Gitzy

Suzuki GSF 1200 Bandit to Suzuki GSXR 600/750 - K4/K5 Front End Fork Conversion.

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This front end conversion applies to all Gen 1 B12 Bandits to accept a GSXR 600/750 K4/K5 USD Radial Fork setup retaining the original B12 Front wheel , Brake rotors, steering stem and steering head bearings..

What you will need to complete this task:

* Generation 1 Suzuki GSF1200 1996 – 2000 Model

NOTE: The front ends for the Suzuki GSXR 600/750 K4/K5 are all Identical this includes yokes, forks, calipers and axle are ALL IDENTICAL so this means if you cannot source a complete front end you CAN purchase the parts separately as I did..

This particular conversion had 6 donor bikes which varied between the K4/K5 GSXR 600/750, the parts are as follows.

1. Forks





2. Calipers



3. Axle



4. Top Yoke – Note: the B12 ignition will not bolt through existing hole so I removed the ignition area on my top yoke and relocated the B12 Ignition to the left side of my bike.



5. Bottom Yoke



6. Front Fender
Various Spacers to use in the conversion will need to be machined in order for all the parts to work together, they are as follows.



* 4 off 10mm i/d x 24mm o/d x 5mm – These are to space the GSXR Radial callipers out 5mm as the original GSXR rotors are 298mm whilst the B12 rotors are 310mm these spacers compensate and allow the larger diameter rotors to spin unobstructed

* 1 off 25mm i/d x 29mm o/d x 73mm - This is the spacer between the two wheel bearings

* 1 off 25mm i/d x 32mm o/d x 12mm - This is the spacer for the throttle side of the axle

* 1 off 25mm i/d x 32mm o/d x 16mm - This is the spacer for the clutch side of the axle

* 1 off 22mm i/d x 25mm o/d x 20mm – This is the spacer/bush that sits in the top yoke under the yoke nut as the B12 Steering stem is 3mm smaller in diameter than the K4/K5 Original, this spacer compensates the void and allows the K4/K5 Top yoke to be used.

* 2 off brake rotor spacers 64mm i/d x 84mm o/d x 2mm these spacers require 5 x 10.4mm holes at 86mm PCD (Pitch Circle Diameter) these spacers are required to space the rotor centres out from their existing B12 128mm to GSXR 132mm

NOTE: You could use 10 x 2mm washers behind each rotor bolt but I do recommend requiring a machined spacer as per picture..



You will need to replace the Stock B12 wheel bearings as the K4/K5 Axle is 5mm larger in diameter.

* 2 off 6005 bearings 25x47x12



*2 off oil seals 32x47x7



NOTE: Please be aware the stock B12 speedo cable will no longer function as it will be replaced by a spacer.
When you have accumulated the parts for the conversion you are ready to begin.

Step 1: You will need to press the original B12 steering stem out of the stock bottom yoke to reuse in the GSXR donor bottom yoke.
Do NOT do this with a hammer, I had access to a hydraulic press but in your case if you do not basically any car workshop should have one and as this is literally a 5 minute job and is relatively easy to do I’m sure they will help..

NOTE: When you press both stems out of their respective bottom yokes, make sure you press both of them DOWN through the yoke as they are tapered and doing this in reverse will damage the bottom yoke.
Once you have obtained the B12 stem you can discard the bottom yoke as well as the GSXR stem..



While you have the GSXR Bottom yoke with no stem, go ahead and remove the lock stops as this will interfere with the setup, you can cut these off and grind the area flat, when you have assembled the new front end onto the B12 you can mark where you want new lock stops and drill and tap this area to insert two bolts to act as the new lock stops.



Then using the same hydraulic press, insert the B12 Stem into the GSXR Bottom yoke pressing in until it is flush with the bottom of the yoke.

NOTE: When you press in the B12 stem to the GSXR Bottom yoke, do so in reverse to how you removed them remembering they are tapered.. The stem should fit perfectly.


Step 2: Depending on whether you will be retaining the GSXR clip ons in which case ignore this step.

I was using handlebars on this particular conversion so I went ahead and drilled the GSXR top yoke and fitted 1 1/8th risers, this was a very simple step I decided how far apart I wanted them taking into account of the underside of the yoke to allow bolts to be tightened on the risers marked out my holes centre punched them and drilled them out. Job done.



Step 3: Prop up the bike on a rear race stand and support the front lower half of the frame either with a Jack, blocks of timber or in my case some purpose built stands, Then strip the complete front end off of your B12, when all that is left is the steering head ready to accept the new front end.



I went ahead and fitted brand new roller tapered steering head bearings, I recommend you do the same.



Step 4: Assembly

*Fit a new tapered steering head bearing to the freshly pressed steering stem in the GSXR bottom yoke.

*Fit both top and bottom steering head bearing races to the bikes steering head.

*Freshly grease both upper and lower bearing sets .
*Slide the new bottom yoke up through the steering head and tighten all required lock nuts to factory torque settings.

*Fit the new top yoke with the 22mm i/d x 25mm o/d x 20mm spacer/bush in the void.



*Fit top yoke washer and nut and torque to factory settings.

* At this point to make things easier you can mount your bars and route all cables and hoses before you fit the forks.





*Slide forks up inside yokes and tighten pinch bolts.





*fit rotor spacers to your wheel and reinstall brake rotors.





*fit wheel with new axle and spacers as per diagram.





*fit caliper spacers, calipers , brakes lines and fender.



*Double check all fittings and bleed brake system.

*Sit back and admire your work.





In conclusion this is and was to me a very very straight forward and effective conversion, It seems like a lot of information to take in but once you have sorted all parts required it really does go together quite easily.

The front end of your B12 will now be 40-45mm lower than stock so it will turn significantly quicker over your old frond end which may take time to get use to.

The Brake upgrade is remarkably superior to stock and bite and feel are increased a lot.

I performed this whole conversion with a basic understanding of home/garage motorcycle mechanics using no special tools out of the ordinary from a standard tool kit.

I take no responsibility for any persons should they replicate this tutorial and fail to safely do so.

NOTE: Some pictures are for reference only.

Updated 31-12-2011 at 07:29 PM by Gitzy

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HOW TO

Comments

  1. BANDITROD's Avatar
    top stuff Todd
  2. Gix11's Avatar
    Top shelf HOW TO mate, nice work.