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zx12 A2 to zx14 A7F fork swap project

32K views 86 replies 19 participants last post by  Paul tankard 
#1 ·
Hi all my front end on the old 12 has not been feeling to grand as of late so i am treating her to a new front :lol:
I am waiting on the forks triples and calipers from an A7F zx14 to turn up this week, but in the mean time i have stripped the old setup from the 12.












I have noticed that the top bearing on the steering stem is smaller the the bottom bearing on the stem 25mm top internal diameter and the bottom is 35mm ID.
This means that i will have to machine the zx14 steering stem to accomodate the smaller top bearing. Newer generation 12s have the same size bearings top and bottom so its nearly a straight swap to my annoyance !:rant:







Will post some more progress in the week when the forks arrive.
 
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#3 ·
The stem on the 12 is one very tight fit and will need a press for sure to remove.
Im going to see if the diameters are the same then i will make the decision wether to swap the shafts or just machine the zx14 one to suit as i have access to a machine shop to turn and thread the correct diameters.
Thanks Mr Kawasaki for making thing a bit more difficult !
 
#6 ·
Got both my front and rear zx14 wheels and rear calliper and will test mount the rear tomorrow to see if the calliper will fit on my zx12 arm.
The steering stem can be pressed out and used in the zx14 yoke as i have today spoke to someone who has done it so for all those that want to do this conversion on their a1 a2 it can be done with relative ease.


 
#9 ·
Right more progress today.
The zx14 rear wheel is a straight swap using the zx14 disc and calliper the sprocket pcd is the same on zx12 and 14 as is the cush drive but they look slightly different,Spindle is also near identical with different chain adjusters only which still fit.Everything lines up perfectly.









zx14 cush drive fitted to zx12 wheel for comparison





 
#11 ·
On the front yes, but no issues on the rear if you use zx14 caliper and disc its straight swap as the zx14 rear disc is bigger and looks as if it is offset a little more on the zx12 wheel so you would have to do some modification to the zx12 calliper mount if you wanted to go down that path.
The spacers on the zx12 and rear spindle are identical to the zx14.
Front requires a lot more work as i will be detailing over the next week.
 
#12 · (Edited)
Right today i have taken the stem out of my zx12 triples which was easy !










Did a few measurements on the zx12 and zx14 front wheel spindles and they are pretty much the same apart from the spacers on the zx12 they measure 21.5mm on the zx14 they are 13mm. The zx14 spacers are crap and made out of alloy so will wear and corrode very quickly so I'm going to machine the steel zx12 spacers to 13mm as these will last a lot longer and seal better within the bearing seals.








The stem if you require to press it out pushes out through the bottom of the yoke so put pressure on the threaded end down.

Notice the lip in the bottom of the yoke this is where the bottom of the stem has a cir clip and locates in when shaft is pressed in.





The rest of my kit will be here on Saturday so more pics will follow then.
 
#25 · (Edited)
Should get a little quicker turn in with the offset of the zx14 front end being set further back which will also shorten the wheelbase.
To make the top steering stem bush I'm using the old zx12 front wheel spindle as its 25mm so all that i need to do is drill it out to 22mm and cut to 16mm in length.I am going to use the zx12 top nut until i can machine a 22mmx1mm locknut to replace it with.
 
#26 ·
Ive dropped a bollock with the discs I've bought zx10 discs off ebay which were earlier than 2008 and they are 300mm not 310mm as i have just found out so if there is anyone in the uk that needs a set !
 
#30 ·
Do you think i will need it then ? Does it make that much of a difference having the front wheel 5-6mm further back ?

A little further again as i don't have my forks i decided to fit the callipers and bleed them through and i got to say its a 10min job compared to my 6 pots these are a doodle and the lever is as hard as a young mans erection !
Found by using a syringe i pulled fluid down into each calliper then hung them up to the highest point then bled them through works a treat :thumb up:


 
#33 ·
Rake on zx14 is 23 deg trail is 94mm
Rake on zx12 is 23.5 deg trail is 98mm 5mm less offset with zx14 triples = 93mm trail
Im sure by doing this mod the geometry of my 12 is going to be in the same region as the zx14.
More offest = more trail
Less offset = less trail
More trail is more stable at speed in a straight line but slower turn in.
Less trail is less stable at speed but more willing to turn in.
The bmw s1000rr uses a rake of 23.9 degrees and a trail of 95.9mm for comparison.
 
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