compact cranks

[mimitabby]

you need to find one of those chain rings and hold it in your hand (if you're trying to decide which would be better a triple or a compact)
they weigh about the same as 3 ounces of water. I doubt that the extra weight of a triple is going to slow you down.
However, further back, i heard someone say it would be easier mechanically speaking for you to switch from what you have to a compact than it would be to a triple.

[Andrea]

SRAM is making an 11-28 now for all you "big range" junkies

Oh yeah, and I had a compact double last year, and it was fine unless I was in a race situation where I needed to go very fast downhill. That's the only reason why I switched to a standard when I upgraded parts, because otherwise, I loved it for hills & long climbs.

[aicabsolut]

SRAM is making an 11-28 now for all you "big range" junkies

Oh yeah, and I had a compact double last year, and it was fine unless I was in a race situation where I needed to go very fast downhill. That's the only reason why I switched to a standard when I upgraded parts, because otherwise, I loved it for hills & long climbs.

For you gals with compacts, how many gears do you actually use?

With my triple, it's the bottom 3 on the small ring, all 10 on the middle ring, and the top 4 on the big ring.

It's not just the range that counts, but also how many different gear choices you have within that range, that will allow you to spin your desired cadence. Even one tooth on the cassette makes a huge difference in cadence and comfort.

I've never actually done a spreadsheet to see how much overlap I have in the gearing, but those are the ones I actually use.

Remember, a 50-11 is bigger than a 53-12. How often do you really need a 53-11? If you love the compact, you can make it work for racing.

I use every rear cog with my compact. It's quite nice for racing overall. The compact lets me spin up big hills (I don't think I'd ever need a 34 for the races I do--the 36 is enough), but the best part is that a greater range of hills are now "big ring climbs" for me with the 50T. So the less I have to shift up front the less I risk dropping my chain, which is nice. Plus, shifting back up is faster when you don't have to jump rings. One thing I really like about the 36-27 is the ability to get started from a stop light on a hill. I appreciate that (which I encounter more often) than the ability to keep going when I really need that gear to get up a hill.

[Andrea]

How often do you really need a 53-11?

Not very often, but last season, I spun uncomfortably in the 50x11 a few times when chasing someone downhill and in a couple of sprints- one with a perfect leadout and one that was downhill. I am much more fond of my 53x39 with an 11x26 rear.

[OakLeaf]

So I had to do a little spreadsheet just to see. Told you I'm a data geek.

With my standard Shimano 30/39/50 triple and a 12-25 cassette, I have three gears on the puppy gear that are lower than anything I get on the middle ring, and four gears on the big ring that are higher than the highest gear on the middle ring, for a usable 17 speeds. Exactly what I posted earlier that I've been using...

With a standard Shimano 50/34 compact and the same cassette, one would have five speeds on the small ring that are lower than the lowest gear on the big ring, for a usable 15 speeds.

With a standard Campy 53/39 compact and the same cassette, one would have five speeds on the big ring that are taller than the highest gear on the small ring, for a usable 15 speeds if you go at it from the other direction.

Low gear on a 30x25 with a tire rollout of 2091 mm and an effective diameter of 26.2" is 31.44 GI. Low on a 34x25 would be 35.63, low on a 39x25 is 40.87.

High gear on a 50x12 with the same rollout is 108.99 GI, high gear on a 53x12 is 115.80.

TMI yet? Bottom line is, with 21% grades like our club climbed last night (the ride leader's Garmin said it was 24%) I NEED those low gears to get up the hills and the high ones to get down them; and the more close-ratio gears I have in between, the more comfortable my knees and muscles are on the flats. So I'm even more confident than before that I made the right decision in going with the triple.

[katluvr]

Ok, no physics here, nor do I race. I recently went from triple to a compact cassette. I live in the flat world of Flordia--so hills are not my fortey--or they used to not be. We do have some hilly areas that I train in.
Nor do I race.
I was very afraid to lose my "granny gear" for when I did ride the hills.
I LOVE my compact cassette. I think it allows me more range while in my "small ring". SO I can hill climb and then handle the flats. With a triple I was always having to then get out of my small ring to my middle chain ring and also dropping back down again. AND dropping my chain. So for me it was a good deal! And I climb much better!

[SadieKate]

Dang, I got it right the first time

So do you feel all powerful? Ready to go rip some pavement?