much sorted anyway :)

[the captain]

i've seen those DHM levers youre talking about......there only about £40 each which as far as folding levers go is quite reasonable but ive only ever seen pictures...they look pretty basic but i guess they do the job!

[Perilous]

I've never used them myself but a female racer (Cherie Christian) had one on her FZR and she had to put gaffa tape on it to keep it from inavertently folding up. Maybe it was just worn or something but I have to say that put me off them.

I've never had a Brembo lever break yet but the disc breaking inside the cylinder if you knock it backwards or slide into the gravel rear first :rolleyes: (Mind your usually more concerned about the gravel going up your nose at that point:laugh1 ) is a major pain in the butt.
Ultimately though, even doing trackdays you guys on the road don't tend to throw yourselves at the scenery as often as us clubbies do (Especially me:laugh1 ) so you'd probably be as well just using the standard lever.
Last one I bought was £27 by the way, but I didn't shop round.

Brembos are dear to buy but cheap to get repaired.

For future reference the place to get them repaired is

Grand Prix Race Wear
Silverstone Technology Park
Silverstone
Towceter
Northampton
NN12 8TH

I just had one repaired and it cost £6.50 (ex postage) and they turned it round in three days. The one before I really mullered still ony cost £25 to be mended.

There is a company you can buy the Master cylinders from online that is apparently the cheapest. I haven't tried them as I tend to deal with people for service more than the last penny but I'll post the address up later (when I've got it off my team mate) if you want to try them. They're about £135 as opposed to £180 apparently, although of course I expect there'll be postage on that.

[Lateshift]

Thats a healthy saving in anyones book that :)

I have to say i had thought about using some CRG levers on mine, purely because the length of the lever is wasted for the majority of the time, i either tend to use 2 fingers or possibly 3 depending on how hard i need to brake and how stiff my fingers feel at the time :D

But having looked at Becky's bike, it would seem that the Crash bungs and R&G bar ends do their job well enough to keep the lever free of any contact with the ground (obviously cant guarantee that it will never hit the ground due to the nature of every crash being different).

[Perilous]

It's a bit easier on a race bike as most of the handlebar switch gear isn't there so you can just push the cylinder further on the bar and just adjust them in a bit more, although possibly not every one would like to have the extra leverage from working on the end of the lever.

Ah this is good this. It's nice to be able to post on on this forum about something I know about with out just being a race bore for a change.

When I'm x-rayed tommorrow, if I'm mended enough not to compromise Brands (pain you just have to get used to) I'm going to burst forth on Lenny's bike at the weekend *so they'll be loads of post about how scary it is avoiding horse, sh#t and cars on my side of the road again and the fact that things are just plain and simple coming towards you. I think it's about five years since I rode on the road. Jeez I'm almost a born again.:eek:
Challenge of the weekend wil be getting the ever expanding Polden belly into the road leathers.:grin2

*She wants me to ride it first to make sure I've put it all back together properly.:grin2

[Perilous]

There is a company you can buy the Master cylinders from online that is apparently the cheapest. I haven't tried them as I tend to deal with people for service more than the last penny but I'll post the address up later (when I've got it off my team mate) if you want to try them. They're about £135 as opposed to £180 apparently, although of course I expect there'll be postage on that.

I'v just spoke to him and he's going to dig the address out tonight. I wasn't quite right they're actually £146.00 now.

[the captain]

right well its all sorted anyways...i got a brembo one from an 05 R1 on its way to me £65 all in (vat and postage)

i did come across some "proper" brembo ones on ebay.....from the states, but for $250 you get the master cylinder, 15mm remote reservoir, new tubing and shipping!!!...that works out at £131!!!!!!....not bad i reckon!

[Perilous]

Glas to see your sorted.

My mate has managed to loose the invoice:rolleyes: but apparently the Ebay seller advertising the item on the following link was where he gets them from but the American one you found sounds like a better bet.
Personnaly unless there's a rediculous difference I prefer to buy them from people I know and get the after sales service. Having said this I've never actually tried to buy one direct from G.R.R. wear so they may well be cheaper than the standard £180 ish.

At least with an R1 cylinder the pin won't fall out in a tank slapper.:grin2


http://cgi.ebay.co.uk/BREMBO-RADIAL-BRAKE-MASTER-CYLINDER-16-x-18-mm_W0QQitemZ200022595625QQihZ010QQcategoryZ25632QQ tcZphotoQQcmdZViewItem