With 2020 models coming out now with Force AXS, I'm wondering if anyone has done any serious crit racing on a 12 speed and has some feedback? I haven't seen anyone racing on it in my area but also there are no CAT 1/2's who are going to show up on a $10,000+ Red AXS crit bike. The crits are flat so I don't need more gears but I am considering trying Force over Ultegra Di2 because there are punchy hills in my area and it would be fun to have some extra options when not racing. Also, SRAM has always treated me well in the past and I've had great experiences with them. I'm not concerned about having enough gearing, but one would think there is a physiological/muscle recruitment difference between sprinting or accelerating out of a corner on a 53 ring compared to a 48. For example, even if the crank length is the same and I had enough gear inches to sprint all-out in a 39, I feel like I would be sprinting "differently" than I would with the same gear inches in a 53. So switching to a 48 up front would scare me. Any truth to that, or no?
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Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
I did P-1-2 crits back in 90s with a 50-tooth big ring. Not very well - generally pack fill. But in any case, my opinion on 53 vs 48 is: whatever.
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Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
There is no difference other than little drivetrain efficiencies.
Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
Itsprettybig wrote:
With 2020 models coming out now with Force AXS, I'm wondering if anyone has done any serious crit racing on a 12 speed and has some feedback? I haven't seen anyone racing on it in my area but also there are no CAT 1/2's who are going to show up on a $10,000+ Red AXS crit bike. The crits are flat so I don't need more gears but I am considering trying Force over Ultegra Di2 because there are punchy hills in my area and it would be fun to have some extra options when not racing. Also, SRAM has always treated me well in the past and I've had great experiences with them. I'm not concerned about having enough gearing, but one would think there is a physiological/muscle recruitment difference between sprinting or accelerating out of a corner on a 53 ring compared to a 48. For example, even if the crank length is the same and I had enough gear inches to sprint all-out in a 39, I feel like I would be sprinting "differently" than I would with the same gear inches in a 53. So switching to a 48 up front would scare me. Any truth to that, or no?No, there’s no difference as long as the gear ratio is the same. You’d just sprint in a 12 cog rather than a 14 (or thereabouts, I haven’t done the math), or an 11 instead of 13, etc.
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Re: 12 speed bad idea for crit racing? [JasoninHalifax]
[ In reply to ]
JasoninHalifax wrote:
No, there’s no difference as long as the gear ratio is the same. You’d just sprint in a 12 cog rather than a 14 (or thereabouts, I haven’t done the math), or an 11 instead of 13, etc....The 52-13 top-end that professional racers often used in the Merckx era is equivalent to 48-12.
Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
An age old adage of criterium racing is, "Race what you can afford to replace." If you are concerned about cost that's my answer. As for me, I roll a Specialized Allez Sprint with original 11-speed eTap with mid-compact chainrings and 11-23 for crits and 11-28 for road races and HED Jet wheels. As someone previously stated a gear-inch is a gear-inch. You'll spin the same RPM just in a different set of gears. For me in crits as with time trials the steps between the gears is what I like to minimize so that my shifts do not drastically change my cadence.
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Last edited by:
GingerAvenger: Jul 18, 19 13:02
Re: 12 speed bad idea for crit racing? [JasoninHalifax]
[ In reply to ]
JasoninHalifax wrote:
No, there’s no difference as long as the gear ratio is the same.And the earth is flat.....
Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
seppo17 wrote:
JasoninHalifax wrote:
No, there’s no difference as long as the gear ratio is the same.And the earth is flat.....
Huh???
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Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
From a biomechanics perspective, I feel like changing your crank arm length would change how you're using your muscles slightly because you're tracing a larger or smaller circle. So I guess the root of my question is, does that also translate in any way to the circumference of your chainring? Sorry, I'm sure that's a really stupid question for anyone that really understands math and science. But from what I'm gathering the answer would be no and the best way to put it would be that "a gear inch is a gear inch". It might just be a mental barrier I have to get over as the only frame of reference I have right now would be thinking about sprinting in a big ring (53) vs a small ring (39), knowing full well that I just don't have enough gear inches in the 39 to make it feel similar to sprinting in the 53.
Re: 12 speed bad idea for crit racing? [GingerAvenger]
[ In reply to ]
GingerAvenger wrote:
An age old adage of criterium racing is, "Race what you can afford to replace." If you are concerned about cost that's my answer. As for me, I roll a Specialized Allez Sprint with original 11-speed eTap with mid-compact chainrings and 11-23 for crits and 11-28 for road races and HED Jet wheels. As someone previously stated a gear-inch is a gear-inch. You'll spin the same RPM just in a different set of gears. For me in crits as with time trials the steps between the gears is what I like to minimize so that my shifts do not drastically change my cadence.+1+1
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Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
Itsprettybig wrote:
From a biomechanics perspective, I feel like changing your crank arm length would change how you're using your muscles slightly because you're tracing a larger or smaller circle. So I guess the root of my question is, does that also translate in any way to the circumference of your chainring?No.
