berner SRAM red cages vs shimaon altus (obviosly not fixed)

Somewhat related to Andys chain drop the other night, anyone noticed how these new cages popping up on PRO bikes is remarkably similar to the cheap end of the shimano derailleur spektrum?

exhibit A

exhibit B

Now I always thought this was so you could run enough chain to shift into your super sweet 34t granny gear while for some reason still being in you big ring (as is the want of our super commuter bretheren). This coming from the increased chain wrap round the bottom sprocket as the chain shifts towards smaller, harder gears.

I would have though that unless the PRO’s are turning soft on us, there would be an excess of chain in the system thus requireing the return spring in the derailleur to work harder. Potentially resulting the excess bounce that may have caused Andys chain off? (I’m pretty sure he and Contador for that matter are runniung said cages).

Thoughts anyone? Happy to stand corrected. Is it stupid to care? Should I just go to the dog thread and forget my troubles?


I was reading about these custom oversized pulley’s on a few Pro’s bikes. Something about decreasing drivetrain friction. Just chuck an Altus RD on there instead?

OH yeah forgot to mention that was the reason alot seem to be doing it, somone did the maths was a stupidly small number but I guess it all counts.

For super DIY PRO points I want to see someone put an altus cage on a DA derailleur

Close enough?