Originally Posted by
Kontact
I'm sorry, you appear to be talking about two different things.
Are forks "off" from "design" because of production tolerances or poor execution? As in a fork that is supposed to be 45mm but just happens to come out of the mold anywhere from 43 to 47mm? Or a fork that was supposed to be 45 but always ends up at 47?
Or are you talking about the tendency to only have a one or two rakes despite 6 different HTAs? So the geometry designer wanted a 48mm rake for the 51cm size frame, but the production manager changed that to 45mm so it used the same fork as the 53cm and 55cm frame size.
The first is a production error that occurs at the factory, while the latter is not a mistake but a design choice based on money. And using only a few rakes departs ideal rake for some sizes by considerably more than just 2mm. The CAAD 12 with a 70.5 HTA and 45mm rake is arguably off by 15mm compared to the trail of a 56mm.
CAAD12 Ultegra | Cannondale Bicycles
So are you talking about production errors, or poor choices?
Both, the claimed rake can drift from the published spec and that companies make production choices based on factors that have little to do with best design sometimes. But I don't call a 2mm drift from claimed rake to be a error, but a result of the process and materials used.
A fork moves back and forth by a few MMs due to various forces encountered while riding, like strong braking. But excepting shudder (which is steerer flex, not blade flex) the effect on steering isn't large enough to have riders complaining, there are far larger things going on that overwhelm any slight trail/flop drift. Andy