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  1. #1
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    I need a not super wide BB and crank combo.

    *EDIT* - This was mostly "answered" by this forum thread: http://forums.roadbikereview.com/com...ne-213649.html

    It more or less confirmed the Q-factor "issue," short term, find a crank with a more narrow Qfactor. Long term: Possibly swap to Speedplays? They have greater adjustability than my current pedals.

    Wide bottom bracket - Imgur

    My fixed gear has always felt great and I love to ride it, but towing trailers, etc I've been wanting some gears (I'm in San Francisco also... and yes, my fixed gear has brakes, two even!). I've set my road bike up again, but it's destroying my knees. I got down to measuring and as you can see, this external BB and crank set are way wider than my fixie. Is this a number that I can look up before ordering BBs? I've found an article on "Q Factor," but that's about it. I'd assume non-external BB will help, but honestly if I could get it more narrow that would be great.

    Bridgestone Bicycle Catalogue 1991-13

    I would love to hear about clipless shoes with lateral float also, my googling hasn't yielded much on that front. As you can see my shoes are as "narrow" as they can be.

    imgur: the simple image sharer

    Will some shoes allow further lateral adjustment? I have 4 pairs of shimano mb pedals, so it would be sad to have to switch.
    Last edited by accordionfolder; 03-13-14 at 02:52 PM.

  2. #2
    has a Large Member Campag4life's Avatar
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    Obvious question is, why your preoccupation with Q-factor? What's killing your knees is gearing. You need shorter gears.
    You could even change the gear ratio on your fixie.
    External bearing cranks have Q-factors close to say Square tapered cranks of yester-year....so BB type isn't going to help much and external bearing cranks are better.

    Speedplay pedals are preferred by many for their wide open float...what I ride for this feature.

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    OP, listen to C4L and don't go down some imaginary garden path that serves no purpose. Use lower gearing and higher cadence, set your cleats up ideally, have sufficient float, and work on your knee form-perfectly vertical circles with the knees tight in near the frame. Make sure your seat is the right height. Q-factor is not likely your problem.
    Robert

    My hero: "Tar-Baby ain't sayin' nuthin'..." (Joel Chandler Harris, Uncle Remus")

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    Did you look at the images or read the post?

    I can and have ridden my fixed gear for 20+ miles with no knee problems what so ever, and I have been riding that bike with that setup for the last 3 years. I've been riding for the last 10 years so I know my setup well and have not had problems in the past.

    Quote Originally Posted by Campag4life View Post
    What's killing your knees is gearing. You need shorter gears.
    The road bike has a 12-32(!) rear cassette and 50/34 front, gearing is not an issue and I spin like a mad man regardless; I'm not new to this game, just to this bike setup.

    I felt like I needed some gears (towing the dog trailer and just general hills on the commute) so I built back up my Trek: same shoes, same pedals and bam my knees feel like they're coming apart from an easy 15 mile (round trip) commute. I've measured the saddle to pedal distance, etc. All those dimensions match.

    Quote Originally Posted by Campag4life View Post
    External bearing cranks have Q-factors close to say Square tapered cranks of yester-year....so BB type isn't going to help much and external bearing cranks are better.
    That's clearly not so. If you look at the measurements there is over an 1/8 of an inch difference in left pedal center to right pedal center. That's massive! That's essentially taking my cleats and moving that outboard by that much. It's the same story on my Cannondale RT-1000 Road Tandem: no knee problems at all on it, non-external BB, and the Q-factor is the same amount as the fixie. I can get the exact difference if you would like, but after setting both cranks on the same side and measuring pedal to pedal it's painfully obvious.

    I'm just curious if this "Q" number is anywhere to be found. There IS a measured difference in between the pedal to pedal.

    Quote Originally Posted by Campag4life View Post
    Speedplay pedals are preferred by many for their wide open float...what I ride for this feature.
    I'm having trouble discerning from the web, do they have lateral float (i.e. side to side)? They seem to just have a lot of rotational float, which doesn't cause a problem for me, I'm already riding mountain bike clips and pedals.

    *edited for clarity.
    Last edited by accordionfolder; 03-13-14 at 02:35 PM. Reason: clarity

  5. #5
    has a Large Member Campag4life's Avatar
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    Quote Originally Posted by accordionfolder View Post
    Did you look at the images or read the post?

