DA shifting compatibility

[tjg]

I want to improve the shifting on my gravel bike. I’m aware that using DuraAce adds to compatibility issues, but I’m looking for some fixes or at least some options to consider. I’d like to keep using my sti shifters.
Here’s what I’m using:
DA 9 speed sti shifters
XTR 9 speed RD
XT 11-34 cassette (cs-M770)
50/34 Sugino 9/10 speed cranks/chainrings

All parts are in excellent condition
SRAM PC951 9 speed chain and Jag cables are almost new.

Shifts cleanly 95% of time but want it better.
Suggestions?

[dave thompson]

Couple of things. I’ve found that KMC chains seem to shift better than SRAM chains. Shimano cassettes seem to offer better shifting than SRAM cassettes. If the rear derailleur you’re using is a long cage model, a medium cage der with the capacity for a 34t cassette will shift quite a bit better than a long cage der.

Using Dura Ace won’t have any compatibility issues with your setup.

[tjg]

I appreciate that. My RD cage is a long one.

[dddd]

I've actually measured the outermost width of the side plate versus the width at the pins for several brands of 9s chains.

Shimano 9s chain has the most "aggressive" profile in terms of grabbing the next-larger cog on the cassette. It's outer plates bulge out the furthest from the ends of the pins in other words.

In the 10s world is where use of Shimano chain can literally make or break the level of acceptable shifting performance on bikes that are otherwise Shimano-equipped, at least this is what I have seen when I changed from using SRAM 10s chain to using Shimano 10s chain.

Having the slickest cabling with shortest practical housing lengths seems to be the other big variable in terms of shifting performance, but other factors such as the B-tension adjustment can also make a big difference.

I use Tiagra 9s levers with a mid-cage XTR 9s rear derailer on my 'cross bike, gearing is 50-34t by 12-34t and the shifting is always first-rate.

[tjg]

Will check B tension on my set up.

Also, If I change rear derailleurs, am I confined to a “9 speed” ?

[Ken Robb]

Is your problem with the front or rear?

[dave thompson]

Originally Posted by tjg

Will check B tension on my set up.

Also, If I change rear derailleurs, am I confined to a “9 speed” ?

8 or 9 speed rear ders will work, 10 speed won't. Check the specs for the derailleur to make sure it's suitable with a 34t large cog.

[palincss]

Originally Posted by dddd

In the 10s world is where use of Shimano chain can literally make or break the level of acceptable shifting performance on bikes that are otherwise Shimano-equipped, at least this is what I have seen when I changed from using SRAM 10s chain to using Shimano 10s chain.

Interestingly, it's not just Shimano-world where a Shimano chain can make a difference. Rene Herse recommends using a Shimano chain on both their 10 and 11 speed cranks, regardless of what's in back.

[jc031699]

There’s no reason that what you have right now shouldn’t shift cleanly 100% of the time if setup properly and all is clean / good condition without excessive wear. It’d be important to know exactly what the 5% incidence problem is to give you adequate help.

Just as an example, not saying that it’s the problem with your bike, but even a rear derailleur hanger out of alignment or a slightly too short rear cable housing segment at the RD could be enough to throw the entire system slightly out of whack.

Sent from my iPhone using Tapatalk

[tjg]

The main problem is in the in the rear, however, the front doesn’t shift as cleanly as my DA 42/39 either. I assumed that the Sugino compact just wasn’t as ideal as a full size DA.

[tjg]

Here is some additional information:

The cranks are Sugino RD1L
Shifters ST-7700-c
Front DA FD-7400
Rear XTR RD M952 long cage

This is my second new chain Replacing a Shimano.

Shifts require a more gentle, intentional touch (vs crisp, flawless, “mindless” shifting of similar full DA on road bike).

There is periodic skipping (minor grinding) during shifts which require re-shifting or additional trimming (remind me of a cassette with incorrect spacing or a worn chain).


***I had forgotten that my front derailleur is a 7400. Would this be the cause of the less than precise front shifting more than the crankset?

[Gummee]

Originally Posted by tjg

Here is some additional information:

The cranks are Sugino RD1L
Shifters ST-7700-c
Front DA FD-7400
Rear XTR RD M952 long cage

This is my second new chain Replacing a Shimano.

Shifts require a more gentle, intentional touch (vs crisp, flawless, “mindless” shifting of similar full DA on road bike).

There is periodic skipping (minor grinding) during shifts which require re-shifting or additional trimming (remind me of a cassette with incorrect spacing or a worn chain).


***I had forgotten that my front derailleur is a 7400. Would this be the cause of the less than precise front shifting more than the crankset?

Front derailleur should be fine.

I've had your setup before. I sustpect a setup problem rather than a compatibility problem.

M

[rccardr]

Originally Posted by jc031699

There’s no reason that what you have right now shouldn’t shift cleanly 100% of the time if setup properly and all is clean / good condition without excessive wear. It’d be important to know exactly what the 5% incidence problem is to give you adequate help.

Just as an example, not saying that it’s the problem with your bike, but even a rear derailleur hanger out of alignment or a slightly too short rear cable housing segment at the RD could be enough to throw the entire system slightly out of whack.

Sent from my iPhone using Tapatalk

This.

Properly assembled and adjusted, and assuming all components are in relatively good condition, this setup should shift perfectly.

Like mine.

[oldpotatoe]

Originally Posted by tjg

Will check B tension on my set up.

Also, If I change rear derailleurs, am I confined to a “9 speed” ?

Only if you want a 'MTB' rear der. A shimano 10s road rear der is compatible with shimano 9s road STI..BUT the setup 'should' work great as is. Good 1.1 der wires, 5mm der housing would help but unless something is worn or something, your rig should shift 100% of the time.

[tv_vt]

I've used a similar setup to yours and thought it worked great. One suggestion I'll throw out is to get a pair of Praxis 50-34 chainrings. They are right up there with the best chainrings I've ever used.

As far as chains, the best 9 speed chain I used was the Dura Ace/XTR model. Very hard to find these days, but that's the best one for 9 speed Shimano setups, far and away.

PS. you sure the RD pulleys don't have any cracks in them?