Bench Seat On Street Twin

That does sound right because Triumph stated that my standard Street Cup seat would not work with a rack or grab rail and they are right, the underside fouls and the back of the seat won’t lock down in to place. This is why I have a Street Twin seat like yours.

I know that doesn’t specifically answer your question but at least you know it is a thing.

Cheers

Geoff

 

The street twin seat has a slightly different base shape such that the seat isn't fouled by the fitting bolts of the rack.

Some have got the bench seat to fit by simply trimming back a little of the plastic webbing on the underside.

There are a few threads that cover it, though those that I've seen are over on triumphrat. There are likely some here too

 

Triumph bench seat can be fitted with luggage rack with minor mod to seat base.