RiddleOfSteel

Hi, everyone.

I have looked online for anyone who has done this and posted it to the interballs and have thus far come up empty. I know we're going back a few generations of DA here, but as this stuff gets older and the allure and functionality/versatility of mid- and long-cage rear derailleurs on high-end road groups filters to some of the older top-tier groups--this includes me presently, naturally--I thought I'd share my exploration into this question that a few have asked here and there. My goal here is to get the 9070 RD to comfortably run a 32t max cog. No 34t dreams as of yet, but that's a cassette experiment away. At any rate:

The standard Dura-Ace 9000 rear derailleur (SS cage) takes an Ultegra 6800 GS rear derailleur cage without modification or issue. It's a great win and I've been using it for a few years now.

The GS length cage for Ultegra 6800 (cable) and 6870 (Di2) is the same.

The Dura-Ace 9070 SS cage has different spring anchor points (about 90° further clockwise than a 9000 SS or 6800 GS) and cage stop pin position (about 20° further clockwise). The spring anchor points fully prevent a direct/no-mod 6800 GS cage swap, which sucks.

The solution? Drill new anchor holes, at minimum. Ideally, drilling anchor holes as well as drilling and tapping a new cage pin hole would be the move. Thankfully, drilling the new anchor holes was sufficient.

Picture progress:

Note the different clocking of the spring anchor holes in the 9070 SS cage outer plate (top) vs the expertly-drilled 6800/6870 GS cage outer plate (bottom). Cage stop pins are definitely in different neighborhoods, too.


A fully assembled 9070 "GS" rear derailleur!


Another view...


Underside view.


View showing the outer cage plate contacting the rear derailleur body in two places. The spring does force the cage into the body, but it's not so bad 1) if you ease it into contact with the body 2) have it hooked to your bike with the correct length of chain. Thankfully.

Atlas Shrugged

That’s great. I “upgraded” my 9150 RD with the longer cage from a 8100 and increased capacity of the derailleur. That worked so well I did similar to my RX810 where I mounted a med cage from a XT. They were direct swaps so nothing as complicated as you performed. Enjoy.

RiddleOfSteel

Once on the bike, we can see how it looks, and where things are either better or worse. For the record, with a 11-28t and 11-32t cassette, shifting was unchanged/great. No adjustment to the B-tension screw and no rumbling in the lowest gear combinations. Success!


Starting gear combination is 53/36t up front and 11-28t out back. Ending combination is the same 53/36t up front and a 11-32t out back.


1A - 36-11 combo, RD up close. The chain length is set up for the SS-length 9070 cage and there is no rubbing in the small-small combo. Obviously none here as well!




1B - 36-11 combo, macro view. Not too bad looking for a small-small combo, eh?




2A - 36-28 combo, RD close up.




2B - 36-28 combo, macro view. Looks pretty standard for a 9000 system. R9100 and R9200 have the cage and chain zig-zagging back and forth with the derailleur body and pulley cage design. Quite the dynamic look. 9000 is always a bit minimal in that regard, in contrast to it's classy-flashy aesthetic (which I really like).




3A - 53-11 combo, RD close up. Aesthetically-pleasing angles here.




3B - 53-11 combo, macro view. Perfect for those GCN Nice/Super Nice contests, lol.




4A - 53-25 combo, RD close up. Reeeeal stretched out here. It will do the full monty 53-28, as I did for all of two seconds, but it's all on the stand stuff with as nice a shift to and from. I wouldn't go as low as a 25t with this setup, but it's good to know I can. The SS cage setup naturally does a 53-28 combo with room to spare.




4B - 53-25t combo, macro view. Almost as cool as the pros doing it up mountains...




5A - 36-32t combo, RD close up. Derailleur is a happy camper.




5B - 36-32 combo, macro view. Is this a touring or gravel bike? Ok ok ok, just kidding. A 28t low is great for this bike as I have two other vintage Treks will comprehensive triple setups and don't need a third. But this is R&D, right?

RiddleOfSteel

6A - 53-?? combo, macro view. Looks cool. Would only go a few cogs larger, to the 25t, like with the smaller cassette. Now to find some dry days and steep hills to test this all out. If you have any questions, feel free to ask, I'll do my best to answer them!

RiddleOfSteel

Great to know and thank you for sharing!

I looked at R9100 derailleur outer cages (online) and they are a different design than 9000, which is unfortunate. I am a fan of direct swapping as well.

RiddleOfSteel

A few more photos here. I was also able to rig up a 11-34t 10-speed cassette to test the derailleur's handling of a 34t max cog.

This is the maximum "big-big" I'll go with this, a 53-25 combo similar to the 53-25 combo in a previous post, just with this 11-32t cassette.


Up-close drivetrain view.


This is the 11-34t 10-speed cassette. With the B-tension screw as is, the rear derailleur labors a bit before making the shift. I angled the derailleur body back (thankfully it held position) to mimic the B-tension screw wound all the way in, and it made the shift to the 34t cog smoothly. Pretty crazy.


Zoomed out view of the 36-34 combo here. Nice to know I have the capability, but I think I'm going to be pretty happy with a 32t big cog.

georges1

great job of modernizing the Trek Riddle of Steel

RiddleOfSteel

Thanks! I've been made aware (or re-aware) of various shift modes, so that will be my next area of exploration. I've been very fortunate (thank you, Seattle living) to have scored electronic groupsets for a relative pittance in the past, but this group I didn't get any 'volunteer discount' or similar on. This 9070 has been on an Orbea Onix and did well, but somehow wasn't a faster ride than these old Treks (ok, a 720 with Compass tires) despite weighing six pounds less. I suppose I'm still slow enough (17 mph cruising speed over an hour on mostly flat/slight rolling terrain) that aero doesn't matter much, but in the few rides I've done with this 510, it's fast. Sometimes frames find 'their' parts and it's more or less magic.

merlinextraligh

Wouldn’t it be easier to print a Dura Ace decal and stick it on the Utegra derailleur?

Atlas Shrugged

Heresy!