What can $134 do? It can change the world for someone in Africa by giving them a Buffalo bicycle from World Bicycle Relief. And it can earn you a chance to get one of these amazing prizes donated by some of the biggest and best companies in the industry. Check it out and donate now!

The teams at SRAM, Zipp, & Quarq have come together in a big way to support the 6th annual Rappstar Charity Challenge for World Bicycle Relief. Get dirty with a CX1 groupset. Own the road with RED22. Power up with an Elsa power meter. Or fly on Zipp Firecrest.

As in past years, the first 100 donors to Jordan Rapp’s World Bicycle Relief Charity Challenge will get a special prize. This year, it’s a limited edition World Bicycle Relief trucker hat from BOCO Gear.

Aero. Is. Everything. So goes the mantra for Specialized’s aerodynamic product development engineering team. They believe in it so much they built their own wind tunnel. Now you can win a once-in-a-lifetime chance to spend a day with them seeing just how much faster they can make you.

For the sixth consecutive year, First Endurance comes on board in a big way to help fuel the 6th Annual Rappstar Charity Challenge for World Bicycle Relief. Get a chance to win one of two $600 gift certificates.

First were bike fit systems. Then were bike fit tools, like motion capture and fit bikes. Finally it’s software, including a powerful program launched today that Slowtwitchers can demo.

We wrote about the GURU fit bike last year, in a series on fit tools. Here we’re talking about the entire GURU system, what it is, what it means for the future of retail and of how you and your bike interface.

Which among the 5 fit bikes reviewed is the best? Which is the best for the money? And why should consumers care at all?

Exit Cycling is to fit bikes what Lucy is to anthropologists: the missing link. All the fit bikes aforementioned owe something to this bike, and Exit is still going strong.

Our series on fit bikes continues with the incomparable Guru. The 2104 edition is without peer. If the original DFU was way ahead of its time, this new version is just as revolutionary.

Our look at the industry’s most important fit bikes (according to us) expands today. We’re looking at the Retul Muve and the bike by Shimano. Shimano’s isn’t out yet, it’s due out the middle of 2014.

Shimano, Cannondale (Guru), Trek (Purely Custom), and Specialized (Retul), join Exit Cycling as makers of first-rate fit bikes. If you’re a fitter, a coach, or a retail store, which among these bikes is for you? Here’s your guide.