Iron discs...

[chris_of_1979]

Wonder if you guys can help shed any light on my latest issue.

I'm running the cast iron full-floating brembo discs (standard fitment on my sps) which when I bought the bike were spot on.

Last year I replaced the standard pads with sintered race compound pads from Ferodo - beliving that as usual, the sintered pads would offer the best performance.

However, they don't perform as I expected. I've run the for about 2000 miles now, so there can't be any further "bedding in" needed. They work very well from higher speeds (when warm of course), but I don't seem to get any real bite when coming to a complete halt, and "stoppie's" are out of the question - in fact, rather than getting a crisp and clean bite, and being able to lock the wheel - all I get it a very load noise from the disc slipping through the pads.

Bled the fluid and checked the calipers - all seems to be fine - so I'm guessing its just a bad combitation of pads and discs.

My query though, revolves around something I saw in a magazine recently, advising that on iron discs, only organic pads should be used, and not sintered ones.

Does anyone know if there's any truth to this?

[DJ Tera]

There was another thread where someone used sintered on his iron discs, f*cked them up a treat!

[Felix]

I think it's easy but often misleading to draw general conclusions from brake setups that are not performing properly for one reason or another. For instance, I know a number of people who run EBC HH (a sintered pad) with the brembo cast iron floating rotors with very pleasing result. That is not to say that you can have problems with that combo. Maybe organic pads are the recommendation. If you were to change pads and the problem goes away, it would be easy to say that Ferodo sintered pads are no good with cast rotors. But clearly some people have success with that combo.

I would try to figure what it is first. Are your rotors badly scored? Are they slightly warped? Maybe the pads have glazed over (my guess) and need removing roughing up with course sanding paper. I would definitely give that a try unless your rotors are warped or badly scored, in which case they need replacing.

Brakes are a funny thing.

[yeti]

Chris, I ran cast iron discs with sintered pads and it wrecked them within 1500 miles. Considered opinion from others seem to be that sintered pads and iron discs are a no go. Certainly my experience has been just that. Further research has indicated that cast iron rotors can be a bit suspect after a time because they can quite litterally explode with pretty dramatic consequences. There could well be some truth in this because Brembo stopped making iron discs about 4 years ago.

Am reliably informed that the new type "cast stainless" are every bit as good and work well with sintered pads. Having just bought a set last night, i let you know the result!

:borg:

[adam]

I was informed that with the PFM discs you could use the Bendix sintered, those were the only ones recommended, though someone will probably say otherwise.

[Jon]

I'm very happy with the PFM cast iron disc's and Bendix pads recomended.

In hignsight I should have gone for the cast stainless steel items. This is mainley due to the fact that even when just washing the bike any water getting onto the disc, immediately starts to rust. Its no problem to rub it off, just that it's all those little places you can't get to unless you remove the wheel and release the disc's from the carriers.

Jon