I currently have Tendonitis in my right achilles tendon, symptoms appeared about 3 weeks ago now.
It's an overuse injury normally and that's what I'm thinking in my case as I've recently upped the amount of cycling and running I do.
I did have slight symptoms back in June this year after doing a marathon MTB race and a couple of weeks rest cleared that up.
This time the symptoms/ pain is worse and it's been 3 weeks now with some improvement but still not right, about 70% towards normal I'd say.
My cycling buddy did mention my spd's and cycling shoes (Spesh body geometry ones) but I don't see how these could cause the tendonitis issue?
Having said that, I always used to use Sidi shoes with spd's and never had any issues.
So it's one of 3 things... too much exercise too soon, a cycling shoe/spd issue, or just age catching up with me lol!
I hope you see an improvement soon dyna-ti, I hate not being able to cycle/run and others don't seem to "get" how much of a pain in the arse this tendonitis thing is.