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Thread: Pedal extenders

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    Default Pedal extenders

    I have a 37 waist, big guy, very tall, 240lbs. How can a person weighing 150 and I ride a crankset with the same Q? I tried extenders a while ago but stopped using them as I am concerned(as in breaking) with the additional torque on the crankarms and bb. Steve Hoag speaks on this issue on his sight. Input appreciated, thanks.

    Take care of yourself in this time of crisis and realize sadness, anger and grief are part of the process Brian Clare

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    Default Re: Pedal extenders

    I'm 6'1" and weigh about the same as you - been using them for years on multiple bikes with no issues.

    I still have 2 sets of the Specialized stainless ones which were recalled and some cheaper ones. They are all pretty burly compared to some pedal axles and while it does seem like the leverage is significant I've never heard of anyone having problems because of them.
    It's not the years, honey. It's the mileage.

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    Default Re: Pedal extenders

    Go by feel. Try a mtb crank vs a road crank and you immediately know if you really need a larger q factor. Maybe the smaller guys could go smaller. For me , the smaller the better.

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    Default Re: Pedal extenders

    Are big guys walking with their feet further appart than smaller people? I don't know the answer.
    --
    T h o m a s

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    Default Re: Pedal extenders

    Quote Originally Posted by sk_tle View Post
    Are big guys walking with their feet further apart than smaller people? I don't know the answer.
    Not really and when you stand every gets real equal.

    Be cautious, in all the years of fitting athletes I've only used these a couple times. The reasons were because their natural hip geometry caused their knees to go wide. Using a modest extender brings the knees back.
    Last edited by Too Tall; 08-03-2020 at 07:02 PM.

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    Default Re: Pedal extenders

    Reach, stack, seat fore/aft, bar reach/drop, cleat placement, etc., all to make the rider more efficient/comfortable. Q-factor, pretty much one size fits all in a given category of bikes. I don't agree that "when you stand every(thing) gets real equal". When I'm in a stable stance my feet are positioned more or less at shoulder width, the stable stance of a smaller rider(smaller shoulder width) will have a lesser distance between his/her feet. I don't know exactly how Q effects efficiency but it seems like a variable that may effect efficiency. Not saying I'm right or wrong, not looking to argue, just looking for and open to opinions/info on the subject. Off to do the google search thing...

    thanks, Brian

    edit, first two abstracts I saw:

    The effect of Q factor on gross mechanical efficiency and muscular activation in cycling

    Abstract
    Unexplored in scientific literature, Q Factor describes the horizontal width between bicycle pedals and determines where the foot is laterally positioned throughout the pedal stroke. The aim of the study was to determine whether changing Q Factor has a beneficial effect upon cycling efficiency and muscular activation. A total of 24 trained cyclists (11 men, 13 women; VO2max 57.5 mlkg/min 6.1) pedaled at 60% of peak power output for 5 min at 90 rpm using Q Factors of 90, 120, 150, and 180 mm. Power output and gas were collected and muscular activity of the gastrocnemius medialis (GM), tibialis anterior (TA), vastus medialis (VM), and vastus lateralis (VL) measured using surface electromyography. There was a significant increase (P < 0.006) in gross mechanical efficiency (GME) for 90 and 120 mm (both 19.38%) compared with 150 and 180 mm (19.09% and 19.05%), representing an increase in external mechanical work performed of approximately 4-5 W (1.5-2.0%) at submaximal power outputs. There was no significant difference in the level of activity or timing of activation of the GM, TA, VM, and VL between Q Factors. Other muscles used in cycling, and possibly an improved application of force during the pedal stroke may play a role in the observed increase in GME with narrower Q Factors.



    Increased Q-Factor increases frontal-plane knee joint loading in stationary cycling

    Abstract
    Background: Q-Factor (QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment (KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants.

    Methods: A total of 16 healthy participants (8 males, 8 females, age: 22.4 2.6 years, body mass index: 22.78 1.43 kg/m2, mean SD) participated. A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic (240 Hz) and pedal reaction force (PRF) (1200 Hz) data in 12 testing conditions: 4 QF conditions-Q1 (15.0 cm), Q2 (19.2 cm), Q3 (23.4 cm), and Q4 (27.6 cm)-under 3 workrate conditions-80 watts (W), 120 W, and 160 W. A 3 4 (QF workrate) repeated measures of analysis of variance were performed to analyze differences among conditions (p < 0.05).

    Results: Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion.

    Conclusion: Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.



    This isn't from either of the articles but represents(I think, this is running abduction) knee abduction on a bike, the wider the hips/pelvis the higher the degree of abduction at the pedals.
    Take care of yourself in this time of crisis and realize sadness, anger and grief are part of the process Brian Clare

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    Default Re: Pedal extenders

    just food for thought:

    big and small people can both, for the most part, put their feet together and stand (i.e. feet touching). bow legged or the opposite (knees touching or splayed far apart) likely represents as great a variance as hip spacing

    there's a good deal of "float" in the foot/ankle/knee/hip joints and a ton of musculature built around them to support them going pretty much as straight as most people need; all those millions of cycles training/ repeating the motion builds that

    now, take big guy #1 and little guy #2 , both standing with feet together, and have them pick up a foot. does either of them have an advantage for balancing on a single foot close to the centerline of body weight? it seems to me that pedaling is closer to standing on one foot than, say, squatting, where clearly a wider stance is indicated for bigger folks

    so, the above is a bit cryptic, but it is just a reminder that we aren't stick men pedaling perfect circles with symmetrical bodies, and while I applaud efforts to study the biomechanics of cycling, there are a sh*t-ton of variables that are hard to control for in these kinds of studies. Bottom line: if it feels good, do it. But I ride with a few really big guys and none of them use them. It could be that they might benefit from them, I don't know, but like crank length, more isn't always better
    am I the only Marvin?

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    Default Re: Pedal extenders

    ^^^ Thanks for that.
    Take care of yourself in this time of crisis and realize sadness, anger and grief are part of the process Brian Clare

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    Default Re: Pedal extenders

    I've had two fits done around ten years apart. In the first one, the fitter noted that my knees seemed to be slightly splayed during the pedal revolutions and that this went away with pedal extenders, so I added them at roughly half an inch each. Over time I decreased that and had no problems. I removed the pedal extenders but used speedplays with slightly longer axles.

    About six months ago, I had a fitting from a much better fitter and had ridden a lot of miles in-between. He made some major changes to my position, rotating me forward, lowering slightly my saddle height to engage both sides, and lowering my torso. However, after looking at my stance on the bike and having me pedal freely and against resistance, he said that he didn't see that the slightly wider stance either helped or hurt my pedal stroke (smoothness) or power output. He said that I could change it if I wanted to but that it wouldn't make much of a difference, at least within my parameters. (Great fit, and I feel more comfortable and faster on the bike btw.)

    The only time that I've really noticed a difference related to pedals is decades ago when I used to get knee pain and was using standard clipless pedals and then began using speedplays with float. My knee pain went away and has never come back.

    Just one data point.

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    Default Re: Pedal extenders

    I am a tad over two bills and just over six feet tall. I have always been sensitive to Q factors. I do much better with a narrow Q. Mountain bikes feel to me like riding a horse and fat bikes are like riding an elephant. If it is just an hour or so I can handle a wider Q, but if it is going to be several hours in the saddle I usually look for a road bike narrow q. I think there are all kinds of body alignments that fitters must work with and certainly the Q factor is one, but I don't think size is the key factor in Q adjustment.

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