Reader’s Ride(s) – Calvin and Bob

Stephen from up in Powell River, BC, Canada sent us this story about the trail building set up that he made for his Ice Cream Truck. Take it away, Stephen!

This is Calvin & Bob.

I modified my B.O.B. trailer to fit ‘Calvin’, my Surly Ice Cream Truck. The standard 26” BOB yoke was lengthened by welding a 4-1/2” long flat bar to each front arm of the yoke. Then the yoke was generously bent open by hand.

I used the BOB’s supplied quick-release skewer and bobbins, but I had to lengthen the shaft of the skewer to 8-3/4” long. This was done by cutting and welding in a piece from another skewer. This quick release now sits inside the 12mm pipe axle that comes on the bicycle.

The BOB’s wheel is from a wheelbarrow and can be found at a local hardware store. The wheel is 6-3/4” diameter, the tire is 3” wide, and overall the wheel and tire measure 13” diameter. I replaced the wheelbarrow wheel’s low-quality bearings with better sealed bearings and mounted it to a bicycle axle with some spacers. The fat wheel with low tire-pressure really keeps the trailer quiet and less bouncy on the trails.


The milk crate is bolted to the trailer deck. A lid from a Rubbermaid ‘Actionpacker’ fits atop and is hooked on with a bungee cord. The BOB can hold all the following trail-building tools at once:  water bottle, gas bottle, shovel, fire-rake, axe, brush cutters, machete, and bow saw (and a chainsaw too with the lid removed). Plus there’s room left over for your hiking boots and lunch!


If you’ve got a fat-bike that you are proud of, let me know about it. Send words and pix to and you may see your pride and joy on these here pages!

About Greg Smith 1127 Articles
Greg Smith, known to many site visitors as Sven Hammer, founded in 2011 and the site quickly became the #1 online community for all things Fat. You can currently find Greg outfitting Everyday Cycles; a Milwaukee, WI retailer of gear for fatbikers, adventure cyclists and urban assault riders.


  1. could you show more photos of the build process of the Bob trailer. its exactly what I want to build. still unclear on the skewer,and trailer wheel bearings. its seems Bob shod make one if these soon.

  2. Love the adaptation. I’d love to see more close-ups of the yoke and welded pieces and how they fit to the bike. I have a 190 rear end fatty that I’d love to be able to put a trailer on for trail work.

  3. I agree with these guys that some close ups of the mods you made to the front end of the trailer arms would really help me out. Already ordered and received a second Bob yoke, hoping to do exactly the same type of mod over the holidays.

  4. I’m in the process of setting up my old BOB yak (from 2003) for use with my Rocky Mountain Blizzard. I ordered a new 29″ bob yoke from biketrailershop and used a 197mm though axle from Robert axle project. Had to open up the yoke with my hands a little, then tweaked the dropouts a little with a crescent wrench to line them up again. There’s good clearance around the tire.

    Looking into replacing the rear bob wheel with something fat too. From photo’s it looks like there was a design change in the rear of the bob frame to hold the wheel. Mine has two smaller struts parallel to the wheel, that limit the tire size to 3″ wide. Would need a little welding to get it to work.

    Would be interested in more details about the rear wheel bearings and spacing.

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