More power on gravel than on road bike because of wider q-factor?

Recently, I realized that the pedal stroke on my gravel bike is different than on my roadbike. On the gravel, I feel like I am pushing through the pedals with a really even pressure distribution on my feet. Also it feels very stable and secure.
On my roadbike it felt more like I was pushing through the outer side of my feet, almost like “falling over the cliff”. Shoes are the same (Bontrager XXX), only one is spd and the other is spd-sl version.

So, I decided to investigate into it. After chaning pedals between the bikes, I realized that the difference is because of two reasons:

  1. The q-factor on my gravel is wider by about 3-4 mm per side (so around 7mm in total).
  2. The cleats are not as straight positioned as on my roadbike. The heels are more towards the chainstay, whereas on my roadbike they are more straight.

After using washers to extend the spindle on my roadbike (only temporary for the fit) and changing the cleat position, the stroke feels far more powerful. I tested on the trainer with resistance and it also feels like I am now using my quads more whereas before it felt like my power was coming to a good degree from the outer side of my quads/hips. I have to test more, especially in terms of cadence and economy, but so far it feels good and I ordered a pair of ultegra pedals with longer axles.

fwiw: I also tested on my MTB, which has a MUCH wider q-factor and I feel like that is too much. Seems like the 3-4mm extension is the sweetspot for me.

Did anyone experience the same or increase the q-factor on his roadbike and can share his experiences?

I have not really noticed a q-factor issue. Cleat position is far more sensitive for me: and my bike fitter has adjusted that width wise as well as fore aft.

You do not mention crank length. Are the cranks the same length?

yes, same crank length on both bikes. saddle height, etc. is also comparable.

I tend to prefer the term stance width, which is a combination of Q factor, pedal spindle length, and cleat position. The formal definition of Q factor is the width from one outside face of the crankset to the other, so it’s fixed for a crankset, and you generally have pretty few options unless you want to go change the entire bike. (But yes, differences exist.) in common speech, though, I think people may say Q-factor but mean stance width. Which is fine.

Anyway, if you meant that you’re more sensitive to your cleats’ lateral position, then you are in fact adjusting your stance width a bit. If you were talking fore-aft or rotational position, then that’s a different thing.

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echoing above, stance width matters for power generation and recovery in training etc. I run 1-2 pedal washers depending on the bike and pedal system to match the center cleat positon on all my bikes, and its wider than most standard road crank/pedal systems

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I was experiencing some outer knee pain. Went through a fit with a great local guy and we talked about the q-factor. We decided to go with pedals with the longer axels. Absolutely worked for me.

Longer axels

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I changed up my pedals last year and took the opportunity to buy ones with longer spindles (Ultegra SPD-SL).

I’m quite tall (190cm / 6’3”) and always felt like my stance was a little narrower than was idea (it just felt a little ‘off’).

Anyway, it could be placebo effect but it feels a lot more comfortable on longer rides (possibly less pinching at the saddle nose) and power delivery, particularly when standing seems somehow easier to maintain, especially in a rhythm when climbing.

:smiley:

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Outer knee pain, or excessive outer hip soreness is a good indicator.

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What power meters are you using on each bike?

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Do some a/b power tests and let us know if you see any differences. Best to use the same bike and same power meter with the different length pedals/shoes.

Did you experience differences in your sprint? Whether positive or negative?

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4iiii left sided, but only on the roadbike. However, I am planning to do a full power test on the trainer with the same bike, but with 2 pais of pedals. Ultegra standard and ultegra with 4mm longer axle.

Yes, will probably do that. I am having my booster vaccine in a few days. Will do the tests after that.

Still, I wonder whether that test is fair as I rode the standard shimanos for many years and ten-thousands of kilometres. Probably, my body is used to that and would need to adapt to wider spindles first. Still, I am planning to do the test.

Oh.

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Not really that I noticed. I think probably I feel more ‘stable’ and comfortable when pushing hard, which may well in turn mean I’m able to offer more of myself when at the limit, but honestly I don’t think it would be so significant as to be obviously noticeable to someone as average as I am riding-wise.

TBH even if I was able to put out say 50 more watts then I’m not sure if I’d be able to notice that at the time (I don’t generally look at my head unit when sprinting) - and if I check the data afterwards I wouldn’t be able to discern if my power numbers were just down to a ‘good day’ as opposed to a change in stance.

:+1:t2:

@Tim_87 I think it’s interesting that you are noticing such a difference based on Q-factor! It’s challenging my belief that Q-factor doesn’t matter too much & I hope you’ll follow up this post with some rigorous testing on the trainer. I’d be curious to see what you find.

My belief that q-factor doesn’t matter that much is based on my years helping people learn how to pull/clean/snatch. I’ve never been able to observe a material difference in the power an individual can express during the first part of the pull based on moving their feet pos’n by single digit millimeters. Now, the counter argument to that in your case is that I would never have been able to detect a pound or so difference in pulling power…but (based on data I have taken) an extra pound of pressure on a bicycle crank represents a LOT OF WATTS! :smiley: So there’s that.

I’ve also observed, while helping kids to learn how to ride bikes, that most children ride around just fine on a Q-factor that is monstrous compared to their hip width. Doesn’t bother them at all. However, this is again just subjective observation! You might be on to something that would change my mind so I’ll be interested to see whatever data you collect.

Thanks for your thoughts on that topic.

Just to make it clear in advance: I don’t know if a larger q-factor (wider stance width) really brings more power, nor do I have reliable power data on the subject. Nevertheless, I’ve always noticed a difference when I’ve switched between individual bikes and can definitely make out differences in my pedal stroke and the way it feels. That’s why i wanted to find out through this post whether my experiences are mirrored with others.

I actually never intended to make a powertest with two different pedal lengths, but in the meantime I have become curious myself :slight_smile:

One more thought on the subject: when I compare the q-factor between a roadbike and a fatbike (or even a normal mtb) we are talking about centimeters, not millimeters. I can’t imagine that both widths are equally optimal for one single person. Probably there is a range that is tolerable. Nevertheless I think it is more likely that there will be measurable differences between the two extremes.

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