My BF and I had SO much fun on our guided 12 mile bike ride from the bike shop to Hoover Dam. The scenery was amazing and the Railroad Trail was really cool! If you're lucky you might even spot a Bighorn Sheep! A delicious lunch was provided and we were well cared for in the hydration department. A tour of the powerplant at Hoover Dam was also included. We were too chicken to bike back to the bike shop (it was all up hill) so we opted for a 3 mile bike ride to the pick-up spot instead. And, we were picked up promptly at our hotel in the AM and dropped off too!
Now let's get down to business... I booked this bike tour through Awesome Adventure Guide. Their customer service is great but if you have a rental car at your disposal I would suggest driving to the bike shop (about 30 mins from the Las Vegas strip) to rent a bike and book your tour through All Mountain Cyclery instead.
Here's why:
Awesome Adventure Guide - $129/person + $10 fee
All Mountain Cyclery - $110/person (guided)
$75/person (self-guided)
The prices above are only for the bike tour of Hoover Dam and Lake Mead. You'll have to browse both sites for more information and other tours if this doesn't float your boat. I'm also not sure if lunch and Hoover Dam tour tickets are provided if you go through All Mountain Cyclery. And I was told by Awesome Adventure Guide that we would make a stop at Lake Mead but we didn't so make sure you ask about that too.
And last but certainly not least, I have to give praise to Jeff Frampton (owner) and "Downhill" Mike (guide) who were so down to earth and friendly! Because of them our initial hesitation of the tour quickly subsided and we had nothing but fun from the second we started pedaling!
PS If you can't make it to Sin City, you can find "Downhill" Mike at Whiteface during the summer! http://www.downhillmike.com/index.php?option=com_frontpage&Itemid=1