Larger tires on a scooter?
If you want to go up a size you could go with 4.10/3.5-4s which is 4.10 wide, 3.5" sidewall, 4" hole. Actual diameter varies from 11" to 11.5".
I thought it might help to show a picture of what Takenaback described with the stainless steel framework running between the batteries.
In case it helps with this discussion, the standard SLA batteries shipped with the chair are the MK Battery ES12-12 and the charger is MK Model: LS 24/4.
It's for my personal transportation device. I'll try to post pictures. You will recognize where the idea came from.
This is the working 36 volt version. It has an on off switch, a thumb throttle, and a hands free cruise control.
We have swing away armrests installed on a 16 x 18 ZRA and use it with the ZX-1 with the anti-tilt mechanism. We do not have any problems because the brackets on the chair are forward of the ZX-1 brackets.