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triple gearing question(17 posts)

triple gearing questionseti
Aug 5, 2002 3:00 PM
can i get a 39t middle ring for my ultegra triple.i think this would be a better set up than te 42t. i tend to stay in my 42x25 when actually something smaller would be more efficient. shifting down to the 30t is sometimes a hassle but i still need it for some long climbs i do weekly. or is there a better combo/gearing that i should try. thanx
almost the sameDougSloan
Aug 5, 2002 3:39 PM
A 42 and a 39 are almost identical in gear patterns, just one gear step apart. Below is a chart. Note that nearly every 39 gear has a matching 42 gear, just over one to right and up one on the chart.

So, using the 42, it just means you are one gear step closer to using the 30 ring. Just get used to using the 30 and things will be all better. You get a much closer gear selection in the 30, anyway.

re: triple gearing questionChen2
Aug 5, 2002 6:38 PM
I would not try to replace the 42 with a 39 unless you can find one that is designed to run in a triple, and the only one I know of is the new Dura-Ace triple middle ring. It is a 39 but I have not heard of anyone trying it with the other triples.
Closer gears in the back?Bolivarroads
Aug 5, 2002 6:43 PM
Has anyone tried using a 12-21 in the back with the Dura-Ace triple? You could have sequential gears all the way up to 19, and still have a decent climbing gear in 30-21.
Aug 6, 2002 10:32 PM
it is, I feel, a good idea.
re: triple gearing questionccrabb
Aug 5, 2002 7:21 PM
I'd agree with the above posts. I've been using a borrowed bike with a triple while I fixed the fork on my bike which does not have a triple. What I found is that you do spend more time in the 30. But I thought exactly as you, wanting a 39 middle ring. I like the 39-53 combo, but with a triple it appears that you'll spend some time in the 30 on the flats/low hills. I used to think, "I ride in the 39-52 and the 30 is there for the big climb." But really, you can ride part of the flats/wind/low hills in the 30 as well. So my rationalization is, "I paid for it, might as well use it." :-) I have a triple for my bike but have not installed it yet.
re: triple gearing questionseti
Aug 6, 2002 5:25 AM
thanks for the info. does anyone know if the dura ace 39t middle ring has the same bolt pattern as my ultegra? i would like to try the 39t to see how it works. i bought the triple to save my knees,but as i get in better shape i find i use it less.except for the big climbs i like to do a couple of times a week.i can spin up in the 30t but i go anerobic if i increase the gear. it would also be nice to have the 39t to measure my fitness with all the other people riding around on doubles.
DA and Ultegra differentDougSloan
Aug 6, 2002 5:54 AM
While both middle rings use a 130 mm bolt circle, the DA triple has the small ring bolted directly to the middle ring, while Ultegra bolts the small ring directly to the crank. You can see the DA in this picture:

compare Ultegra photoDougSloan
Aug 6, 2002 6:01 AM
You can see the middle ring bolted to the crank itself:
Aug 7, 2002 6:45 AM
You can fit a regular DA or Ultegra double 39 tooth ring on your Ultegra triple. It will bolt on OK. It won't shift up from the small 30 tooth ring though. The 42 triple ring has ramps for shifting that 39 double ring does not have.

I tried this on my wife's bike and never could get it to work correctly. The new DA triple is 39-53 rather than 42-52. You might try and see if you can buy a DA triple 39 tooth ring and install it.

I could never understand why Shimano chose a 42-52 over a 38-53 for their Ultegra triple. And why they didn't offer a 39 tooth ring for it.
re: triple gearing questionJimP
Aug 6, 2002 5:40 AM
I think I agree with your assessment. I ride with a DA double 39/53 - 12/23 and the shift from the 39 to the 53 usually requires a 3 shift on the rear cluster. I examined the nice chart DougSloan provided and noticed that the 30-39-52 exhibits a more even shifting pattern than using the 42. The cost of a 39 tooth chainring is cheap enough by mail-order that I would try it. I have used non-Shimano rings in the past and didn't notice any shifting difference and I would question the difference in the double or triple 39 tooth rings so try it.
re: triple gearing questionseti
Aug 6, 2002 8:08 AM
thanks again for the photos and info. does anyome know where i can get a 39t middle that will fit my ultegra crank.i would really like to try a new chain ring. i get a lot of chain rub on my front der.when i'm in the 30t up front and past the third cog out back. you can "feather" the front der. to alleviate the problem .not that big of a deal, but i'm trying fine tune everything i can to make my ride as sweet as possible.
Aug 6, 2002 8:26 AM
You can get just about anything here; check the 130mm Bolt Circle "Alize":
Aug 6, 2002 9:26 AM
thank you doug.does my middle ring have to have any special pick up pins or is a ring a ring. i'm at work and can't look at my bike. is there any torque specs for chain ring bolts?
Aug 6, 2002 9:30 AM
If they are designated as "middle" rings, then they have the pickup pins. I've used a triple without pickup pins, and it still shifts. Nonetheless, this should not be an issue, as the middle rings are available.

Keep in mind that the Dura Ace middle ring is special, having the tabs on it to mount the small ring. There are some TA rings like this, too.

No idea on the torque specs. I always go by feel.

Aug 6, 2002 9:43 AM
if your still there? what is the easiet way to move my brake levers up the bar. is there a set screw inside the levers or on the side under the hoods? will i have to lossen any cables? thanks
Aug 6, 2002 9:36 AM
obviously i didn't go to your site before i replied. i am now getting my chain ring phd at peter white cycles. thanks again.