Hi guys, sorry if this has already been done but I can't find anything on the Internet that indicates it has.
I'm currently trying to fit a 2004 CBR1000RR swinging arm (you know, the lovely Unit Pro Link one) to my 2000 CBR900RR (929). I got the swinging arm complete with shock, linkages and rear brake caliper/mount for a snip from ebay and thought I'd give it a go over the Christmas period.
As you can see, it's pretty similar but (there always is a but) there are some major differences.
Honda are pretty good at evolving their machines, which will hopefully lead to an easier conversion, and you can see this reflected in the 929 - 1000RR swinging arms. It looks like the left hand sides use the same parts and jig for the braced part, dimensionally it's not too far out either. It's slightly narrower at the pivot point and about an inch longer overall. The pivot and wheel spindles on both bikes are all the same diameters.
So, first step is to remove the 929 arm and offer up the 1000RR arm to see if it's anywhere near being possible to swap.
Et voila, looks cute doesn't it.
it isn't a million miles out, but there are 3 main obstacles to overcome.
Obstacle 1 - Pivot Point
If you know anything about the 929 you'll know that the swinging arm pivots on the rear of the engine whereas on the 1000RR it pivots in the usual manner between the frame spars. You can see in the picture above where the new swinger won't go fully into place due to the main pivot tube fouling the engine pivot point.
Obstacle 2 - Different Linkages
The 929 uses triangulated plates and a dogbone fastened underneath the pivot mount to operate the shock as below
the 1000RR uses a triangulated rocking arm with two drag arms fastened under the pivot mount as below
Looks like it might fall into place but if it's not exactly the same fitment as the 929 I'm going to have a bit of jiggery pokery to get the swinger to fit and the bike to sit at the correct attitude.
Obstacle 3 - Shock Top Mount
Last but not least, I may just have shock mount/subframe interfacing issues here but I'm sure an angle grinder
can sort out most of that malarky.
Back to obstacle number 1
The bit I like more than most things, chopping and hacking perfectly good kit in a vague hope I can make it fit something else (after some very careful measurements and not forgetting "measure twice, cut once"), see timelapse sequence below
Notice my workbench - a fridge and a tumble dryer. Necessity being the mother of invention.
I've tried to maintain the counter-bores integrity in the main bearing assemblies and as you can see, the bearings have pressed back into their original retained positions, which is what's required to maintain the swinger in a located position
Yes, I've removed a considerable piece of the swinger's structure but it is on the non-drive side and that can be easily filled in when I can find a decent (cheap!) ally welder to do it for me. In my engineering judgement (Eur Ing Ganzee Geezer BEng (Hons) CEng MIET...ahem!) the integrity will not be too badly affected even if it is left as it is (time will probably evolve some stress fracturing at the sharp corners though so it's wise to get the hole plated to give the structure a bit more support and then it will be fit for the duration)
Tomorrows job, weather permitting, will be to offer up the swinger and see if I got my measurements right! If not I'll slink away never to be heard of again, let's hope I got the measurements right and even if I have cocked up hopefully this may inspire someone to do it properly. More pictures will follow regardless!