I'm 48, in decent shape (6'3", 195 lbs), and just started road biking about 2.5 months ago. I've been building up my distance, starting with 12-mile rides and now I'm up to 45-50 mile rides.

I want to do the MS150 in two weeks, which is what I've been working up to, but it looks like I've hit a problem: my left knee is starting to hurt like h*ll, about 25 miles into my rides. I can push through it for a while, but I suspect it's not something that I should just ignore and tough out - it's getting bad enough that I'm losing all the power in my left leg.

It started when I was out with the wife on the new tandem - I was pushing pretty hard to get us both up a hill. It wasn't a sudden collapse or anything, but I could feel the ache starting then.

I normally keep a fairly high cadence (70-75) and don't try to grind up hills. Except when I was on the tandem!

The pain is on the outside of my left knee, outside and around my kneecap. I've been fitted on my bike, and am reasonably confident that the geometry of my fit is ok. However, I'm thinking it may have something to do with the angle of my foot (in relation to my knee) as I'm clipped in. I've ruled out about everything else...

Not coincidentally, on the tandem I was wearing my secondary biking shoes, and discovered that the cleat in my left shoe was way off, forcing my foot in too close to the crank. This would explain the strain on the left side of my knee.

I did reposition the cleat, but by then there was so much pain that it didn't really help, now I'm limping up and down stairs, etc, waiting for things to get back to normal.

What do y'all think? Probably the cleat and wait for it to straighten itself out? Or could it be something else?

Very depressing... Hope I don't have to bag out on the MS150. Any thoughts on helping the recovery along?