[dave.g75]

I currently have an Sram x9 cassette and sram pc49 chain, but want to replace my old battered xtr rear mech for a dura ace rear mech, does the dura ace need to be run with a road cassette like an ultrega or will it work fine with the sram??
Thanks for any help
Dave

 

[DßR]

dura-ace will work okay, the "max" cog on those is 27t but I've run them up to 34t and they work. It'll rub on the 34t cog pretty bad, but on a 30t it's great, no problems. Not sure about a 32t, haven't tried that yet, it'll probably rub a bit.

 

[Rik]

You're at the mercy of the frame design... I've noticed some hangers are positioned slightly differently to others, so you could get away with running the X9 (isn't it a 909, just to be picky?) cassette, or you might have rubbing... you'll have to crank in the B-tension screw most of the way in either situation, and may have to lock out the top sprocket if rubbing is unbearable, but it should work. 9spd cassette spacing is the same accross Shimano MTB and road, and SRAM uses the same spacing, so your shifting will be fine, it's just the derailleur that mightn't like the bigger stretch.

 

[dave.g75]

yeh cheers guys...dont like the idea of having to not use all my gears, so it looks like Im either gonna lump out for a new cassette as well, or stick with mtb mechs for the time being.
Cheers
Dave

 

[sanjuro]

You're at the mercy of the frame design... I've noticed some hangers are positioned slightly differently to others, so you could get away with running the X9 (isn't it a 909, just to be picky?) cassette, or you might have rubbing... you'll have to crank in the B-tension screw most of the way in either situation, and may have to lock out the top sprocket if rubbing is unbearable, but it should work. 9spd cassette spacing is the same accross Shimano MTB and road, and SRAM uses the same spacing, so your shifting will be fine, it's just the derailleur that mightn't like the bigger stretch.

One trip the owner of my shop taught me was to put the B-screw from the other side, with the head of the screw touching the drop-out. You get another 1mm of pushback with the rear derailleur.

This is critical with a Dura-Ace config with road triples in order to pick up enough slack.