[bwader]

For me I don't like riding cooler than 50F. But right now it's been like summer in the mid to upper 80's and 65F at night or mornings.

Around Nov. then there are a few days in Dec. where its 45F for a low and 50F or higher and I'll ride to work on a day like that if its sunny.
WV in Ohio river valley where I grew up, I road a bicycle year round. I remember it got to as low as the 15F or teens which is "cold" to me. 20-30F is expected for winter. Course riding a bike keeps you warmer peddling and cant go fast like motorcycles do. Had lots of hills to peddle slow up but got to ride it back down, though scary when it had icy spots.
I'd guess sometime in Oct. for end of M/C riding weather for where I was in Parkersburg,WV.
Start would be around mid April maybe even may.
I was in SC for in winter time and man it felt weird to me when I went to go visit home in WV then. It was 50-60F in SC then to the 20's.
Indiana has got to be a lot colder! I watched a youtube video once where someone in Alaska was putting on metal studs in their M/C tires and using an extra battery pack just to start it up.