# Is Q-factor a big deal to worry about?



## Varaxis (Mar 16, 2010)

I was doing a little digging around about Q-factor, and why some motor makers hype up their narrower Q-factors as feeling more normal/natural, and found a few studies to give me a hint on this issue.

One study suggested that going from 150-180 Q factor to 90-120 Q factor improved general mechanical efficiency enough to save 4-5 W. (https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0838.2012.01479.x)

A more recent study also tests on Q-factors of 90, 120, 150, and 180, and said that self selected Q factor performed best, and that there wasn't really any significant difference in general mechanical efficiency nor knee stability between them. https://etheses.bham.ac.uk/id/eprint/5523/1/Disley14PhD.pdf

A 2020 study hypothesized that the wider the Q factor would mimic wider gait width in walking, and lessons learned from gait modification could benefit cycling, but results showed the opposite was true regarding knee rotation, suggesting that wide Q factors shouldn't be a problem for those with knee problems and are sensitive to wider foot stances. (https://www.sciencedirect.com/science/article/pii/S2095254619301061)

Quote from a Cycling Weekly article:

"You really get a sense of the importance of Q Factor if you ride a fat bike," says Specialized's David Alexander. "In order to get the chain past those fat tyres, the cassette needs to be pushed out further. The bottom bracket therefore has to go über wide, and the bottom bracket is massive on most fat bikes. So when you get on a fat bike you feel like you're trying to pedal the sides of a horse. It is an odd experience.​
"At the other end, going too narrow with your Q-Factor in the search for speed has problems, too. When Lance Armstrong tried to copy Jan Ullrich's Walser time trial bike with an ultra-narrow machine, the results weren't all positive. Although that produced some increased power to begin with and was initially fast, the speed rapidly and dramatically dropped away on an average length time trial of between 28 and 40 kilometres," Alexander recalls.​
"It was initially faster but there was no sustainability. So a narrow Q Factor doesn't necessarily afford every rider with a sustainable performance benefit. It might give you something to begin with because you think you're being more aero, but it doesn't work for everyone."​​
My current setup has me running pedal extenders with flat pedals, with my feet landing on them however feels natural. I suppose I gotten used to enough that I had to do it to my other bikes too.


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## rangeriderdave (Aug 29, 2008)

I took a bike fitting class , their take on Q factor was the bike should be made to fit the rider. So depending on your body it could be nothing or it could affect you .During the class we fitted each other ,I found out that I should be using extenders .I never got around to getting any ,I haven't had any problems. I also ride off road moto's ,the pegs are much wider than peddles, and you aren't peddling . But I can go back and forth without any issues.


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## Ilovedoods (Jun 22, 2020)

No, it’s not about the bike. Hammer the climbs and shred the dh. Quit worrying about all the technical bs and work on your riding.


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