Loose chain

[senior micro]

I give my chain the "toe check" before every ride. Its been OK since the last adjustment about 3 weeks ago. This morn it was looking acceptable before I left for my 20 mile ride to work. I rechecked it when I got to work, and it was borderline OK. When I went out at noon I toed it again and it was way slack. This chain is about a year old and was put on at a shop I trust. It wasn't cheap, but it wasn't top of the line. I try to stick to a reasonable cleaning and lube/coat schedule. The rear wheel seems to be properly aligned. If I let go of the grips, the bike stays on course, no problem. I haven't noticed any obvious damage to the rear sprocket.

[RVertigo]

Chains stretch when they're warm...

Or something could have come loose...

Just adjust it.    It's easy.

[senior micro]

AWK!! Just checked. Looked like everything is tight. I think I'll go home on surface streets tonight. No sense threading rush hour traffic with an overly loose chain. I'll adjust it as soon as I get home. I was wondering how I could squander my down time.

[scratch]

Check your chain when you get home.  You should check your chain when it's warm.  I've lost 3/8ths of a inch of slack when I checked the difference between a cold chain and a warm chain.  Here's a visual (not of the difference): http://gstwins.com/gsboard/index.php?topic=28290.msg304153#msg304153
Also, check it in neutral.  On the sidestand.