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Crank Arm Length
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#13
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Crank Arm Length
On 8/7/2017 4:52 PM, wrote:
On Monday, August 7, 2017 at 1:42:28 PM UTC-7, JQ wrote: On 8/5/2017 2:57 PM, wrote: We've probably argued about this before but since I can't remember crap I can get clean opinions. I presently ride 175 mm length crank arms. I have problems spinning and watching the Tour this year what was clear was that there are no more luggers in the peleton. This suggests that spinning is the way to go. So: Has anyone experimented with different crank arm lengths and have they been able to tell the difference between one size different in length? I recently went from a 175 crank arm to 165, I did this because I have severe degenerative arthritis in both knees. My pedal stroke seems to be weakest and 3 to 6 but the top of the pedal stroke is the hardest on my knees. With the shorter crank arm my power out put was a little better on the power graph, the greatest benefit is to knee comfort especially at the top of my pedal stroke. I can know actually ride in the drops comfortably without my knees feeling like they are in my chest and greater knee pains at the top. It is easier to spin at easier gearing because the distance of pedal travel is shorter, now for the downside... pedaling it is much harder takes more effort to turn the pedal using the same gearing. You also feel like you don't get the same amount of power and momentum per pedal stroke because of the shorter distance of the pedal stroke circumference. Gear set up was 53/39 front and 11-23 rear (my flat land and crit racing set up). What I noticed is to pedal with similar effort I needed to drop down at least 2 gears (53/15 would need to be 53/17). This doesn't sound like much of a difference but it is as far as speed and power is concerned. I just changed my gearing set up on my bike to 52/38 and 11-28 (to be able to climb hills). I even have a 12-30 for really steep hills. My original reason for changing out the crank arms was for the arthritis of the knees, but I was hit by a high speed car from the rear and was jacked up pretty good resulting in over 9 weeks in the hospital, over 22 broken bones through out my body including neck, back and both legs, colostomy (after 1.5 years just had it reversed!) and other injuries; in brief the shorter crank arms were even more important because of the additional damage to my knees. I have been on a long recovery and physical therapy to restrengthen my legs and body. The recent change in gearing has made things easier but I have a long ways to go to get back my strength, speed and power. I do like the shorter crank arms for my knees but and being able to ride on the drops but dislike that it takes more physical strength to pedal the same gearing. Keep in mind the strength thing may have only been getting use to the added resistance but adding the accident into the mix may not be a fair comparison to an able body rider, other than I am able to pedal without my knees feeling like they will lock up at the top of the pedal stroke as they felt before I changed out the crank arms. oh few more things that I need to mention; you will need to modify your bike fit by raising the saddle height, your saddle position may need t move back or forward, your bar height and stem length may need to be changed or at least getting used to. I had already shorten up my stem and but have not raised it which may be my next change as I am now in a very aggressive forward lean, tough on the lower back, neck and arms which the accident didn't help. How tall are you? 6 foot and 33.5 inch inseam -- Ride fast, ride hard, ride for health and enjoyment... JQ Dancing on the edge --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
#14
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Crank Arm Length
On Monday, August 7, 2017 at 3:29:34 PM UTC-7, JQ wrote:
