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Arnborg strik
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658 Posts
Discussion Starter · #1 ·
Instead of 3? (other than weight saving)
The reason for the question, is that im being offered a Middleburn RS Duo crankset(square)
with 29/44 chainrings at a very good price.

I have allways been running XTR with 3 chainrings (and been satisfied :)
But maybe it's time to try something new :confused:

Information about pro's and con's are welcome.

Thanks
Thomas
 

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Hack Racer
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2,559 Posts
running a two chain ring crankset is usually not lighter. With a 29/44 combo you can avoid shifting your front derailleur on some climbs if you are strong enough to push 29T front, 32t rear cog up a hill or a 34t rear cog if you are running a 11-34 cassette.

Also running a 2x9 crankset allows you to run a narrower chain line.

I love how a 2x9 works. It's so elegant. You can just pretty much stay in the middle ring for all but the double track fire roads in a race.

For ultimate in lightness a light 3x9 crankset and a dura-ace 12-27 9 speed cassette is the way to go. However recently there has been released a 11-32, 11-34 full titanium cassette that weighs in the same weight or very close to a 9 speed 12-27 dura-ace.
 

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Arnborg strik
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658 Posts
Discussion Starter · #7 ·
Im no good

pagey said:
If you do your gear ratio calculations and select the right rings you get a much better spread of usable gear combos from a 2x9 setup.
at gear ratio calculations.
Normally i run 11-32 in the back and 22-32-44 up front
Which 2 chainring setup would match that best?
 

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GTaholic
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760 Posts
In the last three year I´ve only had 2x8 and 2x9 drivetrains.

I don´t see any needing of a granny gear or 11-34 cassette.

In my current bikes:
GT Zaskar 29-42T and DA 12-27
GT Avalanche 36-48T and Ultegra 12-23
GT Psyclone 30-44T and Ti 11-30
GT STS 36 and 12-32 I think, DH rig.

It´s all what I ride currently.
 

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Commit or eat sh!t
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2,394 Posts
Depends on how much flat riding you do. If you don't, then you don't need it. You can replace the large ring with a light weight bashguard, and ride with the 32 middle ring or replace it with a 34, 36 or 38 ring. That is how most downhill bikes are set up. Make sure to restrict your front derailleur.
 

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If you ride 2x9 and run 22/34 (tops out a 21.5MPH at 90RPM cadence which is fast enough for me on tight singletrack) with a lightweight BBG bashguard (loosing about 30g) you can then run a 9speed road cassette like Dura-Ace (178g) and a Dura-Ace rear derailleur (180g).

You can do all this for much less than $200, especially off ebay. I challenge you to find a more lightweight/cost effective setup.

For me, I don't race so I don't need the big chainring. I spend most of my time climbing so I really need the granny ring. But this is probably the cheapest lightweight powertrain setup you can find.
 

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Hack Racer
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2,559 Posts
Thomas said:
at gear ratio calculations.
Normally i run 11-32 in the back and 22-32-44 up front
Which 2 chainring setup would match that best?
If you are a strong enough rider who never touches their granny I would say 30-44 is the best. 30T gives you some margin in the event you encounter something that would normally require a granny.
 

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Hand/of/Midas said:
just ride 1x9. no shifter, or front derail, or extra chainrings, or cable/housing. much lighter. much better, never having to think about where to shift. and anyone would still have enough gear spread with a 11-34. perfecto.
+1. I can't imagine going back to 18 or 27 gears.
 

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mad aussie
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1,129 Posts
It depends on where you ride and how strong you are as well as if you like to spin or mash.
I like the 2x9 with a 12-34 or 11-32 setup for XC racing as your brain is barely functioning and its easier to keep track of small ring/big ring, plus you never dump into the 22T without meaning to finding yourself undegeared on a climb. When going all out for a couple of hours its rare to find a course where you might need a 22T chainring, if you need it most likely you are off the back in Semi Pro or Pro.
I might still go back to a 3x9 for some marathon races with really steep climbing or at high altitude. For example in the Durango 100 last year I ran in the granny for the steep muddy climbs to save my legs for 11+ hours of misery. I will also keep the triple for long base training rides when I am keeping my HR in a certain zone.

Kevin
 

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Five is right out
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3,176 Posts
Hand/of/Midas said:
just ride 1x9. no shifter, or front derail, or extra chainrings, or cable/housing. much lighter. much better, never having to think about where to shift. and anyone would still have enough gear spread with a 11-34. perfecto.
1x9 is great for simplicity, but pretty useless for XC racing when you either need to move really fast on flat terrain, or need to take a breather while spinning up long hills.
 

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womble said:
1x9 is great for simplicity, but pretty useless for XC racing when you either need to move really fast on flat terrain, or need to take a breather while spinning up long hills.
I'll throw my hat into that ring. I'm all for simplicity but for racing, at least here in the northeast u.s., I've found the need for my granny many, many times. FWIW, I'm a top 5 expert and I would say the exception is to find a race where I don't need a granny at least once in a race. I'm a weight weenie too, and the extra grams of a granny are worth it when you consider the fatigue it saves your legs in 2 hours of racing. The bottom line is, unless you're a WC pro and train all day every day, you can't push big gears and crank out high wattage the whole race. You can only dig deep into your max power so many times. A granny helps you conserve your legs even for short, steep spurts so you can maintain your tempo on flats. I remember a race just a few weeks ago. It was 50 miles with a generous heap of climbs. I passed a guy on a 2X9 setup who was walking. I was actually in my middle ring and he says 'there's no shame in using the granny. I'd use one if I had one." I thought, then why don't you have one? What's silly to some is dogma to others. Go figure.
 

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No longer 26
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3,090 Posts
I run 2x9 only on my geared 29ers now and wish I would have on my 26" bikes. 24/36 is what I am running now but 22/34 would probably be enough on a 29er, 24/36 on a 26er. With a 36 you only lose the 44x11,12. You lose the 13 with a 34 as big ring. I've much more often needed the granny than a 44 big ever in sport racing.

G
 

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womble said:
1x9 is great for simplicity, but pretty useless for XC racing when you either need to move really fast on flat terrain, or need to take a breather while spinning up long hills.
i use it mostly on my race bike! i run a big 36t, im always in a fast gear, and i pass lots of people on climbs as they spin barely moving, thats one of my strong points. using a big 36t only up front is great for the short races, 2 hours or under, for longer races like 6hr or longer a smaller 26 would help alot.
 

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tranquilo said:
I'll throw my hat into that ring. I'm all for simplicity but for racing, at least here in the northeast u.s., I've found the need for my granny many, many times. FWIW, I'm a top 5 expert and I would say the exception is to find a race where I don't need a granny at least once in a race.
I think you and I race the same series Tranquillo -- H2H right? I ride sport in my 1x9 and I don't think my legs are super strong but I rarely miss the granny. 32/11-34 just covers basically everything I need, and much like the singlespeeders say, the simplicity helps me go faster somehow.
 
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