Crossing Deore with Ultegra Drive Components?

[mrfacetious]

My second pester for advice in as many days (but hey i guess that's what the beginner section is for), I just don't want to throw money away, so I'm looking into things before buying.

I'm looking to buy a set of Derailleurs and can get some Deore ones nice and cheap. Now Deore is fine for me, I've been using them for the best part of half a year. But that's on a MTB. How cross compatible are these sort of things?
I'm using a Ultegra 9sp cassette and triple chainset. I believe that the cassette is less spaced on road bikes? (correct me if i'm wrong) and a few other niggly things that may give me compatibility issues. (if it's any help I'm using dura ace shifters [just not yet ] )

Thanks in advance, once again! I owe everyone on this forum a beer.

 

[RedBike]

Ultegra (9spd) and Deore rear shifter pulls the same amount of cable and move the same distance per 'click' .

However, as the deore rear mech moves closer to the wheel it moves down slightly further than a road mech would. (This is so that it will clear the larger sprockets found on a MTB.)

If the rear mech is too far away from the sprockets you'll get sloppy/slow gear changes but things should still work.

 

[mrfacetious]

how much of an effect is it likely to have do you think? I'm standing to save about £60 by getting the deores but i don't want really poor quality shifting..
just what i wanted to hear though really, thanks!

 

[Dave5N]

It will work fine.

Now, about that beer...

 

[Steve Austin]

Try to get a shorter cage Deore mech. you've no need for a big dangly serailleur if your running it on a road bike

 

[Tim Bennet.]

Before anyone can give meaningful advice, we have to know the size of your rear cassette. I have an Ultegra one that goes up to 27 teeth and that works absolutely perfectly with a triple and a mountainbike (XT) rear mech.

 

[RedBike]

I've just realised I miss-read your post. A front Deore mech wont work correctly with road shifters / a road chainset.

However, you do get touring bikes with 'hybrid' chainset and bar end friction shifters.

What about just buying Tiagra or the new Sora?

 

[mrfacetious]

argh! i have conflicting opinions from two senior members! what to do?
I just went and checked, the top sprocket has 25 teeth.
@ Red: I was looking to save money as i can get a set of Deore mechs for £20 (Used but in good nick), and I know that they're not cheapo derailleurs like Tourney, which is probably about the same sort of price in that condition. If I end up shelling out it'll be for Ultegra to complete the set, but I was rather looking to get the bike on the road and upgrade as I go.
Steve: What sort of effect is having too long a cage going to have?

Thanks to all for the advice, guys!

 

[fossyant]

If you are using a triple chainset - and your shifters support that, then a Deore set should be fine - if not sell them on....(for more)....

9 speed spacers are the same Road or MTB....

 

[RedBike]

The Deore rear mech will be fine with a 25 tooth cassette. In theory shifting wont be as quick as an Ultegra mech would be but in practice you'll never notice the difference.

I am still unsure that front mech is going to work though. I suppose it's worth a try.
I don't think a deore and an dura-ace left hand shifter pull the same amount of cable; and even if they did a Deore front mech is only rated to handle a max chainring size of 48 teeth.

 

[mrfacetious]

well i haven't bought the shifters yet, I was just looking to get Dura Ace. If there's something that'd work better that's fine. but the front mech isn't too difficult to find on the cheap anyway. I just saw a 105 mech go for a tenner, so hey. Thanks guys!