Q-Factor in triple vs. double, what problems, if any?
#26
First, make certain that the Q factor is different between the two cranks. Don't assume. Although BF wisdom (such as it is) will almost always claim that triples are wider between the pedals, it's not necessarily so.
Second, if one or the other crank is wider, make certain that the wider Q factor isn't the correct Q factor. It may be some other issue that's causing the problem. For women, it can often be that a little more space between the pedals is a good thing. (And, I wouldn't be shocked to find some compact somewhere that's wider than some triple.)
Second, if one or the other crank is wider, make certain that the wider Q factor isn't the correct Q factor. It may be some other issue that's causing the problem. For women, it can often be that a little more space between the pedals is a good thing. (And, I wouldn't be shocked to find some compact somewhere that's wider than some triple.)
Last edited by FlashBazbo; 12-13-10 at 05:47 PM.
#27
Live to ride ride to live
Joined: Aug 2006
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From: Austin, Texas
Bikes: Calfee Tetra Pro
Thanks for the feedback. I wasn't sure if going with a 12-27 or 12-29 was the better option. I would rarely, if ever, use a 29 but then when you need it, it is great to have it. If the jumps weren't too bad, I would probably go with the 12-29. The jumps on a 12-27 are something like 23-25-27. The rest of the cassette is the same between a 12-27 and a 12-29.
#28
Senior Member
Joined: Jun 2007
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From: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
First, make certain that the Q factor is different between the two cranks. Don't assume. Although BF wisdom (such as it is) will almost always claim that triples are wider between the pedals, it's not necessarily so.
Second, if one or the other crank is wider, make certain that the wider Q factor isn't the correct Q factor. It may be some other issue that's causing the problem. For women, it can often be that a little more space between the pedals is a good thing. (And, I wouldn't be shocked to find some compact somewhere that's wider than some triple.)
Second, if one or the other crank is wider, make certain that the wider Q factor isn't the correct Q factor. It may be some other issue that's causing the problem. For women, it can often be that a little more space between the pedals is a good thing. (And, I wouldn't be shocked to find some compact somewhere that's wider than some triple.)
Normally, to do such a thing, you would have to use a really wide square taper, probably for frame clearance issues, which a road bike will never have and using such a wide axle will also give chainline problems. Now, if this was a MTB crank we're talking about, then it's possible, but for road cranks, it's very unlikely that a double will have a wider Q-factor than a triple.
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Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
https://sanfrancisco.ibtimes.com/arti...ger-photos.htm
#29
Spin Meister
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From: California, USA
Bikes: Trek Ιmonda, 1961 Follis (French) road bike (I'm the original owner), a fixie, a mountain bike, etc.
It's the same with me.
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This post is a natural product. Slight variations in spelling and grammar enhance its individual character and beauty and are in no way to be considered flaws or defects.
#30
All of the input is great, but I didn't want to start another triple vs. compact debate.
I'm more concerned about a wider Q-factor predisposing me or my wife to injuries. I doubt that the triple caused her hip problem, but I'm curious about what effects it has on an injury that is already there.
If the wide Q-factor could hurt either one of us, I wouldn't hesitate to make both compact doubles.
I'm more concerned about a wider Q-factor predisposing me or my wife to injuries. I doubt that the triple caused her hip problem, but I'm curious about what effects it has on an injury that is already there.
If the wide Q-factor could hurt either one of us, I wouldn't hesitate to make both compact doubles.
#33
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From: Loveland, CO
Bikes: Cervelo Rouvida x 2
Some riders may also benefit from Lemond Wedges. I've read postings from Speedplay users who complain about the outer edge of the lolipop wearing out. The problem is foot misalignment, where the outer edge of the cleat is all that contacts the pedal. If the feet are properly aligned, there will be relatively even contact and wear. I discovered that I had the opposite problem, but only with my left foot. The spring clips of my X type cleat wore a groove in the pedal spindle. That a sign of forefoot valgus that require shim with the thick side on the outer part of the cleat.
I've ridden behind riders with some very odd leg movement while pedaling. One of the most common is the knee(s) flaring out much wider at the top of the stroke, rather than straight up and down. I've also seen knees that appear to be rotating in a circle at the top of the stroke and folls with a lot of side to side heel movmement.
https://www.cambriabike.com/shopexd.a...m=051000001100
I've ridden behind riders with some very odd leg movement while pedaling. One of the most common is the knee(s) flaring out much wider at the top of the stroke, rather than straight up and down. I've also seen knees that appear to be rotating in a circle at the top of the stroke and folls with a lot of side to side heel movmement.
https://www.cambriabike.com/shopexd.a...m=051000001100
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