Still not sure which to go with (tall boy or fly). Wish ninner would make a carbon Jet – that might solve my problem. BTW I test road the tall boy and did like the rear suspension better than the Jet – but his might be do to it being larger (Jet 3.1 Tall Boy 3.9 I think). And I like carbon

First of all, the offset and head angle changes for 29″ers originally were pursued to keep the front end steering more like 26″ers. Just increasing the wheel size caused slower steering, due to a thing called “trail”. Trail describes the point at which the tire contacts the ground and how far that point “trails” the imaginary point at which the steering axis (determined by head tube angle) would intersect with the ground. The tire contact patch must be behind this point to provide stability. The longer this distance gets, the more stable, (or sluggish and slow) the handling gets. Bigger wheels automatically increased trail with everything else remaining the same.

Earlier, companies tried just manipulating head tube angles. This caused toe overlap problems, suspension anomalies, and didn’t handle as well as doing things with slacker head angles and more fork offset.

So, Gary Fisher Bikes conducted studies using riders in three different locations using six different offsets and multiple head tube angles. What they unanimously decidedupon is what is now known as G2 geometry.

Other companies, while not quite as radical, have followed suit.

On your second question, the two suspension designs are very different. Fisher uses a modified single pivot with a swing link and the Santa Cruz uses a multiple link system that connects a rear triangle to the main triangle of the bike, which are separate sub assemblies in that arrangement. Some call these designs “virtual pivot point” designs and they include DW Link, Niner’s CVA and VPP designs.

What I really don’t understand about the fly is why have the offset fox fork + steeper angle in the first place? To clarify, why not just design the head tub where you need it and then any fork would work? This isn’t a question about fox, rather the design decision employed on the Fly. Thoughts?

Second – the suspension between the two seems very much the same minus that the Fly has a link in the rear axle. Any additional thoughts on that? Thanks!