    I can and have ridden my fixed gear for 20+ miles with no knee problems what so ever (I have been riding that bike with that setup for the last 3 years); I did earlier this week.

    I felt like I needed some gears (towing the dog trailer and just general hills on the commute) so I built back up my Trek: same shoes, same pedals and bam my knees feel like they're coming apart from an easy 15 mile (round trip) commute. I've measured the saddle to pedal distance, etc. All those dimensions match. The road bike has a 12-32(!) rear cassette and 50/36 front, gearing is not an issue and I spin like a mad man regardless; I'm not new to this game, just to this bike.



    If you look at the measurements there is over an 1/8 of an inch difference in left pedal center to right pedal center. That's massive! That's essentially taking my cleats and moving that outboard by that much. I have sensitive knees to begin with (hence the mountain gears and the "easy gearing on my fixie). It's the same story on my Cannondale RT-1000 Road Tandem, no knee problems at all on it. I'm just curious if this "Q" number is anywhere to be found. There IS a measured difference in between the pedal to pedal. I've set it up and measured it on all my bikes. It's completely wrong to say they have the "same" Q-factor. I can get the exact difference if you would like, but after setting both cranks on the same side and measuring pedal to pedal it's painfully obvious.

    On the speedplay note, I'm having trouble discerning, do the have lateral float (i.e. side to side)?
    Have you noticed how many responses you have received? I have been cycling 4 decades and believe you are dead wrong in your assessment.
    Also, there is no such thing as lateral float, so you need to rephrase. There is lateral adjustment of pedals on shoes however and yes Speedplay can be adjusted laterally to account for degrees of crank Q-factor difference and rider preference. Plus, you can purchase different length spindles for Speedplay that will space the foot more away (increase Q-factor) from the crank arm to accommodate wider cycling shoes in particular.
    Good luck.
    How do you know what Q-factor is ideal? Have you ever had a 3D computer fit to see how your knees are tracking?

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    Please revisit my previous post, I edited it for clarity.

    Quote Originally Posted by Campag4life View Post
    hat Q-factor is ideal? Have you ever had a 3D computer fit to see how your knees are tracking?
    Of my 5 bikes only 1 hurts my knees. I've taken measurements on the rest (well, the other 4, the mountain bike has platform pedals) and the only thing that is different bike to bike is the Q-factor. I use the same pedals and same shoes on all of my bikes. That seems relatively straightforward to me. Obviously your assessment of gearing and cadence was dead wrong, so I'm not sure how my "assessment" is dead wrong? I will probably go get a 3d fit sometime in the near future, there is a company that does 3d fits just a bit away from me now (yay San Francisco)!

    Thanks for the info on the speedplays, I like the idea of that much adjustability and am seriously considering switching to them now. It'll be a shame to have to buy that many pedals at once though.... i
    Last edited by accordionfolder; 03-13-14 at 03:01 PM.

  7. #7
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    Sounds like a poor bike fit. You probably have the geared bike set up significantly different than the fixed gear.

    Bike Fitting Specialists - Cycling Knee Pain

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    Thanks for the input, but there is no pain or discomfort on any of my other bikes (only the orange one) and I have been riding them all for a while now. I made sure that the orange bike matched up in all other dimensions before finding the "q-factor" issue.

    Last edited by accordionfolder; 03-13-14 at 02:31 PM.

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    OP
    If you want to play with Q factor as you want to measure it, switch to a square taper BB and run a 103 mm. Will it screw with your chain line? Yep. Will you have to make sure your chain rings clear the chain stay? Yep. But you can make up some ground on what you are trying to measure.

    I would be very surprised if it boiled down to the real issue, but have no expertise in the matter.

    EDIT: Any chance the crank you were running was a triple crank, and you are now using the inner two rings only? Reviewing the pictures, it looks like a big gap between the outer ring and the crank arm.
    Last edited by RollCNY; 03-13-14 at 02:31 PM.
    Quote Originally Posted by Man in Black
    Life is pain, Highness. Anyone who says differently is selling something.

  10. #10
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    The bike originally had a square taper BB/crankset, but it was a triple. I switched to an external BB Double for this most recent incarnation. I like the looks and ride of the double, but will go back to a triple if I can get it narrow again.

  11. #11
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    You should look at your cleat and pedal fitment for knee pains. It's very unusual for a wider Q-Factor to cause more knee pain, but the opposite sometimes occur.

