Santa Cruz has done an Excellent job in design with their Superlight model.
I've always said that they have been "On Their Game" for the past couple of years.
- The evolution of Superlight from the Heckler
- The redesign of the Heckler to give it a new home in the Freeride
/ All Mountain market.
- The VPP based Blur, probably THE frame of all time.
well, they are to be commended.
The last couple rides I've been noticing a creak from the bottom bracket ( I thought)
so the usual remove, clean, grease was done.
Now there are many, many forces upon a mountain bike frame. These forces are always present
and are taken into consideration when a frame is designed. One of the most challenging of these forces is
the fact that power transmission is from alternating sides of the frame.
Left-Right-Left-Right-Left-Right-Left-Right-Left-Right
All on and through a frame that is designed to be Light!....and Strong.
This is a VERY fine line of Balance and Compromise.
And.....
Sometimes this design strikes back like a snake bite.
Picture of crack in swingarm next to pinch bolt threads.
Notice the sharp 90 degree stress risers where these cracks probably originated
from. As the swingarm flexes back and forth mainly from pedal input, this is an area
where the transmission of these forces are interrupted as they travel from the Crankarm
through the BB, Swingarm bearings, Swingarm, hub, spokes, tires and to the ground.
Side note: If you can still get it, check out Keith Bontrager's article on flex and how it is Cumulative.
All other areas are radiused to prevent the stress risers that
can cause this type of failure.
This is a very nice example of a transition that eliminates all sharp angles.
Everything is smooth, radiused, and flows into the next angle-direction.
Santa Cruz knew of this weakness and designed a whole new swingarm.
I have sent this Swingarm in to S/C to see if they will Warrant it.
As there have been no Consumer Safety recall on this component it is at Santa Cruz's option.
Stay tuned for the Update....
If you have any comments or your own story,
email them to me.
UPDATE
Santacruz has supplied a new swingarm in Warranty continuing to show "Class and Style".
In my book they still are on top of their game.
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