Am I missing somthing here regarding gearing?

[MrWill]

First time riding a compact after only using a triple.

I feel like I am having trouble with the compact and 12-25 cassette. Keep hitting that spot where you have to shift most of the cassette to get the next gear when going from the small to big chainring.
And the 50t is slightly too high of a gear to set off fast on a uphill gradient. And the small produces the problem of running out of gears and spinning 110+

I do need the 34-25 combination for some hills around here. But seems as though 39 -27 is the same gear.

I see most bikes lately come with a compact and 12-25. But a 39/52 with 12-27 has the same lower gear. So what on earth is the advantage to a compact?

May as well put a standard double on and 12-27 right? Or am I missing something?

I'm using the 105 10spd.

 

[Globalti]

Compact gears have helped to bring a lot of non cyclists and former mountain bikers into road cycling but their disadvantage is that the gap between the 50 and the 34 is roughly equivalent to three gears on the cassette. In practice though it isn't a problem most of the time because you change from big to small as you begin to tackle a climb and from small back to big as you crest the summit so in both cases there's a big change in road speed. If you want to change from big to small while climbing a fast, gentle hill you can hit both paddles at once and drop down to the small ring while going down to a smaller cog, simultaneously, as long as you ease off the pedal pressure briefly. Don't do this if there's another rider on your wheel though or they will scream at you.

 

[ushills]

As above, I generally move the front ring and simultaneously move the rear up or down two gears as appropriate.

 

[jay clock]

My maths says a 39/27 and a 34/25 are different (39" vs 36.7")

+1 for a simultaneous left and right change.

 

[mcshroom]

The advantage of a compact over a standard double is the ability to fit a 34x30, 32 or even 34 which allows a much lower gear than can be achieved on a standard double.

 

[ColinJ]

I will stick to triples, and spending most of my time on the 39-tooth middle ring.

 

[KneesUp]

I will stick to triples, and spending most of my time on the 39-tooth middle ring.

And me - you can't easily change both levers at once with bar-ends

 

[raleighnut]

And me - you can't easily change both levers at once with bar-ends

You struggle if they are on drops but its easy enough on bullhorns with straight brakes or reversed "crosstop/interrupters" like my set-up.

 

[Deleted member 1258]

I couldn't get on with 50/34, very quickly after I brought my Verenti the 34 had been replaced with a 42, much better for me, I found the 50 too big, I can only pull it down hill with a following wind, and the 34's too small, would have been fine if I was riding in the mountains but on Warwickshires rolling country side I don't need gears that small, even down in the Cotswolds I don't need gears that small.

 

[srw]

Are you missing something? Yes. Compacts are pointless unless you really want to save tens of grams by not having three chainrings - in which case you're probably not paying for your own bike and are going through Dura-Ace as if theres no tomorrow.

Triples were a sensible solution to the need to lower gearing for hillier terrain. They're practical and convenient and easy to set up. Compacts were invented because people wanted a bike like the pros with only two chainrings. Pros use compacts because of the minute weight saving and because swapping between triples and doubles on the sme bike is not as easy as swapping between different doubles.

 

[swansonj]

Are you missing something? Yes. Compacts are pointless unless you really want to save tens of grams by not having three chainrings - in which case you're probably not paying for your own bike and are going through Dura-Ace as if theres no tomorrow.

Triples were a sensible solution to the need to lower gearing for hillier terrain. They're practical and convenient and easy to set up. Compacts were invented because people wanted a bike like the pros with only two chainrings. Pros use compacts because of the minute weight saving and because swapping between triples and doubles on the sme bike is not as easy as swapping between different doubles.

Umm.... Very mild disagreement here. There is another reason for doubles - they shift more reliably. You may very well be right that most people who use doubles do so for misguided reasons of emulating pros, but Chris Juden for one advocates them to avoid the inherently unsatisfactory front change on a triple. (AIUI, reasonably reliable triple shifts are the norm these days but partly by fancy bodges to the chainring teeth. And those of us who sorted out our gearing preferences twenty years ago certainly remember triples where either the chain fell off the big ring straight onto the small, or where it stubbornly refused to drop off the middle at all as you ground to a halt up the hill.)

 

[deptfordmarmoset]

Are you missing something? Yes. Compacts are pointless unless you really want to save tens of grams by not having three chainrings - in which case you're probably not paying for your own bike and are going through Dura-Ace as if theres no tomorrow.

Triples were a sensible solution to the need to lower gearing for hillier terrain. They're practical and convenient and easy to set up. Compacts were invented because people wanted a bike like the pros with only two chainrings. Pros use compacts because of the minute weight saving and because swapping between triples and doubles on the sme bike is not as easy as swapping between different doubles.

And the weight saving from losing the smallest chainring is not the net weight saving if you want to have the same range of gears because you'll then need bigger rings on the cassette. Yes, I'd agree with that. The gain is minimal, possibly less than the weight of your multitool. Swapping triples and doubles will take more time but swapping differently configured triples-to-triples wouldn't take any more time than swapping compacts to compacts, would it?

I've got 2 compact set ups and a triple. The triple has never shipped its chain. I prefer triples but the occasional simultaneous left and right shift (or with a wide-range cassette, a change on one and a double change on the other) needed on the compacts doesn't bother me enough to change them to triples.

 

[MrWill]

FFS i want my triple back tbh.

 

[Globalti]

No, double chain rings are a badge of seriousness more akin to leg shaving in that a serious roadie will attack that hill in the small ring rather than sit and twiddle up it, the same as he shaves his legs on the off chance that he may need a massage.

There was once a very controversial member on the old CC forum (can't remember his name but he generated a lot of discussion and even acrimony) who wrote that "mountain bike gears have no place on a road bike".

 

[User269]

FFS i want my triple back tbh.

I know exactly what you mean, and like you I find myself constantly changing between the chainrings to find the desired gear, as well as finding the cassette too widely spaced. Fortunately I only have to ride a compact for a few hundred miles each year whilst renting in Mallorca. The rest of the time I enjoy my close ratio 12-23 cassette with a 30-39-52 chainring (Ultegra 10).