There are all kinds of reasons why people pursue voluntary castration. Reduced libido, better physical appearance, gender identity alignment, religion, or even fulfilling a sexual fantasy. But here's a reason for castration I don't hear about often:

Testicles are uncomfortable.

Every male has painfully pinched his privates when wearing jeans or tight pants. In sports, there is a very good chance of taking an excruciating shot to the balls. And let's not even talk about the pain and suffering one endures when riding a bicycle or motorcycle.

For eunuchs, comfortably riding a bike without crushing your testicles is one of the great joys of life.

I will agree with this, going out for a ride has never been more comfortable, you don't have the seat push up into them and when wearing lycra you have the bonus of being flat.

I never did long rides. I just use my bike to locomotion and the discomfort is insignificant to me.

I can't think in any other situation where my balls are uncomfortable, as long as I don't wear underwear.

Have you ever ridden a racing bike? Those long, narrow road bike saddles are brutal on the testicles for long rides. I've never done any serious mountain biking, but I've been told mountain bikers get more testicular injuries that road bike riders.

As far as motorcycles go, bumps and potholes can bounce you up and down slamming your testicles onto the seat or the gas tank.

For eunuchs, riding a bike is so much more comfortable.

I never had any problems w/ either a pedal bike or a motorcycle, but I wasn't an extreme rider, and tended to set my pedal bike so the seat was tilted slightly forwards... I also note that they now sell 'gender specific' pedal bike seats w/ cut out recesses to take some of the load off the tender bits.

Motorcycles again probably depends a lot on the bike and the riding style - I rode touring-style bikes and never felt uncomfortable. I've tried sitting on a few "crotch rockets" and found them uncomfortable, but more the load on wrists and shoulders than sitting on my balls....

However it is worth noting that there has been a long trend on bike tanks to have gas caps that are more flush with the top of the tank, or at least have a smooth surface and approach from the back of the bike... Back in the early days, especially on some of the Brit bikes, one of the "cool" accessories was the spiky gas cap, and even stock bikes had caps that just stuck up out of the tank... This started to go out of fashion when more than a few (not sure of exact numbers) riders had some type of front-end hit, leading to a launch over the handlebars and leaving a couple things lodged on the gas cap....
(No therapist letter required.... )

WheelyFixed