  12. #12
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    Quote Originally Posted by RollCNY View Post
    EDIT: Any chance the crank you were running was a triple crank, and you are now using the inner two rings only? Reviewing the pictures, it looks like a big gap between the outer ring and the crank arm.
    It's the angle of the shot, the gap isn't that large, seem my previous response, it was a triple, but with a different BB and crankset.

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    Quote Originally Posted by link0 View Post
    You should look at your cleat and pedal fitment for knee pains. It's very unusual for a wider Q-Factor to cause more knee pain, but the opposite sometimes occur.
    Quote Originally Posted by accordionfolder View Post
    Thanks for the input, but there is no pain or discomfort on any of my other bikes (only the orange one) and I have been riding them all for a while now. I made sure that the orange bike matched up in all other dimensions before finding the "q-factor" issue.
    Thanks though.

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    Quote Originally Posted by accordionfolder View Post
    The bike originally had a square taper BB/crankset, but it was a triple. I switched to an external BB Double for this most recent incarnation. I like the looks and ride of the double, but will go back to a triple if I can get it narrow again.
    Wait a minute. I think you are busted. Triples generally have wider Q-factor than doubles on the same BB shell. First the spindle is longer, and second the crank design doesn't make up for the longer spindle. Here is an example of a double and triple differing by 1/2 inch! Read down until you find it:Crankset Question: Q Factor and Chainline, post #5 . If you were okay on a triple with square taper, it is highly unlikely the outboard-bearing double is what is causing you the problem.
    Robert

    My hero: "Tar-Baby ain't sayin' nuthin'..." (Joel Chandler Harris, Uncle Remus")

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    Quote Originally Posted by rpenmanparker View Post
    Wait a minute. I think you are busted. Triples generally have wider Q-factor than doubles on the same BB shell. First the spindle is longer, and second the crank design doesn't make up for the longer spindle. Here is an example of a double and triple differing by 1/2 inch! Read down until you find it:Crankset Question: Q Factor and Chainline, post #5 . If you were okay on a triple with square taper, it is highly unlikely the outboard-bearing double is what is causing you the problem.
    Read the whole post, the old BB was on a square taper the new one is an external BB. I can dig it out of the parts box and measure it also, but my Tandem (with a triple and square taper BB) also has a smaller Q-factor than this orange bike build (that's for the stoker though). The orange bike has been only a parts frame for a while now.

    Thanks for the link though, most of the cranksets I'm looking at don't include the "q-factor" number with them. Maybe I'm just looking in the wrong place?
    Last edited by accordionfolder; 03-13-14 at 02:57 PM.

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    Quote Originally Posted by rpenmanparker View Post
    Wait a minute. I think you are busted. Triples generally have wider Q-factor than doubles on the same BB shell. First the spindle is longer, and second the crank design doesn't make up for the longer spindle. Here is an example of a double and triple differing by 1/2 inch! Read down until you find it:Crankset Question: Q Factor and Chainline, post #5 . If you were okay on a triple with square taper, it is highly unlikely the outboard-bearing double is what is causing you the problem.
    This link seems to confirm my issue actually, reading through it has been great help, thanks!

    From the thread:

    "Correct, a lot of riders would rather have a narrow Q-factor than a wider one. Some even base their choice of crank on that—if it's not narrow enough, it doesn't get bought."

    "I know this is an old thread, but I have searched and searched and cannot find a definitive answer. I recently changed bikes from a frame with GXP SRAM Red to a Cannondale with a PF-30 and Hollowgram Crank. Most all parts swapped, I setup the geometry to be almost the same. The only thing that I can tell is really different is the Q-Factor (Stance). The hollowgrams feel a lot narrower, and I can feel a tiny bit of pressure on the outside of my knees. After long rides both my knees start to hurt. As a temporary solution I put a couple pedal washers on each side, and this helped, but the pressure and eventual knee pain persists."
    Last edited by accordionfolder; 03-13-14 at 02:55 PM.

  17. #17
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    Quote Originally Posted by accordionfolder View Post
    This link seems to confirm my issue actually, reading through it has been great help, thanks!

    From the thread:

    "Correct, a lot of riders would rather have a narrow Q-factor than a wider one. Some even base their choice of crank on that—if it's not narrow enough, it doesn't get bought."

