Should I swap front ends?

[sdxp787]

I want to use the 04-05 spindle/hub upgrade on my 86R.  I am looking for performance gains as I race XC.  Is this a gain or no?  I also want to use the newer 450R brake calipers and rotors.  The 450R brake setup is so much better, in my opinion, than the 250R.  Lots of effort to pull the lever on the 250 and virtually no effort on the 450.  this is what is making me want to switch.  Any opinions?  Why arms would I use with the 450 spindles?

[andy@maultechatv]

How about some pictures for explanation and food for thought.  Here is a Walsh chassis with 86 spindles and hubs.  Notice how bad the bump steer is.  Now keep in mind that the chassis manufacturer and steering stem flag height also play a huge factor in this but I'm just showing you what you don't want.  The toe at full shock extension was set perfectly straight.  We did not change spindles on this bike to see if it helped out.

[Tbone07]

How about some pictures for explanation and food for thought.  Here is a Walsh chassis with 86 spindles and hubs.  Notice how bad the bump steer is.  Now keep in mind that the chassis manufacturer and steering stem flag height also play a huge factor in this but I'm just showing you what you don't want.  The toe at full shock extension was set perfectly straight.  We did not change spindles on this bike to see if it helped out.

Wow that's tells the whole story right there. What would you have done to remedy this problem Andy?

Looks like I need to take a look at this on my bike

[andy@maultechatv]

Wow that's tells the whole story right there. What would you have done to remedy this problem Andy?

Looks like I need to take a look at this on my bike

First I would change the tie rod end heights.  Then I would try a different spindle setup to see if it helped.  And if neither of those were significant enough I would change the steering stem flag height.

[Burns363R]

Stem flag height seems to be the weak point on the R from my experience.