PFM cast iron discs on 1150GS

guzzimag

guzzimag

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A quick post from a new 1150 GS rider (got it Saturday morning, bought from a top man through this site)

First off - bloody hell what a bike :D I ragged it across the Peak district for several hours and am amazed how such a heavy tall bike can be flung around and remain utterly composed. Fantastic! Already at the edge of the tyre and never felt remotely on the limit.

One thing I'll need to do is replace the front discs as they are slightly warped. I noticed that Motorworks do PFM cast iron discs - are they better than OEM? My guzzi's are fitted with cast iron as standard and work very well, but suffer wet weather lag.

Anyone used them, any cop?

cheers

Magnus
 
a friend of mine fitted a cast disc to the rear and it warped:rolleyes:
 
Only if you use the brakes :D :D

It's a lardy old lump and I would guess the brakes don't get an easy time if you use them hard. Try not to hold the brakes on when you're stopped after a right royal thrash. Holding the brakes on when they are really hot can warp them (or so I've read).
 
I usually use hedges to slow myself down :D Saves on pad wear and most of the scratches t-cut out.

Iron or stainless is the question now come on you rabble lets have some order here.
 
It's generally acknowledged that cast iron discs perform better than stainless discs, but they just look so fecking ugly on a bike once they have started to rust on the non-rubbing surfaces.

Greg
 
cheers for the link - think i'll be PM ing Steptoe in the next few weeks. £130 a side from BMW is a bit rich. Still tempted by cast iron for the better bite, but they do end up looking very manky.
 
Had cast iron PFMs on my K75s. They had less lag in the wet, I really liked them - they did look dreadful if left unused (even over the weekend) but as I use my bikes daily during the week, and quite frankly, the state my GS is in cosmetically, it would be less of an issue.

One thing to beware of though, when I had to take it to the BMW main dealer, they went on and on and on about them. Wouldn't service the bike without insisting on putting new pads in (even if the old ones were fine - 'these iron disks wear out pads in no time', have to put new ones in blah blah blah)

Then when I p/ed it for the GS (had to use them, they had done an accident repair which had left the bike eating clutches every 1.5k, wasn't prepared to sell it to anyone else) they went on and on and on and on and on about the 'non-standard' disks, disks are a safety item, we will have to replace them etc etc etc.

Needless to say they then sold it with the PFMs still on.

Much as I liked the discs, the grief I got over them would make me think twice about using them on any bike that I might have to take near a BMW main dealer - ie any bike under warranty.
 
I've got one on the rear of my 1150, feels good after only just running it in. I find a light coating of oil helps to keep it looking good in the wet:D:D :D
 
guzzimag said:
I usually use hedges to slow myself down :D Saves on pad wear and most of the scratches t-cut out.

Iron or stainless is the question now come on you rabble lets have some order here.
Click to expand...

You're going to fit in a treat on here! :thumb
 
Fitted PFM discs to front and rear of my 1100 and was impressed with them. They worked out cheaper than the OEM ones as well which was a bonus.
Just have to get used to them going rusty as soon as you stop and having rusty coloured boots if the bikes been stood a bit.

Can't comment on whether they'll last longer as I joined the dark side last year and swapped it for a 1200. :D

Top advice given by the blokes at Motorworks when I rang them about new discs and pads.

Andy
 
I uprated the brakes on my R80GS by fitting a 4pot caliper from a K series & a PFM disc. The rusting was a royal PITA, but worst was the fact that they pitted & warped twice. I sent the disc back to M/works & ended up getting a phone call from PFM to ask about the problem, so I was impressed that they were following up on the issue. They explained that under extreme heat, the cast iron can precipitate the carbon from the metal & this leaves pitting on the surface... They then asked if I was a demon braker!!! On an R80GS!!! Moi?? :rolleyes: Anyway, they gave me some excellent advice to fit AP Racing pads as they had tested every make of pads & found that AP gave by far the best results for initial bite & grip, without completely knackering the discs & with decent life expectancy. I've used them ever since & they work really well , but get even better when they're good & hot...

Never had any probs with them warping the discs after that, either.
 
Magnus

Are discs definitly warped (checked on a flat surface) or do you think they are warped because the brake leaver pulses.

When I went for my last MOT they failed it because the brake dial was fluctuating too much, indicating warped discs. Tester then got some brake cleaner (alcohol??) and thoroughly cleaned both front discs then re-tested the braking and lo and behold 'warped' discs no longer.

Possibly worth a try before shelling out on new discs.

Steve
 
I've got cast iron

I fitted them because the standard ones warp
yes indeed around the edges they go rusty and if you put the bike away with wet discs they will sieze overnight (keep a large hammer next to the bike and then tap the calipers with the handle, this provides the weight needed but doesn't damage the calipers) if its only overnight then pushing the bike off the centre stand will free them.
the discs are far superior to the standard ones in braking power , wet or dry and you don't need all those holes in them.

top conversion, go for it , unless you want to spend lots of money replacing the standard crap ones with more crap ones


and no trouble with the dealer in bristol servicing the bike with these discs on

Rob
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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