Classic & Vintage - Cable routing - dura ace AX rd

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KtotheF
09-02-09, 07:58 PM
So, I didn't think about this until I started building the bike last night- the AX rear derailleur has that little curve that routes the cable up, but my frame has the under the bottom bracket cable routing.

Have any of you guys hit this problem?

Old Fat Guy
09-02-09, 08:08 PM
Yes.
Ex Pres
09-02-09, 08:10 PM
Yes.

Answered like a true attorney.

KtotheF
09-02-09, 08:13 PM
Cool, good to know I'm not alone. That is all.
KtotheF
09-02-09, 08:14 PM
On second thought, mind telling me how you worked around it?
Bianchigirll
09-02-09, 09:06 PM
where does it curve the cable up to?
KtotheF
09-02-09, 09:32 PM
where does it curve the cable up to?

Like this:

http://velobase.com/CompImages/RDerailleur/05241483-14A7-44C9-8B4F-5CBEF7B2C271.jpeg

http://autobus.cyclingnews.com/photos/2008/tech/features/shimano_dura-ace_di208/Shimano_Di2_AX_RD.jpg

If the frame routes the cable above the bb shell its a straight shot, and you don't need any housing, pretty neat actually. Unless your frame routes under the bb shell.
Bianchigirll
09-03-09, 05:23 AM
OH that is very intresting. I think he is going to need a single cable giude for on the bottom, of the seat post
top506
09-03-09, 05:55 AM
OH that is very intresting. I think he is going to need a single cable giude for on the bottom, of the seat post

Or just run a length of housing from the chainstay cable stop. It would look kinda kludgey, running from the bottom of the stay to the top stop of the RD, but it would work.
Top
T-Mar
09-03-09, 06:28 AM
Get a clamp-on guide for the bottom of the seat tube and use the derailleur cable routing as intended. The derailleur guide was meant to eliminate the need for any cable housing. Theoretically, the housing compresses, flexes and adds extra resistance. The Direct Cable Mechanism, as Shimano called it, resulted in faster and more efficient derailleur response.

While it was an excellent idea, it lost out to economical considerations. Manufacturers found it far more efficient to run cables using a guide under the bottom bracket, than to thead the cable through a guide located bewtween the crankset and seat tube. Mechanics, especially from the pro teams, also complained that it made their job harder.
Old Fat Guy
09-03-09, 06:40 AM
On second thought, mind telling me how you worked around it?By switching to Dura Ace 7400.
KtotheF
09-03-09, 09:43 AM
Get a clamp-on guide for the bottom of the seat tube and use the derailleur cable routing as intended. The derailleur guide was meant to eliminate the need for any cable housing. Theoretically, the housing compresses, flexes and adds extra resistance. The Direct Cable Mechanism, as Shimano called it, resulted in faster and more efficient derailleur response.

While it was an excellent idea, it lost out to economical considerations. Manufacturers found it far more efficient to run cables using a guide under the bottom bracket, than to thead the cable through a guide located bewtween the crankset and seat tube. Mechanics, especially from the pro teams, also complained that it made their job harder.

Oh, cool, I didn't know such a thing existed, I'll look for one of those. I thought the design was pretty elegant as well, I was pretty bummed that I was going to have to fiddle with it
KtotheF
09-03-09, 12:36 PM
this is what you're talking about, right?

http://www.lickbike.com/lickimages/0567.gif