On 8/7/2017 4:52 PM, wrote: On Monday, August 7, 2017 at 1:42:28 PM UTC-7, JQ wrote: On 8/5/2017 2:57 PM, wrote: We've probably argued about this before but since I can't remember crap I can get clean opinions. I presently ride 175 mm length crank arms. I have problems spinning and watching the Tour this year what was clear was that there are no more luggers in the peleton. This suggests that spinning is the way to go. So: Has anyone experimented with different crank arm lengths and have they been able to tell the difference between one size different in length? I recently went from a 175 crank arm to 165, I did this because I have severe degenerative arthritis in both knees. My pedal stroke seems to be weakest and 3 to 6 but the top of the pedal stroke is the hardest on my knees. With the shorter crank arm my power out put was a little better on the power graph, the greatest benefit is to knee comfort especially at the top of my pedal stroke. I can know actually ride in the drops comfortably without my knees feeling like they are in my chest and greater knee pains at the top. It is easier to spin at easier gearing because the distance of pedal travel is shorter, now for the downside... pedaling it is much harder takes more effort to turn the pedal using the same gearing. You also feel like you don't get the same amount of power and momentum per pedal stroke because of the shorter distance of the pedal stroke circumference. Gear set up was 53/39 front and 11-23 rear (my flat land and crit racing set up). What I noticed is to pedal with similar effort I needed to drop down at least 2 gears (53/15 would need to be 53/17). This doesn't sound like much of a difference but it is as far as speed and power is concerned. I just changed my gearing set up on my bike to 52/38 and 11-28 (to be able to climb hills). I even have a 12-30 for really steep hills. My original reason for changing out the crank arms was for the arthritis of the knees, but I was hit by a high speed car from the rear and was jacked up pretty good resulting in over 9 weeks in the hospital, over 22 broken bones through out my body including neck, back and both legs, colostomy (after 1.5 years just had it reversed!) and other injuries; in brief the shorter crank arms were even more important because of the additional damage to my knees. I have been on a long recovery and physical therapy to restrengthen my legs and body. The recent change in gearing has made things easier but I have a long ways to go to get back my strength, speed and power. I do like the shorter crank arms for my knees but and being able to ride on the drops but dislike that it takes more physical strength to pedal the same gearing. Keep in mind the strength thing may have only been getting use to the added resistance but adding the accident into the mix may not be a fair comparison to an able body rider, other than I am able to pedal without my knees feeling like they will lock up at the top of the pedal stroke as they felt before I changed out the crank arms. oh few more things that I need to mention; you will need to modify your bike fit by raising the saddle height, your saddle position may need t move back or forward, your bar height and stem length may need to be changed or at least getting used to. I had already shorten up my stem and but have not raised it which may be my next change as I am now in a very aggressive forward lean, tough on the lower back, neck and arms which the accident didn't help. How tall are you? 6' tall with 33.5" inseam Since you're 4" shorter and with a 1/2" shorter inseam I don't suppose I'll have any problems. |
#15
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Crank Arm Length
On Mon, 7 Aug 2017 13:33:40 -0700 (PDT), wrote:
On Sunday, August 6, 2017 at 5:55:16 PM UTC-7, John B. wrote: On Sun, 6 Aug 2017 08:13:39 -0700 (PDT), wrote: On Sunday, August 6, 2017 at 8:05:51 AM UTC-7, wrote: On Saturday, August 5, 2017 at 6:47:46 PM UTC-7, John B. wrote: On Sat, 5 Aug 2017 11:57:18 -0700 (PDT), wrote: We've probably argued about this before but since I can't remember crap I can get clean opinions. I presently ride 175 mm length crank arms. I have problems spinning and watching the Tour this year what was clear was that there are no more luggers in the peleton. This suggests that spinning is the way to go. So: Has anyone experimented with different crank arm lengths and have they been able to tell the difference between one size different in length? Years ago I conducted a personal test of spinning versus lugging (as you call it) I rode 50km out, on a 100 km route, lugging and the returning 50 km spinning. The second half was definitely faster. Terrain in that case was pretty much the same in the two parts of the test. Currently I keep, on Phuket Island where the above test was conducted, a road bike, currently with 170mm cranks, and a utility" bike with 175mm cranks. While most of the utility rides are in the local area I do a 20km ride on it, usually once a week. I can't tell the difference between 170 and 175mm cranks. In fact the road bike originally had a mountain bike triple chain wheel set with 175mm cranks. When I changed it to a road bike triple with 170mm cranks I never noticed the difference. On the other hand spinning is probably not instinctive and lugging (I prefer the verb "Mashing :-) probably is so you need to work at it a little before it becomes instinctive. The Pros spin at pretty high rates, Froome was said to be spinning nearly 100rpm going up hill, but that probably isn't practical for the average rider. Initially, try riding, on level ground, and spinning at say 90 rpm, in a lower gear ratio. When spinning begins to feel natural up the spin to 100 rpm. I think that you will find it becoming natural after a while. Initially the secret is to use a lower gear ratio. 