Topic: Mono shock conversion cb550

[busa]

I guys  I am new to the forum and have made a few post today.   there is some interesting reading and good advice from you all.   many thanks for that.  it helped me make some decisions and what to do.  i have now gone for the cafe racer look with 77/78 cb 550 k3  purely because getting parts for her in the uk is crap.
the only place that helps is david silvers. 

I have gone for mono shock conversion with cbr 600 f2 swing arm and shock  on reading post on here it should be a direct fit.   but it is not.  the pivot bolt for that swinger is 15mm  the original is 14mm.  and is also to short by approx 25mm, but with some thought. cuttting gringing and welding  I got it sorted  and it now fits.

The shock had to be mounted with the same geometry as the cbr 600.   otherwise it will not work.   again taking loads of measurements got it right.  I have also fitted   rear sets

[SOHC4 Cafe Racer Fan]

Well I guess this second thread answers my questions in the other thread. I was wondering if that was a 600 swing arm. The conversion did not look painless.

[Pinhead]

I hate to say it... But I would never trust that monoshock mount; way too much twisting and not enough triangulation...

[busa]

only a mock up at the moment still need to put strengtheners in   but before i do  needed to see if it was in the right place.  before doing more cutting and welding.  But understand where you coming from and without strengtheners it would twist.

[busa]

Just some updates on the Cafe build

I have made a cafe seat unit out of the original seat pan.  still need body filling yet  will post that stage soon,.

also  done rough cut on seat foam  to see what it looks like.  more work  me thinks.







also got the engine part painted  and polished  still some more to do on this



photo quality is not that good   (sorry) 

still got lots to do  but will keep you upto date whats going on.

[Sprocketwerx]

I have the same swingarm/shock going into a CB750. Interestingly I only had to machine about .030" from the spacers and it slid right in. Different bike I know.

Correct on the bigger pivot. Easy option is to use your stock pivot bolt and bush/spacer to fit.

I'm interested in any dimensions you have regarding the front shock mount (op and forward of the pivot) as well as dimensions on  the link (mine didn't come with links and I don't have anything to reference)

Lastly, do you have any pics of the front lower link and it's mounting?
Thanks

[busa]

Hi mate this is the only pic i got at this moment  will take some more tomorrow  along with some measurements.   the linkage will go onto where your centre stand mounted  but you will have to adapt some mounting points for it.   the link i used came with swingarm  CBR600 f2  1994



hope this helps  but will do some measuring tomorrow

[Sprocketwerx]

Thanks.
I'll be machining new links just want the ratio and offset to be correct.
Shock appears to be parallel to the swingarm so upper mount location will fall into place.

Then comes the real work of getting the sprockets lined up
Gonna be a cool ride though!

[busa]

if you are using cbr 600 f2 wheels   4.5inch rear  you will not need to off set the front.  the rear shock mount measurment  is from under seat  (front)



this is where i located the mounting bar



this measurement is from where the spine of frame meets  the seat frame
as you can see from here  where the shock mounts  to the joint in the frame

[busa]

if you take a measurement from where the linkage mounts the swing arm   to the centre of the shock body ( 130mm)


this should give the same angle to mount it  as if it were on cbr600.   the geometry must be the same for the shock to work

[busa]

seat unit body filled 

now ready for final coat fine filler  new foam will be cut and covered