Geometry query - Rake and trail effects on handling
gnomelord
Posts: 5
I have a custom made frame with which I normally use a columbus fork (Carbon blades, alu steerer).
I specified the whole design myself so I knew up front exactly how it would fit and could make a fairly well educated guess on how it would handle. Suffice to say it's 'perfection' in all regards.
I recently removed the fork to have it custom painted.
In the meantime, I fitted an enve fork (full carbon) to be going on with. The Enve fork has 8mm more rake than the columbus.
As such, I expected the handling to a bit twitchier due to the reduced trail.
However, in reality I surprisingly found the opposite to be true! With the Enve fork I found cornering to be quite hard work and almost scary (understeer).
This is all completely counter intuitive to what I expected and commonly accepted geometry facts...
Now I'm curious as to WHY this might be? Can anyone suggest anything that could explain this?
I specified the whole design myself so I knew up front exactly how it would fit and could make a fairly well educated guess on how it would handle. Suffice to say it's 'perfection' in all regards.
I recently removed the fork to have it custom painted.
In the meantime, I fitted an enve fork (full carbon) to be going on with. The Enve fork has 8mm more rake than the columbus.
As such, I expected the handling to a bit twitchier due to the reduced trail.
However, in reality I surprisingly found the opposite to be true! With the Enve fork I found cornering to be quite hard work and almost scary (understeer).
This is all completely counter intuitive to what I expected and commonly accepted geometry facts...
Now I'm curious as to WHY this might be? Can anyone suggest anything that could explain this?
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Comments
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http://davesbikeblog.squarespace.com/bl ... story.html
this explains it I think, more rake = less trail, less trail meaning harder steering0 -
lemonenema wrote:http://davesbikeblog.squarespace.com/blog/2007/5/4/trail-fork-rake-and-a-little-bit-of-history.html
this explains it I think, more rake = less trail, less trail meaning harder steering
Thanks; yes I understand the accepted principles; hence my question.
I also concur with some findings of that blog but there are still no answers.
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I think the best answer is simply that I am experiencing first hand that there are many more factors at play in the way a bike handles than just rake and trail.0 -
The Gnome wrote:lemonenema wrote:http://davesbikeblog.squarespace.com/blog/2007/5/4/trail-fork-rake-and-a-little-bit-of-history.html
this explains it I think, more rake = less trail, less trail meaning harder steering
Thanks; yes I understand the accepted principles; hence my question.
No, you don't. You believed more rake would give you faster steering. You were wrong, it gives slower steering, as stated in the linked to article.0 -
rafletcher wrote:No, you don't. You believed more rake would give you faster steering. You were wrong, it gives slower steering, as stated in the linked to article.
Yes, I do. You are wrong.
The linked article states 'longer trail is "more stable" for touring bikes, less trail is more "twitchy" for racing bikes. [yes terms that are subjective and not really measurable].
If your belief is correct, it would mean that most racing bikes with (relatively) low trail, have slower steering than touring bikes with higher trail and we know this not to be the case.0
