[greenchris]

What is the deal with fork offset? After reading a post somewhere that the reba's offset is from a 26" rather than 29". So how does a shorter offset comapre to a longer offset? Is it bike specific... meaning some offsets would work better for my ferrous more than my sultan? Or is a longer offset beneficial to all 29er designs? I'm confused and I'm being impatient for rock shock to bust out the updated 29er reba in 2009...

 

[jncarpenter]

There is no quick & easy answer to your question. However, I'll try & be concise.

A more insightful "measurement" (more than fork offset) to help ascertain a particular bikes handling, is "trail". The trail measurement is the distance between the contact point (center of the contact patch) of the front wheel on the floor and the point where the "virtually" elongated steering axis meets the ground.

It can be determined by the formula:

where:
Beta Head Tube Angle
R Radius of the wheel
B Fork Offset
N Trail


A higher trail value will produce slower handling & vice versa. With the other variables remaining the same...more offset produces a lower trail and thus, quicker handling (again, vice versa).

You can play around with some of the values on THIS NEAT TOOL to see the relationship they have toward one another.

 

[MMcG]

Have a read up on the new G2 Geometry at the Fisher site - that oughta help ya a bit.

Short and sweet for 29ers - greater offset usually reflects back into quicker handling. For example, the Reba has a 38mm offset vs. say an On One Inbred fork with a 47mm offset. Put em both on an One One Inbred and the bike will handle "quicker" with the 47mm offset fork than the 38mm Reba.

Does this help a bit?

I think that info on the Fisher site will be helpful to you since you are talking about a Ferrous in your post.

Hope this helps a little. I'm sure others can do an even better job of explaining things than I just did. Guitar Ted and jncarpenter know their shiz when it comes to this issue (as do many others).

See I knew jn would chime in with something much more informative (and technical) than me! :biggrin:

 

[greenchris]

thanks for both of your responses. I'm starting to order new parts for both of muh bikes and it's cool looking and understanding all the different measurements and characteristics.