https://www.planetbike.com/store/alx...wide-60mm.html
i have these on my Salsa Journeyman running 650bx 47 mm tires no problem. work great.
I have a knog oi bell and it works well for the greenway or MUP. I just ring it twice so people don't think it is iOS text notification.
i like the low profile. I want to put one on my Cervelo as well for group rides and stuff.