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Dura Ace Triple(11 posts)

Dura Ace TripleTi-Boy
Mar 2, 2003 5:47 PM
Just got a new rig with D/A Triple and 12-25 cassette. I can live with giving up to chain rub a couple of combinations (eg 53-25 and 30-12), but I'm getting rub in about 7 combos. including in the middle ring. What can I reasonably expect a descent wrench to get out of my set up? Running a Sram chain- does that make a difference?
re: Dura Ace Tripleeflayer
Mar 2, 2003 6:07 PM
I have had my issues with my DA triple. The kit is now on its third frame. It's not a frame problem, I just can't make up my mind. On the first two frames it installed perfectly and I was able to get all gear combos without rubbing. On the third frame there appeared to be a problem, but it turned out to be mostly me, the crummy mechanic. Shimano says there is nothing wrong with the system, but I was having trouble with unexpected auto shifting when in the middle ring and the two biggest cogs in the rear. Others have said there is an upgraded middle ring for Treks. In the end, my problem was the number of times I had added links to the chain doing all the frame switches. Sometimes adding links from different model chains. Shimano said older style Shimano chains are more flexible, such as hg91. I put on a new hg 91 and all is working well again. Remember there are two trim cliks on the front d and I need to use them regularly to avoid rub. One other thing that was suggested could be an issue with chain line. Someone suggested an xtr bottom bracket which is available in a 116 mm length and has some adjustability with the included spacers. Short chain stays seem to make these derailleur adjustments more difficult. Beware of local bike shops that don't know what the hell they are doing. In my case two high end shops did not know how to fix this problem.
What's the chain rubbing on?Kerry
Mar 2, 2003 6:39 PM
When most people talk about chain rub, they mean the chain rubs on the next larger chain ring when using the smaller cogs on the cassette. No way is that happening for 7 out of 9 cogs on the middle ring! It must be rubbing on the derailleur cage, which just means you don't have it adjusted right or mounted correctly.
What's the chain rubbing on?Ti-Boy
Mar 3, 2003 5:32 PM
The chain is rubbing on the cage. I know it's not mounted/adjusted correctly. Question is: when it is mounted/correctly, how many combos can I REASONABLY expect to get some chain run in given the long crossover inherent on triples?
How to align and adjust a front derailleurKerry
Mar 4, 2003 4:52 PM
While you may tweak a bit from this, the outer cage of the derailleur should be parallel to the chainrings. This is a starting point, and you may find things work better with the cage slightly pivoted outward at the rear. The derailleur should be positioned vertically so that you have about 1mm clearance above the large chain ring (nearly touching!). The upper limit screw should be set so that the cage is just beyond rubbing the chain when in the large chainring and smallest cog. The lower limit screw should be adjusted so the cage is just beyond rubbing the chain when in the small chainring and largest cog. The cable should be clamped on the derailleur with the shifter indexed all the way "down" (like shifting to the small chainring), the barrel adjuster all the way in, and the chain on the small chainring (this is because you can't remove all the cable slack during clamping, and you will end up turning the barrel adjuster "out" to remove that little bit of slack). Shift through the gears and look for both shifting quality and chain rub. If the derailleur shifts "slow" to larger rings, turn the barrel adjuster out. If it is slow in shifting to smaller rings, turn the adjuster in. If the chain rubs on the outer plate while on any given chainring, turn the adjuster out. If the chain rubs on the inner plate, turn the adjuster in. You should be able to get good adjustment unless you have a system problem. Simply looking at the front derailleur/chain relationship after each shift should guide you to the next step. Your upper and lower limit screws may need slight adjustment after riding a bit to eliminate rub, to improve shifting in certain gears, or to prevent the chain from over shifting the big ring or dropping off the small ring.
Small modification...satanas
Mar 8, 2003 9:13 AM
From years of shop experience, the best solution is to adjust the cage angle (viewed from above) so that when the bike is in top gear (largest ring + smallest rear cog) the *inside* of the cage plate - where the chain would rub - is parallel with the chain. This usually means that the rear of the cage is slightly further out than if you set it parallel with the rings.

Doing this gives the greatest "effective cage width" - and thus more useable gears - before trimming is required.
re: Dura Ace Tripledickruthlynn
Mar 3, 2003 6:23 PM
I put 4,200 miles on a Y-Foil with a DA triple during one 12 month period. I am totally convinced that the DA triple is not manufactured correctly. In addition to chain rub, the DA triple misses a front chain wheel 5 out 10 shifts from the 53 to the 39 going instead to the 30. I am not a mechanic, I just ride. I have had the bike adjusted at 7 different bike shops. Most of these were high end shops. Not one of these shops/mechanics could fix the problem. The adjustments were good for 50 miles at most.
re: Dura Ace Tripleeflayer
Mar 3, 2003 7:47 PM
One more time...I was just out for a 20 mile ride today on my DA triple bike. With trimming, all combos work with no rubbing. I have some new concern that the first trim click when on largest ring seems finicky, but otherwise the system can be adjusted, at least on my 3 frames, to work nearly as well as my Ultegra triple on my other bike. If I was to purchase again, I would buy Ultegra triple.
re: Dura Ace Triplejohnnybegood
Mar 4, 2003 7:43 AM
In response to your question: What should you expect. Go to http://www.shimano-europe.com. Click on the link for "Road Racing", then on the right-hand side, click on "Tips". Read the tip called "Best Gear Combinations" dated 12/12/2001. The other issue is that the chainline must be aligned properly. You don't necessarily need a longer axle. You can shim the entire bb assembly to the right if necessary. Your center chainring should line up to the center of your cassette. If it is lining up toward the larger cogs on the cassette you should install a 1mm or 2mm shim between the frame and the right-hand bearing cup to move the bb to the right.
re: Dura Ace TripleTi-Boy
Mar 4, 2003 6:08 PM
Brought bike to my regular wrench tonight. He couldn't seem to get things right. Decided to switch out chain, Sram PC54 with Shim. D/A 7700. Noticed from manuals that the 7700 is 3mm narrower. On the stand it shifts smoothly in all but extreme cross chain positions. Even in cross chain positions the rub is slight. Will give it a real world test and hope for the best.
re: Dura Ace Tripleeflayer
Mar 4, 2003 8:48 PM
Now there are two of us who have fixed significant DA triple issues by simply installing a new Shimano chain. Good luck with it.