Im doing this with an ultegra tripple to run on my yeti, i just need the mech to turn up, looks much easier than i thought it was gonna be. Thanks !

 

i actually thought of doing it to the triple version as it'll probably work better, but we had a double at the shop and I couldn't be bothered chasing down a triple. let me know how it works.

when's your asr show up? i'm hoping mine arrives this week.

 

cheers! very nice and like you say a good weight without bolt tuning or cf btp clamp! I would like to do something like this with a braze one. Is there no dura ace triple?


O/T where is the the thread on weight weenism dyeing and no significant innovations in the last couple of years? I had found it on a console I was not logged into but now on my personal comput I can't find it . . .

 

now i know why i couldn't fine the original thread on mtbr...because it's actually on weightweenies, it's a braze-on model if you want to check one out.

the conversion is a bit more difficult on dura ace front mechs, or any 10 speed front mech as they use rivets where the allen screws are on the 9 speed ultegra.

 

Shimano 10-speed FD linkage wraps around the pivot, so you can't flip it over. Thanks to Shimano's great website, I made Go/NoGo list:

:sad: FD-7800, 7803 Dura Ace 10-speed, No Good
http://techdocs.shimano.com/media/t...cs/content/cycle/EV/bikecomponents/FD/EV-FD-7800-2255_v1_m56577569830608810.pdf
http://techdocs.shimano.com/media/t...cs/content/cycle/EV/bikecomponents/FD/EV-FD-7803-2447_v1_m56577569830608811.pdf

:sad: FD-6600, 6603 Ultegra 10-speed, No Good
http://techdocs.shimano.com/media/t...ntent/cycle/EV/bikecomponents/FD/EV-FD-6600_6603-2349_v1_m56577569830608807.pdf

:sad: 105 FD-5600, 5603 10-speed, No Good
http://techdocs.shimano.com/media/t...ntent/cycle/EV/bikecomponents/FD/EV-FD-5600_5603-2448_v1_m56577569830608806.pdf

:yesnod: Dura Ace FD-7700 9-speed, OK
http://techdocs.shimano.com/media/t...s/content/cycle/EV/bikecomponents/FD/EV-FD-7700-1659B_v1_m56577569830610847.pdf

:yesnod: Ultegra FD-6500, 6503 9-speed, OK
http://techdocs.shimano.com/media/t...tent/cycle/EV/bikecomponents/FD/EV-FD-6500_6503-1700A_v1_m56577569830611837.pdf

:yesnod: 105 FD-5500, 5501S, 5501L, 5503, 5504S, 5504L 9-speed OK
http://techdocs.shimano.com/media/t...ntent/cycle/EV/bikecomponents/FD/EV-FD-5501_5504-2174_v1_m56577569830608805.pdf
http://techdocs.shimano.com/media/t...tent/cycle/EV/bikecomponents/FD/EV-FD-5500_5503-1737A_v1_m56577569830612175.pdf

Summary: 10-speed bad. 9-speed good.

Related question: Does anyone know the weight of an aluminum braze-on FD boss, such as this http://www.novacycles.com/catalog/product_info.php?cPath=61_144_151&products_id=1287 ?
I'm thinking of adding one to a frame, but wonder if braze-on FD + mount weighs less than clamp-pn FD.

 

the standard shimano braze-on clamp is 30 grams for a 34.9 - there are lighter options from parlee and btp though i wouldn't run them on the mtb. i'm not as weenie as others though.

just be careful with the dura-ace 9 speed, i have seen some that use a rivet at the top of the outer linkage rather than the bolt in that exploded view. this would make it a fair bit more unstable having to file both rivets. before you buy check it has a bolt there.

 

Good old XTR M950 fronts come in at 105-110 grams.. Who needs roadie fronts??

 

Because many frames only suit bottom swing (high mount) derailleurs. The lightest MTB high mount is the M953 at 131 grams, and they're damn hard to find in a top pull configuration.

 

I'm looking to do this conversion on a new project bike (Gary Fisher Superfly 29er) and have a few questions that I hope someone will know.

I plan to run a 2 X 9 set up with a 36, 26 chain rings on a XTR 970 crank set using the middle and small ring locations.

