What should be the minimum clearance for each? I have heard different things on tire-to-chain clearance: 1/4' seems to be a common answer for a tight clearance. I am also going for a pretty tight look (chain-to-tire clearance and chain-to-axle plate clearance). I am running a sprotor and chain: any suggestions on the minimum width my swingarm should be for a 300? I am thinking about 14.5' - 15'? Does that seem about right? If any is running a 300 with a chain/sprotor and could measure their swingarm that would be great. My tire is 12' wide, but I am unsure of how much wider the hub face is compared to the sidewall. I don't have my rear wheel yet, so I am not sure exactly the minimum width I can get away width between the axle plates. However, since I plan on stretching the swingarm, I can get some more width if I stretch it the area where the tubing is angled (just before it parallels and heads straight back to the axle) I hope that made sense? I know I would have to widen more than just at the pivots (that won't give me enough width for a 300). I will probably just copy the look of a common softail mount. I also plan to get rid of the outboard shock supports and go with a softtail style mount. Any suggestions? Do you think the dyna swingarm is a better choice or the sportster swingarm? I am pretty sure the dyna got a 1' axle in 2006 and the sportster got a 1' axle in 2005. I think the dyna mounts to the tranny, but I think I can make it work. I know I would have to widen that area of the dyna/sportster swingarm (the pivot area) which would help my cause in fitting a wide tire (I plan on using a 300 tire - mine measures about 12'). My custom frame has about 10' between the doglegs where the swingarm pivots. I am trying to figure some things out mathematically before I go ahead and buy a used swingarm.

I know there are some custom swingarms out there, but I think using a modified swingarm off of dyna or sportster might work. I like the drag style look of rectangular tubing swingarms.

Swingarm sportster chopper