can span the width of a 9speed cassette and not have chain interference? My tiagra triple has chain rub in the three most extreme gears of each chain ring.

That seems odd. More info is needed. I have a tiagra triple derailer on a xt crank with a ten speed cassette with brifters and I have zero chain rub so i have to assume your problem is not the derailer

I use a triple with a 9sp wide cassette, no real issues.

It helps that I use bar-end shifters. I can use almost the entire rear cassette with the middle ring, by slightly adjusting the FD.

If you are asking "can I cross-chain at will," though, the answer is "no."

I also have no issues using a 105 5603 FD, and I'm using a ten speed cassette. I'm able to use all 30 speeds, but avoid the big-big and small-small as all skilled cyclist should.

I can't adjust out the rub in the extreme ends (not that I use them much, but it bothers me) My factory cables have two areas for fine cable adjustment (one barrel type just as it exits the brifter, and one at the cable stop on the down tube) should I have two or any at all? And my cable is super tight, and the cable adjusters don't seem to work anyways.

My Ultegra 9 speed FDs have no chain rub issues. You need to start your FD adjustment from scratch. Clean and lube the FD, then: https://www.parktool.com/blog/repair-...ur-adjustments

Thank you, that will help. How many "inline" cable adjusters should I have? I figure more than one would cause a headache?

what bike? what is the seat tube diameter? what crank? I had some trouble with mine because of the mountain crank (xt) on a steel frame with a narrow seat tube (soma double cross). I had to move one of the drive side spacers to the other side so i could get it to throw the chain out far enough to get on the big gear.

That sounds like high/low limit screw adjustment needed.

Windsor Tourist, FSA tripple.

yeah, that's already been done. By me and the LBS.

Most bikes have one. If you do the adjustment correctly, you may never need to use it at all. I don't. The FD cable seems to be short enough that cable stretch is less of a problem than with the rear. You probably could benefit by replacing your cables and housings before you adjust things. If you do it yourself, the critical thing is to get the housing ends cut clean and square. This is not easy to do without the proper tools. Check the Park website for instructions.

I've found them very finicky at times. My advice, adjust the cable tension and angle of the bracket so that it doesn't rub in your "common" gears. If, for example, it rubs in the large cog and large sprocket, what the heck are you doing in that gear?! The FD on my old bike sucks, took me an hour to adjust, but it's fine now.

You don't need to use all 9 with each ring. Probably more like 1-5 with the first, 3-7 with the second, and 5-9 with the 3rd. Try to just get those combinations to work, and don't worry about the rest. Stay out of silly gears.

I think that's my next step, new cable and housing. I've got the tool already, so.....

I may have miss understood your question. If when you say "extreme gears of each chain ring" you mean, largest crank ring to largest cassette ring and smallest to smallest, you should just stop doing that. It is very hard on equipment not to mention inefficient. You should also quit reading this thread because you will probably be attacked by some veterans shortly.

On one of my bikes I have a triple crankset with a Tiagra FD. It works well. However I never use the big ring and big cogs nor do I use the opposite small ring small cogs. I do use all 9 cogs when in the middle ring but this requires trimming the FD when at the extremes of the cassette.

Yes! Of course! It's not the best way to ride, but I can go right across my rear 9sp cassette with the 105 double FD and IRD Compact derailleurs, there has to be some trimming along the way.

If you have adjusted the high low limit screws on the derailleur and the angle maybe it's the position of the crank. Make sure your middle ring is lined up with the middle of your cassette.

I rarely ride that way (if at all) most of my riding is in the middle ring in the middle of the cassette, but I'm the type of person that can't handle it when something isnt perfect, even if I never use it.

+1 for friction shifting.

never have this issue. Ever.

anyone want to invent friction brifters?

From what I understand Camp front brifter is basically friction

Your issue is more with the shifter's indexing, rather than the derailleur. Tiagra brifters only have 2 index points on the middle chainring. My wife's bike has Ultegra brifters has many more points (not sure how many), and has no chain rub issues. Friction, with its ∞ index points, will definitely solve your problem. But doesn't come with the convenience of a brifter. That said, if you adjust your Tiagras very precisely, there should be a sweet spot where rub is avoided in any gear combination that you should be riding in. It's just really finicky.

From the two extreme chainrings, you should not be able to reach the far end of the cassette without rub. Bikes just aren't built to cross-chain. There's other gear combinations that will provide the same, or very close, gear ratios without straining your equipment.

Crank installed correctly with required spacers? I had a friend that had this exact problem.....