Whats the deal with this Record RD?

[hd reynolds]

This is Ken Stadler's bike in the Hawaii Ironman. What is striking is the 'modified' Record rear derailleur - see lower jockey wheel and cage. The lower jockey wheel is oversized and the caged customized to fit it.

Does anyone know what this is all about or know the benefits or have an explanation for using such?

[alfeng]

This is Ken Stadler's bike in the Hawaii Ironman. What is striking is the 'modified' Record rear derailleur - see lower jockey wheel and cage. The lower jockey wheel is oversized and the caged customized to fit it.

Does anyone know what this is all about or know the benefits or have an explanation for using such?It looks like a SHIMANO 13t pulley wheel ... from a Dura Ace 7703 rear derailleur.

Are any Campy Only types having convulsions, yet?

Custom cage? It looks like a Shimano long-cage from (possibly!?!) an Ultegra 6503 (?!?) rear derailleur ... the most intriguing thing is that the Shimano cage is interchangeable with a little tweaking.

The reason for the 13t is that it turns a medium cage into a long cage rear derailleur ... a GS into an SGS in Shimano terminology ... so, there is an additional inch of capacity (two links ... OR, two teeth ... three with regard to Campagnolo ... four if the lead pulley wheel is an 11t).

WHY? Possbily, the inner chainring is a 39t ...

The net result, regardless, is that the cage isn't yanked all-the-way forward if the chain is on the big-big as you can see. When the cage is extended to the full-forward position at maximum capacity, it seems to me to be a high-friction posture. So, the additional chain (though obviously "dead" weight that the rider must drag around) subjectively (again, to me) provides slightly less resistance in the big-big WITHOUT having a slack chain when in the small-small -- before ANYONE complains about this line of thinking, consider that when the cage is pulled all the way forward & the chain is minimally serpentined that the chain is exerting slightly more radial force against the pulley wheel (at least, in my mind).

OR, the extra chain capacity means that there can be more variabilty in the chainring & cassette combinatins (e.g., a cassette with a larger maximum cog OR larger inner ring OR ___) can be used without any other tweaking to the drivetrain ... if only for a pre-race ride around the course.

That's my story, and I'm sticking to it ...

[CAMPYBOB]

Are any Campy Only types having convulsions, yet?
aaarrrrggghhh!:eek:

[serenaslu]

Here's another shot, though the cage looks to have a darker finish on it, than the other ones (could be lighting, I guess) :

[alfeng]

Here's another shot, though the cage looks to have a darker finish on it, than the other ones (could be lighting, I guess) :SOMEONE makes/(made) a carbon fiber replacement cage for both Shimano & Campagnolo rear derailleurs ... I don't recall who, off hand ... perhaps, the darker cage is one of those ... or, the "mechanic" simply painted it!

[John M]

This is Ken Stadler's bike in the Hawaii Ironman. What is striking is the 'modified' Record rear derailleur - see lower jockey wheel and cage. The lower jockey wheel is oversized and the caged customized to fit it.

Does anyone know what this is all about or know the benefits or have an explanation for using such?

The folks over on the slowtwitch.com forum discussed this exhaustively in the days after the race. It is a custom modification of the Record RD with a larger pulley and custom cage. The idea is that the larger pulley has a lower friction than a standard. Jan Ullrich has used a similar modification to a DA rear derailleur in the past.

http://forum.slowtwitch.com/gforum.cgi?do=post_view_flat;post=1032465;page=1;sb=post_latest_reply;so=ASC;mh=25;

A pic of Ullrich's RD:

[hd reynolds]

Thanks for all the info guys.

[parawolf]

Is it just me, or is there only one chainring on that bike... thus like the poster suggested it is to better accomodate a 'large-large' scenario.

[bobbyOCR]

Its been posted to death at WW as well. It is to save a tiny bit of energy, because it rotates less and creates less friction on the drivetrain.

[bobbyOCR]

I thought his name was Norman, not Ken.

[hd reynolds]

I thought his name was Norman, not Ken.
Norman it is... don't know where I got the ken:o