shimano triple crank ring selection question

[eddief]

currently running 52, 39, 30 with 105 front derailleur and 11-34 cassette. i know these are granny gears for stronger riders. but next month i will be climbing into Glacier National Park from east to west.

wondering if there would be any issues going to a 50 big ring and 28 small ring to achieve even lower gearing?

would the front d handle this? probably a link or two removed from chain?

[Louis]

Eddie,

28 will work fine with a Shimano triple FD (I'm doing that right now)

I wouldn't bother swapping out the 52. what you need is low gears at the low end. In fact, (assuming it could be done, which it probably can't) a 55 would be better so you don't spin out as much on the downhills.

Shifting from a 52 to 42 to 28 works very well for me (105 9-spd crank) and I can't even remember the last time I dropped the chain onto the BB. (I shouldn't have said that - it will probably happen today.)

Louis

[eddief]

I know Shimano is conservative, but they quote SGS rear derailleur to 45 capacity. Thought I'd be pushing with with big cassette and too big a difference in the front rings.

[Ray]

I'm running a 48-38-24 triple on one of my bikes, on an outboard BB Ultegra triple crank. I've run combinations like this with Shimano FDs before but they can be a bit cranky. I've found that running Campy triple FDs with unusual triple chainring combinations tends to work much much better. And some sort of friction front shifting - I'm using barcons. If you're using STI, good luck with non-standard chainring sizes.

-Ray

[Louis]

If you're using STI, good luck with non-standard chainring sizes.


I should have mentioned that I'm using DT shifters, so the front is friction.

[eddief]

my needs/wants are for this combo to work well with STI. Seems as if spacing should be the same and the STI's should not care about the size of the rings. Now the front d might be another story. Will experiment.

[Pete Serotta]

my needs/wants are for this combo to work well with STI. Seems as if spacing should be the same and the STI's should not care about the size of the rings. Now the front d might be another story. Will experiment.


Many folks are far more knowledgable than I on these things

[Bradford]

I run 51-40-26 on my touring bike with XT FD and RD. Also bar ends, left set to friction, 13-34 on the back.

No problems, going on 15 years. If you run into trouble, pick up some XT on ebay and throw it on, you'll be all set.

[palincss]

No problems, going on 15 years. If you run into trouble, pick up some XT on ebay and throw it on, you'll be all set.

All set except for the fact that the cable pull for an XT front derailleur is not compatible with STI...

[Bradford]

All set except for the fact that the cable pull for an XT front derailleur is not compatible with STI...
For the Glacier ride, I'd throw on the bar ends.

[Louis]

Yet more proof (not that I needed any) that DT shifters are better than those newfangled STI/Ergopower thingies.

However, I'm not so much of a retro-grouch to argue against indexed shifters. For 6-speed they're reasonable to use, but for 9spd it's just too much of a hassle (at least for me).

[eddief]

i just completed a 550 mile tour through all sorts of terrain. up, down, flat, rolling, undulating, etc. i much prefer the pure comfort and convenience of STI. i get there can be some drawbacks, but i'd choose STI brifters anytime for this kind of riding. that said, my Bike Friday is well tuned with bar ends and i can appreciate the option.

i will try going down to 28 on the front with installed 105 front d. if that does not work, then will consider next steps.

[Louis]

i much prefer the pure comfort and convenience of STI

Eddie,

I absolutely agree that for convenience you can't beat having shifters that are integrated into the hoods. I stick to DT shifters because 1) they do what I ask of them (perhaps better than STI when it comes to shifting the front) and 2) I think they look better than STI or Ergopower (which both have a mass of cables in front, which I think detract from the aesthetics of the bike).

When I say that "DT shifters are better" I do so partly tongue-in-cheek, partly because I just like to be different.

Louis

[dave thompson]

Not different Louis.....old.

[Louis]

Not different Louis.....old.

Hello Pot,

How's the cookin' these days?

Kettle