Has anyone had luck using a 48 tooth TA Specialities outer ring on an Ultegra 6500 triple crankset? Does it shift correctly with STI brifters?


I did a little research and am not finding it too encouraging so far, I thought this combo would be fairly straightforward.

Is the TA ring ramped and pinned for use as an outer ring? If not, using it with an indexed front shifter will be problematic.

It is pinned in 4 spots. It is not ramped.

It's the Alize model 48-130.

It will work but from my experience the shifting will tend to hesitate just slightly. Some people are fine with that, others not so much. Nothing works better than the properly matched OEM Shimano rings but of course they don't make a 48 for your 6500. Sometimes better gear ratios are worth the slight inconvenience of slower shifting.

There is another potential problem. Assuming your crank has the original 52/42/30 chainrings, the substitution of a 48T for the largest ring and lowering the front derailleur so it's positioned properly may cause the inner cage of the front derailleur to hit the 42T middle ring. Most current front derailleurs are spec'ed for a 10 tooth or more difference between adjacent chainrings and that 6T difference may cause interference.

Agreed. Current "triple" front derailleurs have very deep inner cage plates. These run into the middle chainring if the derailleur is lowered far enough for the outer cage plate to clear the big chainring "the correct amount". (There can be an element of voodoo to making front derailleurs work in oddball combinations... hence the quotes.)

Two things to try:
1. don't lower the front derailleur. Leave it hanging in midair and see if it shifts OK and doesn't lose the chain to the outside.
2. try a "double" front derailleur. If you're not changing the inner ring (i.e. a 30-42-48 triple) it might work if the derailleur has enough movement to cover all the rings. The "double" inner cage plate is probably skinny enough that you can lower it to where it makes the shift.

The solution would be simple: get a different front derailleur that does not have the ramps. I have a Microshift derailleur that works well for my touring bike, although even late 70s Campagnolo Record front derailleurs (or Suntour, Shimano, Huret, whatever) will also work fine.

Knet, IME shifting without the ramps and pins using an indexed shifter is fine as long as pedaling torque is not too much.

Brad

Maybe a complete Sugino XD triple that comes with a 48 big ring? The TA rings are no bargain and your 6500 crank probably has some miles on it.

I was just starting to consider that...................