The team at Cyclespeed noticed a few highly placed pro's at the tour riding with oversize jockey wheels in their rear deraileurs, we said to ourselves "I dont know why he's got that but I want one".  So began our search.
   
The theory behind the oversize pulley wheel on the rear deraileur is to reduce friction in the drivetrain.  Reports of a 6 watt saving have been mentioned.  We have no data to back this claim (yet) but we saw it on the winning bike at Kona and knew we had to have one.  So we got a custom order completed by Fibre Lyte in the UK and they are now in stock.
  
You get a Shimano Dura Ace 10sp long cage rear deraileur (compatible with 105, Ultegra and Dura Ace Drivetrains) that has been modified with two cabon jockey wheels, one of them the oversize 15 tooth wheel.  A titanium bolt upgrade is an additional extra to further save weight.
 
You will not find this on anyone else's machine, yet...
       
Please note - for optimal performance, you will need to replace your chain to account for the extra diameter of the oversize jockey wheel and the added length of the deraileur cage.  We have found that we were able to continue to ride with our existing chain but that fitting a new longer chain gave the best result.  If you have any questions about fitiing your new deraileur, please contact us.
      
Prices are in Australian Dollars.