Fork Tops

[BigZCas]

Very Strange, could anyone shed any light on this please.
When I purchased my Z1000a2 it had pneumatic valves in the fork top nuts.
I bought a pair of second hand replacement std nuts (I think ?) but when I tried to fit them today I found that the replacements were actually bigger than the nuts that I had remove.
Replacements diameter 30mm, the pneumatic ones that I took out looked to be 27 - 28mm.
I wondered if the replacements could be Z650 ?
(There was no air in the forks)
Thanks for any help

[warren3200gt]

650, 900 and 1000 had the same 36mm dia forks. My 650's, 900 and 1000 defo do.

[BigZCas]

I wonder if the Z1000a2 fork top threads are different from the Z1000a1?
The screw did changed from hex nut to grub screw type ?
Has anyone got an a2 that they could remove the plastic bung and measure the screw top, pretty please ?

[z1bman]

a1 had the aluminium fork top nut then it changed on the a2 on wards to the steel nut with the square in the middle & a rubber blanking plug fitted. your forks are more than likely an a1 set of forks

[BigZCas]

Deffo not a1 forks
are the threads different between a1 and a2 forks does anyone know ?
Thanks

[kev edwards]

Put a picture of the fork legs on here and the chances are you will get the answer you are looking for.

[BigZCas]

Ok there you go -
There first picture shows the fork tops with the nipple.
And before anyone says it "yes and the tit on the bike"
Thanks

[kev edwards]

Well you definately have A2 fork lowers, i have just measured the inside of an A2 top leg and before the thread starts it's id is 30mm so the thread is definately 30mm, if the grey coloured top does not go in, a previous owner has replaced the stanchions with some from a different set of forks.

[z1bman]

a1 fork inners

[BigZCas]

Would be nice if they were a1 inners, I could just buy some a1 Hex Nut tops.
Sounds to good to be true.
Will try to find the thread size for a1 forks ?

[BigZCas]

Looks like I got to get smaller diameter threads machined onto the grub screw type' hopefully enough material on them
Thank you both..

[000zeds]

Contact Z-Power by e.mail z@z-power.co.uk

A1 Inner tubes + springs are different to A2 so possible thread pitch on bolts differ

[kev edwards]

Z power sell the tops for the earlier forks, they fit from Z1 to A1.

[BigZCas]

Ok,
Just measured across the open part of my fork tops and they measure as Kev says 30mm so that means that the threads cant possibly be 30mm other wise the plain part of the grub screw type top would not slip inside.
Measured the silver grub screw type top and the thread is 30mm but the plain part is 33mm so no way would go into the forks either thread or plain part.
Must be different to the Z650 etc so the incorrect parts purchased from ebay.
Think I am going to have to pester Dave (Saisei) tomorrow !!

[z1bman]

i am sure the thread on the a1 fork tube is set deeper than the a2 the a2 thread comes nearly close to the top of of the fork tube where the a1 is set about 15mm below the top of the fork tube. the fork tops you have purchased are probably from an early gpz600 which have a similar fork top but they use 37 mm diameter forks. try john browse in wrexham he will know the part you are looking for