anybody know if its worth taking my bike out there in september?

Absolutely. The trails are fantastic and the scenery is stunning. There is a wealth of trail information on the net.
Enjoy

I sprained my ankle a few days before we got there… Was gutted…

Dont leave home without it!

Trails are fantastic. Try Mr Toads Wild Ride, and the Armstrong Trail.

The Tahoe Bike Shop at South Lake Tahoe were very helpful.

We rode trails all around the lake….on the ridges.

You’ll have a great time.

Certainly worth it for the views alone, let alone the riding (which is supposed to be good too).

There is a bike park too with a gondola and lifts and things:-
http://www.northstarattahoe.com/info/ski/the-mountain/mountain-hours.asp?category=activities-summer

One of the most memerable rides I every did was round there. Take a camera. Its nothing short of spectacular.

You can hire bikes there, my girlfriend at the time hired a Kona coiler which was pretty bloody good. Made a tit of myself outside the hire place after forgeting the brakes are the ‘wrong’ way round.

WATCH OUT FOR THESE AND THESE!

Look out for the wildlife too. I saw a pack of coyote.
The gambling places leave a lot to be desired, worth having a look though for soem nightime entertainment.