improving F2 brakes

redcliffs · 01-26-2004, 1:50 PM

Just picked up a 92 F2 last night for the track... has F3 Forks and a new Fox, so the suspension is pretty sorted, but the brakes are crap. I suspect that the pads are glazed, and the rotors are almost certainly warped, so I'm starting pretty much from scratch... What can I do to improve things? Already has ss lines, BTW... Can I put on F3 rotors? (still has an F2 wheel...) are the calipers between the F2 and F3 the same? Are there any three-pots that I can bolt straight on?

tia...

BDA116 · 01-26-2004, 2:33 PM

Put an F3 front wheel/rotors on it along with F3 calipers and master.
The F3's brakes are night and day better than the F2 setup. If it's just a track bike, get the rotors blasted and use the Galfer BR03 pads. You'll be happy with it then.

CBRBob · 01-26-2004, 2:49 PM

Quote:

Originally Posted by redcliffs

Just picked up a 92 F2 last night for the track... has F3 Forks and a new Fox, so the suspension is pretty sorted, but the brakes are crap. I suspect that the pads are glazed, and the rotors are almost certainly warped, so I'm starting pretty much from scratch... What can I do to improve things? Already has ss lines, BTW... Can I put on F3 rotors? (still has an F2 wheel...) are the calipers between the F2 and F3 the same? Are there any three-pots that I can bolt straight on?
tia...

If it has F3 forks on it, you already have F3 brakes on it. Maybe not the F3 master cyl. but the F3 brakes are completely different than the F2 brakes. F2 brakes have solid mounted rotors and the F3s are floating. The mounting points on the forks are different as the F3 rotors are larger as well. Bead blast the rotors like BDA said and some new pads. Do a good bleeding and you should be set.

TraumaOne · 01-26-2004, 4:55 PM

If you have F3 forks and F3 brakes, they won't work on and F2 wheel. Ask me how I know...

If it really has F3 forks and brakes, just sell the F2 wheel and put and F3 wheel on it. I think the first thing to do is sort out exactly what you have on there.

DCEMotorsports · 01-27-2004, 2:22 PM

My suggestion is put on a 929/954 master cylinder on the bike and use EBC FA*** "kit" race pads. You won't believe the difference. More stopping power than you can use at first. Be gentle!

redcliffs · 01-27-2004, 8:34 PM

so a little research has led me to the following information:

F3 brake calipers are the same from 95-98
F3 forks *may* be different in 95-96 versus 97-98
In any case, both are different from the F2.

Is all this correct?

If so, and if the information about F2 calipers and F3 forks being incompatible, then since I have an F2 wheel and what appears to be F2 brakes, then in fact I must not have F3 forks, but only F3 internals... is that right?

If so, I'll be a little pissed...

TraumaOne · 01-27-2004, 8:39 PM

Well, then you will have what I have.... And it works great for me... just try some new pads and bleed the brakes well. Should make a huge difference.

CBRBob · 01-27-2004, 10:21 PM

Quote:

Originally Posted by redcliffs

then in fact I must not have F3 forks, but only F3 internals... is that right?
If so, I'll be a little pissed...

No, They are completely different forks.

BDA116 · 01-27-2004, 10:37 PM

The only difference between the '95-'96 and '97-'98 forks is the year.
Yes, F3 internals can be placed into F2 forks. In fact, there isn't a whole lot of difference between the '94 F2 forks and the F3 - just a valving difference.

redcliffs · 01-28-2004, 3:34 AM

no, not much difference, you're right -- only the capacity to mount F3 brakes and rotors... anyone know of floating rotors (aftermarket, obviously) for the F2? I have to replace the rotors anyway, I think... and it sounds as though the best way to get more power is to replace the master cylinder, not try to deal with different calipers? thanks

DCEMotorsports · 01-28-2004, 9:26 AM

I think EBC has floating rotors for an F2 wheel.

I'm not sure if that is the way to go! ! ! The F2 calipers move on greased pins for alignment purposes - thus you don't need floating rotors. The F3 calipers are "fixed" and the rotors float.

I'm not sure of the exact dimensions of the F3 rotors vs. the F2 rotors? If the F3 rotors are a larger diamenter than the F2, that might be why the F3 brakes are better.

