So, if your current shifts perfectly and isn’t made of steel, what does an upgrade benefit you?
you could save a few grams of weight, which could save 1 or 2 seconds per ironman. You can also put some nice aero chainrings on, which costs a lot less, and might save 10 seconds per ironman =)
So, pretty much no real difference…
The reason I ask is that my road bike came stock with an FSA Omega which I read is ‘crap’. However, in about 200 miles of riding so far it hasn’t skipped a beat.
Fabian used to ride FSA cheap cranks because he didn’t like their carbon ones.
It just doesn’t matter much.
There a couple fancy aero-shaped cranks out there, but that is a hard thing to do right and it isn’t clear who has really done their homework on them.
If you get the itch to upgrade, just get an aero chainring.
So, pretty much no real difference…
The reason I ask is that my road bike came stock with an FSA Omega which I read is ‘crap’. However, in about 200 miles of riding so far it hasn’t skipped a beat.
Thanks Jack.
Cranks don’t matter much, rings (can) matter a lot. Mostly that is in shifting performance.
Fabian used to ride FSA cheap cranks because he didn’t like their carbon ones.
It just doesn’t matter much.
I’ve been running FSA Gossamers on most of my bikes for several years now. They’re working great, the BB’s are cheap and easy to replace (even if they do shit the bed more often). No complaints.
Basically the only thing that makes one crank better than another is the ego of the rider.
Does crank stiffness matter, outside of perhaps, track sprinting? Queue the “That’s what she said” comments…
The isn’t a whole lot of difference between most mid-price/quality cranksets; a little bit of weight maybe a little stiffer, maybe better pins and ramps on the rings for better shifting.
Shimano is renown for it’s front shifting, part of that comes from Dura-Ace’s hollow 2 piece chainrings. They are really really stiff.
There are two kinds of stiffness in cranksets, the arms flexing under huge loads that most people can’t generate, and chainring stiffness that leads to perfect front shifts.
So, Ultegra, 105, Sram, FSA, meh, take your pick, but Dura-Ace is a step above for shifting performance.
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Does crank stiffness matter, outside of perhaps, track sprinting? Queue the “That’s what she said” comments…
In a TT it doubt it.
On a road bike under the right conditions the average rider can notice the difference between a flexy crank and good one. My Allez came with a Shimano 600 crank. Sometimes I would mash the pedals at a stoplight taking off and drop the chain. LBS suggested that at the right position I could put enough force on the crank to flex the big chain ring and drop the chain. Members of the bike club agreed.
Changed to a 105 crank and it has never happened since.
So, if your current shifts perfectly and isn’t made of steel, what does an upgrade benefit you?
Put the money in the BB instead.
John
I had a Sram Rival crank, changed it out for a Shimano Dura Ace. Wow!! It is hard for me to explain, but it truly made a difference. For me, it was well worth the money. The difference between an old beater car (Sram Rival) and a slick running highly tuned machine (Dura Ace).
Does crank stiffness matter, outside of perhaps, track sprinting? Queue the “That’s what she said” comments…
Well duh, it’s scientific ~ a techy graphic wouldn’t lie, would it?
There are two kinds of stiffness in cranksets, the arms flexing under huge loads that most people can’t generate, and chainring stiffness that leads to perfect front shifts.
many arms and spindles will flex easily under loads of even light riders, especially when standing, sprinting, or climbing. That flex can be the difference between a successful move and competition seeing an attempt and reacting and staying on your wheel. While that scenario doesn’t occur in tri, that little bit of flex during accelerations is power lost.
Most of the issues with the gossamer and omegas have been spindle issues, coming apart from the crank arm or developing play. I think that is why they have gotten the “crap” reputation.
Does crank stiffness matter, outside of perhaps, track sprinting? Queue the “That’s what she said” comments…
Well duh, it’s scientific ~ a techy graphic wouldn’t lie, would it?
LOL. good to know less than 4% is a ~40 degree change! I’d guess no one ever would be able to tell a 4% difference in stiffness. If I’m reading that right, a SRAM Red BB30 takes 427 Newtons to bend 1mm.
Now if it were a crap crank, say in the 100 N/mm range, then you’d defiantly notice a difference!
There are two kinds of stiffness in cranksets, the arms flexing under huge loads that most people can’t generate, and chainring stiffness that leads to perfect front shifts.
many arms and spindles will flex easily under loads of even light riders, especially when standing, sprinting, or climbing. That flex can be the difference between a successful move and competition seeing an attempt and reacting and staying on your wheel. While that scenario doesn’t occur in tri, that little bit of flex during accelerations is power lost.
Most of the issues with the gossamer and omegas have been spindle issues, coming apart from the crank arm or developing play. I think that is why they have gotten the “crap” reputation.
http://www.bikesportmichigan.com/reviews/crank.shtml
John
those cranks are from back when isis/octalink was relevant…seems completely irrelevant testing to current market product, materials, and engineering. Spindle is also static…no forces applied, which again seems completely irrelevant since the cycling motion itself places stress on the spindles. I think most companies doctor their findings on their own product, but they’re probably not testing just one arm with no forces applied to the spindle, with the spindle in a completely static position. Seems about as reliable as gauging ones marathon fitness off of how fast they can walk a mile…it is a somewhat related movement and fitness right?
That flex can be the difference between a successful move and competition seeing an attempt and reacting and staying on your wheel. While that scenario doesn’t occur in tri, that little bit of flex during accelerations is power lost.
Ummm, can you show me how power is lost by the crank deflecting? Here is a hint: draw a free body diagram.
give in the spindle or crank would be power not directly transferred through the crank to drivetrain.
So, if your current shifts perfectly and isn’t made of steel, what does an upgrade benefit you?
Cranks are a bike’s wristwatch. Sure a $25 dollar Timex will tell time with all the accuracy I’ll ever need, but I’d much rather roll with a Patek Philippe.