I did my first metric century about a month ago and have spent the last month with weak thumbs, leading to difficulty buttoning shirts, holding pens, etc. I'm fine now; thumb strength is almost fully restored.
Through my (admittedly risky) internet self diagnosis, I apparently had Cyclist's Palsy.
It resolves in a month or so, without further aggravation of the ulnar nerve.
I thought I developed it because of the stress on tissue between thumb and forefinger while riding on the hoods, but it is apparently due to pressure on the ulnar nerve via the heel of the hand, on the pinky side.
Others ever have this? Is it a bike fit issue? A Clydesdale/Athena issue?
Prevention seems the best remedy with good gloves and better handlebar padding (or a bike fitting). Thoughts on gloves?
Sounds like you're putting too much pressure on your hands, which means you're probably too stretched out over the top of the bike.
I'd start with a fitting, and then buy some good gloves (I like PI Gel Race shorties, and PI Cyclone full fingers). I say fitting first, because if you're putting too much pressure on your hands and you just get some padded gloves, the padding will compress the nerve even worse and amplify the issue.
I ran into the same issue on a half century with my mountain bike last month. The local shop guys had no real answer. I'm thinking vertical bar ends would at least let me shift positions for long stretches. I chalked it up to the ergonomics of a mountain bike not being proper for long distance highway riding. I've never run into the problem in urban or off-road riding, probably because my hands are moving around a lot.
Also, I agree padding may be making it worse. It's the same issue with saddles--a puffy padded seat is actually far less comfortable on long rides than a Brooks.
I also suspect that your handlebars are too low or stretched out. If you are not a pro-racer, you don't need to go that low. And if you do want to go that low, you can always just bend your elbows a little bit more or spend more time in the drops. No biggie.
Because of my body type (long thigh bones, medium torso length, and short arms), I prefer to ride stretched out more than most clydesdale riders. If I'm not stretched out, my knees repeatedly slap my forearms and/or elbows on the up-stroke, whenever my hands are on the hoods or in the drops. So, I naturally put more pressure on my hands than many riders out there.
My solution is to move my hands around a lot, such that I put my weight on different parts of my hands and wrists when I ride. Get the weight off of your palms. Use the outside of your hands, the joint area just below your fingers (I place mine on the very top of the brakes/shifters), pistol-grip the hoods, move down to the drops, and various hand positions on the back bar when going up hills (fist, fingers, heel of the hands, etc.). It works.
Yep. Sure sounds like cyclist's palsy to me. I had mine after my first 50-mile rides. I let mine go too long and eventually had to take 2 weeks completely off the bike to get back to 90% strength. Rough roads, long rides, ramping up distance too fast, not moving my hands around enough on the bars, and putting a lot of weight on my hands seem to be my problem. Thankfully it healed up - I would hate to ignore it then find that the nerves wouldn't recover and I'd have to live with a mostly useless R hand.