Thursday, February 5, 2015

Fat bikes aren't slow

Fat bikes are changing the way we think about what bikes are capable of doing. By now everybody knows that the comically fat tires are able to maintain traction through and over surfaces that would seem difficult or impossible on skinnier tires. The downside, according to popular intuition and Internet experts, is that the large tire size means added rolling resistance. The belief in the added work of pushing the big rubber is the most insurmountable barrier to mainstream fat acceptance.

Last evening after the shop closed at 6pm, I rode my Ice Cream Truck, which is no lightweight, to weekly family dinner at my in-laws' palatial estate in New Brighton. I've done this ride many times (on at least 4 or 5 different bikes) by now, following one of the Google Maps bike routes through South Minneapolis, the U of M, Nordeast, and into New Brighton, for a grand total of 13 miles. Typically, with stoplights and other interruptions, this takes me around 75 minutes, even on a "summer bike". Along the way, I rode some bike lanes adjacent to high traffic streets. The bike lanes on these streets tend to accumulate a chaotic mixture of snow, rutted road slop, and ice chunks, in addition to the ever-present cracks and potholes. It was dark and cold (single digits Fahrenheit), and there was a persistently stiff headwind. These unpleasantries combined with traffic whizzing by a few feet from my left elbow had me ready to throw in the towel and head for home. But I tend to embrace a challenge, so I kept pedaling. My Dillinger 5 studded tires earned their high price tag time and time again, allowing me to pay attention to the traffic situation while they got a firm bite into the unpredictable road surface. After I got through the craziest part of the trip, in the area around the U of M, I checked the time. Because of the wind and the fact that I was riding my heavy wheels with studded tires, I was expecting to be later than usual, but I was making surprisingly good time. I pressed on. When I rolled into my in-laws' driveway, I checked the time. Total travel time: 67 minutes, which I believe to be a personal best. I wasn't trying to break my record. I just wanted to be on time for dinner.

What does it mean that I achieved one of my best times on a familiar route, while wearing heavy winter clothes, rolling studded tires, and fighting a freezing headwind, without actually trying to be fast? I think it means that the high rolling resistance of fat tires is a myth. Fat tires are definitely heavier and slower up hills, but on flat ground, there is nothing to lose. I'd actually make the case that the fatties are faster simply because I could ride through the shit without being careful to pick a line through the winter road hazards.


The Donut Guy said...

It makes sense. At one point I had a 5 inch travel (front and rear) and also own a rigid singlespeed.

On a rocky downhill trail at one of my local riding spots.... the 5 inch bike could just ram it's way through roots and rocks.

The SS on the same trail was faster because it forced me to read the trail better and as a result- I was often way faster on the rigid SS then I was on my SSer.

It forced me to be a better rider.

Anonymous said...

My fat tire bike consistently gets faster mph averages ( as per strava) than my fs 27.50 on the same trails without thinking about it or even trying to better my speed, better traction propels the bike forward with greater efficiency and although the downhills are slightly faster on the fs it is not enough to make up the time lost on flats and uphills. All my record breaking climbs are on the fat tire bike. My fs my soon go on th auction block.