R1 swingarm into GSX-R
by Lee Workman

ok here goes... ( i hope you appreciate this you bastards ! )

First thing is , to get the swingarm physically into the GSXR frame . NOTE ! - the R1 swingarm does not fit perfectly centrally in the R1 frame - it has an offset .

bolt the whole wheel , cush drive , caliper assy into the arm , and mark the centre position of the wheel - onto the swingarm pivot at the front .
you'll notice that it is offset - measure the width of your stock GSXR donor swingarm ( yes- you'll need one !) - transfer this measurement to your R1 swingarm , and chop off the excess ( from memory you'll end up removing about 35mm from one side and 25 from the other .

Now that you've chopped this material off , you no longer have a 'land' to accept the pivot bearings - this is handy because you can now 'bore' the virgin pivot tube out to accept stock GSXR bearings , and use your existing GSXR swingarm pivot spindle .

Now you should have the R1 swingarm in the GSXR frame .
You need to find the position of the linkage point , in relation to the pivot.

then you need to transfer these dimensions onto the r1 swingarm . once the pivot spot is marked each side - drill a hole - it should be in the 'box' section part of the r1 arm that surround the shock .

Cut out the 'horse shoe' shaped linkage mounting from the GSXR swingarm , dont take too much off the sides - you need to cut it as close to the 'spars' of the gsxr swingarm as possible - right through the weld .

there are a couple of flat plates welded to the underside of the swingarm - remove these and slide the GSXR linkage mounting into the space

Thread a long bolt ( i used a piece of M8 all-thread ) through the two holes you made in the R1 swingarm . the bolt should go through the GSXR 'horseshoe' . the bolt is what jigs the horseshoe linkage mounting into position .I made two 'stepped bushes' that fitted perfectly inside the bearings of the horseshoe - then i tapped them out to suit the all thread .

So can now thread the 'bolt' through an M8 nut >then through the 8mm hole in the swingarm bracing > M8 nut > stepped bush > linkage pivot < stepped bush< M8 nut < hole in the other side of the swingarm bracing < M8 nut .

see diagram below

now you can secure the 'all thread' bolt in position using the m8 locking nuts , either side of the 8mm holes that you carefully positioned and drilled into the R1 swingarm bracing . you can adjust the linkage mounting untill it is perfectly central and in line with the make that you made on the centre of the Pivot tube .

You will probably need to remove the 'horseshoe' and file a bit from the sides then re fit - several times - in order to get it a nice close fit , and positioned centrally .

Once in position - you just need to weld it up

the next job is to extend the oval hole in the top of the bracing forwards toward the pivot tube .

the reason for this is , the shock sits vertically in an R1 , but in a GSXR , the shock 'leans' forward - if you dont extend the hole in the bracing , the shock will foul it .

the last job is to open out one of the 8mm holes you made in the bracing - upto 18mm - this is so you can fit the bolt that secures the dogbones to the linkage pivot .



So now , if everything's gone to plan - your R1 swingarm is fitted centraly between the frame rails of your GSXR , Your GSXR pivot spindle slips through the frame , through the GSXR pivot bearings and out the other side , without any play

Your GSXR shock slips through the modified hole is the R1 swingarm , and your dog bones secure the linkage pivot to the rocker arm without any fuss .

if you've done it properly - you havent fucked up the geometry of the suspension , and there isn't any play anywhere .

One last thing -

I told you it was an absolute bastard didn't i ?

which is probably why i've never seen anyone else do this mod

yes it looks trick
yes it's unique
yes the ( extremely light ) R1 6" wheel plops straight in
yes the swingarm is actually lighter and (very much) stiffer than the old GSXR on it replaces
yes , all the original geometry , and linkage ratio's are retained

But would i do it again ?

Would i fuck !