Seat Posts / Fork 'rake'

[CatSpin]

Last season I needed to swap out my cabon seatpost to a Ti model to increase stiffness and power response. Good move.

This year I am considering ordering a seatpost with the clamp directly on top of the seatpost insead of the 'set back' clamps which moves a saddle up to 2cm behind the seatpost deadcenter line.

Q- Will a seatpost clamp located directly on top of the seatpost itself (like the Thompson and Alien USE models) provide a greater transfer of power to the cranks? What is the theory behind these two schools of thought, directly centered or setback?


On this subject, I have also noted that some forks are staight, and others provide some degrees of rake. Why would one choose one over the other? Are there advantages for racing, cornering etc that one fork can provide?

Thanks in advance members,

CatSpin

 

[boudreaux]

Last season I needed to swap out my cabon seatpost to a Ti model to increase stiffness and power response. Good move.

This year I am considering ordering a seatpost with the clamp directly on top of the seatpost insead of the 'set back' clamps which moves a saddle up to 2cm behind the seatpost deadcenter line.

Q- Will a seatpost clamp located directly on top of the seatpost itself (like the Thompson and Alien USE models) provide a greater transfer of power to the cranks? What is the theory behind these two schools of thought, directly centered or setback?


On this subject, I have also noted that some forks are staight, and others provide some degrees of rake. Why would one choose one over the other? Are there advantages for racing, cornering etc that one fork can provide?

Thanks in advance members,

CatSpin

For best pedaling effency ,your knees have a preferred relationship to the pedal spindle.How you get there does not matter with respect to setback or straight post as long as you get there.All forks have rake. The straight bladed ones have the rake built into the crown rather than the dropouts. Your frame is built around a specific rake and headtube angle to acheive desired trail. You can't just fiddle with rake randonly,without possibly hosing handling.

 

[CatSpin]

For best pedaling effency ,your knees have a preferred relationship to the pedal spindle.How you get there does not matter with respect to setback or straight post as long as you get there.All forks have rake. The straight bladed ones have the rake built into the crown rather than the dropouts. Your frame is built around a specific rake and headtube angle to acheive desired trail. You can't just fiddle with rake randonly,without possibly hosing handling.

Thanks Bourdreaux. I won't touch the fork, good point.

Back to the seat though, as most rails provide a good degree of fore/aft travel, one's knee to pedal position should be attainable by adjusting this measurement (my new coach easily adjusted mine up 2.5cm). My question is more one of the configuration of the seat clamp. Thompson components argue that their configuation can withstand more power and weight than competitors, a function of their clamp positioning. If I take the liberty of extending their logic, more power resistance = less flex. Less flex = more power transfer down the seat tube. More power transfer down the seat tube = more power?


CatSpin