Disc carriers

[Andy]

This is how I fitted 320mm discs to my SF2 hub ... no small amount of work. The underside is where it got really complicated. In hindsight there were many other easier ways to fit them plus the 22mm axle for the OW01 front end!! But I learnt a lot about my lathe and the finer points of machining (from very little base knowledge).

You’d be well proud of that!
Worth letting the extension slide for that mate

 

[ozijotati]

320mm discs with the correct offset for our old clunkers can be found on the early YB series Bimota’s and I think they were also fitted to 851 Ducati’s as well . Maybe the Guzzi sport 1100 as well, not too sure on that but do remember seeing them in the Guzzi section on th Stein dins website HTHs.
Tom

 

[Dellortoman]

Hi Tom. I think you're correct that the B series Bimota, 851 Ducati and Guzzi sport 1100 all used the same front disk, but it won't fit a Laverda wheel. For a start, the hole in the middle is too small at 64mm (we need 80mm) and going by the photos they only have a shallow offset of a few mm, certainly not 27mm.

Modern floating disks are probably available that'll bolt straight on, but they're hard to find because very few sellers provide enough information. They just say what model of bike it's for and leave it at that. They sometimes give the centre hole size, and less commonly the bolt PCD, but almost nobody lists the offset among the dimensions.

It's a frustration I come up against with all sorts of parts. Even simple generic stuff like brake light switches. Conversations in parts shops go like this.
Me: "II need a hydraulic brake light switch with a M10 x 1 thread."
Shop dude: "What's it for"
Me: "Well, it's actually for a Laverda motorcycle, but that's not relevant"
Shop dude: "Nah, sorry. We don't carry any parts for Laverda motorcycles"
Me: "It's just a generic part that fits heaps of models of bikes and cars. You'll probably have boxes of them your stock"
Shop dude: "Unless you can give me a make and model I can't help you"
I go away and do some research, then come back.
Me: "I need a hydraulic brake light switch for a VW Beetle"
Shop dude: "What year?"
Me: "Oh, I dunno ... 1964"
Shop dude: "What's the VIN number?"
Me: "For fucks sake, just go and get a VW brake light switch off the shelf. I don't care what year or model or fucking colour"
Shop dude: "There's no need to be rude sir. I'm only trying to help"
Me: "You're being a fucking idiot"
Shop dude: "I'll have to ask you to leave now sir"
I go away and come back later with an AK47

 

[piranha-bro2]

But sadly true!!

 

[Andy]

 

[piranha-bro2]

I've been making a habit of ringing retailers to check stock showing as 'available in store' rather than make the journey to buy only to be disappointed seriously pissed off.

 

[helicopterjim]

View attachment 63504

Myself and the mechanic I worked with were in Mexico and trying to collect parts for the helicopter. We could see the wooden crate with the company logo on it but the girl gave us the Spanish "¡La computadora dice que no!". Darryll started coming unglued and tried to crawl over the counter. Security was called and we were escorted out. The next day we were told the the cargo had finally arrived and we could come and collect it.

Jim

 

[Andy]

I'm interested in this, and a previous thread about brake pads, because I don't like the way mine perform in the wet.
I didn't know anything about this previously and just bought any old pads as and when I needed them, but now I've done a bit of research. Sintered pads give significantly better wet weather performance, but are known to wear iron disks faster. Organic pads are recommended for iron disks but don't do very well with stainless disks.
So if replacement disks are rare and expensive, then I'll get the best organic pad I can find (Ferrodo Platinum seems to review quite well). If original fitment disks are readily available when they wear out, or it is reasonably easy to get a stainless steel replacement, then I might change to sintered pads.
Are original disks rare? What replacement options have been used successfully without too much alteration? And do the calipers need to be changed too? Do cast iron disks really wear out as fast as people say?

 

[ozijotati]

Hi Cam, after a little searching I can confirm that the 320 mm rotors on the yb4 through to the yb8 will fit our old clunkers. They are 101.5PCD and have an 80mm centre bore. I was incorrect on the Ducati and Guzzi discs but in my defence I did say that I wasn’t sure. Still you can’t always be correct can you.
Tom

 

[Dellortoman]

Thanks Tom. That's worth knowing.

