This find from the boys at Biltwell is perfect for custom and garage built Bobbers, Choppers and Brat's of any brand, make or model. A single sheet of vacuum-formed ABS plastic forms the base of the seat which is then covered with molded urethane foam.
The cover is hand stitched heavy-duty vinyl, that is then glued and stapled to the underside of the pan. A laser-cut and hand-polished stainless-steel bracket riveted to the rear underside of the pan mounts securely to the top of the rear fender with one supplied 5/16-18 hex bolt and stainless-steel acorn nut.
Granted, you could fit this to a Honda, or any custom out there, but here's the word from the horses mouth as it pertains to Sportsters, which this product was designed to fit:
"We're reasonably confident the new Biltwell Banana seat will fit your 1986 through 2003 H-D Sportster perfectly. We qualify this statement only because we haven’t tested the Banana seat on every XL model manufactured during these production years. On the model years we DID work on, the Biltwell Banana seat looks awesome and fits even better. Of course, because this product is designed for custom, modified and garage-built motorcycles, we can't guarantee perfection in every application. However, if the frame on your '86-'03 Sporty is straight, if you haven’t modified or chopped the subframe and your rear fender is stock, the Banana seat should fit exactly like the production sample on the test mule in these photos."
Good enough for us!