The F2 calipers are the same as the F3 calipers in that they are a "2 piston on one side" configuration. The F4 calipers are 4 piston and the same as the 900RR and the 929/954.

I think that the F2 and F3 master cylinders are the same. Actually, the F4 master cyclinder is the same as the F2 and F3. I'm using a 954 master cylinder on my F4 race bike and it is fabulous.

IMHO, if you have F2 forks and an F2 front wheel - replace the F2 rotors with OEM (salvage) if they are below the wear limit and/or warped. Remove the pistons from the calipers, replace the seals (keep 'em clean all season, very important). Use braided brake lines, Motul brake fluid and bleed the system. Install a better master cyclinder (929/954) and have fun.

redcliffs · 01-28-2004, 12:08 PM

sounds like a good plan -- thanks for all the input!

FWIW, I just learned that EBC does make floating rotors: an "oversize 310mm conversion" complete with special mounting bracket (presumably for the calipers...) Don't know if I will bother doing this, or just get replacement rotors (they are warped, I think), but it is interesting to know -- sounds like if the calipers are the same that you can get pretty close to or meet F3 braking... thanks again

CBRBob · 01-28-2004, 12:36 PM

I had that kit on my F2, it was great. The bracket moves the calpiers out to meet the larger rotors. For street riding, it's overkill.

redcliffs · 01-28-2004, 12:57 PM

Quote:

Originally Posted by CBRBob

I had that kit on my F2, it was great. The bracket moves the calpiers out to meet the larger rotors. For street riding, it's overkill.

thanks for the feedback -- I can see it not being worth it for street riding, but being used to a 929's brakes on the street, I think I'd like a little more oomph on the track (maybe...)

TraumaOne · 01-29-2004, 12:06 AM

I just rebled my brakes, put some Vesrah pads on them and they rock... you can get cheap front discs on ebay. Heck, I have a set I'll sell ya cheap

redcliffs · 01-29-2004, 12:30 AM

F2 rotors? but your tagline says you have an F3... anyway, might well be interested -- condition? price? feel free to pm me if ya want...

Quote:

Originally Posted by TraumaOne

I just rebled my brakes, put some Vesrah pads on them and they rock... you can get cheap front discs on ebay. Heck, I have a set I'll sell ya cheap

Trouble · 01-29-2004, 10:50 AM

You may already know this, but maybe not and perhaps it'll help you sort out what components you have on your bike:

The F2 drives it's speedometer from the front wheel -- the F3 drives internally from the motor (don't know where/how). So if you look at the left side of the front wheel and see a cable exiting from about the 4 o'clock position off a 'wheel spacer', you are running an F2 wheel. If you swap out your F2 wheel, you'll lose your speedometer. This isn't a really big deal, bicycle speeds work really well, they're just a pain to install -- but that's another thread.

The left fork lower on F2 forks have a little 'teat' that prevents the speedo drive/wheel spacer from rotating when the wheel turns. You need this feature to make the speedo drive work. F3 fork legs don't have this teat.

91 - 93 US F2 forks used damping rod internals. '94 US F2 forks used cartridge internals and are internally the same as F3 foks. The cartridge forks have a rebound adjuster at the top of the fork tube, the damper rod forks do NOT.

F2 brake rotors are solid (meaning one physical piece) and flat as a pancake. If you question that your rotors are flat, remove them and place them on a (truly) flat surface. Any warps or other defects are clearly obvious. These solid rotors will 'cone' if you really over heat them, this was one of the advantages of the floating rotors and a motivating factor to make the change.

F2 calipers have a distinctive appearance from any F3 caliper that I've seen, but the difference is difficult to describe clearly to someone who has never seen both side by side. The F2 calipers use bolt holes that are cast as part of the caliper body, much like a 929/954 to mount to the fork legs. The F3 calipers have something that looks (to me anyway) like the 'rocker' from a rocking chair that runs along the bottom of the caliper, and the mounting holes are located on this rocker. The Ron Ayers microfiche for '96 - '97 clearly show the difference. There is one caveat here -- the fiche show the 95-96 F3 calipers to be the same as the F2 calipers. I have no experience with that, so can't comment.

Too much information?