If you happen to be a bigger guy maybe looking to start cycling to get fit, or perhaps you are fit and carry a lot of muscle.... Perhaps maybe you're coming from a bodybuilding, powerlifting or rugby-playing background, and you're looking to do some cycling to keep the fitness up or as an alternative for cardio during off-season, you would know that it is challenging to find bikes and bike components that are officially tested to take your weight.
Most production bike companies design bikes based off the average cyclist build - meaning pretty damn light (and not too tall, but that's a topic for another day). Components, too, are difficult to find. Just take wheels for example. Most wheels (and frames) are built to support a total weight of 110kg to 115kg, meaning rider + bike + accessories = 110kg - 115kg. This essentially means that if your bike is say 7kg and two bottles of water weight 1kg, you would have to be 102kg to 107kg.
Now we're not going to pretend that 102kg is the average size of a human being, people heavier than 107kg is pretty common, especially if you're looking at cycling to get yourself fit and maybe lose some weight. The average professional rugby player weighs around 105kg and powerlifters can go way north of 110kg.
Because a lot of production bike companies do not manufacturer bikes that support heavier riders, the next avenue to look into would be custom bikes and components (this applies to riders who are too tall for production bikes as well). One of our interns is a heavy guy and he used to commute on his mountain bike daily. He's currently getting a custom frame and considering a custom wheelset for himself as well.
However, with that said, going custom is almost always not very cheap. Essentially, the penalty fees are imposed on heavier riders for simply being big, or heavy. This isn't the most welcoming or inclusive to someone who's only starting to look into getting into the hobby or sport.
Bicycling recently wrote about this as well. And they were having trouble looking for a bike for a friend of theirs, who happened to be pretty big. They looked into going custom as well as the easiest alternative, but looking further, Matt Phillips, senior test editor for Bicycling, managed to find a production bike, but not without some digging and challenge!