GPZ1100 A1 Uni Callipers on GPZ1100B2 forks and wheel

[Mr Bump]

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

Hello,

sorry to contradict you:

on Kawasaki.com part fiches B1 disk is 41080-1127, B2 is 41080-1038

B1 LH outer fork lower is 44005-1072, B2 LH fork outer lower is 44005-1094.

I know about this because a year or two ago I ended up with the same issue from the other direction - I had a B2 with a standard front end and unitrack callipers with 10mm spacers. The fork lowers were worn out and I replaced them with B1 lowers, assuming that they'd be the same. The callipers then wouldn't fit. It took a bit of head scratching to work out what was wrong.!

Funnily enough, it was this line in the Wikipedia entry for Gpz1100B2 that made the penny drop: 'The front disks of the B1 are 10 mm smaller in diameter and 1 mm thinner than the B2'.

Anyway, details aside, it looks like Roger has got the info he needs to proceed:

Use B2 280mm disks and make 10 mm spacers and weld them to the unitrak brake callipers, ending up with improved brakes that don't look out of place on the bike. Hopefully I haven't made any more errors or omissions....

Cheers all, I'm off for my lunch.

Olly

[Roger Hill]

Hi Olly
I can confirm your calculations.
If you Google GPZ1100 DISCS you will get conflicting information some sellers say that the B1 and the B2 are the same a few say they are different.
I spent about 10 minutes on the phone to Phil at ZPower and he did some checking.
https://www.z-power.co.uk/merchantmanag ... cts_id=655
The EBC disc MD4038 is 280mm 7 hole fixing and suitable for FRONT Z1000J3 Z1000R2 GPZ1100B2
I really did not want to throw £260 at a pair of discs just at the moment especially those with the naff yellowy gold finish.
Back to the shed for another head scratch to see if an engineering solution can be worked out.
I have still got to work out how I am going to graft a set of Z1000 clocks on to the top yoke along with standard handlebar clamps.
But have learned to tackle one problem at a time as I tend to get too pi**ed off with it if I have three or four problems on the go at the same time.
I also find it spurs me on to the next task when I am successful sorting something out.
I am going to place another Wanted request next just in case someone out there in Zed land has some 280mm discs they want to sell me.

[steve.w]

thought the bs had 270 discs ?? the unitrac 1100 has 280 discs I have a pair of 280s off a uni

[Roger Hill]

Hi Steve
I also thought that the GPZ1100 Bs had 270mm discs the same as the As and the Z1000 J but no they do not they have 280mm discs but still retain the 7 hole mounting unlike the A1 Unitrac that have 280mm discs but only 6 holes.

[Richard L]

Hi Roger
Can sympathise with you, I bought a B1 as a donor bike for my B2 and was amazed
at how many parts are different .. Luckily it was very cheap but I learnt a lot .
Don't ever make the mistake of buying a B1 tank for your B2 it also will not fit without serious alterations, and no sorry I have no spare 280mm discs just a pair of 270's like everyone else !
Richard

[z1bman]

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

Hello,

sorry to contradict you:

on Kawasaki.com part fiches B1 disk is 41080-1127, B2 is 41080-1038

B1 LH outer fork lower is 44005-1072, B2 LH fork outer lower is 44005-1094.

I know about this because a year or two ago I ended up with the same issue from the other direction - I had a B2 with a standard front end and unitrack callipers with 10mm spacers. The fork lowers were worn out and I replaced them with B1 lowers, assuming that they'd be the same. The callipers then wouldn't fit. It took a bit of head scratching to work out what was wrong.!

Funnily enough, it was this line in the Wikipedia entry for Gpz1100B2 that made the penny drop: 'The front disks of the B1 are 10 mm smaller in diameter and 1 mm thinner than the B2'.

Anyway, details aside, it looks like Roger has got the info he needs to proceed:

Use B2 280mm disks and make 10 mm spacers and weld them to the unitrak brake callipers, ending up with improved brakes that don't look out of place on the bike. Hopefully I haven't made any more errors or omissions....

Cheers all, I'm off for my lunch.

Olly

if you look at the parts listing for both bikes you will find two part no's for the brake discs on the b1 & b2 41080-1127 & 41080-1038 use the same discs