Forks to short

[blackie]

Hi' all new here, I've got a Z1100r that l want to put later forks in, still RWU forks but 70'mm to short what's the best solution, stepped yokes, or screw in extensions, or is there another way, just want it to look neat,cheers all...

[chrisw1]

You could fit emulators and springs in your forks and bring them up to date ?

[blackie]

Hi' thank's for reply, yes I could but I want a more beefy looking fork, I'm putting a bigger swing arm in as well, I just want it to look right, longer fork tube's would be great, but not sure how you'd alter the damper gubbins in side for the extra length, just putting feeler's out at the min, to see if any body's had the same problem,

[bunnysZ]

check out this site he can do either
https://www.billetbikebits.com/yokes

[Julian_Boolean]

Find some longer forks is the correct answer, but that may not be an option, I think in that case I'd go for screw in fork extensions, but I'd rather have the standard forks than two piece fork stanchions.

[KWACKERZ1]

If you want bigger fatter forks, You're best options are 43mm ones according to my scribbling in my workshop book here are some dimensions from forks'bikes we have measured for just such a reason. Measuring spindle center to fork top.

ZRX1100 30.5"
zzr1100 30"
Gsxr1100l 29.5"
Gxr750 slabby (41mm forks) 29.5"
Bandit 1200 mk1 28"
ZX9RC1 29"
96 BLADE 28" (45mm forks.

My mate swears by his bandit forks in his GPZ11 track bike so ts an easy mod that works.
If your using 43mm forks zzr top yokes are offset so allow you to regain an extra inch in height so they are worth considering, but zrx ones look better.

The other option is Triumph triple forks they are 43mm and I think they are longer than bandit ones. (I have some with missing top screws if you can source the tops I could measure them later for you)

Other considerations are your spindle sizes, if your keeping standard wheels your probably working with 15mm spindle so if you used slabby forks you could use a 15mm slabby spindle. Or a better option would be use 17mm*42*12 bearings in your wheel and accommodate the bearing thickness difference (2mm different to standard) with your wheel spacers. Then you can bandit , zrx ,zzr forks which have a 17mm spindle.

If you want modern performing suspension but classic looks have a look at modding your forks with these,

http://sportsvalve.com/glyn-robinson/

They allow external adjustment unlike most emulators, they also actually work. (unlike many emulators)
They are expensive but not as expensive as a full cartridge kit from maxto, ktech etc.

Hope this helps,

[Julian_Boolean]

This thread has prompted me to investigate the front end of my J (no physical measurements just internet info as I'm attending work)

My J has 89 FZR1000 EXUP RWU forks and yokes, which are probably 50mm (ish) shorter than the original forks, the yokes have a lot less offset than the originals.

It handles fine at over 40mph, but upto that speed it drops into corners and isn't very nice, this isn't helped by the rear shocks being a little long, it looks good, but it doesn't make for great handling.

[Julian_Boolean]

To add to the above, it also has a 17" front wheel and ground clearance is a bit lacking, especially in right hand corners.

[KWACKERZ1]

The rolling dimensions between a 17 and 18" tends to be about 1/2" less due to the tyre profiles of the front wheels.
Bobs and Als bikes all use 18" wheels and I think this helps the clearance issue.
Offset is obviously different as modern forks have much less offset that the old gpz/100j ones normally by about 20mm less.

[neilbarrett]

early suzuki gsxr1100 h or j model worth a look

[blackie]

Kin'el" slow down I can't read that fast, I'll measure the length of the bimota fork's, the bike has got astralights in, so wheel spindle I'm not worried about, I've got a myford lath, so can make any size spindle spacers I need, thanks for all the info lads, great site...

[Julian_Boolean]

If you find somewhere to make some fork extensions let me know, as I think a set might sort out the handling on my J, though I'm also considering swapping the EXUP forks with the ones in my FZ750 which are longer

[blackie]

The Bimota forks are 745mm, 29''1/4'' a tad longer than zx9's, so if I get a 30'mm stepped yoke, it'll not be far off, i've got the Bimota yokes aswell, so i'm gunna do a mock up this weekend to see how it'll look with a lower top yoke, I'll keep ya'posted...