No idea about bench press etc. But i was really surprised when i counted the weight on my dumbbells and im doing same as that 6 Foot '5, 16 stone geeza Dumbbells are 22.5 kg each, (like 50 lbs) And i do 3 sets of 15 with them. About twice a week, Im not struggling no more like i did a while ago so im gonna buy some more soon and move up to 25kg cause ive ran out of weights. I'm not really seriously into it cause i have a fair bit of muscle naturally, which is why i only do twice a week not sure about them affecting my riding to be honest, I just do them to make sure i don't get weaker. I am 5'11 also, weigh 172 pounds