calamarichris

I've always gone with the narrowest Q-factor possible, but I recently built up a bike that had a non-performance crank and bottom bracket that were much wider (over 2cm wider at least than my usual Dura Ace 7800 crank & BB.) And I noticed that my legs were less prone to tightening up when digging deep/pedaling hard.

I'm a larger rider, 185 pounds, 6'2" with proportional hips, and I wonder if perhaps riders my size do not benefit from the narrowest Q-factor possible? There isn't much information on it (the best I was able to find so far is the below pasting on the Wikipedia entry, but my local bike fitter said that the narrowest-Q-factor is basically a wives tale that doesn't apply to everyone.
******Pasted from Wikipedia:
A larger Q Factor (wider tread) will mean less cornering clearance (while pedaling) for the same bottom bracket height and crank arm length. A smaller Q Factor (narrower tread) is desirable on faired recumbent bicycles because then the fairing can also be narrower, hence smaller and lighter.[4] Sheldon Brown said that a narrower tread is ergonomically superior because it more closely matches the nearly-inline track of human footsteps.[5]Research from The University of Birmingham in the United Kingdom suggests narrower Q Factors are more efficient, likely due to improved application of force during the pedal stroke, as well the potential for reduced knee variability and risk of injury.******

calamarichris

Has anyone else experimented with widening the "tread"/Q-factor? What did you learn?

How did you do it? Shift cleats inward?

Are Hollowtech spacers suitable for outboard bottom brackets to help?
I don't want to use the pedal spacers, because I don't need to go 2cm wider--perhaps 5 to 10 mm wider.

79pmooney

Interesting challenge, going to substantially wider Q-factor. I will not be of much help. I'm of the as-narrow-as-possible type. (My knees do not like wide Q-factors at all and have never seen too narrow. A bike they love is my latest fix gear with a narrow Phil Wood BB, set up asymmetrical for chainline on the right and crank close to the chainstay on the left. I do my best to stay away from Shimano cranks and look for older Sugino cranks because they are straighter with smaller clearances to chain and chainstay.

We all have to find what works of us. I love seeing the creativity people use to meet that need.

Ben

trailangel

Standing up going uphill you will find if the Q gets too wide you are fighting the bars/bike.

calamarichris

I actually experienced the reverse when standing with these wider cranks. One thing I've been incorporating in my focus when training is dynamically and fluidly bracing one pedal against the other when pedaling. It might simply be psychosomatic, but I've found that when my focus is good and I'm able to do it well, it feels stronger and easier, AND my HR-to-watts ratio also confirms its benefit. And when I did it with the wider cranks, the additional leverage was slightly offset by the awkward lateral feeling of the wideness. it didn't exactly feel like I was fighting the bars (which are 52cm wide, to accommodate the dog chariot.) or bike though.







So today I drove up to Santa Monica visit Nate Loyal to check on this. He explained to me why and how I do not need a wider Q-factor. Also did an 8-year check up on my fit on 3 bikes. He left a lazer pointed at my knees while I pedaled for a few minutes and he believed going wider would be a mistake.

My saddle on my "base" bike, (my beloved 86 Schwinn Peloton) had somehow crept back and down over half a centimeter since I last saw Nate in 2010.


A lot happened over the last 8 years. He's fathered two kids, I've broken 6 (or so) bones, including a femur, which I feared would affect my leg strength imbalance. Thankfully it appears I dodged that bullet, but Nate told me a few stories about clients of his who'd broken femurs, who'd had some interesting anatomic anomalies. In addition to Nate's expertise and meticulosity when performing the personal fit, it was also an enlightening experience.


LA traffic just gets worse and worse every time I go up there, (which happily is not often), but Nate is worth the drive.

fietsbob

I intentionally widened the Q on my touring bike because I started the trip on the last weeks of February and wore shoe-covers to keep mt feet warmer and drier,

with pedal extenders , so those shoe covers did not rub against the crank arms , with every pedal stroke .. you get used to it .. Bike tour was 3 seasons long..

I now have a somewhat wide setup to get the chain-line right, for the requirements of the Rohloff hub in the back..

Single chainring on inside of crank spider , disc chain guard on the outside...








....

philbob57

I put 15 mm pedal extenders on my bike last year. I feel more natural on my bike. My knees go straight up and down almost automatically. Without the extenders, I need to concentrate to do that.

I'm a clyde, though - big thighs.

tyrion

Wider Q-factors are much more comfortable to me. Narrow Q-factors give me a funny feeling in my knees - doesn't feel right. I use pedal extenders on some bikes. (I'm big, 6'5").

Nikola88

I use 20mm pedal extenders on my road/fixed bikes, my hips are a little bit wider and i found that my knees feel better now, especially when riding single speed (it even helped with toe overlap on one bike), its easy to try, there are cheap 15mm ones on ebay

ride_2_fast

I have been riding all sorts of bikes..road, CX and mostly MTB... Lately for last 10y almost exclusively MTB... there Q factor (and naturally stance too )... Q being around 168- 170 mm for shimano XTR triple and now for 1x12 SRAM boost cranks too.
Lately hopped on my older CX bike with Specialized Carbon Pro FACT crankset which measured is about 149mm Q-factor. Substantially less.
I felt quite a discomfort in hips when riding the and felt less power to cranks on this narrower Q-factor of CX bike... I was also slower on gravel when compared the two bike with same tires/wheelset combo.... which was a unexpected first, but given the discomfort understandable....

