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bass4dude 05-29-2011 10:34 PM

Brake Questions (Search used)
 
Getting my 900rr Calipers in the post in a few days (Thanks again, Micky), have a 16mm Radial M/C and a double banjo pressure switch for the brake lights in my "shopping basket" (why do no radials have brake switches incorporated?!?! damnit.) and have some questions before I jump on the M/C

Now, couple of questions:

1. I've seen all the #s for the leverage calculations of piston size to M/C size but cannot make heads or tails of it. Which # gets divided or multiplied by which in order to get the leverage ratio? I've been doing it on paper and I couldn't get a feasible answer and I'd like to be able to know it before opting for a 16 or a 19mm M/C

2. What is the maximum rotor size for the VTR with f4i calipers on it without extension plates for the calipers? they're the same as 2nd gen 900rr and I'm not in the mood to make some brackets although someone who has a CNC owes me some pretty expensive favors :evillaugh:

3. Stock rotor size is 296mm or something, 17mm offset, 6 bolt, but what is the bolt pattern (how many mm. between the center of bolts)? I've been looking around for the info but I can't seem to find anything anywhere and I, much like much of my generation, find it easier to spend hrs and hrs on the computer searching for the information rather than step outside for 30seconds and measure :D (I'm kidding, I love being outside and doing stuff but I can't really measure accurately on the bike ;))

4. Just to double check, banjo is 10mmx1.25 pitch?

smokinjoe73 05-29-2011 10:52 PM

Thats alot of questions, and I have just a comment. I would not worry about bigger rotors until you put on the beefier calipers and try them. The power difference is huge. Also without brackets how would you fit a larger rotor? One of my hawks has a 1000RR front end and that radial master has the brake switch on it.

bass4dude 05-29-2011 11:12 PM


Originally Posted by smokinjoe73 (Post 304406)
Thats alot of questions, and I have just a comment. I would not worry about bigger rotors until you put on the beefier calipers and try them. The power difference is huge. Also without brackets how would you fit a larger rotor? One of my hawks has a 1000RR front end and that radial master has the brake switch on it.

When ya wanna learn something, why learn half when the whole matters? :p
That's just my way of looking at things.

And I ask about the bigger rotors because I didn't know (nor think to check) whether the 900rr accepts a larger diameter rotor, hence, why finding one with the same offset and bolt pattern with a larger diameter would effectively be a Over-sized conversion for the hawk because I've been looking for brackets and haven't seen any floating around and don't really have the bank-roll to do so right now.

future mods are going on my list of things that I look at in the morning that convinces me not to buy that extra cup 'o joe at Starshmucks =)

And I, again, oversaw the fact that I could use Honda master's instead of say, Brembo. My sources that I've been looking at don't have switches included and are extra, which to me is a kind of..... DUH thing to have.



The reason I'm going on such a "STOPPING" spree is because the KTM superduke that I rode had reaaaaaaaaaaaaaaaaly nice brakes and I'd effectively like to have a cheap(er) compromise.

Apples to oranges... or... Brembo to late-model Nissin, I know.

Tweety 05-29-2011 11:16 PM


Originally Posted by bass4dude (Post 304404)
Getting my 900rr Calipers in the post in a few days (Thanks again, Micky), have a 16mm Radial M/C and a double banjo pressure switch for the brake lights in my "shopping basket" (why do no radials have brake switches incorporated?!?! damnit.) and have some questions before I jump on the M/C

Now, couple of questions:

1. I've seen all the #s for the leverage calculations of piston size to M/C size but cannot make heads or tails of it. Which # gets divided or multiplied by which in order to get the leverage ratio? I've been doing it on paper and I couldn't get a feasible answer and I'd like to be able to know it before opting for a 16 or a 19mm M/C

The M/C has another number specified except the width of the piston, ie the length of the chamber... That gives you the fluid volume it pushes... Compare that to the fluid volume of the calipers... That gives you the ratio...


Originally Posted by bass4dude (Post 304404)
2. What is the maximum rotor size for the VTR with f4i calipers on it without extension plates for the calipers? they're the same as 2nd gen 900rr and I'm not in the mood to make some brackets although someone who has a CNC owes me some pretty expensive favors :evillaugh:

Well, since the new calipers sit at the same place as the stock one's, you cant really fit any oversize rotors at all without extensions... The shape of the calipers, being "open" to a wider rotor doesn't matter much when it's the perimeter of the rotor that's going to hit...


Originally Posted by bass4dude (Post 304404)
3. Stock rotor size is 296mm or something, 17mm offset, 6 bolt, but what is the bolt pattern (how many mm. between the center of bolts)? I've been looking around for the info but I can't seem to find anything anywhere and I, much like much of my generation, find it easier to spend hrs and hrs on the computer searching for the information rather than step outside for 30seconds and measure :D (I'm kidding, I love being outside and doing stuff but I can't really measure accurately on the bike ;))

What's hard about measuring accurate on the bike? Since the numbers aren't published in any place, the measurements you get from anyone else is also taken from the bike... And usually I tend to trust my own measuring over others, but I guess I'm odd...

A tip, measure inside of the bolt head, and outside... Then measure the bolt head in size and do some math and you have the C-C measurement, that's the same thing you do with the hole, inside/outside/holesize and math...


Originally Posted by bass4dude (Post 304404)
4. Just to double check, banjo is 10mmx1.25 pitch?

Now, THAT'S hard to measure on the bike... ;)

bass4dude 05-29-2011 11:23 PM


Originally Posted by Tweety (Post 304414)
The M/C has another number specified except the width of the piston, ie the length of the chamber... That gives you the fluid volume it pushes... Compare that to the fluid volume of the calipers... That gives you the ratio...

Thank you for that bit of info :) 20mm is the key here now I just need to put my thinking cap on!



Well, since the new calipers sit at the same place as the stock one's, you cant really fit any oversize rotors at all without extensions... The shape of the calipers, being "open" to a wider rotor doesn't matter much when it's the perimeter of the rotor that's going to hit...
See above comment hehehe.


What's hard about measuring accurate on the bike? Since the numbers aren't published in any place, the measurements you get from anyone else is also taken from the bike... And usually I tend to trust my own measuring over others, but I guess I'm odd...

A tip, measure inside of the bolt head, and outside... Then measure the bolt head in size and do some math and you have the C-C measurement, that's the same thing you do with the hole, inside/outside/holesize and math...
my digital caliper is at the shop and I'm trying to compile a shopping list, budget and what I have to sacrifice to get it (the devil is still getting back to me about the whole soul for a NCR)



Now, THAT'S hard to measure on the bike... ;)
HEY! I just wanted to double check, hence, "just double checking" :cool:
Wanted to make sure it wasn't a 7.327mm x .7mm thread

mikstr 05-30-2011 08:48 AM

16mm piston may be a bit small for those calipers (although this is piston size used on the F4i, it's an axial MC and I don't know what the leverage ratio is). Most Brembo aftermarket MCs are 16x18 and you have to fit a microswitch. I have a Discacciati 16x19mm (same piston size but slightly more mechanical advantage, so less lever travel) and have the microswitch for it. If you want it, send me a message (see my original ad in the classifieds, it's brand new and comes with titanium hardware).

As for the rotors, I think that once you fit everything together (along with braided lines and good pads, like Vesrah RJL), you will be VERY happy with the set-up.

cheers

Tweety 05-31-2011 02:23 AM

One option would be a stock CBR 1000RR M/C... It's 17.*** mm so it's in between the 16 mm and 19 mm pistons, and it's radial... And it has the switch built in like all OEM's...

smokinjoe73 05-31-2011 07:40 AM

Is there and echo in here?


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