Influence has two main connotations that affect doesn't. The first is that of relation to process rather than state, so that something might affect a rock but rarely would circumstances arise where we could speak of that rock being influenced. The second, and weaker, connotation is of emotive response being involved; this is probably the connotation that makes it feel less appropriate to use in reference to a bike's performance. (We do speak of mechanistic processes being influenced, though, especially complex ones.)
Would you please explain these explanations more readily? especially I have some problem with the bold part. I am much too confused to differentiate between these.
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