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Discussion Starter · #1 ·
I'm running a 2x9 (granny & middle). Which models of Dura Ace front D are suitable for this application? Am I ok to continue using 9-speed chain, or is the cage too narrow?

Thanks!
 

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adept1 said:
I'm running a 2x9 (granny & middle). Which models of Dura Ace front D are suitable for this application? Am I ok to continue using 9-speed chain, or is the cage too narrow?

Thanks!
Depends on what frame you are running. What way does the cage swing? Whats the clamp size? Is the cable routing on the down tube? Is it coming down from the seat tube?

You really gave us no information on your bike. Since it is 2x9, the 9th in the rear may rub the cage of the FD.

Edit:

After looking at pics of your bike on your profile, I think that you could run a road FD, but can't be positive...your pic is kinda small.
 

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Discussion Starter · #3 ·
amillmtb said:
Depends on what frame you are running. What way does the cage swing? Whats the clamp size? Is the cable routing on the down tube? Is it coming down from the seat tube?

You really gave us no information on your bike. Since it is 2x9, the 9th in the rear may rub the cage of the FD.

Edit:

After looking at pics of your bike on your profile, I think that you could run a road FD, but can't be positive...your pic is kinda small.
My current one is 34.9mm high clamp, bottom pull, downtube routed.

 

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the FD-7700 asily will do the job also with a 9s chain and even with triple rings.

My current FD-7800 with integrated 34,9 clamp is very light but you might need to run a 10s chain to avoid rubbing on the small/big or big/small combinations. The 7800 series has a much narrower cage.

From wha i hear the actual FD-7900 got wider cages again but i can't verify that since i haven't measured on my own.

BUT why don't you run a 10s chain anyway?? They aren't any weaker but lighter:thumbsup: It's not the sideplates that got slimmer but the pins width so the chains tension strenght is still the same...

Shown below my FD-7800 with integrated 34,9 clamp.This one would fit right away on your bike (using a 10s chain)

For those with Top-Pull there is a german company that offers Top-Pull adapters: www.speen.de
As shown below these adapters weigh 7g
 

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Discussion Starter · #5 · (Edited)
nino said:
the FD-7700 asily will do the job also with a 9s chain and even with triple rings.

My current FD-7800 with integrated 34,9 clamp is very light but you might need to run a 10s chain to avoid rubbing on the small/big or big/small combinations. The 7800 series has a much narrower cage.

From wha i hear the actual FD-7900 got wider cages again but i can't verify that since i haven't measured on my own.

BUT why don't you run a 10s chain anyway?? They aren't any weaker but lighter:thumbsup: It's not the sideplates that got slimmer but the pins width so the chains tension strenght is still the same...

Shown below my FD-7800 with integrated 34,9 clamp.This one would fit right away on your bike (using a 10s chain)

For those with Top-Pull there is a german company that offers Top-Pull adapters: www.speen.de
As shown below these adapters weigh 7g
Thanks for all the info. I actually tried running a KMC X10SL a while back, and my front derailleur would always want to toss the chain over the side of my big (44T) ring (despite my limit setting being correct). Neither I, nor my very competent LBS (shout out to Attitude Bikes) could get it working properly. So I went back to KMX X9SL and everything was good. Now I've ditched the big ring altogether though and replaced with a bash ring, so maybe the X10SL would work now.

I think I'll try the 7700 first since they'll be available for pretty cheap and will allow my to use my current chain which I just replaced only about 1 week ago. 7700 sounds the most versatile.

Edit: Now I just started looking at the SRAM Red... very nice looking. I checked some other threads and people seem to like it. I'm not trying to chase the absolute lightest thing out there, but my current SRAM X-9 seems very overbuilt (but works fine).
 

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nino said:
the FD-7700 asily will do the job also with a 9s chain and even with triple rings.
I know this is slightly off the original question's topic, but I just want to confirm - if I have a 34,9 clamp, bottom pull FD, you're saying I can replace it with the FD-7700 straight across, no changes? ( normal 3x9 XTR crank/rings ) i have that horrible XT dual pull FD now, i should be beat up for even mentioning it here.
 

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slcpunk said:
I know this is slightly off the original question's topic, but I just want to confirm - if I have a 34,9 clamp, bottom pull FD, you're saying I can replace it with the FD-7700 straight across, no changes? ( normal 3x9 XTR crank/rings ) i have that horrible XT dual pull FD now, i should be beat up for even mentioning it here.
Basically yes.

BUT on some cranks the rings are too far out so the derailler can't reach the outer ring. Most integrated shimano cranks have the rings farther out than normal which then asks for the end-stops of the deralleur to be modified slightly to accept a wider reach. I don't use newer Shimano cranks , never will, just because of the bad chainline and bad Q-factor (and too high weight as well)
 

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nino said:
Basically yes.

