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Greetings, Building up a bike which will accept both 156Q and 168Q and wondered what the effects/advantages/disadvantages of going with the narrower Q-factor would be. I'm 195lbs and around 5'11 with a 32-34' waist if that helps.
-Has anyone ridden both Q-factors? and what do you think of a 156Q
 

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> /dev/null 2&>1
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Allegedly, narrower Q-factor is more efficient, because it more closely resembles the width of your feet when walking/running. I have never seen a formal study however, and you might need a power meter and need to measure output over time to detect it.

Sheldon's Q-factor definition is in the Tread definition (#2)
Sheldon Brown's Bicycle Glossary Tp--Tz
 

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Carbon & Ti rule
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I have both & there is very little in it.

If anything with the 168Q I feel a little more sure footed on the bike.

I have a friend that had 156q & we took them off his bike because he was scuffing the cranks & his bike with his shoes.

I can run 156Q no problems, But they are not for everyone, Short CS & big shoes make it even worse.
 

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I agree with muzzanic. I feel much more sure footed with the 168.
 

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ballbuster
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I like narrow Q-Factor myself, but yeah... like others have said, I think it's like audiophiles trying to tell you that the silver solder in their $3000 preamps sound better than lead solder.... like picking gnat shiz out of pepper, as they say.

I used to run 1st generation Shimano LX Hollowtech2 cranks. The Q on those cranks was annoyingly wide, but still not so bad I was motivated to change them out for that a lone. I would still be running those cranks if I didn't move to 180mm cranks.

I'm currently running M952 XTR 180mm cranks on a 112mm single/DH bottom bracket. I love this combo, but kinda heavy by today's standards. Also, Spiderless charinrings are getting hard to find. Nobody else seems to make a spiderless crank these days in 180mm, except for Enos.
 

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I like narrow Q-Factor myself, but yeah... like others have said, I think it's like audiophiles trying to tell you that the silver solder in their $3000 preamps sound better than lead solder.... like picking gnat shiz out of pepper, as they say.

I used to run 1st generation Shimano LX Hollowtech2 cranks. The Q on those cranks was annoyingly wide, but still not so bad I was motivated to change them out for that a lone. I would still be running those cranks if I didn't move to 180mm cranks.

I'm currently running M952 XTR 180mm cranks on a 112mm single/DH bottom bracket. I love this combo, but kinda heavy by today's standards. Also, Spiderless charinrings are getting hard to find. Nobody else seems to make a spiderless crank these days in 180mm, except for Enos.
I too love my 180 crank!

Sent from my SAMSUNG-SGH-I537 using Tapatalk
 

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1*14*29*2.1 & 1*1*29*2.4
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I like a wide Q. I use a 123 BB and it works well also with my SS chainlines. One thing to consider, which is important to me is that body geo plays a part. I have feet that are toes out-heel in. I have trouble keeping my heels from contacting my cranks and chainstays, and so I feel Q factor isn't important for me. What matters for me is where my heel is, not my toe. Since the weight and force from the body and leg goes through the heel to the toe, I figure a wide Q puts my heel in the right place.
 

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I try to run narrow Qfactors as much as possible, mostly by using narrow bottom bracket (108/110/111/112mm) and narrow square cranks (m900's) but is not much you can do with the newer types since the Bottom bracket length is fix..

Another great side effect of narrow QF is less pedal strikes when the bike is lean to the sides.

They just feel better and I'm pretty big at 6'2" with 36" pants.

Ps: when I ride my fatbike or my Nicolai with a 100mm (151mm BB) it feels weird..
 
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