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I'm thinking of buyng a Scott Sportster P6 hybrid for a bit of touring/offroad. It's got straight alloy forks, which I've only seen on racing bikes. I heard curved forks absorb some of the bumps from the road, so am I in for a rough ride with straight forks?
I'm thinking of buyng a Scott Sportster P6 hybrid for a bit of touring/offroad. It's got straight alloy forks, which I've only seen on racing bikes. I heard curved forks absorb some of the bumps from the road, so am I in for a rough ride with straight forks?You heard BS.
No...............
You heard BS.
No...............
Oh no you didn't (sort of). All else equal, a curved fork will be more compliant. The key is "all else equal" which it never is.
I wouldnt' worry about it.
All else equal, a curved fork will be more compliant.
BS................
BS................
Very elegant answer, lots of detail to motivate your conclusion.
Very elegant answer, lots of detail to motivate your conclusion.
motivate??
motivate??
You are taking a very in your face, disrepecting view. So, I assume you have very strong "proof" that it is this way? I do not know, but someone telling me that it is not, by saying it is BS is not going to "educate" me. So, please, if you have some ideas around it, share those. I would like that. I am always up for learning something. Now, I know, this is not kindergarten and all that but if you can spare a moment, I think it would be a good thing.
You heard BS.
No...............
I was always told that it does matter, although running a thought experiment gives me a hunch that it is indeed not true at all. I'm sure some smarter peeps as me can tell the truth as I am not that hot with mechanical physics.
The skinny on my reasoning:
Angle from drop (hub) to frame remains the same with curve or straigth. The force of a bump goes from the ground straight up to the drops. As the angle is the same, I would think that the force on the frame and thus ultimately to you would be the same.
-As a curved fork is heavier it could be that it gives more shocks through as it has more mass, but I am not a physicist, so that might be a completely ridiculous theory. Oh well, considering the tiny difference in weigth it is probably insignifcant if it was true.
Anyway: I would say tire-pressure and saddle choice would be a lot more important in shock absorbence.
I was always told that it does matter, although running a thought experiment gives me a hunch that it is indeed not true at all. I'm sure some smarter peeps as me can tell the truth as I am not that hot with mechanical physics.
The skinny on my reasoning:
Angle from drop (hub) to frame remains the same with curve or straigth. The force of a bump goes from the ground straight up to the drops. As the angle is the same, I would think that the force on the frame and thus ultimately to you would be the same.
-As a curved fork is heavier it could be that it gives more shocks through as it has more mass, but I am not a physicist, so that might be a completely ridiculous theory. Oh well, considering the tiny difference in weigth it is probably insignifcant if it was true.
Anyway: I would say tire-pressure and saddle choice would be a lot more important in shock absorbence.
Really? Think of a MUCH more extreme curve to the fork blade, yet with the same total rake (i.e., if the fork followed along the wheel's rim). Still think that it doesn't matter? Of course it does. So now shrink it back down to what we really see on forks. Is it measurable? Probably. Does it matter? Pfff, probably not. But it's not B.S.
Really? Think of a MUCH more extreme curve to the fork blade, yet with the same total rake (i.e., if the fork followed along the wheel's rim). Still think that it doesn't matter? Of course it does. So now shrink it back down to what we really see on forks. Is it measurable? Probably. Does it matter? Pfff, probably not. But it's not B.S.
And given the real world of how forks are really made in todays world, it's BS. I'll keep looking for the link To the real skinny from a well regarded framebuilder.
I am a mechanical engineer.
It is most certainly true that ALL OTHER THINGS EQUAL a curverd fork is more compliant.
Ultimatly we are talking about is determining the deflection in responce to a given load. A strait fork takes all of this in compresion, a curverd fork can bend, placing one side (front vs back, not left vs right) in tension and the other in compression (in case you care the back is in tension and the front is in compression).
Without writing a book on beam theory here, about all I can say is that bending is alot easier than compressing.
There is also an analog to S bend stays giving a softer ride. teh bend intoduces a location for the frame to flex and lessen the displacement transmitted from the road to the seat.
A strait fork takes all of this in compresion, ............
That's BS too.
I am a mechanical engineer.
It is most certainly true that ALL OTHER THINGS EQUAL a curverd fork is more compliant.
Ultimatly we are talking about is determining the deflection in responce to a given load. A strait fork takes all of this in compresion, a curverd fork can bend, placing one side (front vs back, not left vs right) in tension and the other in compression (in case you care the back is in tension and the front is in compression).
Without writing a book on beam theory here, about all I can say is that bending is alot easier than compressing.
There is also an analog to S bend stays giving a softer ride. teh bend intoduces a location for the frame to flex and lessen the displacement transmitted from the road to the seat.
Uhm no, that is actually wrong. I'm no engineer, but it is obvious that the force applied goes straigth from the ground to the drops. So the force reaches the fork at an angle and the fork will simply bend.
That's BS too. Alright, I didn't mention the caveat, but here it is...
a straight fork takes all of the load in compression unless there is buckling. Buckling is an unstable process (caused when a load is reached for which there are an infinite number of solutions to the equations governing the shape of member) that you would never build into a fork because it could easily cause the wheel to spontainiously turn (left side bends one way, right side the other).
Was that your objection, or do you just not like the conclusion I reached in my previous post?
Uhm no, that is actually wrong. I'm no engineer, but it is obvious that the force applied goes straigth from the ground to the drops. So the force reaches the fork at an angle and the fork will simply bend. That is the steady state situation, but what we are really looking at is the dynamic situation where a load is suddenly applied (potholes, bumps...), and the direction is not nesisarrily straight up.
You are right though, I did oversimplfy the problem, there would be some bending. But the prefered bending path intrduced by the curve should still give a more complient ride, all other things being equal (which they never would be).
thanks...
I'm thinking of buyng a Scott Sportster P6 hybrid for a bit of touring/offroad. It's got straight alloy forks, which I've only seen on racing bikes. I heard curved forks absorb some of the bumps from the road, so am I in for a rough ride with straight forks?
Well either way as you can see here, if it makes a difference or not, the difference is negligible.... focus your thoughts on other things such as a nice comfy saddle...
Well either way as you can see here, if it makes a difference or not, the difference is negligible.... focus your thoughts on other things such as a nice comfy saddle...
Exactly. It might be true that a curved fork blade may flex a bit more readily because of the curve in the blade but a straight blade is going to flex with an impact too. Will you notice the difference at the handlebar? Not likely!
Like another poster already said, your tires are going to make a noticable impact on the quality of your ride. Get some nice, compliant tires and don't even worry about the construction of your fork.
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