All of the Fender basses and guitars used the 7.25" radius until about the mid-80's where it changed to 9.5" radius. My first "good bass" was a 1965 Jazz that I bought in 1966. Played it in high school and some college and then toured using it for three years across the mid-west and western US playing 5-nights a week, 50-weeks a year. Was a great bass and I got real used to that narrow and slim neck with 7.25" radius. After coming off tour I still played it for weekend gigs. Then all my touring gear got stolen including my '65 Jazz in 1976. I didn't really have the money to replace it working a "normal" job with a wife and 2 kids. Nonetheless, I was on the lookout for another Jazz that had that "60's slim C-shape neck with a 7.25" radius". Couldn't find one anywhere. Found all the Jazz basses seemed to have that same width at the nut (just under 1½") but none of them were slim. They were all thick necks what I refer to as fat necks.
Then in 1985 while working part-time at a music store while back at college, someone brought in my current bass as a trade-in. When I played it, it felt like coming home. so I bought it and have played it for the last 36-years. I didn't buy it because it had the 70's-era pickup spacing (4" center to center), or because it was Olympic white, or because it had a white bound maple neck. I bought it because the neck shape, profile AND radius was the same as my 1965 Jazz. Most people thing there's not much difference between a 7.25" radius and a 9.5" radius, but the difference of course is that the 9.5" radius is flatter across its width than 7.25" radius. They can be made the same width and still have a different radius. When I pickup a bass with that radius, it just feels off to me...so I don't play one with that radius.
If you can find a Jazz with that "60's slim C-shape neck with a 7.25" radius", pick it up and play it. You'll find that it is extremely comfortable to play and really is a very "fast" neck. You can't get one from Fender USA now unless you have it custom built. However there were a number of MIM Jazz basses that were made with that neck and their re-issues of the 62 and 60's basses do have that neck. The re-issues from Fender US do not have that neck on them, which is really a sad state of affairs. They pronounce how this has all the original features on it and then go and put a modern Jazz neck on it. That neck is what determines the playability of the bass...OK, I'll stop. I'm just ranting now. See if you can find a Jazz with that "60's slim C-shape neck with a 7.25" radius" and give it a try. I think you'll see in an instant what I mean.
of course I kid just came to me
