Group Set Decision - Help!

[ivorygorgon]

I am building a Madone 5.5. I am trying to decide between two groupsets. The SRAM Force with a compact double 50/34 - 11/28 and Shimano Ultegra triple 50/39/30 - 12/27.

On my bike right now I have a 50/39/26 - 12/27.

I live in SoCal and I ride fairly hilly rides. Usually between 3-5000 feet of gain but occasionally up to 10,000 feet of gain. I ride hilly centuries 2-3 times a year.

I have (so far) been able to climb everything, but I am a pretty slow climber. I always get dropped on the hills on club rides. I would like to be a faster climber. I can hang with the group on flats and inclines up to about 4%. I do use my granny gear now, but only on pretty steep inclines and sometimes on smaller inclines (8-10%) at the end of a long ride. On my triple I ride in the middle about 85% of the time, in the little ring about 10% and the big ring only about 5% - usually on extended flats and downhill.

Any discussion on the merits of the two group sets, given the kind of rider I am and my goals, would be really appreciated.

[indysteel]

I ran those numbers using Sheldon Brown's gear calculator. I made a couple of assumptions (700 x 23cc wheels and 170 mm cranks). Based on those assumptions, it looks like with either of the SRAM Force choices, you'll lose your two smallest granny gears on your current set up. So, if you can live without those two gears, from a climbing perspective either SRAM crank/cassette combo will work for you.

However, in my experience switching from a triple to a compact, it's not the climbing gears I miss the most. It's some cruising gears in the middle. Sometimes, I just can't find the "perfect" gear for relatively flat and/or windy conditions. With a compact--especially one paired with an 11-28 (as opposed to, say, an 11-23, you'll find that you have some big jumps in between gears. It may prove harder to find just that right gear for the conditions.

Here's what I would recommend before making a decision. On your next few rides, note the exact gear combo(s) that you use the majority of the time when you're just cruising along at your favorite pace. Then play around with Sheldon Brown's gear calculator and make sure that the crank/cassette combos you're considering offer those gears (as measured in gear inches/gear ratios). For instance, I spent most of my time in my middle ring using the 15, 16 and 17 cogs in the rear. Before choosing what to put on my bike, I made sure that the set up I was considered offered those gears. Be sure to factor in cross chaining into the equation as well.

FWIW, I switched to a compact because most triples irritate my IT band because of their relatively wide q-factor. I was otherwise quite happy using a triple. I would go back to it if I could, although I do like the ease of shifting with a compact.

ETA: After reading V's post, I wanted to note that I live in a relatively flat area. Climbing rides are not my norm.

[Veronica]

My race bike came with Force, compact double and with 11 - 25. I did climb faster with it, but only if the ride had only one major climb. My knee joints couldn't handle it. I kept hoping it would get better, because I was riding so much faster. But when I did one ride last year that had me in tears at the top one climb and with more climbs to come (Fairfax -Bolinas Rd. for you NorCal folks) I decided to switch out the rear for an Apex RD. I now have an 11-32 (I think) and I'm much happier.

Veronica

[Hi Ho Silver]

I recently had to go through the same decision process that you are now facing. My old bike had a Shimano triple, and the new bike I wanted was available in both a Shimano triple and a SRAM compact double. Interestingly, my use of the chainrings on my old bike was about the same as what you mentioned.

You really have 3 issues here: - Shimano shift method versus SRAM shift method, triple versus compact double, and cassette cog range.

Shimano shift method versus SRAM shift method- This is an issue that you will have to test out for yourself at a bike store. Some folks love SRAM shifting (I'm a recent convert) and some folks don't.

Shimano triple versus SRAM compact double - The SRAM Force group will be lighter than the Shimano Ultegra triple (and also the Shimano Ultegra compact double). The compact double will be faster shifting than the triple.

Cassette cog range - If you choose the SRAM compact double route, I'd suggest you opt for the SRAM 12-32 cassette (12-13-14-15-17-19-22-25-28-32). It would give you the same high gear that you now have and nearly (within a half-step) the same low ratio that you are currently have.

