Ultegra Chainring Compatibility

[Brian]

I currently ride an Ultegra 9-speed triple (52-42-30). The 52 and 42 rings are getting worn and need to be replaced. I’d like to replace them with 53 and 39 rings to be compatible with the double chainrings a lot of other people ride.

From what I can gather, the 53 ring is not a problem because it comes in Ultegra A-Type (ramps and pins) configuration. The Ultegra 39 ring, however, seems to only come in B-Type configuration (no ramps and pins). Using a B-Type ring, I’m told, would significantly degrade shifting.

I could replace the Ultegra crankset with a Dura Ace 53-39-30 crankset, but that would also require a Dura Ace rear derailleur, and now we’re talking real money…

So… What is the cheapest way to get to the 53-39-30 configuration?

[JohnS]

Why would you need a DA RD? Can't you just use DA rings on your Ultegra cranks?

[bubba]

Why would you need a DA RD? Can't you just use DA rings on your Ultegra cranks?
No need for a RD, but the DA triple 39 won't work on an ultegra crank. And if subbing the 42 for a 39, A DA triple FD will shift it better.Some claim the ultegra triple FD won't work at all with a 39, others have had better results.

[Brian]

JohnS,

I was told that the Bolt Circle Diameter of the DA is different than Ultegra and that a DA rear derailleur would be needed to maintain proper chain tension.

[bubba]

JohnS,

I was told that the Bolt Circle Diameter of the DA is different than Ultegra and that a DA rear derailleur would be needed to maintain proper chain tension.You got told alot of BS. The BCD for the 39 isn't different, it's 130(the BCD for the granny that bolts to it is proprietary),but the machining for the ring/crankarm is. Sheldon Brown has the skinny in his DA compatibility article. If you are running an ultegra triple with a long cage, you certainly don't need a DA Triple RD as the wrap capacity requirement hasn't changed and the Uletgra long cage has the same wrap as the DA long cage anyway. You can even run a short cage on alot of triples if you don't go nuts with a big cog in back and avoid the small cogs when in the granny.

[Dave]

The DA RD is not needed. You may need the DA FD for the best shifting though. Personally, I think a campy triple system is far better.

If you go to the Shimano website, the exploded view of both cranks will explain the diffrence in the chainrings. The DA has the same 130mm BC on the middle and big rings, but the DA little ring has a different BC and it's bolted to the DA middle ring, not to the crank, like the "normal" ultegra model,which has a 74mm BC on the little ring.

You can get 130mm BC 53/39T FSA triple chainrings with the proper ramps and pins. The FSA part numbers are CR4034 and CR4028.

http://aebike.com/site/page.cfm?sort=Price&PageID=30&Category=203&Brand=149&currentpage=1

Chain length seems to be a confusing topic, with shortcut methods that don't produce the best results. Here's how to do it right.

Two simple tests will determine if the chain is the correct length. First, it must not hang loose in the little ring, little cog combination. If there is no tension on the chain in the little ring, little cog combination; remove two links (one inch) at a time, until there is. When the ends of the chain are brought together, some movement of the lower pulley should occur, indicating tension is being applied. Two more links (another inch) may need to be removed, beyond the point of absolute minimum tension, to keep the chain from rubbing on itself as it passes under the upper derailleur pulley. If you want to see how much lower pulley movement will occur, without removing the extra inch of chain, shift up four teeth (11 to 15 or 12 to 16). This has the same effect as removing two links. Once this is done, the chain is set to the maximum useable length. Removing additional links will do nothing but reduce the derailleur's capacity.

Second, the chain must be long enough to avoid over-extending the rear derailleur when shifted to the big ring and biggest cog combination. If the chain is set to the maximum length as described, it should always pass this test, unless your setup exceeds the derailleur's stated wrap capacity. If you deliberately exceed the derailleur's capacity and the derailleur is over-extended in the big ring/largest cog combo, then you must either avoid that combo or add another inch and avoid using the little chainring and the smallest 3 or 4 cogs (since the chain will hang loose).

[Serotta PETE]

While I have not personally tried it...I have been told be sources that I respect that a 39x53 with triple is not a good shift. Person to really talk to is White is NH. I have acquired TA chain rings from him and they did the job very well.


Pete

[bubba]

While I have not personally tried it...I have been told be sources that I respect that a 39x53 with triple is not a good shift. Person to really talk to is White is NH. I have acquired TA chain rings from him and they did the job very well.


Pete
I have 3 set up that way. No issues.