Crank length affects pedaling because it changes where the pedal contact point is. Chainring diameter doesn't.
In theory, the stress distribution on the frameset might be slightly different with different-size chainrings due to the chain following a different path, so the way the frame flexes under pedaling and drivetrain forces might differ very slightly. This is going to be a vanishingly small effect, though, and there's no reason to suspect that one chainring size would be better than another.
Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
Itsprettybig wrote:
From what I'm gathering the answer would be no and the best way to put it would be that "a gear inch is a gear inch."GingerAvenger wrote:
For me in crits as with time trials the steps between the gears is what I like to minimize so that my shifts do not drastically change my cadence.
Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
seppo17 wrote:
JasoninHalifax wrote:
No, there’s no difference as long as the gear ratio is the same.And the earth is flat.....
What exactly are you smoking?
Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
I raced a 50/34 for a season as a Cat 1 and it sucked. I hateeeee being in the 11 and 12. Just feels like massive friction (in my head while riding, but every time I had it in the stand...ughhh).
So anyway, I would never do that just because of that. In fact, if I had the opportunity, I'd run a 54 or 55.
So anyway, I would never do that just because of that. In fact, if I had the opportunity, I'd run a 54 or 55.
Re: 12 speed bad idea for crit racing? [exxxviii]
[ In reply to ]
exxxviii wrote:
Itsprettybig wrote:
From what I'm gathering the answer would be no and the best way to put it would be that "a gear inch is a gear inch."GingerAvenger wrote:
For me in crits as with time trials the steps between the gears is what I like to minimize so that my shifts do not drastically change my cadence.Yes a gear inch is a gear inch, regardless of chainring size. However, GingerAvenger's comment above is significant. For a given gear inch, the larger the chainring you are riding, the smaller the increment will feel when you shift in back. So, if you run a huge CR, then individual rear shifts will not be as dramatic feeling, which could be desirable.
This. A 44/11 and 52/13 are the exact same ratio, but the next step from 11 to 12 is effectively larger than the same 1T from 13 to 14.
The other way I looked at it was that on an typical cassette, a larger chainring means running a cog or 2 further inboard for a straighter chainline rather than living on the outer smallest cog or 2 (say, a 54/13 vs a 48/11 or 50/12). Obviously that's not a huge difference, but I can hear it in a workstand even if I can't feel it on the road ~ that added sound is basically nothing but more metal-on-metal grinding; even if it's a tiny amount, it's always there. Of course for a hilly course it's worth more to have extra teeth available on the larger cogs for climbing, but on a flat course you only ever use the 17-19-21+ cogs for warm-up & cool down ~ so unless you only have 1 cassette/wheel combo for everything, I look at the smallest cogs as little more than spacers when choosing a cassette for flat courses.
Re: 12 speed bad idea for crit racing? [T-wrecks]
[ In reply to ]
T-wrecks wrote:
seppo17 wrote:
JasoninHalifax wrote:
No, there’s no difference as long as the gear ratio is the same.And the earth is flat.....
What exactly are you smoking?
It's called physics.
Why do track riders race big chain rings and not little tiny cogs? Why were all the recent TDF TTT bikes set up with 58 and 60 tooth chaing rings?
You gain leverage with the bigger chain ring. The ratio between cogs will also be smaller at the smaller end of the cassette.
Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
seppo17 wrote:
Why were all the recent TDF TTT bikes set up with 58 and 60 tooth chaing rings?And, a bigger front CR will have lower drivetrain friction. A gear ratio is a gear ratio.
Re: 12 speed bad idea for crit racing? [exxxviii]
[ In reply to ]
exxxviii wrote:
seppo17 wrote:
Why were all the recent TDF TTT bikes set up with 58 and 60 tooth chaing rings?And, a bigger front CR will have lower drivetrain friction. A gear ratio is a gear ratio.
That and it lets the rider select a gear more in the middle of the cassette, straighter chain line.
As for the difference between the jump from a 48/12 to the 11 and a 52/13 to the 12, at 90 rpm in the 48/12 or 52/13 that’s 45 km/h assuming a 2.1m wheel circumference. Dropping to the the 52/12 puts the rider at 83 rpm, whereas dropping to the 48/11 puts the rider at 82 rpm. Is that a significant difference?
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Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
seppo17 wrote:
It's called physics.
Why do track riders race big chain rings and not little tiny cogs?
You need to be more specific about which discipline here, but this one I'll cut you some slack, because there is an element of chain friction considered, as well as gear inches, when choosing gearing for an event.
seppo17 wrote:
It's called physics.
Why were all the recent TDF TTT bikes set up with 58 and 60 tooth chaing rings?
