ZXR 400 front end question

Wheels, shocks, forks, frame
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buzinc
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ZXR 400 front end question

Post by buzinc »

This is a question for all you folk who have zxr400 front ends on their KR1.
Been shopping on evil bay and purchased a pair of zxr400 forks. Minus wheel, yokes, clip ons etc. Only problem the previous owned didnt know was, which model they were off. So can somebody please tell me?

From the gold anodizing at the top, to centre of wheel spindle 744mm ish
At the top where the yokes mount is exactly 50.38mm and where the bottom yoke mounts is exactly 50.46mm.

Adjuster at top of fork
Image

Secondly. What wheel can I use. I have the kr1, could I use the kr1 or would it be easer to use the zxr400, as its a three spoker. Do the zxr wheels differ andy way from each other?

Also somebody please put me out of my misery. This bracket I guess goes near the generator - cant see where!

Image

Thanks Buz
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scooble
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Post by scooble »

I think the L forks (that use 310mm discs) are 52mm at the bottom yoke. The ones pictured here are narrower, so I assume these are H forks (Also uses 300mm discs).

would be worth getting a few other opinions to just confirm though
KR-1R
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ZXR forks identification

Post by KR-1R »

.
.

They look like H1 model forks.

The easy visual way to tell is the fork bottoms because the mudguard mounts are different.

The L models fingers for the mudguard mounts are longer going half way along the chrome stanchions.
The rear mount on the H model is shortish closer to the caliper mounts
ZXR250 forks are notably different again at the bottom with 3 step change in section (and longer axle to top clamp)

The H models had the same calipers as KR-1S and common ZZR models bohemouths.
The L model changed to smaller less grunty calipers

even though there were several options for the anodising colour
the H models are pale yellow gold and
the L models generally more deeper gold or bronze colour (it does fade). The L models with the black frames/bodywork have matching black fork bottoms (bronze anodising)

the H1 model had the triangulated braced swingarm. (10mm shorter than the KR-1S, 30-40mm wider at the pivot, but can be reduced)
the H2 went to the fish shaped swingarm (not a good translant)
the L also had this swingarm but with the pressed style frame rather than the extruded blocky square one of the H.

Diameters...
as scooble says (I think) and your dimensions confirm...
the H models are ~50mm ~50mm triple clamp mounts
the L models more modern 50mm top, 52mm bottoms diameters at the clamps (ready to accept trick R6 forks :wink:)

Wheels
The ZXR400 wheels are all the same (F 3.5x17, R 4.5x17). not to be confused with narrower (earlier) ZX-4 wheels
============================

92170-1028 carb vent hose wire hanger/tidy clamp (from the carb parts diagram) but its not the one down by the right footrest - cant think where it lives (alternator?)

============================

triple clamp/fork spacing betwen front wheel (very rough info)
ZXR400 yoke 210mm Hub xx Brakes 130mm total Disk offset ACROSS HUB ModelYear (centreline plane braking surface)
GSXR1000 yoke 207mm Hub xx BRAKES 132mm Disk offset ModelYear
YZF750 yoke 210mm Hub xx Brakes 135mm Disk offset ModelYear
R-1 yoke ?? Hub ?? Brakes 127mm Disk offset ModelYear
ZX-6 yoke 210mm Hub ?? Brakes 135mm Disk offset ModelYear
CBR600RR wider than 210 at yoke? ?214mm? hence Brakes 137mm rotor plane to plane

each manufacturer has their preferred fork spacing determining or determined by the front wheel hub width and brake offset,
if you stick to one make/breed generally less hassle (shaving/spacing) involved than picking clamps, forks, wheels from three different donor makes (different axle diameters accomodated with wheel bearing swap)
... a narrower wheel hub you could space the disks outward or offset calipers inwards (not radial calipers... need to alter hub or triple clamp)
... hub too wide.. you could have the hub milled/lathed narrower by several mm without reducing rotor bolt thread depth
Last edited by KR-1R on Thu Jul 01, 2010 12:26 am, edited 11 times in total.
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JanBros
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Post by JanBros »

scooble is right : L forks are 52mm at the bottom yoke.

there are lot's off wheels you can use : ZXR400/750, ZX6/9 (allthough some ZX6 wheels are narrower where the discs mount, they still fit the calipers), probably some ZX12 and ZRX wheels to.
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buzinc
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Post by buzinc »

Thanks guys. That is some smashing information. :D

Cheers Buz
dougon2wheels
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Post by dougon2wheels »

odd,the measurements sound right for h forks,but the fork top is different to my h model forks.....
Image
least i hope so.... :mrgreen:
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