    "I know this is an old thread, but I have searched and searched and cannot find a definitive answer. I recently changed bikes from a frame with GXP SRAM Red to a Cannondale with a PF-30 and Hollowgram Crank. Most all parts swapped, I setup the geometry to be almost the same. The only thing that I can tell is really different is the Q-Factor (Stance). The hollowgrams feel a lot narrower, and I can feel a tiny bit of pressure on the outside of my knees. After long rides both my knees start to hurt. As a temporary solution I put a couple pedal washers on each side, and this helped, but the pressure and eventual knee pain persists."
    Yeah, you are referring to comments by other folks, but getting back to your facts, how could your triple have been satisfactory and your double not?
    Robert

    My hero: "Tar-Baby ain't sayin' nuthin'..." (Joel Chandler Harris, Uncle Remus")

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    Quote Originally Posted by accordionfolder View Post
    This link seems to confirm my issue actually, reading through it has been great help, thanks!
    That seems to be the exact opposite of the issue that you're having...?

    Just out of curiosity, how much space is there between the inside of your crank arm and the chainstay? The photo attached is my bike, obviously different than yours, that has a little under " between the crank arm and chainstay, which is why Q-factor issues are almost always addressed with cleat positioning on the shoe and pedal spindle length...

    I know that you don't have issues with your shoes on your other bikes, but the cleat positioning (how far off center the mount is, not where you've mounted the cleat) probably isn't helping things, especially since the soles *probably* aren't stiff enough to mask the cleat placement.

    photo.jpg

  19. #19
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    Quote Originally Posted by rpenmanparker View Post
    Yeah, you are referring to comments by other folks, but getting back to your facts, how could your triple have been satisfactory and your double not?
    Quote Originally Posted by accordionfolder View Post
    Read the whole post, the old BB was on a square taper the new one is an external BB. I can dig it out of the parts box and measure it also, but my Tandem (with a triple and square taper BB) also has a smaller Q-factor than this orange bike build (that's for the stoker though). The orange bike has been only a parts frame for a while now.

    Thanks for the link though, most of the cranksets I'm looking at don't include the "q-factor" number with them. Maybe I'm just looking in the wrong place?
    Square taper vs External is what is looks like.

  20. #20
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    Quote Originally Posted by bahula03 View Post
    That seems to be the exact opposite of the issue that you're having...?
    Same issue, his was the "opposite" direction, but same Q-factor related problem

    Quote Originally Posted by bahula03 View Post
    but the cleat positioning (how far off center the mount is, not where you've mounted the cleat) probably isn't helping things
    I'm not positive if I'm interpreting this correctly, but I've run out of adjustment room on these particular shoes. The cleats won't go any more narrow than they are. This current configuration also feels good on my other bikes so I don't really want to mess up my fit for one bike out of five. The pedals themselves have no lateral adjustment unfortunately (that I'm aware of?).

  21. #21
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    Quote Originally Posted by accordionfolder View Post
    Same issue, his was the "opposite" direction, but same Q-factor related problem



    I'm not positive if I'm interpreting this correctly, but I've run out of adjustment room on these particular shoes. The cleats won't go any more narrow than they are. This current configuration also feels good on my other bikes so I don't really want to mess up my fit for one bike out of five. The pedals themselves have no lateral adjustment unfortunately (that I'm aware of?).
    That's what I was trying to express with cleat positioning vs where you have it mounted...I guess another way to say it is that the cleat mounting points/track is so far off-center that you've had to mount the cleats adjusted laterally to an extreme, and that extreme still isn't enough. -Or- if the mounting track was centered, you'd have enough lateral adjustment in the cleat to get your ⅛" back and be good to go. Hope that makes more sense

    And yeah, I've yet to see a pedal that has lateral adjustment. You either shop whole pedal systems based on effective spindle length, or go with something like Speedplays where you can get custom length spindles that are easy to install.

  22. #22
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    Quote Originally Posted by accordionfolder View Post
    Square taper vs External is what is looks like.
    Let me try again. A square taper triple is as much as a half inch wider (longer spindle) than a sqaure taper double. And I don't think the crank arms are shaped to take away from this width. On the outboard bearing BB the width is a little more than the square taper triple, but the crank arms lean back in a little. Bottom line is if you could use the square taper triple, you shouldn't have trouble with the outboard bearing double. Do you still have the triple so you can compare?
    Robert

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