# Sram derailer with oversized Berner pulleys



## Classic Bikes (Jun 14, 2010)

What is the technology and benefit behind this:


----------



## aengbretson (Sep 17, 2009)

Larger pulleys are supposed to reduce drivetrain friction. I'm guessing that either a custom-modified part, or modified using an after-market kit.


----------



## PlatyPius (Feb 1, 2009)

They tell everyone within 20 yards that while your bike may not have come from WalMart; it should have.

Only the cheapest of the Shimano derailleurs (the odd Dura Ace triple rear derailleur not included) have the Fisher Price pulleys. This tells me it probably isn't a good idea.


----------



## AvantDale (Dec 26, 2008)

Is there a reason the pro's use them? They seem to be popular in the TDF this year...or do they run whatever the mechanic puts on there?


----------



## PlatyPius (Feb 1, 2009)

AvantDale said:


> Is there a reason the pro's use them? They seem to be popular in the TDF this year...or do they run whatever the mechanic puts on there?


They run whatever the mechanics put on there. And the mechanics put on whatever the team manager tells them to put on there. And the managers pick up whatever someone will give them and pay them to ride.


----------



## Keeping up with Junior (Feb 27, 2003)

*Wrapping it up*



Classic Bikes said:


> What is the technology and benefit behind this:


Larger pulleys let you get more chain wrap without having a longer cage. About a decade ago Shimano had a Dura Ace triple with oversized pulleys. It looks like a traditional short cage derailer but will wrap enough chain to run a triple. We have one of the DA derailers installed on our tandem.


----------



## AvantDale (Dec 26, 2008)

Heres one on Contador's bike...


----------



## aerodinamico (Dec 27, 2011)

I buy this pulleys


----------



## PlatyPius (Feb 1, 2009)

aerodinamico said:


> I buy this pulleys


You dug up the corpse of a 2 year old thread just so you could tell everyone (inarticulately) that you bought Fisher-Price pulleys?

Awesome. It must be Thursday.


----------

