Stack height and stability/handling
07-01-08, 09:06 AM
#2
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If you've got too much stack height you can be adding some flex, and the possibilty of failure. ( some fork manufacturers with CF steerer tubes, say no more than 40mm of stack.)
Other than that, I think the total fit, and the geometry of the setup is more important, than the stack height.
i.e. ceterus peribus, 20 mm of stack and a 6 degree plus stem, shouldn't handle different than 40mm of stack, and 6 degree minus, if the bars are in the same place.
Other than that, I think the total fit, and the geometry of the setup is more important, than the stack height.
i.e. ceterus peribus, 20 mm of stack and a 6 degree plus stem, shouldn't handle different than 40mm of stack, and 6 degree minus, if the bars are in the same place.
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07-01-08, 09:19 AM
#3
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Keep in mind that stack height safety only really applies to carbon steerer tubes.
With aluminum, it is safe enough to go 2-3 inches if necessary.
With steel, you can keep it full length if you so desire, and it's perfectly safe.
For carbon steerers, which is rapidly becoming the norm for road bikes, generally you don't want any more than 1.5" of stack height from the top of the headset.
With aluminum, it is safe enough to go 2-3 inches if necessary.
With steel, you can keep it full length if you so desire, and it's perfectly safe.
For carbon steerers, which is rapidly becoming the norm for road bikes, generally you don't want any more than 1.5" of stack height from the top of the headset.
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07-02-08, 03:56 PM
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I'm thinking this is related...
I'm tall (6'7'') and have been looking into getting a Zinn Bike. He specailizes in bikes for tall people and I know he designs the front end geometry of his bikes to eliminate the shimmy that can happen with bigger riders.
I have this on one of my current bikes (and old Ralieigh) - if I take my hands of the handle bars and stop pedalling - the front end of the bike starts to shake and shimmy like mad.
I thought it was just my bike (does happen to a lesser degree on my mountain bike) - but from what I hear it is a reasonably common problem with bigger taller riders. So he uses a fork with a beefed up carbon steerer and extends the length of the head tube above the top tube. So I'm guessing you don't need as big a stack height on his bikes as this is a design feature of his bikes.
www.zinncycles.com - have a look at the project big bikes.
Adrian.
I'm tall (6'7'') and have been looking into getting a Zinn Bike. He specailizes in bikes for tall people and I know he designs the front end geometry of his bikes to eliminate the shimmy that can happen with bigger riders.
I have this on one of my current bikes (and old Ralieigh) - if I take my hands of the handle bars and stop pedalling - the front end of the bike starts to shake and shimmy like mad.
I thought it was just my bike (does happen to a lesser degree on my mountain bike) - but from what I hear it is a reasonably common problem with bigger taller riders. So he uses a fork with a beefed up carbon steerer and extends the length of the head tube above the top tube. So I'm guessing you don't need as big a stack height on his bikes as this is a design feature of his bikes.
www.zinncycles.com - have a look at the project big bikes.
Adrian.
