GS550 info needed

[cm113]

Anybody got any info on this. Had it post in the tech board, but haven't gotten anything yet.

Thanks,


Hello,

I am currently in the middle (just starting) of restoration/building of a '78 GS550. The plan for this, is a little light weight cafe racer style bike. I have just got a line on a early '90's model 750 Katana. It is mostly complete other than a blown engine. I can get this for a reasonable enough price, which leads to my questions.

I would be looking to swap from the swing arm back (swing arm, wheel, brakes, shock, etc) and the complete front end from this Katana to the 550. I know some of you have done this sort of thing to the bigger 750 and 1000cc bikes, but has anyone done this to the smaller 550/650 bikes? I know I can get the front end to work, but my main concern is the width of the later model swingarm. Is it too wide to go into the 550 frame? Spacers and such are no problem, as I have access to a complete machine shop. I just don't want to get this the swing are not even fit in the frame. I have not taken any measurements yet, but would just like some input on this before I jump into buying the other bike.

Any help, ideas, or insight on this would be appreciated,

Thanks,

[oldschoolGS]

I bought a complete '93 Kat 750 chasis for my '83 750 project. The front end is nice- 41mm tubes with dual piston brakes and a 17x3 front. You should be happy with the front end.

The rear swingarm is junk, very heavy and long, IIRC, it was 1-2in longer than my stock 750 arm and at least twice as heavy. Very crude stamped steel construction, I threw it in the trash as I considered it worthless.

I would look into using a mid '80's 550E or 750E aluminum mono arm as these are much lighter and nicer than the Kat arm. Either should suffice on your '78 model. Of couse you have the GSXR and Bandit arms but they are probably overkill for your application.

I may still have a spare '83 750 swingarm if you are interested.

Good Luck, Ed.
1983 GS750ED
2005 GSF1200SZ
1992 900SS

[cm113]

Thanks for the reply. This is very good info.

cm

[Nerobro]

I would look into using a mid '80's 550E or 750E aluminum mono arm as these are much lighter and nicer than the Kat arm. Either should suffice on your '78 model. Of couse you have the GSXR and Bandit arms but they are probably overkill for your application.

I may still have a spare '83 750 swingarm if you are interested.

The swingarms on the 83-86 550's are steel.

[oldschoolGS]

The swingarms on the 83-86 550's are steel.

Well thats good to know, I guess the only '83 with a alum arm was the 750 then. Always have liked the 550ES-especailly in blue/white. Out of curiosity, can you get a 3.5 rear with a 140 in the stock 550 arm?

[Nerobro]

You probally could. :-) Other than looks i'm not sure why you'd want to though. Other than painted stripes and tar snakes the back tire on the 550 is very unwilling to break traction.

[oldschoolGS]

I was just thinking that a peped up 550 with wide wheels and premium rubber/suspension would make a nice, light street package. I liked the 140/3.5in rear on my '83 750, also its a better size for rubber selection.

I know what you mean about breaking traction, my old 2v Ducati has an overkill 170/5.5 rear combo, but this makes for almost unlimited traction with Michelin Pilot Powers mounted. Its the first bike I have been able to scrub the rear tire right to the edge without being concerned about breaking the rear loose.


Ride On, Ed
1983 GS750ED
2005 GSF1200SZ
1992 900SS

[facekicker550]

Thanks for the reply. This is very good info.

cm

check out my 78 550 w/a 150 outback on a stock swingarm