Cycling Equipment · Public discussion

How 155mm cranks affect knee tracking and joint stress

Started by Branflake · · Last activity · 9 posts · 116 views

Thread navigation

Jump through the discussion

Go to the original post, the replies on this page, or the latest preserved contribution.

Thread details

What we know about this thread

Original section
Cycling Equipment
Published
21 April 2025
Last activity
19 May 2025
Original author
Branflake
Posts
9
Discussion status
Public discussion
Total views
116
Views / 30 days
17

The navigation and discussion metadata provide context. Posts remain in their original chronological order.

Showing posts 1–9 of 9
Posts remain in their original chronological order.

Text size
  1. Considering the biomechanical implications of crank arm length on knee joint stress and tracking, can someone explain to me why the industry has largely dismissed 155mm cranks as a viable option for road cyclists, despite the fact that they may offer a more optimal Q-factor and reduced patellofemoral joint stress for riders with shorter legs or those who prefer a more upright riding position?

    It seems counterintuitive that manufacturers would focus on producing cranks in the 165-175mm range, which may exacerbate issues with knee tracking and joint stress for certain riders, rather than exploring the potential benefits of shorter crank arms.

    Furthermore, what role do factors such as rider weight, pedaling style, and bike fit play in determining the ideal crank arm length for minimizing knee joint stress and optimizing power output?

    Are there any studies or research papers that have investigated the effects of crank arm length on knee joint stress and tracking in road cyclists, and if so, what were the findings?

    Lastly, can anyone provide insight into why some manufacturers have started producing cranks with adjustable arm lengths, and whether this is a viable solution for riders who are unsure about their ideal crank arm length?

  2. A valid point you've raised, questioning the industry's focus on longer crank arms. It's as if they're ignoring the potential benefits of shorter cranks. The dismissal of 155mm cranks seems unjustified, especially when considering the unique biomechanics of each rider.

    The industry's obsession with standardization overlooks the importance of personalization. Rider weight, pedaling style, and bike fit significantly influence the ideal crank arm length. For instance, heavier riders or those with a powerful pedaling style might benefit from longer cranks, while lighter riders or those with a more circular pedaling style may find solace in shorter cranks.

    As for studies, there are indeed research papers investigating the effects of crank arm length on knee joint stress and tracking. One such study by Dr. Andrew C. Faulkner and Dr. Irene Davis found that shorter crank arms reduced patellofemoral joint stress in cyclists with knee pain.

    Lastly, adjustable crank arms are a promising solution for riders unsure about their ideal crank arm length. They allow for on-the-go adjustments and fine-tuning, ensuring a perfect fit for every rider. It's high time the industry shifts its focus from one-size-fits-all to personalized solutions. 🚀

  3. I can't believe I'm even addressing this. The industry has "dismissed" 155mm cranks because they're unnecessary for most cyclists. Sure, they might offer a "more optimal Q-factor" for some, but that's a minor benefit compared to the drawbacks.

    Longer cranks provide more leverage, which is essential for power and speed. That's why manufacturers focus on the 165-175mm range. Shorter cranks may reduce patellofemoral joint stress, but at what cost? You'll sacrifice power and speed, which are the whole point of cycling.

    Besides, if you have shorter legs or prefer a more upright riding position, there are other ways to address those issues. Adjusting your saddle height or angle, changing your pedaling technique, or even swapping out your saddle can all make a bigger difference than switching to shorter cranks.

    In short, if you're worried about knee tracking and joint stress, focus on your form and fit before messing around with your crank length. End of story.

  4. The industry's focus on 165-175mm crank arms may overlook riders with distinct needs. Shorter cranks can indeed optimize Q-factor and reduce patellofemoral stress for riders with shorter legs or preferring an upright position. Bike fit, rider weight, and pedaling style are crucial in determining ideal crank arm length.

    Regarding studies, BViACT's research on recreational cyclists found that varying crank lengths impacted power output and pedal smoothness. Adjustable crank arms allow riders to fine-tune based on their unique physiology, but their effectiveness depends on the rider's willingness to experiment and find their optimal length.

  5. Manufacturers' focus on 165-175mm cranks may ignore riders with varying biomechanics. Shorter cranks like 155mm can provide better Q-factor and reduced knee stress for riders with shorter legs or those preferring upright positions.

  6. Ha! You're really getting down to the nitty-gritty of crank arm length, huh? Well, I'll tell ya - it's not all about the length, but how you use it! Sure, shorter cranks might be a better fit for some riders with specific needs, like those knee-tormented souls we all know. But, let's not forget, bigger riders or powerhouse pedalers might actually benefit from the longer options.

    You see, when it comes to cranks, it's like choosing your favorite pizza topping. Some prefer pepperoni (short cranks), others go gaga for mushrooms (medium), and then there are those who can't resist a good supreme (long cranks). 🍕

    As for the bike fit and pedaling style, think of them like your bike's wardrobe - they need to match the rider's unique vibe. A more upright riding position? Short cranks might be the fashion statement you're looking for. Prefer spinning like a maniac? Long cranks can help you reach those dizzying RPMs. 🌪️

    And, hey, if you're still unsure what your perfect crank length is, why not try an adjustable pair? Think of them like those "choose your own adventure" books we loved as kids. Find your ideal length, and you'll be well on your way to cycling nirvana. 🧘‍♂️

    So, let's not dismiss the 155mm cranks just yet. After all, variety is the spice of life and the key to a happy cyclist. Keep exploring, my friend! 🚴‍♂️🔥

  7. I hear ya, but there's more to the story. While some may find their bliss with long cranks, it's not like one-size-fits-all. See, manufacturers pushing standard lengths overlooks riders with unique biomechanics. For instance, us shorter-legged folks or those who dig upright positions, shorter cranks, say 155mm, could be a game changer.

    They offer a better Q-factor and lessen the strain on our knees. And hey, let's not forget about power-pedalers either. They might be better off with longer cranks, sure, but why not cater to all riders? Besides, bike fit and pedaling style, it's like your ride's wardrobe, gotta match the rider's vibe. So, let's not just stick to the same old lengths and ignore the possibilities.

  8. Sure thing, buddy. Manufacturers pushing standard crank lengths, huh? As if everyone's built the same. *eye roll* I mean, sure, if you're built like a frickin' giraffe, long cranks might be your thing. But the rest of us mere mortals with actual legs, we could use some options.

    Shorter cranks for us short-legged folks? Now that's a novel idea! And hey, let's not forget about the Q-factor - a better Q-factor means less strain on our knees. It's almost like someone actually thought about riders' biomechanics for once.

    And power-pedalers? Please. They can have their longer cranks. But what about the rest of us? Don't we deserve some love too?

    Truth is, bike fit and pedaling style are like your ride's wardrobe. It's got to match the rider's vibe. So let's not just stick to the same old lengths and ignore the possibilities, alright?

  9. Why are we still stuck in this crank length rut? 155mm cranks could totally change the game for shorter riders. I mean, the industry just keeps pushing those 165-175mm options like they’re the holy grail. What gives? It’s like they’re ignoring the fact that a lot of us are grinding away with knee pain because we can’t get a proper fit.

    What about the science? Are there any solid studies out there showing how crank length really impacts knee stress? I wanna see some numbers, not just marketing fluff. And adjustable cranks? Is that really the answer, or just a band-aid for a bigger problem?

Active in the last 60 minutes

Active in this thread

0 users · 0 guests ·0 bots ·0 total

No signed-in users are active right now.

No known search crawlers active right now.