inboard disc

[Scooterlam]

Ive got an original disc which has got a hydraulic conversion.

The problem is the fixed pad cant be adjusted out to make contact.
What am I missing?

[Adam_Winstone]

D,

I'm not sure exactly what you're experiencing so am trying to imagine what your issue might be.

Is it that you've bench assembled it and the hydraulic piston is simply sitting too deep into the cylinder, meaning that the hydraulic side pad is not in the correct position and allowing the disc too far over? I'm not sure if this is even possible but I'm scratching my head with you. If this is the case then the hydraulic pad would find its own depth when you assemble it and bleed/operate it, and allow for you to set the static pad.

On the hub side, there should be nothing other than the grub screw, locking tab washer, nut and the static pad. Providing you've got these then there is nothing missing.

Adam

[HxPaul]

Why not ? Just undo the locking nut and screw in the grub screw until the pad makes contact with the disc,back off the grub screw 1/2 turn.

[Scooterlam]

Why not ? Just undo the locking nut and screw in the grub screw until the pad makes contact with the disc,back off the grub screw 1/2 turn.

Grub screw is already halfway thru the nut, just enough thread left.
Going by the lack of surface rust on the disc it's making full contact on the windows side back

[HxPaul]

Have you had the disc stripped down ? It sounds to me like you havn't got a fixed pad,or its very worn.

[Adam_Winstone]

You've not got dodgy thin pads have you?

[Scooterlam]

There's a fixed pad, a out 6-8mm plus the metal.
The piston side had worn away to the metal, both fitted at the same time.

[Scooterlam]

How thick Sholden they be.

[HxPaul]

Sounds about right.The only other thing is that the grub screw must be too short.

[Adam_Winstone]

Manual says 5mm new, replace when worn to 3mm, however, this refers to the brake pad and does not include the backing material, making it a pretty worthless bit of info without backing thickness details. This is made worse when Webster's old Scootering feature about setting up his hydralic inboard says that you need to watch out for some of the pads that dealers sell as their backing plate is too thin and can crack. He goes on to say that people fit shims to these thin pads but that it is really bad practice as the pad can become too thin, fall out and jam up the brake!

So, in light of the sh** info available from various texts, I've just popped out to the garage and can tell you that the one NOS pair of pads that I have from an old dealer (sadly that's all I got!) are 9mm thick. I also checked some worn used ones I have and the measure 7mm.

Adam

[Scooterlam]

It must be the adjuster. How do they come out?
Can still see the Allen key hole so it's not snapped at that end.

[Adam_Winstone]

Grub screw simply unscrews out. Pad you have to split the hub in half and take the disc out.

[Scooterlam]

Disc is split for new pads
I'll check the length of the screw.
I had a flick around the wider Web and some report different lengths of screws.
May be it's just inadequate length wise,
An allegation I've never had personally

[Scooterlam]

I took the adjuster screw out and it measures 20mm
It just doesn't have the length to push the fixed pad out.
Any ideas as to how long they should be.
It looks like an SX one that's lost its grease nipped.

[Adam_Winstone]

Just checked... can't find one to measure. Soz

[Scooterlam]

I read an article and a guy recons the one he had was 25mm and too long and needed a 20mm one.
I've got a 20mm and need a 25.
Co maybe the TV SX and gp are different.

[Adam_Winstone]

How thick are your pads?

[Scooterlam]

Fixed one is 8-9 mm floating pad flew out. Just metal left
Picked up a longer grub screw today.
Casa one is 20mm.
A 25mm one will let me use the pad till almost worn out but stop just short of the metal.

[Adam_Winstone]

Just another thought, has your disc been skimmed at some stage to reface it? It might be worth putting a vernier across the disc faces to see how thick the disc is.

Adam

[Scooterlam]

Nick had the same thought,
9mm for disc same as the one in his shed.