 

[Paul Marx]

I'm interested in this, and a previous thread about brake pads, because I don't like the way mine perform in the wet.
I didn't know anything about this previously and just bought any old pads as and when I needed them, but now I've done a bit of research. Sintered pads give significantly better wet weather performance, but are known to wear iron disks faster. Organic pads are recommended for iron disks but don't do very well with stainless disks.
So if replacement disks are rare and expensive, then I'll get the best organic pad I can find (Ferrodo Platinum seems to review quite well). If original fitment disks are readily available when they wear out, or it is reasonably easy to get a stainless steel replacement, then I might change to sintered pads.
Are original disks rare? What replacement options have been used successfully without too much alteration? And do the calipers need to be changed too? Do cast iron disks really wear out as fast as people say?

Cast iron discs wear fast with sintered pads, otherwise, they'll last a lifetime.

Phil Todd made some discs from cast iron bar. Malcolm Cox is currently having discs made, so can be done.
We'll have to get used to DIY if we want to keep our Lavs running.
Paul

 

[redax5]

Metalgear in Brisbane sell stainless version rotors to suit the Laverda carriers and work really well with sintered brake pads
Been using them for years with no issues at all, far better than the cast iron version

The 320mm rotors we use on our race bikes are Metalgear supplied, very good kit

When we built Mike's Mk3 Motodd we used Ducati Multistrada Showa upside down forks mated to 1986/7 Slabside GSXR 18" rims so we had to machine our own brake rotor carriers as they were a custom offset, bolt patter which we did to match a 320mm Ducati rotor using the Ducati carrier design as the basis
Went over to Metalgear and the owner Bernie told us that we were the very first customers that he had ever had that turned up with custom machined rotor carriers to have rotors fitted to them
He gave Max and I a guided tour of his set up, not a bad at all

Brake Disc Rotor outer - MetalGear

Brake Disc Rotor outer - MetalGear - Replaces 70777343, 80277340 MetalGear brake disc rotor can be bolted straight onto the original centre re-using your original bolts. You must check your centre for accuracy before fitment.

www.metalgear.com.au

 

[The Sock]

Cast iron discs wear fast with sintered pads, otherwise, they'll last a lifetime.
Phil Todd made some discs from cast iron bar. Malcolm Cox is currently having discs made, so can be done.
Paul

Not quite a lifetime, Paul.
I'm on my third set of front discs, second ones were a set of Todd's Spurious Specials which lasted much longer than the OEM ones but, eventually, made < minimum thickness.

 

[Paul Marx]

Not quite a lifetime, Paul.
I'm on my third set of front discs, second ones were a set of Todd's Spurious Specials which lasted much longer than the OEM ones but, eventually, made < minimum thickness.

I should think that there's a huge margin after minimum thickness. My SF2 is on it's original discs. They'll outlive me no doubt.
Paul

 

[piranha-bro2]

I should think that there's a huge margin after minimum thickness. My SF2 is on it's original discs. They'll outlive me no doubt.
Paul

True, but RWC, MOT - whatever you call it in your country - inspectors - will measure them. I use an undersize 280 on one of my rear disc conversions - fitted to a Kwaka Z1000 rear hub and alloy disc carrier.

 

[Dellortoman]

Blimey. I've never had a roadworthy inspector even cast a glance at a disk, let alone measure it.

 

[The Sock]

I should think that there's a huge margin after minimum thickness. My SF2 is on it's original discs. They'll outlive me no doubt.
Paul

I've had two brake pack failures on Cessna Citations (suspected bad batch, but it was never admitted to), where a section of disc fractured and locked the wheel.
Both times, fortunately, at low speeds but it's not something I would risk on a motorcycle, Paul.
If there's a specified minimum thickness, I will respect it.

 

[piranha-bro2]

On a drum brake SF1 the RWC guy was obligated to actually remove each wheel and photograph the shoes after measuring them and the drums!!

 

[Paul Marx]

True, but RWC, MOT - whatever you call it in your country - inspectors - will measure them. I use an undersize 280 on one of my rear disc conversions - fitted to a Kwaka Z1000 rear hub and alloy disc carrier.

We don't have inspection of motorcycles here.
The government wanted to apply an EU ruling bringing in inspection on motorcycles.
Too many motorcyclists out in the street protesting and arguing that the minute proportion of badly maintained motorcycles were not a road hazard.
The plan was cancelled.

Paul

 

[Paul Marx]

I've had two brake pack failures on Cessna Citations (suspected bad batch, but it was never admitted to), where a section of disc fractured and locked the wheel.
Both times, fortunately, at low speeds but it's not something I would risk on a motorcycle, Paul.
If there's a specified minimum thickness, I will respect it.

One of my sons had a disc break up on his car due to lousy work from a garage.
I'll risk it.
I eat yogurts past thier sell by dates and take medications past theirs as well.
And eat very smelly cheese.

Paul