80 rpm in a 50 - 18 gear results in ~27 kph. 100 rpm in a 50 - 23 gear results in ~27 kph. I think that I would like a 50-11 top gear and a 34-28 bottom. This should give me everything I have with the triple except the bottom 2 gears which I never use (well, once up a 30% grade - how common are those?) By the way John - thanks for the information and I'll be sure and let you know the results of the experiment. I might mention that when I first tried spinning that I seemed to bounce in the saddle. It takes a little practice. I pedal circles so I don't bounce. You'd be surprised. Get a tachometer and see how high you can go without bouncing :-) -- Cheers, John B. |
#16
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Crank Arm Length
On 8/7/2017 7:42 PM, wrote:
On Monday, August 7, 2017 at 3:29:34 PM UTC-7, JQ wrote: On 8/7/2017 4:52 PM, wrote: On Monday, August 7, 2017 at 1:42:28 PM UTC-7, JQ wrote: On 8/5/2017 2:57 PM, wrote: We've probably argued about this before but since I can't remember crap I can get clean opinions. I presently ride 175 mm length crank arms. I have problems spinning and watching the Tour this year what was clear was that there are no more luggers in the peleton. This suggests that spinning is the way to go. So: Has anyone experimented with different crank arm lengths and have they been able to tell the difference between one size different in length? I recently went from a 175 crank arm to 165, I did this because I have severe degenerative arthritis in both knees. My pedal stroke seems to be weakest and 3 to 6 but the top of the pedal stroke is the hardest on my knees. With the shorter crank arm my power out put was a little better on the power graph, the greatest benefit is to knee comfort especially at the top of my pedal stroke. I can know actually ride in the drops comfortably without my knees feeling like they are in my chest and greater knee pains at the top. It is easier to spin at easier gearing because the distance of pedal travel is shorter, now for the downside... pedaling it is much harder takes more effort to turn the pedal using the same gearing. You also feel like you don't get the same amount of power and momentum per pedal stroke because of the shorter distance of the pedal stroke circumference. Gear set up was 53/39 front and 11-23 rear (my flat land and crit racing set up). What I noticed is to pedal with similar effort I needed to drop down at least 2 gears (53/15 would need to be 53/17). This doesn't sound like much of a difference but it is as far as speed and power is concerned. I just changed my gearing set up on my bike to 52/38 and 11-28 (to be able to climb hills). I even have a 12-30 for really steep hills. My original reason for changing out the crank arms was for the arthritis of the knees, but I was hit by a high speed car from the rear and was jacked up pretty good resulting in over 9 weeks in the hospital, over 22 broken bones through out my body including neck, back and both legs, colostomy (after 1.5 years just had it reversed!) and other injuries; in brief the shorter crank arms were even more important because of the additional damage to my knees. I have been on a long recovery and physical therapy to restrengthen my legs and body. The recent change in gearing has made things easier but I have a long ways to go to get back my strength, speed and power. I do like the shorter crank arms for my knees but and being able to ride on the drops but dislike that it takes more physical strength to pedal the same gearing. Keep in mind the strength thing may have only been getting use to the added resistance but adding the accident into the mix may not be a fair comparison to an able body rider, other than I am able to pedal without my knees feeling like they will lock up at the top of the pedal stroke as they felt before I changed out the crank arms. oh few more things that I need to mention; you will need to modify your bike fit by raising the saddle height, your saddle position may need t move back or forward, your bar height and stem length may need to be changed or at least getting used to. I had already shorten up my stem and but have not raised it which may be my next