Has anyone exstended there swing arm without buying a custom made one.
I am going to be taking my 84 fj600 and making a drag bike out of over the winter.
If anyone has any links on this suject it would help.

I guess out of 44 views and not one reply means none of you do your own MODS.

i guess your breaking new ground here
between the slipping clutches and varnished up carbs there ain't much need for extended swingarms here
did you try any hillclimb forums ? they get into that sort of thing
kzriders.com has some drag bike guys on it
all i can tell ya is double sticky tape on the seat

In our defense, most of us here are trying to make bikes that are relatively useful. Not just a single purpose bike. If I was gonna try and tackle such a project, I'd do some digging for the guys on here that have xj trikes. I don't know if any of them did their own work but you can at least see their photos and get some ideas. Good luck man.

changed

I have done this on a bike with a friend. Keep in mind that we did this on a chain drive motorcycle and it was not a yamaha like these.

First, we took the whole back of the bike apart. This is a great time to check those swingarm bearings. Then with the swing arm off the bike cut it in half from front to back. or where it seemed logical We placed it on a welding table to make sure that it was nice and flat. We had our choice of two ways to do this. The first being finding a tube that fits over the stock tubing that makes up the swing arm. Second was to find the same tubing and take solid bar stock that fit inside the tubing. We cut two pieces of solid bar stock and fit them into both ends of the stock tubing. We drilled small holes on the stock swingarm as far back as the bar stock went. We then welded that hole shut, welding the bar stock to the tube. We felt like it added a little ridgidity to the thing. A piece of tubing (however long you want to extend your arm) is placed onto the bar stock and welded into place. We left a 3/16 gap so that we could fill it up with welds. It also made it look much better after we ground the welds. You actually couldn'
t tell where the new piece was. If you use tubing that fits over the stock swing arm tube then it looks a little fatter. Of course you will do the same thing to each side measuring lengths to make sure it will track properly. Hopefully I haven't lost you yet. The shocks for us posed a problem as they might for you. We ended up using a stiffer springs on ours. Of course you will most likely lower the bike to make it into a drag bike, so you will end up messing with all of that anyway. I will note that we had a hard time keeping the chain good and tight. Always seemed to whip a bunch. We would tighten it, and then the chain would break because it was too tight. We used a chain tensioner on it after awhile and that helped.

Cutting and pluging the square tubing and adding the same size inbetween seems likr the best way to do this. I dont have to worry about the shocks sence it is a mono style and i am going to replace it with a strut for more harder launch. I will keep digging around and keep you all informed on the progress during the build. Thanks for all the info guys.

how much longer are you making it?
consider removing the shock puts a lot more stress on the components add to that a longer arm with more leverage....just be carefull

You mean like this? CLICKY!!

LOL

kickstand wrote:

I guess out of 44 views and not one reply means none of you do your own MODS.

Most of the bikes on here are shaft drive.

Not so great of a mod... maybe switch out to a drive off of a new v-star?
That's probably a bit longer.

If you can find one Cal fab used to make some for the seca 550, It is an extra inch or two but what really helped was all of the bracing that is done on it. You might take the bike over to the local welder and see if they would take on the job of adding a couple of inches or best case scenario would be to have them make one up. Just remember when you go longer on the swingarm, then the chain, brackets and brake hoses need to be longer too. Best bet would be to just put your weight further up front when you launch. The fj motors when they are built can really be fun, not to mention that they can really launch. My best 1/4 mile times were 11.7 seconds for a seca 550 at a speed of 104. I did my best to piss off guys on new 600's, 750's and the occaisional 900 in the early 90's

kickstand wrote:

I guess out of 44 views and not one reply means none of you do your own MODS.

Get bent.

I did it on my XS1100, added 6 inches to the length. It is a shaft driven bike just like the XJ1100. I made a jig to hold the swing arm , then cut and welded pieces in place. I had a machine shop make the round drive shaft tube, then cut apart another old swing arm to make the other side. The drive shaft was spliced together from two shafts.
The bike looked prety neat, then I chopped the front and put 12" longer fork tubes in place. It's a project bike, not finished yet, but maybe soon.