I have a 2004 softail standard and I need to buy a new back wheel my stock wheel is a 16x3 40 spoke wheel. I've been looking online to purchase one and I've been seeing things said about dual flange or single flange wheels. I'm not sure what they mean by that if anyone here could help me I'd really appreciate it thanks.
Assuming the rear wheel is OEM, it is mounted to a dual flange hub. The hub flanges are the mounting locations for the brake disc and the drive pulley. There is no difference in repairing a flat between a spoked and mag type wheel unless the spoked wheel requires running a tubed tire; some do and some don't. One of my bikes is a BMW R9T and, for some unknown and unexplainable reason, this new addition in 2014 comes with spoked rims that require a tubed tire.
Well, unless you have ever had to repair a flat tubed tire in the Texas hill country in July, you can't imagine what a pain in the neck that little job is. However, there are work arounds to avoid that situation. One is to replace the spoked wheels with mag type wheels that run tubeless tires; pretty price work around though.
Another is much cheaper and a bit more labor intensive. Remove the spoked wheels, seal the wheels and re-install the tires. Did that on both the front and rear wheels on the R9T and should I have a flat, I can easily make the repair with the StopnGo patch kit and mini compressor.
If the bike sits in the garage for a couple of weeks, I do have to check pressure and add some air but I have to do that with the tubeless tires on my Harleys as well. Check the link on how to seal spoked wheels should that be necessary. All spoked rims do not require tubes.
https://cyb.smugmug.com/Motorcycles/KTM/Tubeless/
Depending on why you need to replace the wheel, you may just need to purchase a new hub, maybe a few spokes and just re-lace your wheel to the new hub.