Fork differences Z1000J / GPZ1100 B2

Hi everyone,

My last topic got deleted due to the update, so here I go again. I've found quite a bit information already, I own a KZ1000 J from '82 according to the VIN.

I'm looking for a set of original forks with the air control valve on top of the tubes. Now I might have found a set of forks from a GPZ 1100 B2.

I cannot find out if they are interchangeable or not. Wikipedia says that the mounting points of the B2 is different because they use a larger front brake disc.

CMSNL gives me a range of parts numbers, which seem the same. I don't know if I can swap the wheel over that easily since there are differences between electronic and mechanical speedo drives. Plus, I don't know if I can re use my headlight brackets from my Z1000J on a GPZ1100 B2 fork since they have the equalizer tube just above the lower triple tree..

Anyways, thanks already for the advice.

Cheers

I don't know if this will do you any good, but the diagrams at Partzilla are easier to use than most other places. signing-in makes them a little easier, but not necessary. click the diagram reference number or part number for the cross reference. From checking various fork & brake parts it seems that the J1/J2 & 1100-B1 share some of the same parts, while the J3 & B2 are similar to each other. It may be that some of the J3 & B2 parts supersede the earlier part numbers, but I have no idea if any would be interchangeable.
note: the partzilla x-ref isn't 100% accurate, so I always double-check stuff at Kawasaki.com if possible.

As for the fork lowers & brake rotors, maybe you can find the dimensions of aftermarket rotors to see if they are the same. If the diameter is the same, then I'd guess the fork lowers are interchangeable. ???

Wikipedia says that the mounting points of the B2 is different because they use a larger front brake disc.

The B2 discs are 10mm larger, probably the caliper mount brackets different - this is a part numbers research thing, I'm pretty certain the fork bodies are the same. The 280mm discs are the ones to go for.

My ELR is wearing B2 forks; IIRC 10mm length difference, top air valves or air linked differences.

Well, I've been comparing the part numbers and honestly, they are the same. I'm also guessing that it's the caliper mounting bracket that is different. When I check it on ebay it seems there might be a difference, but maybe also not. I couldn't even find any part number on the bracket itself. Not on any diagram. When I check part numbers from the lower forks, llower triple tree, and brake discs between B2 and J bikes they are all the same. But then again, they give the part number a letter from A to C and don't specify the details.

Tyrell Corp, the forks from the B2, are they 10 mm shorter or longer?

I might just go for the B2 forks since someone not very far from me offered me a set in good condition.

Thanks!

From memory J and R models fork stanctions are about 10mm shorter than the GPz .

IIRC The B1 and earlier zeds had the 270mm disc, the b2 had 280mm discs.

The 260 / 270 /280mm 7 bolt discs are all interchangeable on the 19" front wheel, caliper mount differences I'm not sure about. Both my 550 and 1000 have big 280mm front discs on them, I think maybe unitrack calipers.

Ok thanks a lot for that info. I have one last question..

I have the upper triple tree from the J model. Can I mount it on a B2 lower triple tree? Or is the offset different? I have someone saying it is different.

Thanks for this last question .

Hi all,

Still desperately looking for an answer.

Anyone knows if the lower tree T piece from the J series is different than the GPZ B2? I have someone saying the offset is different and that the top triple tree plate from a J series will not mount on a GPZ B2 series. Part numbers are the same though.

Also, can I just buy standard 38 fork caps to mount on the B2 forks, instead of those standard fork caps? I will be mounting the J series handlebars on top.