riding a frame size that is too large??
12-06-07, 10:48 AM
#51
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I suggested putting the saddle at mid-rails in setting up your bikes so that you can dial in a cockpit length that is consistent and identical on each of your bikes, even though your saddles may vary a bit. After you know your best cockpit length, you can move the saddle forward or back, based on the length of the saddle and saddle rails, and based on your own riding style. It is common for guys who doing fast, stop-and-go riding, such as bike messengers, to move their saddles forward a bit, and a lot of folks doing all day cruising seem happier with the saddle back a bit.
KOPS, as with many "scientific" formulas in cycling, is based on studies of what is best for racing. But, even among guys who race, KOPS formulas are rejected based on personal experience. Many guys who specialize in sprints "feel" they can accelarate better with the saddle out in front of the bottom bracket. Greg LeMond felt that the key to being able to maintain high cruising speed for three or four hours at a time was having the saddle back, relative to the bottom bracket.
What about "Joe Average Cyclists"? Each of my road bikes has a cockpit length of precisely 31 1/2 inches. On the bikes with steep geometry, the saddle is forward relative to the bottom bracket. On the bikes with relaxed geometry, the saddle is back relative to the bottom bracket. Yet, each of those bikes feels the same on the road, because my "fore/aft" weight balance is identical, and the distance from the rear of the saddle to the front of the stem is identical, and the saddle height is identical.
The problem with "KOPS worship" is that, unless you have a custom-built bike, by moving the saddle to dial in some mythical ideal KOPS forumula, you are likely to end up with a cockpit length that is too short or too long.
Too short, you are bunched up on the bike, which can restrict breathing, and cause you too feel cramped. Too long, and your weight shifts to your hands, leading to pain in the hands, and wrist, and then to the neck and shoulders.
KOPS, as with many "scientific" formulas in cycling, is based on studies of what is best for racing. But, even among guys who race, KOPS formulas are rejected based on personal experience. Many guys who specialize in sprints "feel" they can accelarate better with the saddle out in front of the bottom bracket. Greg LeMond felt that the key to being able to maintain high cruising speed for three or four hours at a time was having the saddle back, relative to the bottom bracket.
What about "Joe Average Cyclists"? Each of my road bikes has a cockpit length of precisely 31 1/2 inches. On the bikes with steep geometry, the saddle is forward relative to the bottom bracket. On the bikes with relaxed geometry, the saddle is back relative to the bottom bracket. Yet, each of those bikes feels the same on the road, because my "fore/aft" weight balance is identical, and the distance from the rear of the saddle to the front of the stem is identical, and the saddle height is identical.
The problem with "KOPS worship" is that, unless you have a custom-built bike, by moving the saddle to dial in some mythical ideal KOPS forumula, you are likely to end up with a cockpit length that is too short or too long.
Too short, you are bunched up on the bike, which can restrict breathing, and cause you too feel cramped. Too long, and your weight shifts to your hands, leading to pain in the hands, and wrist, and then to the neck and shoulders.
12-06-07, 06:08 PM
#52
Bike ≠ Car ≠ Ped.
12-06-07, 06:39 PM
#53
Dammit!
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And in effect, depending on your anatomy and biomechanics, you could injure yourself if you're legs, knees and ankles are not used to that new position (relative to the BB), like I did when I hurt my Achilles tendons after only 2 rides when I experimented moving the saddle forward 1.5 cm on a bike that was 2 sizes too large for me. Moved it back to the same position as my other bikes cleared the pain away.
12-06-07, 08:45 PM
#54
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Fifty years of riding has taught me that the MOST important factor in comfort for all-day bike rides is "fore/aft" weight balance. The problem with "KOPS worship" is that, unless you have a custom-built bike, by moving the saddle to dial in some mythical ideal KOPS forumula, you are likely to end up with a cockpit length that is too short or too long, either of which will make it impossible to have perfect fore/aft weight balance.
12-06-07, 11:08 PM
#55
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I'd have to agree with you on that.Saddles do vary with different nose lengths.
Therefore one should probably start their measurement from the back of the saddle to wherever.
I prefer the closest edge of the bars just because it's easiest for me.
Not that I have a lot of experience at it.
My fit session set for Dec 31.
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12-08-07, 05:13 AM
#57
Bike ≠ Car ≠ Ped.
Maybe it should be from the center of the seat rails, but that might not be so definite, either. Riders may prefer to sit a little farther forward or aft of the center point.
12-08-07, 05:48 PM
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^ That would probably be more accurate, but I guess riders will just have to accept that a different saddle might require a different cockpit length.
12-09-07, 07:28 AM
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My view is Alan's method of measuring to the rear of the saddle is the most effective. It isn't perfect but the reality is the sit bones are closer to the rear of the saddle then the front. The offer referenced "measure to tip of saddle" just doesn't hold up in this day of considerable saddle length differences.