Because any team of 8 world tour guys drafting each other easily went over 55 kph. You aren't pedaling a 53 tooth ring that fast.
seppo17 wrote:
It's called physics.
You gain leverage with the bigger chain ring. The ratio between cogs will also be smaller at the smaller end of the cassette.
You have nearly the exact same leverage. That is dictated by the crank length, and even then there is little difference in leverage across the most commonly used crank lengths.
Re: 12 speed bad idea for crit racing? [T-wrecks]
[ In reply to ]
T-wrecks wrote:
seppo17 wrote:
Why were all the recent TDF TTT bikes set up with 58 and 60 tooth chaing rings?
Because any team of 8 world tour guys drafting each other easily went over 55 kph. You aren't pedaling a 53 tooth ring that fast.
What do you mean? 53/11 at 95 rpm is 35.8 mph(56.7kmph) If gear ratio is everything then that is prefectly fine, right?
T-wrecks wrote:
seppo17 wrote:
You gain leverage with the bigger chain ring. The ratio between cogs will also be smaller at the smaller end of the cassette.
You have nearly the exact same leverage. That is dictated by the crank length, and even then there is little difference in leverage across the most commonly used crank lengths.
The crank arm is a lever. The chain rings and cogs are a pulley. By increasing the chain ring you are adding mechnical advantage(aka leverage). In theory so does a smaller cog. The problem with the cog is it is attached to a relatively large radius fly wheel. The cost in force of a smaller cog is greater than a bigger chain ring, because of the large radius to the mass(the wheel vs the crankarm).
Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
seppo17 wrote:
T-wrecks wrote:
seppo17 wrote:
Why were all the recent TDF TTT bikes set up with 58 and 60 tooth chaing rings?
Because any team of 8 world tour guys drafting each other easily went over 55 kph. You aren't pedaling a 53 tooth ring that fast.
What do you mean? 53/11 at 95 rpm is 35.8 mph(56.7kmph) If gear ratio is everything then that is prefectly fine, right?
T-wrecks wrote:
seppo17 wrote:
You gain leverage with the bigger chain ring. The ratio between cogs will also be smaller at the smaller end of the cassette.
You have nearly the exact same leverage. That is dictated by the crank length, and even then there is little difference in leverage across the most commonly used crank lengths.
The crank arm is a lever. The chain rings and cogs are a pulley. By increasing the chain ring you are adding mechnical advantage(aka leverage). In theory so does a smaller cog. The problem with the cog is it is attached to a relatively large radius fly wheel. The cost in force of a smaller cog is greater than a bigger chain ring, because of the large radius to the mass(the wheel vs the crankarm).
No. They’re both moving the same mass, because they’re connected by this thing called a chain. Outside of very tiny marginal losses due to friction, the only thing that matters is the ratio of chainring size to cog size.
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Re: 12 speed bad idea for crit racing? [Itsprettybig]
[ In reply to ]
IMO increasing your willingness to crash will increase your crit results alot more that chasing marginal gains.
So having a "walk away" bike (with ok wheels) is better that a super bike you will want to scratch.
So having a "walk away" bike (with ok wheels) is better that a super bike you will want to scratch.
Re: 12 speed bad idea for crit racing? [seppo17]
[ In reply to ]
seppo17 wrote:
What do you mean? 53/11 at 95 rpm is 35.8 mph(56.7kmph) If gear ratio is everything then that is prefectly fine, right?Regarding TTT gearing, yes, a 53x11 at 95 RPM might be fine for the average speed. But they are not riding average, they are well above and below that speed, and they need headroom. So, jumping up to a 58 would let them ride 5 MPH faster at the same cadence. And, don't forget the intangibles of reduced chainline friction and smaller incremental jumps between rear cogs, which is important when precision riding in a TTT paceline.
Re: 12 speed bad idea for crit racing? [benleg]
[ In reply to ]
benleg wrote:
IMO increasing your willingness to crash will increase your crit results alot more that chasing marginal gains. So having a "walk away" bike (with ok wheels) is better that a super bike you will want to scratch.
Where do people come up with this?
It's utter nonsense.
If you crash, you lose. Pretty simple concept. No one wants to crash.
rubik wrote:
benleg wrote:
IMO increasing your willingness to crash will increase your crit results alot more that chasing marginal gains. So having a "walk away" bike (with ok wheels) is better that a super bike you will want to scratch.
Where do people come up with this?
It's utter nonsense.
If you crash, you lose. Pretty simple concept. No one wants to crash.
Yeah, I posted the same thing above, then deleted it because I wrote it too dickish.
The really good crit riders are among the safest, and don't do stupid things. You don't see Justin Williams, Holloway, Young, et al. with a lot of road rash.
I'm not really good, but have ~300 crit starts from Cat 5 to P12, and have crashed twice that I can remember. Once in a Cat 4 yard sale, once I slid myself out in the rain in a breakaway. I use my "good bike" for crits.