[superdosser]

Yes, I've searched -- but I can't find the answer to the complete question.
I want to throw drop bars on my MTB - so can I just by a 9 speed dura ace STI and run my XTR front and rear Ds and Avid Road disks?

Mucho thanks for any wisdom.

 

[Unoveloce]

There are a few problems

The issues will be the front derailleur. Mtn front derailleurs operate ona slighty different leverage ratio than a road. Some times you can get it to work by changing how the cable attaches to the derailleur, but more often than not the indexing is all wrong. If you switch to a road triple front derailleur, the cage is the wrong size and profile to match up with the mountain sized rings. SSometimes it works, but more often than not it's just a bunch of headaches.

 

[atpjunkie]

well I've had 2 cross bikes

that ran XTR fr. ders. (I like TT cable routing and by doing so I've avoided needing the pulley for a road FD. Always shifts fine though I've never tried it with D/A shifters. I'm a Ult. / 105 /600 type. doesn't hurt as much if I dump it in the mud.

 

[wunlap togo]

Dura ace 9spd sti levers come in 2 models- double and triple. The Dura-ace triple is quite finicky, it's made to work only with a DA front derailleur/ chainring combos as well. Ultegra and 105 9spd levers are comparible with both triple and double chainring setups, and will work with a broader range of front derailleurs. IME, the fudge factor will be greater with 105 or ultegra. I recommend getting ultegra 9 and trying it with the XTR front derailleur.

 

[MShaw]

I've got Ultegra/XTR on my Crosshairs, but with a little fiddling, it works well enough to not throw the chain off. Rubs a little bit in certain gears, but since I know why, I can live with it.
Rear der is fine as long as yer not running that backwards spring tension stuff.

HTH,

M

 

[superdosser]

OK, what is the backwards spring tensinon stuff?

I've got Ultegra/XTR on my Crosshairs, but with a little fiddling, it works well enough to not throw the chain off. Rubs a little bit in certain gears, but since I know why, I can live with it.
Rear der is fine as long as yer not running that backwards spring tension stuff.



Is that the "Rapid Rise" and if so - how do I know if my D has it?

 

[wunlap togo]

Is that the "Rapid Rise" and if so - how do I know if my D has it?

Yes, he means Rapid Rise or "low-normal". In the relaxed position, the rapid rise deraileur defaults to the easiest (biggest, innermost) cog. Traditionally, shimano derailleurs default to high-normal i.e. smallest cog when not under tension. Either type will actually work with any 9 speed sti lever.

 

[Lutarious]

Ultegra/XTR

I use Ultegra 9 speed and XTR with limited success. The ront is the problem, but I am thinking of just offing the whole mess and using straight Ultegra triple.

 

[superdosser]

What do you mean by "straight Ultegra"?

I use Ultegra 9 speed and XTR with limited success. The ront is the problem, but I am thinking of just offing the whole mess and using straight Ultegra triple.

The entire set up? Cranks front, rear d, and shifters? Or just front D? as it's what's giving you trouble?

 

[Lutarious]

Super D

Here's the thing.... I have an Ultegra triple crank set up, and as mentioned earlier, the front will work best if I use all Ultegra, then I have the gearing to run 12-27 out back, so I might as well use an Ultegra rear as well. Chain length has a lot to do with good shifting, and the long cage XTR is really long. (up to a 32 cassette)

I use this bike almost exclusively on roads, and it's the only "road" bike I have now, so maybe this advice doesn't apply if you're riding more honest cyclocross. I can still swap wheels and run CX tires if I get the notion. All I lose is some super low gears, which is okay.

 

[TurboTurtle]

Here's the thing.... I have an Ultegra triple crank set up, and as mentioned earlier, the front will work best if I use all Ultegra, then I have the gearing to run 12-27 out back, so I might as well use an Ultegra rear as well. Chain length has a lot to do with good shifting, and the long cage XTR is really long. (up to a 32 cassette)

I use this bike almost exclusively on roads, and it's the only "road" bike I have now, so maybe this advice doesn't apply if you're riding more honest cyclocross. I can still swap wheels and run CX tires if I get the notion. All I lose is some super low gears, which is okay.

Some confusion here.

I agree that road/road for the front end would be the best though there are those who do it and like it. My wife's bike has the opposite of what the OP wants (XTR shifters and Ultegra front end) and shifts at least as good as with road shifters.

For the rear - what does chain length have to do with shifting? Also the cage length has little to do with the cassette and is mostly a function of the front where there is a much larger difference between the size of the gears.

TF

 

[The Walrus]

It looks like some of the responders missed the fact that you're doing this on an MTB, so presumably you've got a triple, rather than using Dura Ace/XTR on a 'crosser with a double (which would work fine...). I tried 105 STI (triple-specific) with an LX front once, and spent weeks trying to get it to work. Trouble is, road brifters have a different amount of cable pull than MTB shifters, and your chances of finding a way to make them compatible with an MTB front mech are slim. One thing you could try is to move the cable to the opposite side of the "normal position" on the fixing bolt on the derailleur; your leverage will be increased, but my experience was that that was too much. Who knows? You might get lucky. I ultimately gave up and bought a 105 triple derailleur and cobbled together a pulley for the cable. Works great now....

 

[superdosser]

Walrus - If you had 105 STI triple shifters -- why did you have to (and what is ??) use pulley for the cable? Thanks. Ahh, I was hoping this was going to be easy! Oh well...

 

[khill]

Walrus - If you had 105 STI triple shifters -- why did you have to (and what is ??) use pulley for the cable? Thanks. Ahh, I was hoping this was going to be easy! Oh well...

Mountain bikes typically run top-pull front derailleurs meaning the shift cable runs along the top tube and then down the back of the seat tube to connect to the derailleur.

Road bikes typically run bottom-pull front derailleurs meaning the shift cable runs along the downtube, under the bottom bracket, and then up the back of the seat tube.

If you want to use a bottom-pull front derailleur on a bike with top-tube routed shift cables, you need a pulley. I guess the same would be true in reverse as well.

 

[xcmntgeek]

Why not just run a barcon or thumb shifter for the front der? It's be easier and you could fine tune it to eliminate rubbing and it would always work no matter the conditions.

J

 

[wunlap togo]

Walrus - If you had 105 STI triple shifters -- why did you have to (and what is ??) use pulley for the cable? Thanks. Ahh, I was hoping this was going to be easy! Oh well...

105 (and ultegra) 9speed shifters will shift a triple and a double. There is no triple specific shifter for these groups.

 

[The Walrus]

Yeah, what he said--beat me to it....

 

[The Walrus]

This was an 8sp drivetrain, and there was a triple-specific brifter....

 

[wunlap togo]

This was an 8sp drivetrain, and there was a triple-specific brifter....

Ah-ha! Never mind.