Whether you’re looking to convert your road bike into a fixed gear or want to learn how a derailer functions, this site has all the info you could ever want — a giant glossary, bits of cycling history and plenty of specific instructions and photos.

I started doing home adjustments to my BMX when I was eight years-old. Always got hand-me-downs because I couldn’t afford the best parts, and sending my bike to a shop would have been more expensive than the parts. These days I am always working on a bike — either getting new bikes or always on the search to complete a vintage group of components.

Even with my experience, I’ve been using Sheldon’s site religiously for the last year and half, basically every week. When I purchased my first Italian frame last year, I needed the correct measurement for the bottom bracket, but had no idea where to find a figure I could trust. My friend recommended Sheldon’s site. Since then, his site has helped me purchase, repair and build two road bikes (my Gios Torino and a Tom Ritchey built Palo Alto). And I just picked up a Tommasini that will also need a complete overhaul (I am currently on a vintage Italian kick). When I first saw some Gios Torinos on Craigslist, I went to the site to get the lowdown for purchasing. I needed to know what the value is or isn’t, if the bike is rare or not and what to look for, and also signs of a knock off.

I’ve seen, in the process, just how precise Sheldon’s attention to detail is. I had no idea that there was English and Italian threading. I learned that Italian is 36 mm X 24 tpi and English is 1.370″ X 24 tpi. Sheldon has a chart that gives you the measurements for every BB out there, anything from French to Swiss. And I totally didn’t listen to his tip on Italian threaded bottom brackets and paid the price. He notes how Italian BB’s tend to work their way out while riding. I experienced that on my commute home from work one day and ended up eating it right in front of a huge crowd. I wound up pulling out my crank and rethreading it with a tiny bit of lock tight, just as he recommends. Since then, no troubles whatsoever.

Even if you have no interest in working on your bike or going deeper than the basics of maintenance, this site can really boost your understanding of how a bike works (it has in my case) and even how to ride. There are great tips for beginners, including articles like “Everything You Wanted To Know About Shifting Your Bicycle’s Gears, But Were Afraid To Ask.”

-- Benjamin Gaffney 05/29/07

(Sheldon Brown (RIP) wrote a monthly column on maintenance and repairs for Bicycling Magazine in the late '70s and '80s; a number of them have been reprinted on his site -- SL — editors)