I have ran in asics 2100 GTs a bunch of times and before that the 2090\\\'s. I have never had a problem with either shoe. Recently I moved to a comprable shoe- Brooks Adrenaline 2. I am on my 2nd pair of these (200ish miles in) and now my achilles\\\' have been acting up. Do you think this has to do with the shoe or is it something else? Up to this week I am running somewhere between 90-100 miles per week with a pretty slow build up. Does it make sense that after a few years my footstrike has changed and I now need a different type of shoes? Thank you.