Greetings all and sundry it's been a while again.
I wondered if anyone has ever either made up a new frame or modified the existing one to suit a swing arm twin shock rear ?
It's just an idea I've been toying with when my hands are idle which is not often

I'd be looking to fit an after market King sportster tank , flat seat and mid point controls. I'd keep the stock rake and wheels.
Any thoughts or advice including the 'you've got to be kidding me line ' are welcome..
Kev

You would have to build up a hell of a frame extension for the upper shock attachments and your swing arm travel would have to remain pretty much the same due to the large diameter of the front pulley. Unique would be all there was to achieve.

you could possibly tie in where the main frame & rear sub-frame bolt together by fabricating brackets & laying the shocks down. But, as jd said, swing arm travel & belt clearance would be issues to deal with

ironman wrote:
you could possibly tie in where the main frame & rear sub-frame bolt together by fabricating brackets & laying the shocks down. But, as jd said, swing arm travel & belt clearance would be issues to deal with

Hi Ironman! Don't see you on much anymore.

I'v e looked in to this and reality is building a new frame would be a much easier exercise.
Virtually the whole rear half of our frame would have to go to make it work right. Geometry doesn't work for a flat seat either. Mid controls is possible but without the flat seat its not a good option. Not to mention due to the width of the engine and pipes its tough to get mid's put in that look right. Last I have put a King Sportster tank on my Roadie (did it first year I had it). Its a bitch. Our frame backbone is quite wide so you have to find the right tank to fit. It must ride in the Frisco position due to how high the heads come up on our engine (stock tank is form fit over them). Also our backbone bedns downward exactly where you need to bolt the rear tab down. Trust me its not much fun to figure out the dimensions (i at one point owned 4 tanks as none of them would work) and I'm leaving out your Sawzall, hacksaw and grinder work you have to do.

Excellent idea. Should not be a problem. If you have the skills.
Twin shocks are easier to put on and remove since you can do one at a time and not need to use a jack.
Make sure that when the swing arm is all the way up that the wheel does not contact the the fender.
The swing arm pivot point needs to be as close to the drive sprocket- like other bikes.

takehikes wrote:
I'v e looked in to this and reality is building a new frame would be a much easier exercise.
Virtually the whole rear half of our frame would have to go to make it work right. Geometry doesn't work for a flat seat either. Mid controls is possible but without the flat seat its not a good option. Not to mention due to the width of the engine and pipes its tough to get mid's put in that look right. Last I have put a King Sportster tank on my Roadie (did it first year I had it). Its a bitch. Our frame backbone is quite wide so you have to find the right tank to fit. It must ride in the Frisco position due to how high the heads come up on our engine (stock tank is form fit over them). Also our backbone bedns downward exactly where you need to bolt the rear tab down. Trust me its not much fun to figure out the dimensions (i at one point owned 4 tanks as none of them would work) and I'm leaving out your Sawzall, hacksaw and grinder work you have to do.

Hey Brent how many of those tanks you got laying around? I have a project for my daughter in law I'm working on.

And I think you could make a swingarm and be able to run dual shocks on the outside.

thanks all for the tips and advice. i shall go away and distill these thoughts.. it might take a while ; off the road f##ing about with it vs riding it
kev

hardone2get wrote:
takehikes wrote:
I'v e looked in to this and reality is building a new frame would be a much easier exercise.
Virtually the whole rear half of our frame would have to go to make it work right. Geometry doesn't work for a flat seat either. Mid controls is possible but without the flat seat its not a good option. Not to mention due to the width of the engine and pipes its tough to get mid's put in that look right. Last I have put a King Sportster tank on my Roadie (did it first year I had it). Its a bitch. Our frame backbone is quite wide so you have to find the right tank to fit. It must ride in the Frisco position due to how high the heads come up on our engine (stock tank is form fit over them). Also our backbone bedns downward exactly where you need to bolt the rear tab down. Trust me its not much fun to figure out the dimensions (i at one point owned 4 tanks as none of them would work) and I'm leaving out your Sawzall, hacksaw and grinder work you have to do.

Hey Brent how many of those tanks you got laying around? I have a project for my daughter in law I'm working on.

And I think you could make a swingarm and be able to run dual shocks on the outside.

sent you a PM...got 2 left.....

You can buy a swing arm online for a very low cost. Why build it?
FXR swing arm for instance.

My bike