So I feel the same as OP.
I too am about 180lb and 6'2'', like to use wider saddle 155mm generally so can assume wider hips.....
Looking at ways to extend stance by 20mm which is not easy with Shimano XTR pedals... axle options are not there for 2x10mm increase and pedal axle extenders I am finding are mostly 20mm each side, which is too much... Any suggestions there?

Ed Wiser

I found this video helpful to explain it to me.

margoC

I need a wider Q. My right foot has always pointed out somewhat. I've always had to adjust my cleats at the maximum angle to pedal comfortably.

Fast forward 15 years. I now no longer ride a road bike but after a recent vacation I dusted off my "comfort" bike. I've been tweaking it for a couple weeks now.

This weekend I got wider mtb pedals and extenders. What a difference!! For the first time since I can remember I enjoyed a ride without thinking about my knees and feet!

At first I put both extenders on but my left foot wanted to creep back to a closer position. I took that one off. My right foot can be in the position natural for it. I rode 10 miles!

I had given up on cycling altogether after several knee hand and shoulder surgeries. My right knee has been replaced. I should also mention I'm 63. I resorted to walking and hiking as recreation but after riding a beach cruiser on vacation I decided a little leisure cycling would be therapeutic for my knees.

I'm not crazy about my new upright riding position but I can ride pain free! And I'm finding it very enjoyable. It's awkward riding with so much weight on my butt but I have severe neck injuries in addition to other ortho problems and it isn't in the cards anymore. I tried and tried to make it work years ago.

My position wasn't that extreme when I first got that bike, I'm guessing the surgery must have exerbated an underlying issue.

I'm just thrilled I found a fit that makes cycling fun again. I can ride a lot of traffic free miles in my neighborhood and there are some stretches I can burn the carbon out. I can even run errands at the store!

63rickert

My bikes all have very narrow Q. As little as 134mm and high of 142. Requires antique parts. My brother, who is sometimes mistaken for a twin, wants >160mm and will not complain about >170mm. He is not wrong.

Short riders on wide cranks can look like they are trying to ride a big horse. For those riders it is sort of obvious they should try narrower. Anyone else it is guesswork. If it works for you, good enough. Trying something different is always worthwhile. Even if you hated narrow (wide) last time you rode it give it another try if some years have gone by.

madonemike

It's interesting how times change. Back when this thread started, few riders knew about Q factor. Now, most riders I know, know a lot about Q factor, and there are many product options to match your stance width to your hip width, if that's what you prefer.

79pmooney

I suspect some of this is because tires are getting wider, number of cogs is going up and dropout spacing ha increased. And the word has gotten back to manufacturers and innovators that these changes, all driving bigger Q-factors aren't to everybody's liking.

Iride01 

Way way back in 2019? Or perhaps you thought this was from 1819?

Welcome to BF, but Q factor has been a known thing for quite a while. I'm pretty sure I'd seen the term used back into my younger days without internet in the 70's and before.

prj71

I don't even notice the Q-factor between my road bike, mountain bike and fat bike. All feels the same to me.

koala logs

There are advantages to wide Q factor. Like in a steep climb while seated pedaling, you can "lock" your quads and calves and just sway your body left and right to drive the pedals with your waist and glutes. It's a clever way to rest your tired quads and calves up a long and steep climb.

If you know that pedaling technique it can save you from doing the "walk of shame" up a steep climb.

One thing I'll never do however is use pedal extenders to get wider Q factor. If my bike has narrow Q factor like a road bike, I won't change it a bit. The advantage of wide q-factor is only marginal. The technique I described above can be adapted to narrow Q factor by using more glutes and less waist to drive the pedals. If you have strong glutes, the Q-factor won't even matter.

Making a narrow Q bike like a road bike wider with pedal extender is risky. With the low BB of road bikes, it increases risk of ground strike. If you stand to pedal often, the pedal extender increases the load on the crank and the chance of the pedal breaking off the crank which can result to a serious accident if that happened while pedaling out of the saddle.

63rickert

Nope. The term 'Q' was created by Grant Peterson in early 90s during his stint as sales manager for Bridgestone USA. Before that it was called 'tread' and while a few were aware of the factor not much was made of it because the range between different cranks was not that great. Shimano and mountain bikes changed what had been static a long time.

63rickert

Nope. The term 'Q' was created by Grant Peterson in early 90s during his stint as sales manager for Bridgestone USA. Before that it was called 'tread' and while a few were aware of the factor not much was made of it because the range between different cranks was not that great. Shimano and mountain bikes changed what had been static a long time.

Iride01 

Tread! I knew there was some other term for it. That was bugging me a tad. But not so much that I looked.

Thanks for jogging my memory and reminding me of of that.

GAtkins

A wider Q factor eliminated my hip pain.

xseal

A professional bike fitting can tell you. For my road bike fitting they recommended 3mm wider/longer pedal spindles than standard, for a 6mm wider Q factor. Depends on the width of your hips. Wider hips need wider foot position to keep legs/knees in line.

Moisture

I find that it depends on the width of the saddle you are using.

GAtkins

I recently went from a 138mm (Bontrager Arvada Pro) to a 165mm saddle (Bontrager Verse Pro) (tried a 155mm). I have a wide arse. Much better. Should have done it years ago.