Should I use a Dura-Ace FD-7700 (Double) or FD-7703 (Triple) Derailler ? since I will be using inner ring location I was thinking the FD-7703 might be better ? I will also need a 34.9 clamp for the frame.

Does anyone know if the FD-7703 or FD-7700 comes with a integrated 34.9 clamp or do I need to use the bolt on clamp with a braze on type derailler for the 34.9 clamp.

Jeff

 

I'm looking to do this conversion on a new project bike (Gary Fisher Superfly 29er) and have a few questions that I hope someone will know.

I plan to run a 2 X 9 set up with a 36, 26 chain rings on a XTR 970 crank set using the middle and small ring locations.

Should I use a Dura-Ace FD-7700 (Double) or FD-7703 (Triple) Derailler ? since I will be using inner ring location I was thinking the FD-7703 might be better ? I will also need a 34.9 clamp for the frame.

Does anyone know if the FD-7703 or FD-7700 comes with a integrated 34.9 clamp or do I need to use the bolt on clamp with a braze on type derailler for the 34.9 clamp.

Jeff

I think you'll need to use the braze-on type with clamp adapter.

I think the 7703 would be a better match for 2 reasons. As you stated, you're using the granny position. Also, you're using small rings, so the triple cage 'should' be better for picking the chain up off the 26t. WeightWeenies says the 7803 + clamp is 130g, so may not be worth the effort. If I were in your shoes, I would just use a MTB FD.

 

Thanks for the update and weight,

I am also looking at a XTR FD-M971, but it's coming in at 150g with a 34.9 clamp and will work right out of the box.

 

Correct me if I'm wrong but the only way it *might* be worth it is if he were to get the BTP braze on clamp?

So what I would want is a braze on triple ultegra 7703.

Looking at the weight of a ultegra with a alloy clamp it's sub 100grams which isn't to shabby compared to 130grams.

Seems like I have seen circa 105 gram tuned xtr top pulls but a 34.9 would be a little heavier.

What about campy triples (braze on) vs. ultegra in weight?

 

What is the BTP braze on clamp ?

I think with the Superfly frame I will need a top pull derailler (I just wish the bike would show up )

Any campy top pull conversions being done ?

 

I plan to run a 2 X 9 set up with a 36, 26 chain rings on a XTR 970 crank set using the middle and small ring locations.
Jeff

Jeff, you'll need some chainring spacers if using non XTR rings on the 970s. I went through a similar conversion, and the middle ring is too close to the big ring, I believe I used 1.2mm spacers.

Also look on ebay for an older XTR, much lighter than the new crap.. m950, m952, m953, replace the clamp on bolt with a m5x20 alloy bolt, and the pinch bolt with a m5x10 alloy bolt..

 

What is the BTP braze on clamp ?

I think with the Superfly frame I will need a top pull derailler (I just wish the bike would show up )

Any campy top pull conversions being done ?

www.b-t-p.de/

It's available in a couple different standard sizes and custom ones. They changed the design a little so I guess they are stronger. Ninos broke (old design) but mine has been really solid. Basically the old version was a single bolt design but the new one is a more standard two bolt clamp design.

 

Thanks for the heads up,

I'm using TA Chinook chainrings, inner and middle for the 2 X 9 set up I'll check for spacing.

 

same rings i'm using, i would get some .06, and 1.2 spacers, i honestly can't remember which ones i used..

 

If you're looking at using a braze-on derailleur also consider the Parlee clamp. For the granny/middle setup I'd also think the triple model would be better suited, but it's purely speculation.

OT: slobberdoggy - old Sachs fd! very nice. had one for a while but got rid of it, kind of regretting that.

 

i have a 105 9 speed that i took off a trek XO1 its 34.9 clamp, its bottom pull, getting ready to convert it for my superfly, it weights 108g i thing you can find them on ebay pretty cheap.. i think change a few bolts it will be sub 100g

 

Sorry to rain on the parade, but I have a DA Bottom-pull I was looking at for doing this conversion, and I realized that it was a really bad idea, mainly because of the angles.

