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How real is a tall head tube to ride?
With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the benefits they bring. My question is, what ride differences are there b/n a frame with a longer head tube and a regular road frame that has more spacers inserted below the stem, thereby achieving a longer virtual head tube? I've asked this question a number of times elsewhere and no one seemed to be able to answer it directly. -- |
#2
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How real is a tall head tube to ride?
"Artoi" wrote in message ... With Paris-Roubaix, everyone's talking about the value of "relaxed" frame geometry again, specifically the long head tube and the benefits they bring. My question is, what ride differences are there b/n a frame with a longer head tube and a regular road frame that has more spacers inserted below the stem, thereby achieving a longer virtual head tube? I've asked this question a number of times elsewhere and no one seemed to be able to answer it directly. -- I've never ridden cobbles very far but for normal road riding a longer head tube will result in a frame that is torsionally softer. Think of a twisted frame with the top tube and down tube out of plane. A shorter head tube is torsionally stiffer than a long head tube and will resist this kind of flex. The closer the top tube is to the down tube where they connect to the head tube, the stiffer the frame (all other things being equal). Adding spacers will achieve a taller geometry without affecting frame flex and handling. The worst affect of torsional flexing is in the handling of the bike where the wheels go out of alignment (head tube out of plane with seat tube) and the bike does not track well. Phil H |
#3
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How real is a tall head tube to ride?
that's relaxed carbon tube geometry? tall head tube geometry? tall? what does tall have to do with geometry? the angle determines geometry. would seem the rear lever from longer seat tube vastly overpowers effects at the realtively shgort, nay fractional comparable lengths up at the head tube. anyway, its carbon right? who knows ??? you ask a good question. spacers? (forgive me being an *&&&**) "Adding spacers will achieve a taller geometry without affecting frame flex and handling. " adding spacers automatically adds flex everywhere. spacers, as geometry ? hmmmm non-euclidean ? reimann space effetc? anyway ignore this post. gibberish |
#4
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How real is a tall head tube to ride?
In article
, datakoll wrote: that's relaxed carbon tube geometry? tall head tube geometry? tall? what does tall have to do with geometry? the angle determines geometry. would seem the rear lever from longer seat tube vastly overpowers effects at the realtively shgort, nay fractional comparable lengths up at the head tube. anyway, its carbon right? who knows ??? you ask a good question. spacers? (forgive me being an *&&&**) "Adding spacers will achieve a taller geometry without affecting frame flex and handling. " adding spacers automatically adds flex everywhere. spacers, as geometry ? hmmmm non-euclidean ? reimann space effetc? anyway ignore this post. gibberish Well, not if you look at what those companies have to say about their bike models like Giant's OCR and Specialized's Roubaix models. Even Cervelo have a R3 SL model. So irrespective whether the concept is gibberish, these statements are real. -- |
#5
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How real is a tall head tube to ride?
datakoll aka gene daniels wrote:
[...] anyway ignore this post.[...] No. -- Tom Sherman - Holstein-Friesland Bovinia The weather is here, wish you were beautiful |
#6
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How real is a tall head tube to ride?
In article ,
"Phil Holman" piholmanc@yourservice wrote: "Artoi" wrote in message ... With Paris-Roubaix, everyone's talking about the value of "relaxed" frame geometry again, specifically the long head tube and the benefits they bring. My question is, what ride differences are there b/n a frame with a longer head tube and a regular road frame that has more spacers inserted below the stem, thereby achieving a longer virtual head tube? I've asked this question a number of times elsewhere and no one seemed to be able to answer it directly. -- I've never ridden cobbles very far but for normal road riding a longer head tube will result in a frame that is torsionally softer. Think of a twisted frame with the top tube and down tube out of plane. A shorter head tube is torsionally stiffer than a long head tube and will resist this kind of flex. The closer the top tube is to the down tube where they connect to the head tube, the stiffer the frame (all other things being equal). Adding spacers will achieve a taller geometry without affecting frame flex and handling. The worst affect of torsional flexing is in the handling of the bike where the wheels go out of alignment (head tube out of plane with seat tube) and the bike does not track well. This makes sense. So in other words, what people/companies refers to as "relaxed geometry" is actually one that is a torsionally less stiff frame. Then the issue here is, why would it be considered to be more comfortable? By comfortable I would have assumed its more vertically compliant. Frames in this category include Giant's OCR range, Specialized Roubaix range etc. -- |
#7
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How real is a tall head tube to ride?
