Stiffest Proflex frame?

[boro92]

I've been reading reviews and there's a lot of talk about how many Proflex frames seem to be flexible (likely due to the location of the rear pivot).
As for me personally, I ride a 656 and the bb area is reinforced for the pivot location and do not experience anything discerning.

However, looking at bikes like an 855 or 956 etc, I notice that the swingarms are mounted completely differently than the 656.
Question is:: Anyone know what the stiffest Proflex frame is?  Thought I'd ask...by nature, a single pivot with dinky rear strut isn't going to be very stiff, but I'd consider stiffness/power transfer more important than weight here...

Any thoughts welcomed!

[w2zero]

I was asked that on a trail once, I borrowed the questioner's hard tail bike and put my foot on the bb and pushed sideways.  Then did the same on my 855.  Try it.

[fyrstormer]

When I'm standing on my bike, if I wiggle the frame back and forth, it seems to flex more at the head tube than anywhere else. What I understand about physics supports this observation; the torsional force of flexing the frame side-to-side is concentrated in a much smaller area at the head tube than at any other point on the frame.

[Colin]

I quote from the Carbon_Tech_sheet

Compared to the 857 frame, the
new K2 carbon frame is:
• Over 50% stronger
• About 50% stiffer
• About 10% lighter (2.85 vs 3.1lbs)

Sounds like the x500/Oz frame is the stiffest!

Col.

[whisperdancer]

Frames look to be stiff enough.
The problem is the more flexible and bigger carbon swingarm.

[shovelon]

Frames look to be stiff enough.
The problem is the more flexible and bigger carbon swingarm.

Not just that but the level of compression damping on the noleen shocks. Seems to me they were a bit overdamped from the factory to overcome slight bobbing on the x57 and evo style frames.

When my shocks puked all the oil, the first thing I noticed was how smooth the stroke was without the oil. Sundance Cycles did the rebuild and used lighter oil for the back shock on my 97 beast, and huge improvement. Then I switched to Manitou shocks on my Oz, and same thing. I reckon that the stiff compression damping of the Noleen shock caused some side to side wobble at the swingarm, that went away with faster compression damping.

Make any sense?

[w2zero]

Makes sense, the force has to go somewhere and the motors on these things are anything but smooth and balanced.  However, learning to pedal smoothly in circles is a huge source of power and easier on the equipment.

[whisperdancer]

I remember my favourite setting on the NR4 was a fast compression damping but slow rebound.
I've tried to fix the shock in a shop, but they said the shaft is scratched, although visually there is nothing wrong with it.
Is it posible for it to be scratched inside the shock body?

[shovelon]

I remember my favourite setting on the NR4 was a fast compression damping but slow rebound.
I've tried to fix the shock in a shop, but they said the shaft is scratched, although visually there is nothing wrong with it.
Is it posible for it to be scratched inside the shock body?

That's funny. Mine failed because gravel was driven into the rubber seal, then all the oil spewed. If you can't see the scratch, and is internal, it may be useable. These noleens seem to fail unless a shock boot is on it.

[whisperdancer]

I remember my favourite setting on the NR4 was a fast compression damping but slow rebound.
I've tried to fix the shock in a shop, but they said the shaft is scratched, although visually there is nothing wrong with it.
Is it posible for it to be scratched inside the shock body?

That's funny. Mine failed because gravel was driven into the rubber seal, then all the oil spewed. If you can't see the scratch, and is internal, it may be useable. These noleens seem to fail unless a shock boot is on it.

I will have to find a way to open it, but I don't know how to start in the first place...