It's possible to carry two full sized 26" mountain bikes in a standard bob trailer, but it does take a bit of juggling and the bikes rattle around and rub on various parts of the trailer. It's an OK solution if you only need to do this once or twice, but I've found myself having to do this on more than a few occasions. Accordingly, a better solution was needed.
My first thoughts were to make a custom trailer for the purpose from the ground up, but when I reviewed my steel stockpile, I didn't have enough lightweight tubing to begin construction. As a result, I ended up building an extension for the bob trailer and a front wheel rack / holder. Here's what I came up with:
There's two parts and they are both easily removed from the bob trailer without any tools:
- rear extension: this holds the two rear wheels;
- front fork mount: this holds the forks by their dropouts.
Total weight of the additional items are 2560g including the two quick releases.
It's a surprising stable setup and very quick and easy to use. Total weight of the trailer when loaded with the two bikes must be around 30kg but the trailer tows well and there's good ground clearance at the rear. The two extra pieces just pop out when I don't need them, so my bob trailer isn't cluttered up with unnecessary stuff when I'm not carrying bikes.