On Apr 16, 7:27 am, Artoi wrote:
In article , "Phil Holman" piholmanc@yourservice wrote: "Artoi" wrote in message ... With Paris-Roubaix, everyone's talking about the value of "relaxed" frame geometry again, specifically the long head tube and the benefits they bring. My question is, what ride differences are there b/n a frame with a longer head tube and a regular road frame that has more spacers inserted below the stem, thereby achieving a longer virtual head tube? I've asked this question a number of times elsewhere and no one seemed to be able to answer it directly. -- I've never ridden cobbles very far but for normal road riding a longer head tube will result in a frame that is torsionally softer. Think of a twisted frame with the top tube and down tube out of plane. A shorter head tube is torsionally stiffer than a long head tube and will resist this kind of flex. The closer the top tube is to the down tube where they connect to the head tube, the stiffer the frame (all other things being equal). Adding spacers will achieve a taller geometry without affecting frame flex and handling. The worst affect of torsional flexing is in the handling of the bike where the wheels go out of alignment (head tube out of plane with seat tube) and the bike does not track well. This makes sense. So in other words, what people/companies refers to as "relaxed geometry" is actually one that is a torsionally less stiff frame. Then the issue here is, why would it be considered to be more comfortable? By comfortable I would have assumed its more vertically compliant. Frames in this category include Giant's OCR range, Specialized Roubaix range etc. -- Not really. Geometry only affects rider position and handling dynamics. "Relaxed" generally means slacker tube angles to get the rider's weight back and slow down steering. Any shaped frame can be built to varying degrees of torsional stiffness, and vertical compliance is a myth. The trend of adding taller head tubes is purely for people who want higher bars without spacers. |
#8
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How real is a tall head tube to ride?
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#9
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How real is a tall head tube to ride?
On Wed, 16 Apr 2008 11:27:40 GMT, Artoi wrote:
In article , "Phil Holman" piholmanc@yourservice wrote: "Artoi" wrote in message ... With Paris-Roubaix, everyone's talking about the value of "relaxed" frame geometry again, specifically the long head tube and the benefits they bring. My question is, what ride differences are there b/n a frame with a longer head tube and a regular road frame that has more spacers inserted below the stem, thereby achieving a longer virtual head tube? I've asked this question a number of times elsewhere and no one seemed to be able to answer it directly. -- I've never ridden cobbles very far but for normal road riding a longer head tube will result in a frame that is torsionally softer. Think of a twisted frame with the top tube and down tube out of plane. A shorter head tube is torsionally stiffer than a long head tube and will resist this kind of flex. The closer the top tube is to the down tube where they connect to the head tube, the stiffer the frame (all other things being equal). Adding spacers will achieve a taller geometry without affecting frame flex and handling. The worst affect of torsional flexing is in the handling of the bike where the wheels go out of alignment (head tube out of plane with seat tube) and the bike does not track well. This makes sense. So in other words, what people/companies refers to as "relaxed geometry" is actually one that is a torsionally less stiff frame. Then the issue here is, why would it be considered to be more comfortable? By comfortable I would have assumed its more vertically compliant. Frames in this category include Giant's OCR range, Specialized Roubaix range etc. The longer head tube causes the front triangle to not be a triangle. Instead of having all tubes in tension/compression they are more in flexion. How big a difference, probably not a hell of a lot. Enough to tell? Take that up with the propellor heads who think that as long as it has pneumatic tires no change in frame design could possibly make a difference. |
#10
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How real is a tall head tube to ride?
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