change as I am now in a very aggressive forward lean, tough on the lower back, neck and arms which the accident didn't help. How tall are you? 6' tall with 33.5" inseam Since you're 4" shorter and with a 1/2" shorter inseam I don't suppose I'll have any problems. being 4" taller 6'4" tall and 34" inseam and having longer legs will mean you will have more radical changes than I did. If you were shorter the shorter crank arms will may be more beneficial all the way around. I am not sure I understand what you mean by not having any problems. What problems were you thinking of? -- Ride fast, ride hard, ride for health and enjoyment... JQ Dancing on the edge --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
#17
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Crank Arm Length
On 08/08/17 12:43, John B. wrote:
On Mon, 7 Aug 2017 13:33:40 -0700 (PDT), wrote: I pedal circles so I don't bounce. You'd be surprised. Get a tachometer and see how high you can go without bouncing :-) Practise spinning by riding on rollers. You'll soon find out how fast you can pedal smoothly. -- JS |
#18
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Crank Arm Length
On Monday, August 7, 2017 at 10:33:15 PM UTC-7, JQ wrote:
On 8/7/2017 7:42 PM, wrote: On Monday, August 7, 2017 at 3:29:34 PM UTC-7, JQ wrote: On 8/7/2017 4:52 PM, wrote: On Monday, August 7, 2017 at 1:42:28 PM UTC-7, JQ wrote: On 8/5/2017 2:57 PM, wrote: We've probably argued about this before but since I can't remember crap I can get clean opinions. I presently ride 175 mm length crank arms. I have problems spinning and watching the Tour this year what was clear was that there are no more luggers in the peleton. This suggests that spinning is the way to go. So: Has anyone experimented with different crank arm lengths and have they been able to tell the difference between one size different in length? I recently went from a 175 crank arm to 165, I did this because I have severe degenerative arthritis in both knees. My pedal stroke seems to be weakest and 3 to 6 but the top of the pedal stroke is the hardest on my knees. With the shorter crank arm my power out put was a little better on the power graph, the greatest benefit is to knee comfort especially at the top of my pedal stroke. I can know actually ride in the drops comfortably without my knees feeling like they are in my chest and greater knee pains at the top. It is easier to spin at easier gearing because the distance of pedal travel is shorter, now for the downside... pedaling it is much harder takes more effort to turn the pedal using the same gearing. You also feel like you don't get the same amount of power and momentum per pedal stroke because of the shorter distance of the pedal stroke circumference. Gear set up was 53/39 front and 11-23 rear (my flat land and crit racing set up). What I noticed is to pedal with similar effort I needed to drop down at least 2 gears (53/15 would need to be 53/17). This doesn't sound like much of a difference but it is as far as speed and power is concerned. I just changed my gearing set up on my bike to 52/38 and 11-28 (to be able to climb hills). I even have a 12-30 for really steep hills. My original reason for changing out the crank arms was for the arthritis of the knees, but I was hit by a high speed car from the rear and was jacked up pretty good resulting in over 9 weeks in the hospital, over 22 broken bones through out my body including neck, back and both legs, colostomy (after 1.5 years just had it reversed!) and other injuries; in brief the shorter crank arms were even more important because of the additional damage to my knees. I have been on a long recovery and physical therapy to restrengthen my legs and body. The recent change in gearing has made things easier but I have a long ways to go to get back my strength, speed and power. I do like the shorter crank arms for my knees but and being able to ride on the drops but dislike that it takes more physical strength to pedal the same gearing. Keep in mind the strength thing may have only been getting use to the added resistance but adding the accident into the mix may not be a fair comparison to an able body rider, other than I am able to pedal without my knees feeling like they will lock up at the top of the pedal stroke as they felt before I changed out the crank arms. oh few more things that I need to mention; you will need to modify your bike fit by raising the saddle height, your saddle position may need t move back or forward, your bar height and stem length may need to be changed or at least getting used to. I had already shorten up my stem and but have not raised it which may be my next change as I am now in a very aggressive forward lean, tough on the lower back, neck and arms which the accident didn't help. How tall are you? 6' tall with 33.5" inseam Since you're 4" shorter and with a 1/2" shorter inseam I don't suppose I'll have any problems. being 4" taller 6'4" tall and 34" inseam and having longer legs will mean you will have more radical changes than I did. If you were shorter the shorter crank arms will may be more beneficial all the way around. I am not sure I understand what you mean by not having any problems. What problems were you thinking of? Knee pain. |
