I’m fabricating a rear tire license mount and was curious how much clearance I should set between the tire and mount? There will be 2 parallel 3/8 bars going back to the axle nut and shock mount. This minimize any flex I hope.
Because this is hub mounted, suspension travel is irrelevant.
It will, however, deform due to drag and road vibration. You'll need to allow clearance for that.
Also, consider that your next tire could be slightly larger than what's currently mounted.
Good point on future tire sizes. I’m hoping in the future I can find a 18in rear wheel so I’ll check the tires sizing for that. I guess for now, I’ll tentatively give myself 1inch of clearance directly aft of the tire and to the side.
It will be mounted be mounted to the hub so suspension movement will not be a concerned as it is fixed.
I’m shooting to have something similar to this, but without the fender, it would just be a rectangle plate for the license and a light.
Could you tell me where you got this picture, I'd like to see the rest of the bike!
As for the plate mount, you could go and look at a few modern bikes that have them, the Husqvarna Svartpilen has one, the 2020 Yamaha MT-09 has one too. They look to have at least a good inch of clearance. You need to have clearance for rocks, especially if you plan on running knobby tires.