Question: I’ve been getting into riding on Zwift on my smart trainer. Recently I’ve begun to feel numbness in my crotch after about 45 minutes. What can I do to eliminate this scary problem? — Walter H.
RBR Replies: Move around and stand up.
Most cyclists ride trainers predominantly in the saddle because there aren’t reasons to stand. Your living room has no small hills to sprint over, no stop signs to accelerate away from, no riding partners to hammer in the sprint. So we tend to sit and grind away, then constant crotch pressure leads to numbness.
Assuming that your riding position is correct, your saddle is level and it’s compatible with your anatomy, the solution is as simple as standing frequently to relieve numbing pressure. Make it a rule to get out of the saddle for at least one minute in every five. Set your watch’s countdown timer as a reminder if you tend to forget.
Also, make sure your bike isn’t pointed “downhill” on the trainer. Even a small angle can cause you to slide forward onto the saddle’s narrow nose, increasing pressure on the nerves between your sit bones.
Raise the front wheel with a block of wood or fat phone book or a commercial device meant to hold your wheel and level the bike. Some riders like it to be angled slightly “uphill” to help them stay back on the wide part of the saddle.
Finally, pay close attention to your outdoor rides. If you are experiencing any numbness at all riding outdoors too, then I’d suggest looking for a new saddle.