#19
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Crank Arm Length
On Monday, August 7, 2017 at 7:43:38 PM UTC-7, John B. wrote:
On Mon, 7 Aug 2017 13:33:40 -0700 (PDT), wrote: On Sunday, August 6, 2017 at 5:55:16 PM UTC-7, John B. wrote: On Sun, 6 Aug 2017 08:13:39 -0700 (PDT), wrote: On Sunday, August 6, 2017 at 8:05:51 AM UTC-7, wrote: On Saturday, August 5, 2017 at 6:47:46 PM UTC-7, John B. wrote: On Sat, 5 Aug 2017 11:57:18 -0700 (PDT), wrote: We've probably argued about this before but since I can't remember crap I can get clean opinions. I presently ride 175 mm length crank arms. I have problems spinning and watching the Tour this year what was clear was that there are no more luggers in the peleton. This suggests that spinning is the way to go. So: Has anyone experimented with different crank arm lengths and have they been able to tell the difference between one size different in length? Years ago I conducted a personal test of spinning versus lugging (as you call it) I rode 50km out, on a 100 km route, lugging and the returning 50 km spinning. The second half was definitely faster. Terrain in that case was pretty much the same in the two parts of the test. Currently I keep, on Phuket Island where the above test was conducted, a road bike, currently with 170mm cranks, and a utility" bike with 175mm cranks. While most of the utility rides are in the local area I do a 20km ride on it, usually once a week. I can't tell the difference between 170 and 175mm cranks. In fact the road bike originally had a mountain bike triple chain wheel set with 175mm cranks. When I changed it to a road bike triple with 170mm cranks I never noticed the difference. On the other hand spinning is probably not instinctive and lugging (I prefer the verb "Mashing :-) probably is so you need to work at it a little before it becomes instinctive. The Pros spin at pretty high rates, Froome was said to be spinning nearly 100rpm going up hill, but that probably isn't practical for the average rider. Initially, try riding, on level ground, and spinning at say 90 rpm, in a lower gear ratio. When spinning begins to feel natural up the spin to 100 rpm. I think that you will find it becoming natural after a while. Initially the secret is to use a lower gear ratio. 80 rpm in a 50 - 18 gear results in ~27 kph. 100 rpm in a 50 - 23 gear results in ~27 kph. I think that I would like a 50-11 top gear and a 34-28 bottom. This should give me everything I have with the triple except the bottom 2 gears which I never use (well, once up a 30% grade - how common are those?) By the way John - thanks for the information and I'll be sure and let you know the results of the experiment. I might mention that when I first tried spinning that I seemed to bounce in the saddle. It takes a little practice. I pedal circles so I don't bounce. You'd be surprised. Get a tachometer and see how high you can go without bouncing :-) Right now I'm just returning to condition but last year at this time I could accelerate through yellow lights up to 32 mph in third gear without bouncing. This was a 52/15. In a 52/12 I could ride for four or five miles at 28 mph. In the first case that's 116 rpm without bouncing. |
#20
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Crank Arm Length
On 8/7/2017 10:43 PM, John B. wrote:
On Mon, 7 Aug 2017 13:33:40 -0700 (PDT), wrote: I pedal circles so I don't bounce. You'd be surprised. Get a tachometer and see how high you can go without bouncing :-) There's a five-year-old in our extended family who's been riding a pedal bike for about 15 months now. The bike is a tiny thing, nominal 12" wheels and very low gearing. While he was trying to go fast on a slight downhill, he was spinning at an astonishing 175 rpm. I checked it with my watch, then confirmed it by noting his speed and working out the bike's gear inches. He did fall once when his feet suddenly couldn't keep up, so I advised him to just coast when the downhill is steep enough. But he's coming along nicely! -- - Frank Krygowski |
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