Is this an indication that I need a double?

dbmnk

But isn't more a question of getting the gear you need? With a12-27 you definitely get too big jumps to find an adequate cadence. That is what the other chain ring is for. Don't think of the little ring as for the hilly stuff and the big for the flats - in that way you cheat yourself for 7 extra gears, in stead flip/flop the chainring to get the gear for your pace/cadence. Take another look on Sheldon Browns calculator, and you will find all the intermediate gears you need on different chainrings, with two or three postitions up/down the cassette.

nmcgann

nolf wrote:

biondino wrote:

Having a compact does not mean you have a small penis. It's okay. No-one's judging you.

My sentiments exactly, people shouldn't mock the guy for having a double!

I would be interested to see what a 39/50 combo would be like. I find 53 a little too big to cruise on the flat unless doing harder rides. I run a 12-25 casette as it's hilly near here, and with a 50 up front most of the time rarely go into the small ring.

A good combination. I have 38/50 on my summer bike and 40/50 on my winter bike which I run with a 12-23 cassette. It's a good combination for rolling and flattish areas as there's a good range of practical gears on both rings.

I tried a 34/48 compact some time ago, but it was hopeless for the area I live in. I'd definitely have one in the dales though (or a triple), as doing long 15-20% climbs on 38-27 as I did last time I was up there is OK for rides of 2-3hours, but would be pretty grim for 5-6h when tired.

Neil

redddraggon

I reckon you should get a 54/42 hubmeister

bahzob

Riding in the UK you wont really find out. Brute force and a stubborn streak can get you up everything here. Try doing some rides in the Alps/Pyrenees/Dolomites. On the 3rd HC climb of a day you'll discover what gearing you need.

freehub

But I hear climbs in the alps are 7% average or something and the real thing you need is endurace, so what I really need is some uber steep hills and I'm sure the UK has plenty of those to offer, there is a 33% about 50 miles from here.

ded

freehub wrote:

But I hear climbs in the alps are 7% average or something and the real thing you need is endurace, so what I really need is some uber steep hills and I'm sure the UK has plenty of those to offer, there is a 33% about 50 miles from here.

True, climbs in the Alps are not as steep but they are VERY long. Low(er) gears definitely help here, allowing you to spin your way up things without cramping up. In contrast, massively steep things in the UK can often be overcome by a bit of brute force and ignorance (not all of them before somebody jumps down my throat...). You don't need incredibly low gears for Park Rash for example, you just need to be bloody minded. OK, it hurts, but it only hurts for a little while if your gears aren't low enough. Try riding all of Alpe d'Huez at 40rpm or so and it will hurt a lot more.

Basically, only you can answer your own original question, because the gears you need depend on:

a) where you ride
b) how long you ride for (each day)
c) how you ride (are you Mr Ullrich or Mr Armstrong)
d) how often you find yourself switching sprockets/chainrings
e) how often you find yourself at the "wrong" cadence

I don't think there is a scientific answer by the way - it's how you feel about it. I changed my 39/53 for a 34/50 compact because, although the compact is more of a pain in flatter places, it gives me much more freedom/enjoyment when I go to hillier places! And although I do spend a lot of time in the big ring, it is by no means all the time. And I've never "run out" of top end speed yet (maybe I'm not very fast :?) But then I prefer to spin than grind...

simon_e

ded wrote:

I don't think there is a scientific answer by the way - it's how you feel about it.

ded speaks sense.

If you're interested in seeing a visual representation of ratios I have a graph of 52/42/30 triple against 50/34 compact using a 9 speed 12-25 cassette, data sourced from Sheldon's gear calculator. Piccy here - solid lines are the triple, dashed are the compact.

I created one using 39T in place of the 42T on my SCR's triple but it was only a little lower on the graph so I didn't bother uploading it.

freehub

In respons to these:

a) where you ride - Dales, moors, peak district.

b) how long you ride for (each day) - Some days none, but when I do ride, if I do a short ride it's flat with one very short 7% that you can bomb up loosing no speed fromt he flat, but I do long hilly miles usually.

c) how you ride (are you Mr Ullrich or Mr Armstrong) I'm not sure about that?

d) how often you find yourself switching sprockets/chainrings - Well this is interesting, it's brought up another question I had in mind, relating to my winter bike and my summer bike, my winter bike is a 9 speed, 12-26 SRAM cassette, both bikes have the same chainsets, and I find on my winter bike I find I am always ending up in the wrong cadence and changing gears and I think, how did I ever cope? I can't imagine coping with it on a ride now, I don't know if that's because I was used to it before but my summer bike has a 12-27 cassette which may make me become not used to the SRAM cassette? When I can afford it I think I best change that to a 12-27. I find on my summer bike, I don't really change gears much, I tend to push power and not spin fast on the flat, on, I'm usually in the 4th cog from the smallest on the flat and when I go up a hill I change to a bigger one when I find I am grinding too much on the current gear.

e) how often you find yourself at the "wrong" cadence - I've answered that in the above.

I did the easier side of Park Rash (you know which side that is right?) in 34/21-24 and by my readings that was 23% max.


Simon E, I'm struggling to make sense of the graph? Unsure what exactly it means?

simon_e

I don't think ded was asking you for info, just suggesting the answers to those questions would help you with your decision.

freehub wrote:

I'm struggling to make sense of the graph? Unsure what exactly it means?

It shows gear ratios (in inches, from Sheldon's calculator) for a 9 speed 12-25T cassette using 52/42/30T chainrings for the triple and 50/34T chainrings for the compact.

Each coloured line is 1st to 9th (25 to 12 teeth) used with the respective chainring. In the key T1, T2, T3 are the 30, 42 and 52T rings on the triple respectively; C1 and C2 the 34 and 50T of the compact.

I can visualise the difference between the dark blue (52T) and dashed light blue (50T) in a way I find much easier to process than the numbers alone.

bahzob

freehub wrote:

But I hear climbs in the alps are 7% average or something and the real thing you need is endurace, so what I really need is some uber steep hills and I'm sure the UK has plenty of those to offer, there is a 33% about 50 miles from here.

True most of the tour climbs are around 7-8% so as an average. Couple of buts though
- thats an average, often for 10-15 miles of climbing. There will be peaks along the way, Ventoux good example, starts with 7km at 4% then 10 km or so at closer to 10% with pitches mid teens
- Climbs on the Giro/Vuelta are much steeper. e.g Mortirolo and Zoncolan average over 10% for the whole climb with pitches in mid 20%s.

You are right that you need endurance to get up these but thats why you need lots of gears so you can make sure that you can still turn the pedals at a reasonable cadence despite being tired.