BUT on some cranks the rings are too far out so the derailler can't reach the outer ring. Most integrated shimano cranks have the rings farther out than normal which then asks for the end-stops of the deralleur to be modified slightly to accept a wider reach. I don't use newer Shimano cranks , never will, just because of the bad chainline and bad Q-factor (and too high weight as well)
Fair enough. Thanks for the info
 

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limba said:
Which cranks do you use on your bikes Nino? I know you have old RaceFace Nexts on one of your mtn.bikes, do you own a cross bike? Which crank do you use on your road bikes?
Roadbike: Zipp Vumaquad
http://luckynino.blogspot.com/2009/03/ninos-roadbike-516-kilo115-lb4.html

Scale LTD; Storck Powerarms square with 103mm BB
http://luckynino.blogspot.com/2009/03/ninos-scott-scale-ltd-66-kilo.html

Scale 10: Race-Face Next LP with 108mm ISIS (Road Size)
http://luckynino.blogspot.com/2009/03/nino-winterbike-78-kilo.html

I have kind of a cross-bike too. A MTB-converted 700c touring bike.It has a Token Carbon MTB crankset with only the outer 2 rings also with a 108mm ISIS BB

I am expecting some sweet intergated carboncranks for both MTB and roadbike these days. Both lighter AND slimmer in q-factor:thumbsup:
 

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Discussion Starter · #13 · (Edited)
Sorry to bring this up again but I want to be clear.

Should the Dura Ace FD-7700 (Double) work for me? I'm running external Chris King BB with 2x9 (Granny & Middle) - chain line currently 50mm. Or would it be better to use the FD-7703 (Triple)? But it looks like the triple is 100+ grams!

The FD-7900 looks great too. Is anyone using it with a similar set up to mine?

My main worry is that it seems most people are running 2x9 w/ road deraileur do middle & big ring, but I'm doing granny & middle.
 

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Should have no problems with regard to gear spread and limit screw issues. What may change is how hard it is to change at the front. You really won't know that until you've set it up. Gripshift and adapted top-pull on a yeti asr and arc is ok, but some posters reported way more tension required for a shift.
 

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adept1 said:
I'm running a 2x9 (granny & middle). Which models of Dura Ace front D are suitable for this application? Am I ok to continue using 9-speed chain, or is the cage too narrow?

Thanks!
I use (or should say used) a Dura Ace 34.9mm double on my JET 9 using the middle and big ring slots on a Race Face Turbine crankset with a Race Face Taperlock Ti BB and a 9 speed chain. The BB allows for chainline adjustment, so the Dura Ace double was just fine. Now that the frame got recalled, I will have to wait and see if the newly designed JET 9 will still work with the Dura Ace Double and my 2 x 9.

I am contemplating trying a triple Dura Ace 34.9mm and a 10 speed chain on a new frame of mine, but I don't know if it would work. Probably the 7803 with an older set of Shimano XT Octalink cranks and a 73/113mm Octalink BB. I guess if it doesn't work, I could always sell the BB and use the heavier Shimano XT or XTR front derailleur.

The XT FD I need for the frame (need the 771) weighs 154g. It looks like the Dura Ace triple would be about 106g. I'd save a bit of weight on the 10 speed chain as well. If it would all line up and work, it would probably be 80 - 100g in weight savings between the chain and FD.:thumbsup:

I won't even mention this would be a weight weenie RIP 9 from Niner.:D

BB
 

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Just came accross this thread, great information but I have a very newbie question. What about the shifter itself, I have XT shifter trigger shifters, can I use the Dura Ace front D with an XT trigger shifter?
 

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Dura Ace 7900...

here. Running it on my new Blur XCc build, with a Rotor 2 ring crank and the speen tp pull adapter. I filed a flat on the arm of the derailleur to allow a better interface for the speen adapter. I am using a Suntour XC Pro thumbshifter to shift it, as I do not feel the need for a fancy trigger to shift two rings. This setup is working great with a Dura Ace 9 chain. The 7900 is a great derailleur for 2 x 9 (or 10).
 

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Barrows, thanks for the info. My 29er did have thumb shifters and I loved it. It is now a single speed but imo thumb shifters work great. BTW What cassette are you running ?

I would like to get a 7800/Speen (a little cheaper) and run it with a Crankbrothers113 Isis BB. Do you think the 7800 would shift a 28/40 combo running on the granny and middle ring?

Not trying to hijack the thread but it is very timely for a current project of mine!
 

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I...

am running 26-40 rings (Specialties TA), and a 11-34 XTR cassette, I have also run a 11-32, but I need the lower gear of the 34. I would expect the 7800 would shift the 28-40 combo with no problem, but if you plan to use a 9 speed chain you might experience some rubbing. The cage on the 7900 is wider, so there is no need for derailleur trimming, even with a 9 speed chain. I run a dedicated two ring crankset (Rotor) to take advantage of the better chainline and lower Q factor. With my set up the big ring can easily access all gears, and the small ring can access everything but the smallest cog.
 
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