If you inspect a proper Top Pull you will see that the angle the cable makes with the lever arm is acute (less than 90deg). So when you pull the cable, it ends up making about a 90deg angle with the lever arm. Now if you know your high school physics. You know that:

Torque = Force X Radius

But, this is a vector cross product, which in magnitude becomes

Torque = Force x Radius x sin (theta)

So, maximum torque is had at the sin(90deg) = 1, any angle less or greater will
reduce the torque. After about 45deg or 135 deg (same difference) the force is reduced by quite a bit, sin(45deg or 135deg) = 0.707

Ultimately, the problem with converting a BP to a TP is that you start with an obtuse angle that is already almost 135deg, then when you start to pull the cable you're loosing torque, which the only way to rectifiy (because the radius (or length of lever arm) is static) is to increase the force. This puts more strain on you shifters and your thumb, and would probably lead to premature failure of the shifter.

Personally, I would not do this modification, and I would not recommend that anybody else do it.

 

Sorry to rain on the parade, but I have a DA Bottom-pull I was looking at for doing this conversion, and I realized that it was a really bad idea, mainly because of the angles.

So, maximum torque is had at the sin(90deg) = 1, any angle less or greater will
reduce the torque. After about 45deg or 135 deg (same difference) the force is reduced by quite a bit, sin(45deg or 135deg) = 0.707

Ultimately, the problem with converting a BP to a TP is that you start with an obtuse angle that is already almost 135deg, then when you start to pull the cable you're loosing torque, which the only way to rectifiy (because the radius (or length of lever arm) is static) is to increase the force. This puts more strain on you shifters and your thumb, and would probably lead to premature failure of the shifter.

Personally, I would not do this modification, and I would not recommend that anybody else do it.

I did this exact conversion on a Campy Record Titanium, and at first had trouble with the lack of leverage. I was careful with the placement of the cable exit from the clamp to maximise the angle of attack, and it shifts fantastic - 1,000 times better than the top pull XTR it replaced.

 

Sorry to rain on the parade, but I have a DA Bottom-pull I was looking at for doing this conversion, and I realized that it was a really bad idea, mainly because of the angles.

If you inspect a proper Top Pull you will see that the angle the cable makes with the lever arm is acute (less than 90deg). So when you pull the cable, it ends up making about a 90deg angle with the lever arm. Now if you know your high school physics. You know that:

Torque = Force X Radius

But, this is a vector cross product, which in magnitude becomes

Torque = Force x Radius x sin (theta)

So, maximum torque is had at the sin(90deg) = 1, any angle less or greater will
reduce the torque. After about 45deg or 135 deg (same difference) the force is reduced by quite a bit, sin(45deg or 135deg) = 0.707

Ultimately, the problem with converting a BP to a TP is that you start with an obtuse angle that is already almost 135deg, then when you start to pull the cable you're loosing torque, which the only way to rectifiy (because the radius (or length of lever arm) is static) is to increase the force. This puts more strain on you shifters and your thumb, and would probably lead to premature failure of the shifter.

Personally, I would not do this modification, and I would not recommend that anybody else do it.

my god, you are the wizard of CAD and linkage angles arent you?

 

ginsu, i was worried about this exact thing before i did the conversion. luckily parts don't cost as much when you work in a shop so i figured it was worth a try. if my frame ever arrives i'll be able to tell you all if it works. the fact that i use gripshift should help along with the rather narrow chainline of middleburn duo cranks with a 110mm spindle.

 

same rings i'm using, i would get some .06, and 1.2 spacers, i honestly can't remember which ones i used..

I wound up inspecting the rings and measuring it out...the teeth for the original 970 22T ring sit back 2mm from the plane of the ring/crank interface. The teeth for the Chinook "little ring" sit on the plane of the ring/crank interface. The teeth for the original 32T and the Chinook "big ring" both sit on the plane of the middle ring/crank interface. To make a long story short, I ordered a set of 2mm spacers...we'll see how they work out when they get here.

Also, if I am running a 2x9 setup on XTR M970s with a 28T in the little ring position and a 40T in the middle ring position with grip shift, which of these front derailleur options would be ideal? Current FD is an XT 760 top swing.

 

there is a adapter, that converts every rodderrailleur to top pull
http://crossladen.de/shop/article_1...article_194/Umwerferadapter-zum-Ersatz-der-Rolle.html?shop_param=cid=1&aid=194&