Chainring question.

[false_Aest]

Hey,

I'd like to swap an Ultegra 39T chainring for a 42T since I happen to live in the NoCoast and everything here is flat.

Is there a brand that is more compatible with Shimano 10 speed?

Thanks,
T

[Bruce K]

Where are you riding in the northeast?

Obviously not NH, VT, ME, or western MA.

I'm not sure I'd want to change that 39t out quite so fast.

Just sayin'

BK

[false_Aest]

I live in Chicago.

[Kervin]

For me, when the rings get closer in size, the pins and ramps matter less. That said, I'd go with an 11/21 cluster first, if you don't already have one.

[RPS]

Is there a brand that is more compatible with Shimano 10 speed?

Thanks,
THave you ruled out Shimano?

[false_Aest]

I haven't ruled out anything. Just seeing what people might recommend.

[RPS]

I asked because I think Shimano only makes it available in Dura Ace, which means it's probably more expensive than necessary.

[Peter P.]

I've mixed TA Alize chainrings with Shimano. They work. You can get them here:

http://www.peterwhitecycles.com/chainrings.asp

Incidentally, I run a 42x50 setup here in Connecticut.

[EastCoastRoadie]

You can pick up an FSA Pro 130mm 42T chain ring for the same price as the Ultegra 39T ring ($30). Should be a perfect fit, and much cheaper than adding the DA ring for twice the price.

[palincss]

Perfect fit - sure, it's hard to screw up the 130mm bolt circle - but how well will it work with indexed front shifting?

I have no personal experience, being a bar end shifter user, and with friction just about anything works; but when you go to front indexing matching the tooth difference between the chain rings to the design parameters of the front derailleur become important, and in this case you'd be introducing a large mismatch.

[Ti Designs]

Where are you riding in the northeast?

Obviously not NH, VT, ME, or western MA.

I'm not sure I'd want to change that 39t out quite so fast.


I run a 44 inner ring, I've hit three of those states in one ride...


To answer the question, shifting is going to work best with both rings being Shimano. Yes, it's Shimano being Shimano again. They have an A series set of chainrings which is 39/53, and a B set which is 42/53. The ramps and pins need to line up, which is their excuse for making two sets.

I run an FSA set of chainrings, they work OK, but not as well as the Shimano chainrings do. When I went to the 44/55 I noticed that front shifting didn't bother me as much 'cause I could stay in the small ring more. If you ever watch someone using compact gearing, about a third of the shifts include the front derailleur. With the larger small ring you hit most of your cruising range without touching the left shifter.

[johnnymossville]

I recently bent up a 39t FSA Chainring (SL-K Light) by pedaling hard. I don't trust them anymore. I replaced it with an Ultegra ring.

[Ray]

Perfect fit - sure, it's hard to screw up the 130mm bolt circle - but how well will it work with indexed front shifting?

I have no personal experience, being a bar end shifter user, and with friction just about anything works; but when you go to front indexing matching the tooth difference between the chain rings to the design parameters of the front derailleur become important, and in this case you'd be introducing a large mismatch.
In my experience, "indexed" front shifting is really only an operative term with triples. Doubles are generally binary by definition - its either in one position or the other with a bit of trim available once you get onto the ring in question. I've mixed and matched all manner of front chainrings with no ill effects on doubles. With all types of shifters. Triples can get tricky, particularly if you're not running the standard sized middle and big rings. That's when friction makes your life much less complicated.

That said, even though I run a compact, I don't shift much in the front. I run a wide enough range and small enough big ring that I stay in the big ring the vast majority of the time. And I don't remember the last time I tried shifting the front ring to a bigger ring under any sort of load.

-Ray

[RPS]

Perfect fit - sure, it's hard to screw up the 130mm bolt circle - but how well will it work with indexed front shifting?

I have no personal experience, being a bar end shifter user, and with friction just about anything works; but when you go to front indexing matching the tooth difference between the chain rings to the design parameters of the front derailleur become important, and in this case you'd be introducing a large mismatch.The older 9-speed Ultegra front derailleur for doubles was rated for 50-56 tooth large chainrings and 15-T capacity. My older catalog also lists available ring combinations as 53-42T, 53-39T, and 52-39T.

Being that it’s on the inside of a double where it’s not required to lift the chain off a granny ring, I’d expect that even an inexpensive ring would work fairly well.