[indysteel]

Which one did you ultimately go with Hi Ho? And if you ended up using the 11-32 cassette, do you find yourself bothered by any of the bigger jumps between cogs, i.e, the jumps between the 19, 22, 25, 28, and 32? Veronica, do they bother you?

When I switched between my triple and compact (both Campy) I honestly didn't notice any difference in weight betwen the two. Shifting ease, yes, but not to the point that it was a deal maker or breaker. I'm sure others might disagree. I had a lot more shifting issues up front with an older Sugino triple crank. The Campy triple shifted much better. I, personally, still miss my triple. My knees don't, but I do.

[Hi Ho Silver]

Which one did you ultimately go with Hi Ho? And if you ended up using the 11-32 cassette, do you find yourself bothered by any of the bigger jumps between cogs, i.e, the jumps between the 19, 22, 25, 28, and 32? Veronica, do they bother you?

When I switched between my triple and compact (both Campy) I honestly didn't notice any difference in weight betwen the two. Shifting ease, yes, but not to the point that it was a deal maker or breaker. I'm sure others might disagree. I had a lot more shifting issues up front with an older Sugino triple crank. The Campy triple shifted much better. I, personally, still miss my triple. My knees don't, but I do.

I went with the SRAM compact double coupled with a 12-32 cassette. (I didn't like the large gap between the 13 and 15 tooth cogs, on the more common 11-32 cassette, and I have absolutely no need for the 11 tooth cog. The 12-32 has a more even progression of high gears, yet still gives me an adequate highest gear.)

I'm not bothered by the gaps at the low end of the cogset. Percentage-wise, the biggest jump is from the 19 to the 22 (which are 48 and 41 gear-inches respectively when on the 34 ring). By the time I shift to that end of the range, I'm getting pretty desperate anyway and I appreciate the larger-than-average gap.

My current setup provides for a lowest gear of 28.4 GI versus 27.8 GI for my previous triple setup (46-36-26, 12-25). So I basically have the same low end provided by the triple. The compact double is very doable for me (60+ years old with a really bad knee) here in the Texas "hill country".

[tzvia]

ivorygorgon

There is very little reason to use a triple any more with wider range cassettes and a mid cage length rear derailleur (to handle the extra chain needed for the larger rear cogs). Triples have so many overlapping gears that shifting can be a pain, and lugging the extra weight makes no sense.

I setup my commuter with a mid cage Ultregra SL rear derailleur but I'm still using an 11-28 with it. As the WiFli is compatible with RED and FORCE, it should also be compatible with Shimano, as RED and FORCE cassettes are. So it can be done with Shimano. It's really nothing new, mountain bikes have been using long cage derailleurs to provide the extra chain needed to wrap those larger cogs for decades. SRAM just put the pieces together as a road package first.

The chainline will also be improved over a triple (angle that chain deflects from rear cogs to front) so shifting will be smoother with less chance of the chain dropping off the chainrings. Q-factor was already mentioned here. Yes the gear jumps are greater at the lower end but I prefer living with that over shifting a triple any day.

[ivorygorgon]

Thank you for all of the food for thought. This is exactly what I need.

I want to build up my bike, but I an frozen with indecision.

[OakLeaf]

ivorygorgon

There is very little reason to use a triple any more with wider range cassettes and a mid cage length rear derailleur (to handle the extra chain needed for the larger rear cogs).

Except for the reason Indysteel pointed out.

It's not the range from high gear to low so much (you'll always lose a little with a compact vs. a triple, but only a little), it's the jumps from gear to gear. You can get from point A to point B in big steps with a compact, or in smaller steps with a triple.

HiHoSilver outlined it pretty well. The jumps in number of teeth may be large at the very low end of the cassette, but for one thing it's not necessarily that big of a jump from gear to gear when you're up there, and for another, when you're in your lowest gears you probably aren't spinning all that fast anyway.

I can't imagine going from 13 to 15. I can't even go from 15 to 17. I have to give up the 11 in order to get a 16 on either SRAM or Shimano cassettes with a low of 25 or greater. I don't race or hardly ever even join in sign sprints, so it's not like I need the 11, but I do miss it on descents. But not as much as I miss that 16 on every single ride, if I don't have it.