GPZ1100 A1 Uni Callipers on GPZ1100B2 forks and wheel

[Roger Hill]

I have transferred this to the Bike help section from the Wanted section.
I hope you guys can help/advise me.

I have a what I believe to be a set of GPZ1100B1 forks and a GPZ1100B1 wheel with 270mm disks .
It has been said that GPZ1100 A1 unitrac callipers are a straight replacement for the original calipers and are a great improvement as well.
I have tried the A1 calipers on the forks and find that they will fit with a set of spacers around 10mm wide as the bolt spacing is the same as the B1.

This picture shows the caliper bracket on the forks and the gap between the bracket and the mountings on the forks of aprox 10mm



When the caliper bracket is installed and the pads fitted the pads are not aligned with the disk and are slightly high particularly at the top indicating that the caliper is not aligned with the disk.
G][/URL]IMG][/URL]
I can correct this partially by filling and redrilling/tapping the holes with around a 6mm offset to the caliper mounting holes if necessary.
Has anyone else had this problem and what did you do ?
I am glad that I found this our before restoring the calipers.
Think that covers it.
Thanks
Roger

[Coose]

If you drop out the top bolt can you rotate the bracket on the bottom bolt so that the pads line up? If so, you could swap the brackets left to right and redrill as suggested.

Spacing off the calipers will not be a problem so long as the bolts pass through the brackets completely.

[Roger Hill]

I have had more of a look this afternoon.
If I clamp the pads to the disk in the right place using large vice grips with them located in the caliper mounting both holes are out of line.
I did try replacing left for right but this did not help.
If I have to I will fill the holes and drill and tap new ones .
I just wondered if I had missed something somewhere as it is definitely out of line both sides.

[Taffus]

Those do not look like b1 brakes to me, these are what are fitted to mine

[Mr Bump]

Now, looking at these photos, I have to confess that I was wrong when I stated that they bolted straight on - I'd forgotten all about the 10 mm spacers I made up and welded to the carriers!

Apologies for misleading you - I'll post a correction on yr other thread too so that I don't lead anyone astray in the future. Oops.

Looking at your photos - is there any chance you have B2 fork legs and b1 disks? I've just nipped out to the garage with a tape measure:

B2 disks are about 280 mm diameter, b1 lower caliper lugs are 50 mm above the center lineof the ffront axle. Ive got a set of shagged b2 forks I could measure too, but they are a bit buried.

The slight misalignment front to back would be explained by the different disk diameter.
Have you ever had the original calipers fitted, and how did they line up?

If you do have a mixture of b1 and b2 disks and legs the standard calipers wont fit either.

As I said, apologies for the misleading info.

Olly

[Taffus]

Legs are B1, disks are PFM cast disks (brilliant upgrade to the braking)
The PFM disks tend to rust as you can see but clean up in a mile or so
I'll try and get measured up

[paul doran]

I have a set of J calipers if You need them

[Roger Hill]

Hi Taffus/Paul
I think we may be getting our lines crossed a bit here.
Olly was referring to my set up when he said about the spacers.
But I think he has sussed out the problem.
I have got 270mm disks.
The wheel did not come with the forks and may well be a B1 wheel.
so I need 280 disks this will be the equivalent of moving the calipers in 5mm and that would make a big difference as the whole of the pads would be bearing on the disk.
This will teach me to pick and mix parts from different bikes.
anyone got a decent set of 280 disks to sell ?

[Taffus]

The pfm disks are 280 but not for sale, I have some 270s

[z1bman]

brake disc's are the same part & dimensions on most of the 1100's including b1 & b2

[Roger Hill]

Now I am totally confused.
Can you tell me if any Kawasaki models use 280mm discs with the same mounting as the 270mm discs ?

[z1bman]

according to my EBC brake rotor reference the b1& b2 are fitted with 280mm disc's & they both share the same kawasaki part no's

[Taffus]

according to my EBC brake rotor reference the b1& b2 are fitted with 280mm disc's & they both share the same kawasaki part no's

#
I wonder where I got the 270's from.... they are definetly 270 so my original ones are safe somewhere

[Coose]

They could be J discs perchance?

[Taffus]

They could be J discs perchance?

I don't honestly know