clearance caliper to fit rotor? Brembo WSBK Narrow band stuff....

[TAftonomos]

I've still got these rotors here after more hassle than I know what to do with.

Since I've got them, I'm going to make them work (if possible) on my bike.

Rotors are Brembo WSBK narrow band, 320 x 6mm.
Front end is a mid 2000's ohlins setup. The calipers are from a 1098.

Now, with the rotors bolted on and centered on the caliper, there is very little clearance between the caliper body and the rotor itself. Maybe .5mm on either side. The rotor can float, and if moved by hand it looks like it might just touch the caliper body. It's not making a noise, but it's DAMN close.

After removing the caliper, I can easily see where there is material I could remove without too much trouble. Terrible idea?   Other 2 options include finding a buyer for the rotors and getting some different/proper thickness ones, or coughing up $1500 for a set of HP calipers (GASP).

[stopintime]

Would it be possible to machine the rotors down a mm without damaging them?
Maybe .5mm off the calipers isn't too bad? Doesn't sound bad, but I'm no expert!

Or sell the stock calipers to part finance HP ones?
(I'm sure that would make you happier in the end)

[TAftonomos]

I'm not going to spend another $1500 on the bike for calipers....I'm nearing completion with this one and have my eye on other projects which need $$$ and attention.....this one has gotten enough of it so far.

As far as machining the rotors....Dunno about that.

[TAftonomos]

Not mine, but representative of about the amount of clearance I have from the caliper body to the rotor.

My questions are ....is this OK?

Other one is, since the spacers I had made up my be a smidge off one way or the other (I'm talking .2-.3mm), will that cause a problem?  The rotors are full floating, but I'm curious if the pads/pistons in the calipers would compensate for something like that....

[jim_0068]

i'd try to talk to an engineer, all of that is going to heat up and expand and tolerances are going to get even tighter.

[gatorgrizz27]

If it is just part of the casting mount and in a fairly small surface area, I would remove about 1mm from either side to get that clearance a little bit bigger.  Would it be doable with a pneumatic file?

[TAftonomos]

I can add some clearnace if needed.  Mine arn't quite that tight, but not much more.  I think I've got ~.25mm worth of space on each side.

What about the centering question?  The pads squeeze on the rotor, in theory they shouldn't be pushing the rotor side to side at all correct?  Therefore a slight offset issue would be in affect, self correcting?

[DarkStaR]

I can add some clearnace if needed.  Mine arn't quite that tight, but not much more.  I think I've got ~.25mm worth of space on each side.

What about the centering question?  The pads squeeze on the rotor, in theory they shouldn't be pushing the rotor side to side at all correct?  Therefore a slight offset issue would be in affect, self correcting?

The pistons will make up for the difference.  It's possible to get the difference you mention just from pad wear.

[BK_856er]

Does "narrow band" refer to the rotor thickness or the pad contact area?  My Brembo narrow band rotors are 4.5mm thick.  Looks like you are combining "thick" 6mm rotors with calipers designed for thinner (maybe 4.5mm?) rotors?

As for your centering question, my understanding is that the caliper is self-centering and the opposing pistons will equally squeeze.  A small amount of caliper offset should not be a problem.

Sorry, nothing really useful to add here.

BK

[TAftonomos]

Thanks guys!  Yeah, AFAIK they are called narrow band because I have no idea...HA!

They are 320x6mm, so thicker yes.  Designed to be used with the Brembo HP calipers which I no longer have.  Really designed for a race bike, but I've been unable to sell them so I'm stuck with'em/reason I'm using them.

[DarkStaR]

From what I gathered so far:

The contact surface is narrower which results in a weight savings.  The pic posted above is what happens when a narrow band rotor is used on a wide band caliper.  Note the rotor button interfering with the pad.

Wide band rotors can be used with narrow band calipers.

Narrow band rotors can be used with wide band calipers, but the pads have to be modified.

As for the rotor thickness of 4.5, 5, 5.5, and 6, ... I haven't figured that out yet...

[hooligan machinist]

 If it has anything at all to do with the spacers i made, i'll happily correct the problem for you.

[He Man]

I would say no to 0.25mm

Thermal expansion is probably a very small part of it. but your whole front flexes from hitting bumps or when u slam on the brakes or just from really getting into a corner hard. Im sure you can get very close to eatting up 0.25mm just from flexure + a little bit from thermal expansion.

That's just my educated guess.

[junior varsity]

From what I gathered so far:

The contact surface is narrower which results in a weight savings.  The pic posted above is what happens when a narrow band rotor is used on a wide band caliper.  Note the rotor button interfering with the pad.

Wide band rotors can be used with narrow band calipers.

Narrow band rotors can be used with wide band calipers, but the pads have to be modified.

As for the rotor thickness of 4.5, 5, 5.5, and 6, ... I haven't figured that out yet...

+1.

And the pistons/hydraulic system will self center about the disc with no left-to-right force. Even when rotors warp, the perceived feel should be a pulsation, not from the rotor really being pushed one way, but from it dragging against the pad it begins to interfere with, so what i mean to say is that with respect to that, you'd be good.

i believe 6mm is thicker than normal. 4.5-5.5mm is normal.

the clearance between buttons and caliper are the biggest issue i can think of here.